Dissertations / Theses on the topic 'Nectar'

This thesis explores the dynamic patterns in the secretion, reabsorption and concentration of nectar, and their relation with microclimate, flower visitors and the innervation of the nectaries. Case studies are presented, comprising Impatiens glandulifera, Brassica napus, Fritillaria imperialis and Borago officinalis. Nectar secretion rate and nectar solute concentration are affected by the environment, and probably by the genetic composition of the plants. Significant differences in nectar secretion rate and nectar concentration are found between plants, between times of the day and between days, but not among flowers on the same plant. Correlation matrices and correlograms help us to disentangle multiple interactions. In all the species studied, the environmental factor most likely to affect nectar secretion rate seems to be the temperature of the air. Other factors also contribute to explain the variation in nectar secretion rate, among them the stand age (probably acting through the relative sink strength of the flowers), and the number of flowers and fruits per module. The supply of assimilates to the nectary is explored by experimental defoliations and deprivation of light. In both cases an immediate response is elicited, but the degree of response varies between species. Brassica napus, for example, is much less sensitive to light deprivation or total defoliation than Fritillaria imperialis. Nectar solute concentration seems to depend mainly on the relative humidity of the air. However, some evidence suggests that plant water status might affect nectar concentration. These results, obtained from field experiments, were confirmed in controlled conditions in growth chambers. Other minor factors probably play a role, but their effects are obscured by complex physiological interactions. We conclude that in a given plant the nectar secretion rate will depend mainly on its physiological age, and on variations in air temperature, while the nectar solute concentration at a given moment will be mainly the product of the short-term plant-microclimate interaction. In this context, constraints on the evolution of nectar presentation systems are considered.

Thesis (Ph. D.)--Ohio State University, 2004.
Title from first page of PDF file. Document formatted into pages; contains xii, 138 p.; also includes graphics. Includes abstract and vita. Advisor: Richard A. Bradley, Dept. of Evolution, Ecology, and Organismal Biology. Includes bibliographical references (p. 124-138).

How will the intrusion of other species that remove rewards without providing reciprocal services affect the interaction between mutualists? How do costs and benefits from these "cheaters" compare to costs and benefits from potentially mutualistic visitors? Finally, did nectar-robbing, one kind of cheating, promote the evolution of complex levels of sociality by allowing bees access to a wider range of resources? I investigated these questions in the research described below. I found that pollinators visiting Chilopsis linearis (Bignoniaceae) spent less time visiting robbed flowers than visiting unrobbed flowers, and did not visit them as often as expected. Thus, robbing appeared to have a negative effect on pollinators visiting Chilopsis linearis . I compared costs and benefits of floral visitors to Chilopsis linearis (desert willow). Chilopsis had sensitive stigmas that closed immediately upon touch and may have reopened later. I found that the probability of stigma reopening depended on the source and number of pollen grains deposited. I compared visitors by number of pollen grains deposited, viability of pollen that they deposited, and their effect on stigmas. Nectar-robbers did not benefit plants by pollen deposition, but they also did not cost plants by causing stigmas to close without adequate pollen having been deposited. I investigated the effects of robbing on pollinator behavior and plant reproductive success. Nectar volumes were lower in robbed flowers than in unrobbed flowers. However, the most effective pollinators, bumblebees, did not avoid robbed flowers. In investigating male reproductive success, I found that on some days, dye mimicking pollen traveled farther from robbed flowers, indicating that robbing may sometimes be beneficial to plants. In investigating female reproductive success, I found that there was no difference in pollen tube number between robbed and unrobbed flowers. Thus, a negative effect on one mutualist may not affect the other mutualist. I hypothesized that the evolution of robbing in bees was associated with a broad diet breadth and the evolution of complex sociality. Using phylogenetically independent contrasts for taxa within three geographical regions, I found that in some cases, a broad diet breadth was associated with sociality and robbing.

Pollination success of animal-pollinated flowers depends on rate of pollinator visits and on pollen deposition per visit, both of which should vary with the pollen and nectar "neighborhoods" of a plant, i.e., with pollen and nectar availability in nearby plants. One determinant of these neighborhoods is per-flower production of pollen and nectar, which is likely to respond to environmental influences. In this study, we explored environmental effects on pollen and nectar production and on pollination success in order to follow up a surprising result from a previous study: flowers of Ipomopsis aggregata received less pollen in years of high visitation by their hummingbird pollinators. A new analysis of the earlier data indicated that high bird visitation corresponded to drought years. We hypothesized that drought might contribute to the enigmatic prior result if it decreases both nectar and pollen production: in dry years, low nectar availability could cause hummingbirds to visit flowers at a higher rate, and low pollen availability could cause them to deposit less pollen per visit. A greenhouse experiment demonstrated that drought does reduce both pollen and nectar production by I. aggregata flowers. This result was corroborated across 6 yr of variable precipitation and soil moisture in four unmanipulated field populations. In addition, experimental removal of pollen from flowers reduced the pollen received by nearby flowers. We conclude that there is much to learn about how abiotic and biotic environmental drivers jointly affect pollen and nectar production and availability, and how this contributes to pollen and nectar neighborhoods and thus influences pollination success.

Thesis (Ph. D.)--University of Missouri-Columbia, 2007.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on September 25, 2007) Vita. Includes bibliographical references.

Zahlreiche Forschungsarbeiten haben gezeigt, dass nicht nur Menschen, sondern auch Tiere konstante individuelle Unterschiede im Verhalten aufweisen. Zu verstehen warum sich diese Verhaltensunterschiede im Laufe der Evolution entwickelt haben, ist ein Ziel dieses Forschungsbereiches. In dieser Arbeit wurde untersucht wie verschiedene Modulatoren das Nahrungssuchverhalten von Blütenfledermäusen (Glossophaginae) beeinflussen um individuelle Verhaltensunterschiede zu quantifizieren und theoretische Vorhersagen zu testen. Alle Experimente wurden in naturnaher Umgebung mit programmierbaren, künstlichen Blüten durchgeführt. Es wird angenommen, dass die Plastizität von Verhalten ein generelles Merkmal ist in dem sich Tiere unterscheiden, da manche Individuen allgemein stärker auf Reize aus der Umwelt reagieren könnten als andere. Um diese Vorhersage zu testen, wurde die Nahrungsverfügbarkeit experimentell manipuliert und zwei Arten von Verhaltensplastizität in denselben Individuen gemessen. Die Ergebnisse unterstützen diese Annahme jedoch nicht, da die beiden Arten von Verhaltensplastizität nicht korrelieren. Neben Umwelteinflüssen können auch innere Merkmale wie die Stoffwechselrate das individuelle Nahrungssuchverhalten beeinflussen. Die Ergebnisse zeigen, dass sich die Individuen in ihrem täglichen Energieverbrauch unterscheiden und dass diese Unterschiede mit dem Explorationsverhalten während der Nahrungssuche korrelieren. Zusätzlich kann das individuelle Nahrungssuchverhalten auch von sozialen Faktoren beeinflusst werden. Bei limitierter Nahrungsverfügbarkeit verteidigen einzelne Männchen Blüten gegen andere Männchen, jedoch nicht gegenüber Weibchen. Individuelle Unterschiede in der Aggression und Aktivität werden dagegen nicht von der sozialen Gruppenzusammensetzung beeinflusst. In dieser Arbeit wurden nicht nur individuelle Unterschiede im Nahrungssuchverhalten von Blütenfledermäusen bestimmt, sondern auch Vorhersagen aus dem Bereich der Persönlichkeitsforschung bei Tieren überprüft.
Animal personality research has shown that animals express individual differences in their behavior that are consistent over time and/or across situations. Furthermore, animal personality research aims to understand how these individual differences in behavior evolve and how they are maintained within populations. This thesis focuses on how different modulators influence the foraging behavior of nectar-feeding bats (Glossophaginae) in order to investigate consistent individual differences in their behavior and to test predictions proposed in the field of animal personality. All experiments were conducted in a semi-natural environment by using a setup of computer-controlled artificial flowers. One prediction of animal personality research is that behavioral plasticity is a single trait in which individuals differ because some individuals might be generally more responsive to changes in the environment than others. In order to test this prediction, resource availability was manipulated and two types of behavioral plasticity were quantified within the same individual. However, the two types of plasticity did not correlate and therefore this hypothesis was not supported. Individual foraging behavior can not only be modulated by changes in the environment but also by individual differences in internal traits like metabolic rates. Experiments confirmed that individual differences in daily energy expenditure correlated with consistent individual differences in exploration. Additionally, foraging behavior can also be modulated by social factors. When resources are limited some males started to defend flowers against other males but not against females. Furthermore, it could be shown that individual differences in aggression and activity are internally driven and not influenced by changes in the social group composition. This thesis not only assessed individual differences in the foraging behavior of nectar-feeding bats but also investigated predictions proposed in the field of animal personality research.

Extrafloral nectar (EFN) mediates food-for-protection mutualisms between plants and defensive insects. Senna mexicana var. chapmanii is a perennial legume native to the pine rockland habitats of south Florida. My dissertation focuses on how anthropogenic changes to the pine rocklands might affect EFN production by S. chapmanii, and the outcome of EFN mediated interactions. First, I investigated the influence of time of day, leaf damage, and leaf age on EFN production in S. chapmanii. Plants produced more nectar at night than during the day, and leaf damage resulted in increased EFN production. Furthermore, the response to leaf damage was greater when plants were damaged in the morning than when plants were damaged at night. Damage to young leaves elicited a stronger defensive response than damage to older leaves, in line with optimal defense theory. Second, I conducted a field experiment to determine the effects of ant activity, and light intensity, on herbivory rates, growth, and reproductive fitness in S. chapmanii. In shaded habitats, the presence of ants had no effect on herbivory rates, seed set, or plant size. In sunny habitats, however, plants with ants suffered less herbivore damage, produced more seeds, and grew larger over the duration of the one year study. Third, through a controlled greenhouse experiment I examined the effects of light intensity, and red/far-red light ratios, on EFN production in S. chapmanii. Plants in light-limited conditions produced less EFN, and leaf damage elicited increased EFN production regardless of light conditions. Ratios of red/far-red light, however, did not affect EFN production in either damaged or undamaged plants. Finally, I conducted a field study to determine how ants affect reproductive fitness in S. chapmanii. Over a period of eight months I observed the effects of ants on the activity of herbivores, predators, pollinators, and pre-dispersal seed predators. Relative pollinator efficiency, and rates of pre-dispersal seed predation, were unaffected by ants. Plants with ants, however, were quicker to establish, grew larger, and produced floral displays that attracted more pollinators. In S. chapmanii ants affected plant reproductive fitness simply by facilitating growth and establishment, with coincidental effects on reproductive investment.

Pollen and nectar are the two most common floral rewards, and bees must collect both. Many plant species offer both rewards to bees; however, reward availability on such flowers varies. Pollen and nectar availability is constantly changing, and bees must be able to adapt to the various environments they encounter. Yet little is known about how bees partition the collection of resources on these flowers. Here I investigate how bees behave on flowers offering both nectar and pollen, and how this behavior shifts depending on reward presence. To do this I tested bumblebee workers, Bombus impatiens, on arrays of Orange Jubilee (Tecoma x alata) flowers. Bees were assigned to either a treatment with intact nectar and pollen rewards, or a treatment with depleted nectar and intact pollen rewards. I found that bees were reward generalists, collecting both pollen and nectar, often on the same flower visit. I also found that bees made fewer attempts to collect nectar and only collected pollen when nectar rewards were depleted. This strategy, which has not previously been described, likely promotes foraging efficiency by reducing time wasted searching and failing to find nectar. This work suggests that individual bees are able to adapt rapidly to changing reward environments in order to maximize collection of available rewards.

The interaction between Xylocopa californica and Chilopsis linearis was used to test the hypothesis that nectar robbing is costly to plants. No evidence for these costs, either in terms of decreased pollination or increased energy demands, was found. In fact, the mean number of seeds per fruit and the mean individual weight of seeds per fruit was higher from fruits that developed from robbed flowers than from fruits that developed from unrobbed flowers, indicating that the presence of Xylocopa californica enhanced pollination. Chilopsis linearis pollen was isolated from the tips of the abdomens of robbing Xylocopa californica and it was determined that these bees could be transferring pollen from flower to flower as they position themselves to rob. This association was found to be one of mutual benefit rather than one of exploitation.

Pollinator visitation patterns should affect pollination success and mating patterns in flowering species. In the orchid family, about one third of the species do not provide any reward for their pollinators. Pollination by deceit is typically associated with low fruit set but may increase the chance of cross-pollination since the pollinator should soon leave the individual plant when there is no reward in the flowers. This may be beneficial if self-fertilisation results in inbreeding depression. I studied the mating patterns of one rewarding and one deceptive orchid in two closely related genera by tracking the fate of stained pollinia. I also conducted controlled crosses to estimate inbreeding depression. The results show that the deceptive orchid Dactylorhiza lapponica has lower pollination success, but higher cross-pollination rate (ca. 90%) than the nectariferous orchid Gymnadenia conopsea (ca. 18% cross-pollination). The results further suggest that in G. conopsea, nocturnal visitors mediate higher geitonogamous pollination rate (ca. 100%) than diurnal visitors (ca. 60%). In both study species, fruits produced from cross-pollination were heavier than fruits produced from selfing. Inbreeding depression for fruit mass did not differ significantly between the two species (δ = 0.21 in D. lapponica and δ = 0.29 in G. conopsea). These data support the hypothesis that pollination by deceit can enhance cross-pollination. A literature study including several rewarding and non-rewarding orchid species indicated lower geitonogamy in the deceptive orchids, but the difference was not statistically significant.

"July 2003".
Thesis (PhD)--Macquarie University, Division of Society, Culture, Media & Philosophy, Department of Anthropology, 2004.
Bibliography: p. 337-345.
Introduction: representing ISKCON: spreading the message of Krishna Consciousness -- "Easy journey" to another planet: fieldwork, culture conversion, and the location of the spiritual -- A taste for Krishna: aesthetic theology and transubstantiation of culture -- Spiritual culture: varnasrama-dharma and brahminical training -- ISKCON and imitation: appropriating the model in Gaudiya-Vaisnavism -- Remembering Prabhupada: hagiography as spiritual practice -- The nectar of translation: mantra, text and the "yoga of spiritual transmission" -- Conclusion: conversion, mimesis, translation: self-realisation and the other in Krishna Consciousness.
This is a cultural anthropological study of The International Society for Krishna Consciousness (ISKCON), or the Hare Krishna movement. Data for this research derive primarily from ethnographic participant-observation, and include tape-recorded interviews with Hare Krishna informants as well as ISKCON literature collected during fieldwork. -- Analysis focuses on Hare Krishna techniques (saddhana, or yoga) of religious transformation, including physical, aesthetic, and discursive practices involved in the pursuit of spiritual realisation in ISKCON. Conversion, mimesis, and translation are the three key conceptual themes which inform a critical analysis of the production and effect of cultural difference in Hare Krishna spiritual practice. Ethnicity and conversion emerge as parallel concerns as the involvement of diasporic Indian and Indo-Fijian Hindus at the congregational level of ISKCON's ministry in Sydney, Australia, is examined for its effect on Western converts' experiences of Krishna Consciousness. A new conceptual approach to the meaning of 'conversion' to ISKCON is developed from this account. -- Recent sectarian developments in ISKCON's relationship with the Indian tradition of Gaudiya-Vaisnavism are also examined within a comparative theological framework. Hagiographic practices surrounding ISKCON's Bengali founder, A.C. Bhaktivedanta Swami Prabhupada (1896-1977), and textual practices surrounding the founder's translations of Vaisnavite scripture, are both analysed as core features of Hare Krishna spirituality. The theological significance of these practices is directly correlated with recent sectarian tensions between ISKCON and the Indian tradition.
Mode of access: World Wide Web.
345 p. ill. (some col.)

Orientadores: Marlies Sazima, Jose Roberto Trigo
Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: Foram estudadas quatro espécies de Passíflora. P. alata, P. galbana (Parque Estadual de Setiba, Guarapari, ES) e P. mucronata (Parque Estadual da Serra do Mar, Núcleo Picinguaba, Ubatuba, SP), que pertencem ao subgênero Passíflora e ocorrem em vegetação de restinga. P. speciosa Gardn. , subgênero Distephana, ocorre em mata atlântica de tabuleiro da Reserva Florestal da CVRD (RFCVRD), Unhares, ES. Foi analisado qualitativa - e quantitativamente o recurso alimentar e foram identificados os constituintes químicos que compõe as unidades de atração visual e olfativa nestas espécies de Passiflora. Foi observado que as espécies de Passiflora estudadas dependem de vetores de pólen para a produção de frutos. P. alata é melitófila, P. galbana e P. mucronata são quiropterófilas e P. speciosa é ornitófila. A polinização é favorecida pela deflexão dos órgãos reprodutivos, que permite que os animais os toquem. O néctar é o recurso alimentar procurado pelos visitantes florais, sendo que o comportamento dos polinizadores vertebrados parece refletir a disponibilidade do recurso, forrageando quando há mais volume de néctar e quando a previsibilidade da quantidade de recurso é maior. A dinâmica de secreção de néctar das espécies estudadas está relacionada com a hidrólise de amido armazenado no nectário. Parece haver uma relação entre o tipo de polinizador e a composição do néctar, inclusive a quantidade de lipídios presentes e a razão Na+/K+. O espectro de absorção nas faixas UV-VIS encontrado nestas flores se adequa à sensibilidade espectral da visão dos polinizadores, com presença de antocianidinas em P. a/ata e P. speciosa. As espécies quiropterófilas possuem pigmentos que refletem na região do visível, e devem ter uma função menos importante na localização das flores por morcegos. Nas espécies polinizadas por animais cujo olfato é bastante desenvolvido, há maior abundância de classes de compostos voláteis. Compostos aromáticos hidroxilados e monoterpenos são provavelmente os responsáveis pelo perfume adocicado das flores de P. alata. Em P. galbana, estes compostos tem participação expressiva no seu perfil de odores. P. speciosa tem leve odor acre, provavelmente conferido por hidrocarbonetos. Sinais olfativos devem estar permitindo a localização do recurso a longa distância, enquanto que a localização do recurso a curta distância seria possível através de orientação visuail ou acústica. Vários compostos que formam as fragrâncias destas espécies de Passiflora ocorrem em outras espécies de plantas; alguns destes também ocorrem em secreções exócrinas de abelhas
Abstract: Four species of Passiflora were studied. P. alata, P. galbana (Parque Estadual de Setiba, Guarapari, ES) and P. mucronata (Parque Estadual da Serra do Mar, Núcleo Picinguaba, Ubatuba, SP), belong to the Passiflora subgenus, and occur in restinga vegetation. P. speciosa Gardn., Distephana subgenus occurs in Atlantic forest in the Reserva Florestal da CVRD (RFCVRD), Unhares. The central aims of this study were to analise qualitative and quantitative aspects of the food resources, and to identify visual and olfactory chemical constituents of the units of attraction in these species of Passiflora, to verify their role in pollinator selection, since they have distinct pollination syndromes. Those Passiflora species depend on pollen vectors to produce fruits. P. alata is mellitophylous, P. galbana and P. mucronata are chiropterophylous and P. speciosa is an ornithophylous species. Pollination is facilitated due to the deflection of the reproductive organs. Floral visitors search for nectar as a food resource; the vertebrate pollinator behavior seems to reflect resource availability, as they forage when large amounts of nectar are found and when quantitative resource predictability is greater. The dynamics of nectar secretion is related to nectary starch hydrolysis. There seems to be a relationship between pollinator type and the nectar composition, such as amounts of lipids and Na+/K+ ratio. The UV-VIS spectral absortion of flowers is adjusted to the pollinators' visual spectral sensitivity, with anthocyanidins present in P. alata and P. speciosa. Pigments of the chiropterophylous species reflect in the visible spectra, and might have a little importance in flower location. There is a higher class diversity among the volatiles compounds in the species pollinated by animais with an acute olfactory sense. Hydroxylated aromatic compounds and monoterpenes are probably responsible for the sweet scent of P. alata. In P. galbana, they are also important compounds in the scent profile. P. speciosa has a very faint acrid smell, probably from hydrocarbons. Long distance resource location is probably accomplished by olfactive signals, although visual or acoustic signals could be responsible for short distance orientation. Fragrance compositions of these Passiflora species show compounds also present in other species and in the exocrine secretions of bees
Mestrado
Ecologia
Mestre em Ciências Biológicas

Orientador: Hilary Castle de Menezes
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: A pitanga (Eugenia uniflora L.) é um fruto nativo das regiões Sul e Sudeste do Brasil, e muito pouco investigado cientificamente. Graças às suas qualidades vitamínicas e sensoriais, a pitanga foi o principal objeto de estudo deste trabalho de tese. A acerola, excelente fonte de vitamina C, também foi abordada neste trabalho. O estudo da acerola consistiu basicamente na avaliação da polpa como matéria-prima para a indústria de néctares mistos, objetivando o enriquecimento em vitamina C do néctar de pitanga. Em relação aos processos tecnológicos aplicados às polpas e néctares, foram estudados os processos de extração de polpa e os métodos de conservação tradicionais: congelamento e pasteurização térmica. Como conseqüência lógica, também foi avaliada a estabilidade dos produtos processados com o intuito de determinar a ocorrência de alterações físicas, físico-químicas e sensoriais. O estudo do processo de extração de polpa (Capítulo 2) foi realizado em dois diferentes tipos de despolpadores: despolpador de escovas inclinado e despolpador de pás horizontal. Para os frutos de pitanga, os equipamentos de escovas e pás apresentaram rendimentos de polpa de 58,47±3,92% e 46,61±1,80%, respectivamente. A polpa obtida no despolpador de pás apresentou uma diferença total de cor (.E*) em relação aos parâmetros de cor L*, a* e b* dos frutos in natura, significativamente superior (p¡Ü0,05) a polpa processada no despolpador de escovas. Por isso, o despolpador de escovas se mostrou mais eficiente que o despolpador de pás para obtenção de polpa de pitanga, devido ao maior rendimento e menor .E*. No estudo de estabilidade da polpa de pitanga preservada por congelamento (Capítulo 3) durante 90 dias, os resultados obtidos mostraram que a reação cinética da degradação dos parâmetros de cor a* e diferença total de cor (.E*) se ajustaram aos modelos cinéticos de 1a ordem e zero ordem, respectivamente. Ao mesmo tempo, houve uma forte queda na aceitabilidade sensorial e na atitude positiva de compra do néctar formulado com a polpa de pitanga armazenada por 90 dias a ¿18oC, devido às significativas mudanças na qualidade física do néctar formulado com a polpa de pitanga congelada. No estudo de pasteurização térmica da polpa de pitanga (Capítulo 4) foi empregado um planejamento composto central (22), onde as variáveis independentes foram os parâmetros tempo e temperatura de processamento, e as variáveis dependentes foram cor instrumental (a*, b* e .E*) e atividade enzimática. O binômio tempo-temperatura de pasteurização térmica mais adequado para a conservação da polpa de pitanga foi de 59 a 68s a 90oC, considerando as mínimas alterações de cor instrumental e a inativação das enzimas presentes. O estudo do comportamento reológico da polpa de pitanga (Capítulo 5) na faixa de temperatura de pasteurização de 83 a 97oC determinou que a polpa de pitanga apresentou comportamento pseudoplástico e o modelo de Herschel-Bulkley foi considerado o mais adequado. Os índices de comportamento de fluido (n), variaram na faixa de 0,448 a 0,627. O efeito da temperatura sobre a viscosidade aparente pôde ser descrito pela equação análoga à de Arrenhius, observando-se a diminuição da viscosidade aparente com o aumento da temperatura. A energia de ativação do escoamento viscoso da polpa de pitanga, para a taxa de deformação de 100s-1, foi de 2,947 Kcal.gmol-1. No estudo de avaliação dos processos de despolpamento e estabilidade da polpa de acerola (Capítulo 6) preservada por congelamento durante 180 dias, foi determinado que o despolpador mais adequado para a extração da polpa de acerola foi o extrator de escovas, pois apresentou um maior rendimento (62,83%) e menor alteração da cor instrumental. No estudo de estabilidade da polpa de acerola, obtida no extrator de escovas, foi verificado que a mesma apresentou ótima estabilidade física, físico-química e sensorial até o final do experimento, exceto para o parâmetro de cor instrumental .E* (diferença total de cor), que variou significativamente (p¡Ü0,05) durante o período de estocagem da polpa de acerola. Paralelamente, foi observado um decréscimo significativo estatisticamente (p¡Ü0,05) no teor de antocianinas totais (16,23%). De acordo com a análise sensorial do atributo cor, a variação no teor de antocianinas totais não comprometeu significativamente (p>0,05) a aceitabilidade da polpa de acerola estocada por 180 dias a ¿18oC. No estudo de formulação e pasteurização térmica de néctar misto através da metodologia de superfície de resposta (Capítulo 7), foi verificada a maior aceitabilidade das formulações com maiores proporções de polpa de pitanga (26,4% a 32,9%). Na etapa de pasteurização do néctar misto foi determinada que na faixa de tempo entre 39s a 60s em temperaturas que variam de 83oC a 85oC, os néctares mistos pasteurizados de acerola e pitanga apresentaram as menores alterações sensoriais, e conseqüentemente maior a aceitabilidade
Abstract: Pitanga (Eugenia uniflora L.) is a native fruit of the southern and south-eastern regions of Brazil, little studied scientifically. Pitanga was the main objective of this thesis due to its vitamin content and sensory qualities. West Indian cherry, an excellent vitamin C source, was also included in the study. The research on West Indian cherry was basically the evaluation of its pulp as a raw material for the mixed nectar industry, aiming to enrich the pitanga nectar with respect to vitamin C. The technological processes applied to the pulps were the extraction processes and the traditional methods of preservation: freezing and heat pasteurisation. As a logical sequence, the stability of the processed pulps was also evaluated, checking for physical, physicochemical and sensory alterations. The extraction process (Chapter 2) was carried out with two types of pulper: an inclined brush pulper and a horizontal blade pulper. For pitanga, the brush and blade pulpers gave pulp yields of 58.47±3.92% and 46.61±1.80% respectively and the pulp obtained using the blade pulper presented a significantly greater (p¡Ü0.05) total difference in colour (.E*) with respect to the colour parameters L*, a* and b* as compared to the in nature fruits, than that obtained using the brush pulper. Thus the brush pulper was shown to be more efficient due to a greater yield and smaller .E*. The study of pitanga pulp stability during 90 days of frozen storage (Chapter 3) showed that the degradation kinetics of the parameters a* and .E* fitted the 1st and zero order kinetic models respectively. At the same time there was a distinct loss in sensory acceptance and in the positive attitude to buying the nectar formulated with the pitanga pulp stored for 90 days at ¿18ºC, due to significant changes in the nectar formulated with this pulp. A 2² central composite experimental design was used in the study of the heat pasteurisation of pitanga pulp (Chapter 4), the independent variables being the process parameters of time and temperature and the dependent variables, the instrumental colour (a*, b* and .E*) and enzyme activity. The most adequate time-temperature binomial for the preservation of pitanga pulp by heat pasteurisation was from 59 to 68s at 90ºC, when considering minimal alterations in instrumental colour and inactivation of the enzymes. A study of the rheological behaviour of the pitanga pulp (Chapter 5) in the pasteurisation temperature range (83 to 97ºC) showed that it presented pseudoplastic behaviour, adjusting best to the Herschel-Bulkley model. The fluid behaviour index (ç) varied from 0.448 to 0.627. The effect of temperature on the apparent viscosity could be described by the Arrenhius analogical equation, the apparent viscosity decreasing with increase in temperature. The activation energy for viscous flow of the pitanga pulp was 1.947 Kcal.gmol-1 for a deformation rate of 100s-1. In the study on extraction procedures and stability of West Indian cherry pulp (Chapter 6) stored frozen for 180 days, the brush pulper was shown to be more adequate, giving a higher yield (62.83%) and lower alteration in instrumental colour. The West Indian cherry pulp extracted with the brush pulper showed excellent physical, physicochemical and sensory stability up to the end of the experiment, with the exception of the parameter .E*, which varied significantly during frozen storage. In parallel, a statistically significant (p¡Ü0.05) decrease in total anthocyanins was observed. According to the sensory analysis of the attribute colour, the variation in anthocyanin content did not significantly compromise the acceptability of the West Indian cherry pulp after 180 days of storage at ¿18ºC. In the study on the formulation and heat pasteurisation of the mixed nectar using response surface methodology (Chapter 7), a greater acceptance of the formulations containing higher proportions of pitanga pulp (26.4% and 32.9%) was observed. With respect to heat pasteurisation, temperatures between 83 and 85ºC for 39 to 60s presented the smallest sensory alterations and consequently the greatest acceptability of the mixed pitanga and West Indian cherry nectars
Doutorado
Tecnologia de Alimentos
Doutor em Tecnologia de Alimentos

Nectarivorous birds are represented by three major radiations: hummingbirds, honeyeaters, and sunbirds. These lineages share a number of convergent features in ecology, morphology, physiology, and behavior, and have served as important models in the study of foraging strategies and energetics. Because their diet is rich in water and sugar but poor in nitrogen and electrolytes, nectarivores provide a striking opportunity for evaluation of physiological constraints. My research emphasizes a novel aspect of the water-energy interaction: water overingestion in nectar-eating birds. The dual purpose of my dissertation research was to investigate the physiological mechanisms that allow nectar-eating birds to cope with exceedingly high ingestion of water and to elucidate the consequences of ingesting and processing large quantities of water for energy intake and for the maintenance of balance of important metabolites such as glucose. In nectar-eating birds, water overabundance in food has the potential effect of constraining energy procurement by overwhelming osmoregulatory processes and limiting digestive function. My research has allowed the development of an integrated quantitative description of gut and kidney function under the broad range of water loads and hydration conditions that birds can experience in the wild. Understanding limits to water processing will provide general insights into how animals are designed, on how aspects of design constrain their ecological performance, and into how aspects of design in one physiological system can impose limits on other systems. The osmoregulatory processes of nectar-eating birds highlight the relevance of understanding the impact that events taking place in the gut can have for feeding behavior, and renal and metabolic function. Adopting a broadly comparative approach to understanding the interaction between feeding behavior, digestion, and osmoregulation is pertinent because is unclear whether the many extreme physiological characteristics of hummingbirds that have traditionally been assumed to be associated with a nectar-feeding habit are shared by other nectar-eating birds. In my dissertation research I have begun to examine the similarities, and have found some important differences, in the responses of two major radiations of nectar-eating birds to their sugary and watery diets.

Nectarivory has evolved independently eight times among birds. In the neotropics specialized nectarivory evolved in hummingbirds and flowerpiercers (genus Diglossa). Flowerpiercers are nectar-robbers of hummingbird-pollinated plants. Because flowerpiercers and hummingbirds are found in the same habitats feeding on the nectar of the same flowers, they provide us with a unique opportunity to understand the pressures that nectarivory imposes on animals. Flowerpiercers present beaks that have a long hook at the tip of their maxilla. The hook is used to hold tubular flowers in place while they stab them by projecting their lower mandible. Then, they insert their tongues in the puncture and extract nectar. I investigated the following questions: (1) What is the function of the flowerpiercer's hook, and which are the consequences of its evolution? (2) Are the digestive traits of flowerpiercers convergent with those of hummingbirds? (3) How do digestive traits affect sugar selection by nectar feeding birds? And (4) What are the effects of Diglossa baritula's physiology and behavior over its annual cycles? I found that nectarivorous flowerpiercers evolved from a frugivorous ancestor with a hookless beak. The evolution of a hooked bill allowed flowerpiercers to become efficient nectar-robers, but hindered their efficiency to feed on fruit. Using a phylogenetically informed approach, I found that the digestive traits of flowerpiercers and hummingbirds are not convergent. Unlike hummingbirds which have astounding intestinal sucrase activity levels, flowerpiercers had low sucrase activity. Nectar intake in D. baritula seems to be limited by its ability to digest sucrose. I also found that sugar preferences in nectar-feeding birds are concentration-dependent. At lower concentrations birds preferred hexoses, whereas at higher concentrations they preferred sucrose. Although nectar composition and concentration are often discussed as two different floral traits, they have a synergistic effect on the sugar preferences of nectar-feeding birds. D. baritula individuals exhibit biannual reproductive and molting cycles that are synchronized with flower and fruit abundance in the mountains of Mexico. The ability to rob nectar appears to have molded the evolution of the most important morphological, physiological and behavioral traits of D. baritula.

A key question in biology is how changes in gene function or regulation produce new morphologies during evolution. The nectar spur is an evolutionarily labile structure known to influence speciation in a broad range of angiosperm taxa. Here, the genetic basis of nectar spur development, and the evolution of differences in nectar spur morphology, is investigated in Linaria vulgaris and two closely related species of orchid, the primitively longer-spurred Dactylorhiza fuchsii, and more derived short-spurred D. viridis (Orchidinae, Orchidaceae). Despite considerable morphological and phylogenetic differences, nectar spur ontogeny is fundamentally similar in each of the study species, proceeding from an abaxial bulge formed on the ventral petal relatively late in petal morphogenesis. However, spur development is progenetically curtailed in the short-spurred orchid D. viridis. In each case spur development involves class 1 KNOTTED1-like homeobox (KNOX) proteins. KNOX gene expression is not restricted to the spur-bearing petal, indicating that additional components are required to define nectar spur position, e.g. canonical ABC genes, determinants of floral zygomorphy, and additional (currently unknown) factors. However, constitutive expression of class 1 KNOX proteins in transgenic tobacco produces flowers with ectopic outgrowths on the petals, indicating that KNOX proteins alone are, to some degree, capable of inducing structures similar to nectar spurs in a heterologous host. Interestingly, KNOX gene expression is high in the ovary of all study taxa, suggesting that KNOX proteins may also have been involved in the evolution of this key angiosperm feature. Although principally involved in maintaining indeterminacy in the shoot apical meristem (SAM), members of the KNOX gene family have been co-opted in the evolution and development of compound leaves where they suppress differentiation and extend the morphogenetic potential of the leaf. A similar model is presented here to explain the role of KNOX proteins in nectar spur development. Co-option of KNOX gene expression to the maturing perianth delays cellular differentiation, facilitating the development of the nectar spur but requiring additional, unknown factors, to determine nectar spur fate. As facilitators of nectar spur development, changes in the spatio-temporal patterns of KNOX gene expression may alter the potential for nectar spur development and explain the critical length differences observed between the orchids D. fuchsii and D. viridis (and among other angiosperm taxa). Taken together, the available data indicate that KNOX genes confer a meristematic state upon plant tissues in a variety of morphogenetic contexts, making the gene family a potentially versatile tool to mediate a wide variety of evolutionary transformations.

Orientador: Hilary Castle de Menezes
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: No presente trabalho foi estudado o armazenamento de acerola sob refrigeração (8°C) e congelada (-18°C). Paralelamente foi elaborado néctar de acerola que foi submetido a diferentes tratamentos térmicos e estocado a temperatura ambiente e sob refrigeração. As matérias primas utilizadas foram: a) fruta "in natura" colhida na região de Campinas, para o estudo do armazenamento da fruta e b) suco integral de acerola para o estudo do néctar. No estudo do armazenamento, as frutas foram selecionadas e acondicionadas em sacos plásticos transparentes de polietileno e divididas em dois lotes. Um lote foi armazenado sob refrigeração por 168 horas e outro lote foi congelado por 180 dias. Foram feitas determinações de ácido ascórbico periodicamente durante a estocagem. As perdas de ácido ascórbico para a fruta armazenada sob refrigeração foram de 19% após 48 horas e 35,6% após 144 horas, sendo que após esse período a fruta apresentou bastante alteração em sua aparência. A fruta armazenada congelada apresentou perdas de 21,45% de ácido ascórbico após 180 dias de estocagem. Para o estudo do néctar foi preparada a formulação do néctar e este foi dividido em 3 lotes. Um lote após acondicionamento em latas foi congelado em túnel de congelamento e armazenado em câmaras frigoríficas a -18°C. O segundo lote foi tratado termicamente em trocador de calor a placas e imediatamente procedeu-se o enlatamento ("Hot Fill"), após o resfriamento o néctar foi armazenado a temperatura ambiente e sob refrigeração (8°C). O terceiro lote foi acondicionado em latas e estas submetidas a tratamento térmico em trocador de calor rotativo ("Spin Cooker") e então armazenados nas mesmas condições que o segundo lote. O néctar congelado foi utilizado como padrão para avaliação dos resultados. Os resultados mostraram que em relação ao tipo de processo, o processo "Spin Cooker" apresentou menores perdas de ácido ascórbico e menores alterações de sabor e cor que o processo "Hot Fill". Em relação as temperaturas de armazenamento, as amostras estocadas a temperatura ambiente apresentaram elevadas perdas de ácido ascórbico após 180 dias, 27,04% para amostra "Spin Cooker"e 27,39% para amostra "Hot Fill", sendo também bastante evidentes as alterações de cor, sabor e aspecto visual. . Para as amostras armazenadas sobrem geração a amostra "Spin Cooker" após 180 dias apresentou menores perdas de ácido ascórbico (5,76%) em relação ao processo "Hot Fill"(9,84%). As perdas de ácido ascórbico do néctar congelado (padrão) foram de 3,02%. Em relação ao sabor e aspecto visual as amostras acondicionadas sob refrigeração tiveram uma maior aceitação que as amostras mantidas a temperatura ambiente
Abstract: In this project the storage of West Indian Cherries, both frozen (-18°C) and refrigerated (8°C), was studied. In parallel, West Indian Cherry nectar was formulated, submitted to different thermal treatments, and stored both at room temperature and under refrigeration. The following raw materials were used: a) raw fruit harvested in the Campinas region, used for the storage study; and b) whole West Indian Cherry juice, used for the study of the nectar. For the fruit storage study, the fruits were separated into several samples after selection, and stored in plastic bags, which were divided into two batches. One batch was stored under refrigeration for 168 hour and the other frozen for 180 days. For the fruit stored under refrigeration, .the losses in ascorbic acid were 19% after 48 hours and 35.6% after 144 hours, at which point the fruit was also considerably ahered in appearance. The frozen fruit presented losses of 21.45% in ascorbic acid after 180 days storage. For the study of the nectar, the chosen formulations was produced and divided into three batches. One batch was canned, frozen in a tunnel and stored in a cold chamber at 18°C. The second batch was treated in a plate heat exchanger, hot filled, and, after cooling, stored both at room temperature and under refrigeration(8°C). 1Jle third batch was canned, heat treated in a spin cooker-cooler, and stored under the same conditions as the second batch. The frozen nectar was used as a standard to evaluate the results. The results showed that with respect to the type of process, the spin cooker process produced sma1ler losses in ascorbic acid and less alterations in flavour and colour than the hot fill process. With respect to storage temperature, the samples stored at room temperature showed considerable losses in ascorbic acid after 180 days, 27.04% for the spin cooker sample and 27.39% for the hot fill sample, accompanied by evident changes in colour, flavour and visual appearance. For the samples stored under refrigeration, the spin cooker sample showed lower losses in ascorbic acid (5.76%) after 180 days than the hot fill sample (9.S4%). The losses in ascorbic acid of the ftozen nectar were of the order of3.02%. With respect to flavour and visual appearance, the samples stored under refrigeration were considered more acceptable than those stored at room temperature
Mestrado
Mestre em Tecnologia de Alimentos

Les nectaires extra-floraux etudies sont portes par des plantes croissant en milieu ouvert, confrontees a des conditions climatiques extremes (temperature elevee, humidite relative faible, eclairements forts). Les lianes suivies au cours de ce travail appartiennent a trois familles distinctes: passiflora glandulosa cav. , passiflora vespertillo (passifloracees); stigmaphyllon convolvulifolium a. Juss. , stigmaphyllon hypoleucum miq. (malpighiacees); mimosa gurlandinae aubl. , et mimosa mycradenia benth. (mimosacees). La secretion nectarifere est envisagee sous deux approches fondamentales complementaires: physiologique et ecologique. Plusieurs orientations sont donnees a ce travail en ce qui concerne le role que peuvent jouer les dispositifs secreteurs dans les mecanismes biologiques et physiologiques de la plante entiere. En effet, les nectaires sont envisages successivement comme des reservoirs a carbone et a calcium, remobilisables au cours de la croissance des jeunes feuilles; comme des organes puits augmentant le transport de metabolites vers les organes jeunes porteurs des nectaires; enfin comme des soupapes de surete permettant d'evacuer les composes excedentaires du metabolisme des feuilles. Les nectaires sont ensuite, envisages dans leur fonction ecologique et la relation existant entre la secretion nectarifere et la presence de fourmis consommatrices de nectar est recherchee. La protection biotique des organes aeriens de la plante assuree par les fourmis contre les attaques des phytophages est consideree. L'importance de la protection biotique est comparee a celle assuree chimiquement par la plante en synthetisant dans les feuilles, des composes repulsifs pour les herbivores. En dernier lieu, les fourmis tres presentes sur les nectaires pourraient faciliter la secretion nectarifere par leur consommation, en entretenant un gradient de concentration entre les cellules secretrices externes et la surface du nectaire. En conclusion, la secretion nectarifere est au moins aussi importante dans la fonction physiologique de la plante que pour sa protection. La fonction secretrice est a reconsiderer en mettant en parallele les deux approches fondamentales soulignees dans ce travail

We examined several aspects of nectar production in Campsis radicans to better understand how standing crop is affected and how production affects pollinator visitation. In all experiments, nectar and concentration of flowers were measured and total sugar was calculated. Flowers do not produce additional nectar unless nectar is removed, and it is not resorbed. Volume of standing crop and total sugar fluctuates throughout the day, whereas concentration remains constant. Age and time of day significantly affect regeneration of nectar and sugar. The number of removals did not significantly affect the amount of nectar or sugar regenerated; however, concentration declined significantly after the initial removal. We have established several factors affecting nectar production, although clearly there are other aspects influencing the production of nectar in C. radicans. Focus should be placed on determining the physiological aspects of secretion as well as studying the role that environmental factors have on physiological aspects.

Urbanisation typically results in homogenisation of the constituent avifauna, as generalists that are able to adapt to and persist within the urban landscape replace specialist species whose specific habitat needs are removed. Recently, within some major urban centres, parrots have become a conspicuous component of the avifauna, present in higher abundance in the urban landscape than in the natural environment. This thesis examines the composition and distribution of the parrot community within a large urban centre and evaluates the relative importance of key abiotic and biotic factors that may explain the increase in abundance of urban parrots. I demonstrated that parrot species were present in higher abundance within the urban landscape, compared to natural habitat and that, historically, both drought and wild fire resulted in an influx of some parrot species into the urban landscape. I demonstrated that the standing crop of nectar was consistently higher within streetscapes compared to the non-urban habitat and is capable of sustaining large populations of large-bodied nectarivores. I also demonstrated that trees within the urban landscape produce more flowers and flower for longer than the same species of tree outside the urban landscape. I showed that there were significantly more visitations to hollows by parrots within the urban landscape, compared to forest, as well as significantly more aggressive interactions. My results demonstrate that the urban landscape is capable of sustaining a diverse community of native parrots, particularly nectarivores such as the rainbow lorikeet. The urban landscape provides food resources in excess of that found in natural habitat, however nesting resources are fewer compared to natural habitat. My research suggest that there may be a shortage of tree hollows and I discuss how, if the density of parrots continues to increase, there may be a simplification in the current avifauna due to a shortage of breeding resources.

This thesis explores the impacts of ozone pollution on the nutritional quality of nectar and pollen. We report the use of HPLC and HPIC to quantify the amino acids and carbohydrates in nectar and the development of a microwave-assisted acid hydrolysis to quantify the proteinbound amino acids available in pollen, allowing back-calculation to estimate total protein content. Utilising ten cultivars of broad bean (Vicia faba L.), exhibiting considerable variation in response to ozone, we explored what parameters are meaningful when attempting to determine the impacts of ozone (reductions in biomass, seed yield etc.) and whether these measures are consistent with the influence of the pollutant on pollen quality. We found little correlation between impacts on pollen quality and any usually-measured plant traits affected by ozone. We concluded that ozone influences pollen qualities in two ways; (i) exposure to ozone during plant growth influences the allocation of proteins to pollen, and (ii) ozone may cause direct oxidative damage to pollen once dehisced from anthers. We investigated the impact of ozone on the allocation of amino acid and carbohydrate resources to nectar and pollen, using broad bean (Vicia faba L.) as a convenient model. Plants grown in O3 and exposed to charcoal/purafil® filtered air (CFA) at flowering allocated significantly more sucrose and amino acids into their nectar than plants in other fumigation treatments. We discovered a reduction in the amount of free amino acids recoverable from the outer surface of the pollen in all treatments subject to O3 exposure, but most significant in plants maintained throughout in O3. We also found a significant shift in the proportions of amino acids in the respective ozone treatments. The final experimental thesis chapter explored the potential impact of ozone-induced changes in nectar quality on bee behaviour. Simulated ozone-induced changes in nutrient composition of nectar were employed in an olfactory conditioning assay using honeybees. Bees trained with nectar matching that of plants subject to O3 and exposed to CFA at flowering demonstrated an initially improved rate of learning, but association with reward decreased rapidly, whereas those trained with nectar matching that of plants from CFA was sustained.

The ecological success of social insects is frequently ascribed to improvements in task performance due to division of labour amongst workers. While much research has focused on improvements associated with lifetime task specialization, members of colonies can specialize on a given task over shorter time periods. Eusocial bees in particular must collect pollen and nectar rewards to survive, but most workers appear to mix collection of both rewards over their lifetimes. We asked whether bumblebees specialize over timescales shorter than their lifetime. We also explored factors that govern such patterns, and asked whether reward specialists made more foraging bouts than generalists. In particular, we described antennal morphology and size of all foragers in a single colony and related these factors to each forager's complete foraging history, obtained using radio frequency identification (RFID). Only a small proportion of foragers were lifetime specialists; nevertheless, >50% of foragers specialized daily on a given reward. Contrary to expectations, daily and lifetime reward specialists were not better foragers (being neither larger nor making more bouts); larger bees with more antennal olfactory sensilla made more bouts, but were not more specialized. We discuss causes and functions of short and long-term patterns of specialization for bumblebee colonies.

This is an applied study that critically analyzes the Arabic-English translation of a key cultural text: the biography of the Prophet Muhammad entitled The Sealed Nectar. It aims at assessing the translation to see how successful the translator was in composing an equivalent text to such a culture-specific one. The study adopts Juliane House's (1997) translation quality assessment model which is based on Systemic Functional Linguistic theory and relates texts to their situational and cultural contexts. In order to introduce a qualitative judgement of the work, the study enhances House’s model to make it applicable to culture-bound texts that call for overt translation. It introduces a consilience of: 1) Nord’s notion of culturemes; 2) Nida’s categorization of cultural features to help in analyzing religious terms and culture; 3) Dickins et al.’s compensation strategies that show the translator’s endeavor to balance the translation loss while dealing with such sensitive terms; 4) Martin and White’s appraisal theory which explores attitudinal meaning and, hence, helps in investigating the translator’s evaluation of these terms; and 5) Katan’s model that helps in highlighting the correlation between levels of cultures and discourse variables (field, mode and tenor). Application of the enhanced model reveals mismatches on all the discourse variables which indicate the application of a cultural filter that adopts the norms of English academic discourse, in addition to overt errors that distort the message of this sensitive text. The study thus complements House’s framework of translation quality assessment and introduces a model that can be further applied to assess overt translations.

Orientador: Hilary Castle de Menezes
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: Produziu-se sucos de beterraba, cenoura e carambola e polpa de morango em planta piloto. Os sucos e a polpa foram conservados sob congelamento durante períodos variados. Após uma avaliação sensorial prévia, quanto a formulação de um néctar misto de frutas e hortaliças, o que melhor aceitação sensorial teve quanto a aparência e aceitação global foi uma bebida composta por duas hortaliças e duas frutas na proporção de 2:2:2:1 que são beterraba, cenoura, morango e carambola respectivamente, e brix final de 13°. No primeiro processamento, formulou-se um néctar misto de frutas e hortaliças composto pelos sucos e polpa de morangos, congelados, utilizando a formulação melhor avaliada sensorialmente. A polpa de morangos participou na forma integral em pedaços. Fez-se uma homogeneização dos componentes congelados, adição de açúcar, aquecimento, enlatamento e pasteurização. Estudou-se durante seis meses a vida de prateleira desse néctar, medindo mudanças ou não através de avaliações microbiológicas, sensoriais e físicoquímicas. Ao final do estudo de vida de prateleira do primeiro processamento os resultados das análises sensoriais feitas mês a mês mostraram que os precipitados, compostos principalmente de pedaços de polpa e componentes insolúveis do morango, foram considerados aparentemente indesejáveis. Fez-se um novo processamento do néctar misto para verificar melhor a aceitação sensorial entre amostras com polpa de morango em pedaços, e polpa homogeneizada peneirada, e verificou-se que o néctar compolpa homogeneizada peneirada, foi o melhor aceito. O terceiro processamento diferiu do primeiro em uma melhor mistura do néctar misto com prévia homogeneização, peneiragem da polpa de morango. Dois conservantes, ácido ascórbico e EDTA (etilenodiaminotetraacetato diácido dissódico ), foram adicionados individualmente no néctar, resultando em três tipos de amostras: sem aditivos; com aditivo ácido ascórbico 0,03%; com aditivo EDTA 0,01%. Foram verificadas mudanças ou não através de avaliações microbiológicas, sensoriais e físico-químicas durante três meses de vida de prateleira. O melhor néctar misto de frutas e hortaliças quanto as avaliações verificadas foi o com adição de 0,03% de ácido ascórbico. Podendo ser considerado como uma bebida saudável que pode contribuir com seus conteúdos de vitaminas ( 20% e 283 - 205% da ingestão diária recomendável de vitamina A e C respectivamente), como fonte de sódio e potássio e como bebida que contém fibras solúveis e insolúveis.
Abstract: Beetroot,carrot and star-fruit juices and strawberry pulp were produced in a pilot plant and preserved in the frozen state for different periods. A preliminary sensory evaluation was carried out to formulate a mixed fruit and vegetable nectar. The formulation best evaluated with respect to appearance and global sensory acceptance was that composed of two fruits and two vegetables in the proportion of 2:2:2:1 of beetroot, carrot, strawberry and star-fruit, respectively, with a final brix of 13°. In the first trial the best evaluated formulation was prepared using frozen juices and pulp. The strawberry pulp was used in the form of the whole fruit in pieces. The frozen components were blended, sugar added, and the whole mixture heated, canned and pasteurised. The shelf life of this nectar was studied for six months, measuring any changes via microbiological, sensory and physicochemical evaluations. At the end of this shelf-life study the results of the monthly sensory evaluations showed that the precipitates, composed mainly of the pieces of strawberry pulp and insoluble components, were apparently considered to be undesirable. A second trial of the mixed nectar was then carried out to compare the sensory acceptance of samples containing the whole strawberry pulp in pieces with samples containing the homogenized sieved pulp. This second option was shown to be batter. The third processing differed from the first in that it was much better blended as well as including a prior homogenization of the sieved strawberry pulp. Two additives, ascorbic acid and EDTA (ethylenediaminotetraacetic acid disodium salt) were added individually to the nectar, resulting in three types of sample: no additives, plus 0.03% ascorbic acid and plus 0.01% EDTA. The changes were evaluated during a three month shelf-life using microbiological, sensory and physico-chemical analyses. According to the results, the best nectar was that containing 0.03% ascorbic acid, which could be considered as a healthy beverage, contributing vitamins (20% and 283-205% of the recommended daily intake of vitamin A and C respectively), as a source of sodium and potassium and as a beverage containing soluble and insoluble fibres.
Mestrado
Mestre em Tecnologia de Alimentos

Orientador: Pilar Rodriguez de Massaguer
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: Em 2005, a produção mundial de manga ¿in natura¿ foi de 850000 toneladas, sendo o que Brasil ocupa o sétimo lugar no ranking mundial de produção. Neste mercado, o néctar de manga ocupa o terceiro lugar da preferência mundial por sabor. Considerando-se que os contaminantes emergentes deste produto são fungos que apresentam características de resistência ao processo de pasteurização empregue pelas indústrias, torna-se essencial que se conheça o nível de contaminação do produto por estes bolores ermoresistentes, bem como que se identifique qual espécie é a mais termoresistente isolada do produto. Além disso, como o processo de pasteurização por si só não é capaz de eliminar totalmente essa micobiota contaminante, sem alterar sensorialmente o produto, é indispensável o estudo do efeito de fatores controladores do crescimento destes microrganismos termoresistentes, bem como que se modele seu crescimento em função de alterações nestes fatores. Considerando o exposto, esta pesquisa visou: i. quantificar, isolar e identificar o bolor mais termoresistente presente em néctar de manga; ii. avaliar o efeito das variáveis controladoras do crescimento sobre os parâmetros de crescimento desse isolado, quando em dois níveis de inoculação, 6,8x100esp./mL e 9,3x103esp./mL, selecionando as variáveis de maior impacto, via modelagem preditiva primária; iii modelar os parâmetros de crescimento, como tempo de adaptação (l; dias) e taxa de crescimento (m; mm.dia-1) do bolor mais termoresistente utilizando a modelagem polinimial de superfície de resposta. Para tanto, 50L de néctar de manga foram utilizados para o isolamento das linhagens termoresistentes, conforme descrito por Bechaut & Pitt (2001). Para delineamento da termoresistência dos isolados utilizou-se metodologia adaptada de Baglioni (1998). No teste do nível baixo de inóculo (100esp./mL de néctar de manga), a temperatura variou de 12 a 25°C, o pH, de 3,2 a 4,8 e a aw de 0,979 a 0,988, mediante um desenho fatorial 23 acrescido de 3 pontos centrais e 6 axiais; já para o nível de inóculo de 103esp./mL, a temperatura variou de 18 a 22°C, o pH de 3,5 a 4,5 e aw de 0,970 a 0,990, mediante desenho fatorial 23 com 3 pontos centrais. Os dados do incremento diário nas medidas de diâmetro foram ajustados pelos modelos de crescimento de Baranyi (Baranyi & Roberts, 1995) e de Gompertz modificado (Zwietering et al., 1994). Para a modelagem secundária do crescimento, utilizou-se um desenho fatorial 22 com 3 pontos centrais e 4 axiais, sendo que a temperatura variou de 17,2 a 22,8°C e o pH variou de 3,2 a 4,7, com aw fixada em 0,980 (comum ao produto). Para estas avaliações o fungo foi inoculado em 230mL de néctar de manga, previamente esterilizados, dispostos em garrafas PET, higienizadas segundo Petrus (2000). A contagem total de bolores termoresistentes presentes no néctar de manga foi de 7,4x103esp./mL, deste total foram isoladas 8 linhagens diferentes, sendo a que apresentou maior termoresistência (100°C/15min) identificada como Aspergillus niger. Considerando-se o nível de inóculo baixo (6,8x100esp./mL de néctar de manga), observou-se que reduções de pH causaram aumento do tempo de adaptação (4 para 10 dias), bem como incrementos de 0,01 na aw o diminuíram em 3 dias, sendo que em temperaturas inferiores a 18°C não foi observado o crescimento do fungo. Já considerando-se o nível de inóculo de 9,3x103esp./mL, observou-se que a aw, na faixa natural ao produto, não apresentou impacto significativo (p<0,05) sobre os parâmetros de crescimento do microrganismo. Em condições de abuso de temperatura, uma redução de 5,6°C (22,8 para 17,2°C), implicaram em aumento de 23 dias no tempo de adaptação do fungo. De maneira semelhante, quando o pH do néctar de manga passou de 4,0 para 4,7, o tempo de adaptação do microrganismo passou de 11 para 3 dias e o diâmetro final da colônia triplicou. Cabe salientar que o modelo de Baranyi demonstrou melhor performance no ajuste dos dados de crescimento, com valores maiores valores de R2 (0,998). Para a modelagem polinomial de superfície de resposta a aw foi fixada em 0,980 (natural do produto). O modelo obtido para tempo de adaptação, com parâmetros significativos (p<0,05) temperatura, linear e quadrática e pH linear (com valores codificados) foi: . Este modelo foi verificado com R2 0,981, 1.06 de fator bias, 1,16 de fator exatidão e relação Fval/Ftab de 23,4. As análises estatísticas do modelo demonstraram que reduções no valor de pH em 0,5 unidade podem ser capazes de duplicar o tempo de vida útil do produto (10 para 20 dias). Efeitos semelhantes foram observados para reduções de temperatura da ordem de 0,8°C. Considerando-se a taxa de crescimento, o modelo polinomial obtido, tendo como fatores significativos (p<0,05) pH, linear e quadrático e temperatura linear e quadrática, com valores codificados, foi: Este modelo foi verificado com R2 0,882, 1.06 de fator bias, 1,16 de fator exatidão e relação Fval/Ftab de 2.6. Análises estatísticas do modelo demonstraram que, em pH 4,0 e 20°C é observada menor taxa de crescimento (1,33mm.dia-1). Assim sendo, os resultados demonstraram que pH e temperatura são fatores que exercem influência significativa sobre o crescimento de A.niger, em néctar de manga. Entretanto, estes fatores, nos níveis estudados, somente retardam o crescimento do microrganismo, não o impedindo. É essencial então o controle por refrigeração, visando evitar abusos de temperatura, já que em temperaturas =15°C, independentemente do nível de inóculo utilizado, não foi notado o crescimento de A.niger. De modo similar, deve-se também optar pelo controle rígido nos valores de pH, pois alterações de 0,5 unidade podem implicar em mudanças severas na vida de prateleira do produto. Entretanto, somente alterações em valores de pH e temperatura não são suficientes para garantir a estabilidade microbiológica do produto, já que esta depende da qualidade da matéria-prima, dentre outros fatores, contudo, tanto pH quanto temperatura podem atuar como coadjuvantes na preservação do néctar de manga
Abstract: In 2005, the world production of mango fruits was 850,000ton and Brazil was the 7th in ranked of world production. The mango nectar is the third ranked in flavor preference. Concerning the emerging contaminant microorganisms of this product are molds, which are able to survive pasteurization process, it is essential to know the contamination level of heat resistant molds in this product and to identify the most heat resistant. Moreover, pasteurization process is unable to eliminate these molds, so it is necessary to study both the effect of hurdle factors and the interaction of factors in the growth. The aim of this research was: i. to quantify, isolate and identify the most heat resistant mold in the mango nectar; ii. to evaluate the effect of hurdle factors on growth parameters of the isolated, considering two levels of inoculum, 6.8x100 and 9.3x103spores/mL of mango nectar, selecting the most impact variables through primary modeling; iii. to model growth parameters such adaptation time (l; days) and growth rate (m; mm.day-1) of the most heat resistant mold by polynomial response surface. For this purpose, 50L of mango nectar were used for isolating the thermal resistant strains (Bechat & Pitt, 2001). To screen of heat resistantance of the isolated was performed as indicated in Baglioni (1998). Concerning low inoculum level (100spores/mL mango nectar), temperature was from 12 to 25°C, pH, from 3.2 to 4.8 and aw, from 0.979 to 0.988, which were tested by a central composite design, 23 with 3 central points and 6 star points. For 103spores/mL of mango nectar, temperature was from 18 to 22°C, pH, from 3.5 to 4.5 and aw, from 0.970 to 0.990, tested by factorial design 23 with 3 central points. Fungal growth was measured as colony diameter on daily basis. Primary predictive models of Baranyi & Roberts and modified Gompertz were used to fit growth data. For a secondary polynomial model was used a central composite design 22 with 3 central points and 4 star points, in which temperature varied from 17.2 to 22.8°C and pH, from 3.2 to 4.7, and aw was fixed at 0.980. For all experiments conducted the mold was inoculated in 230mL PET bottles mango nectar, sanitized according to Petrus (2000). The total count average of heat resistant molds from mango nectar was . 4x103spores/mL, from this total were isolated 8 different strains and the most heat resistant was Aspergillus niger (100°C/15 minutes). Concerning the low inoculum level (100spores/mL of mango nectar), was observed that pH reductions increase adaptation time from 4 to 10 days, as well, an increase of 0,01 on aw reduced shelf life in 3 days. In temperatures =18°C the growth mold was not observed. For inoculation level 9.3x103spores/mL of mango nectar, was observed that aw was not significant (p<0.05) on the mold growth parameters. In abuse temperatures conditions, reductions of 5.6°C (from 22.8 to 17.2°C), increase the adaptation time in 23 days. Same effects were observed when pH of mango nectar changed from 4.0 to 4.7, while adaptation time decreased from 11 to 3 days and the maximum diameter tripled. It was verified that Baranyi & Roberts¿ model adjusted better the experimental data, with higher adjustment coefficients (0.998). The obtained model for adaptation time, with temperature, (temperature)2 and pH as significant factors (p<0.05), was: . This model was verified with R2 0.981, 1.06 bias factor, 1.16 accuracy factor and Fval/Ftab 23.4. The statistical analyses demonstrate that a decrease in pH of 0.5 unit could double the product shelf-life (from 10 to 20 days). The same effect was observed with reductions of about 0.8°C in temperature. The maximum shelf life obtained (about 30 days) was for pH 3.28 and 17.2°C. The obtained model for growth rate, with pH, (pH)2, temperature and (temperature)2 as significant factors was: This model was verified with R2 0.882, 1.06 bias factor, 1.16 accuracy factor and Fval/Ftab 2.6. Statistical analysis demonstrated when pH was 4.0 and temperature was 20°C, the growth rate was lower (1.33mm.day-1). Thus, pH and temperature were significants factors (p<0.05) on growth of A.niger in mango nectar. However, for the studied levels, this factor only retards the mold growth, without eliminating. So, it is essential to control storage refrigeration, avoiding abuse temperature, since temperatures = 15°C, do not permit A.niger growth, no matter the inoculum level. In the same manner, variation in pH of 0.5 units can implicate in strong changes in product shelf life. However pH and temperature variation are not able to guarantee the product microbial stability, since it depends on raw material quality assurance, among other factors. Hence, pH and temperature can contribute to mango nectar preservation
Mestrado
Mestre em Ciência de Alimentos

In the theoretical part the thesis focus on consumer behavior and marketing research. Describes three models of buyer behaviour, main factors influencing the behaviour and the purchase decision-making proces. The second part of the thesis presents results of the primary marketing research.

How does variability in nectar secretion rates affect the interaction between hummingbirds and the plants that: they pollinate? Other researchers have suggested that variability may influence pollinators to leave a plant earlier, thus increasing the potential for cross-pollination. My dissertation asks the following questions: Does variability in nectar secretion rates influence hummingbird visitation at a flower patch? Does it do so in a manner that is likely to increase; cross-pollination? And, does variability in these rates benefit the hummingbird by improving their foraging efficiency? By asking if variability benefits both plants and hummingbirds, I implicitly ask the question: Can variability in nectar secretion rates be a mechanism that helps keep this potentially antagonistic interaction positive? I developed an artificial flower that simulates nectar secretion. Using patches of these artificial flowers, I varied renewal rates of flowers found within a patch. The appendices describe the results of my studies. The aviary experiment (Appendix A) investigates how Broad-billed hummingbirds (Cynanthus latirostris) forage given variability in nectar renewal-rates. The field experiment (Appendix B) investigates how hummingbird visitation to patches with different renewal-rates might affect cross-pollination. Appendix C describes the hummingbird community at the study site. Appendix D identifies the plants visited by these hummingbirds. In the aviary experiment, Broad-billed hummingbirds changed their foraging when exposed to high variability and limited nectar. They visited a higher percentage of rewarding flowers, foraged more systematically, and significantly decreased their foraging time. These changes made their foraging more efficient. In the field experiment, increased renewal-rate variability was associated with hummingbirds visiting fewer artificial flowers per foraging bout. These results suggest cross-pollination may be increased. However, levels of renewal-rate variability did not affect the visitation rates to the flower patch or the distribution of nectar within the patch. Hummingbirds spent significantly more time probing the last flower in a foraging bout than other flowers, and preferentially ended foraging bouts on a rapidly renewing flower. I suggest that the energetic cost of hovering flight likely influenced this behavior. My results support the hypothesis that variability in nectar secretion rates may benefit both partners in this pollination mutualism.

Flower seed mixes are increasingly used to enhance the biodiversity and amenity values of urban green spaces. Urban or “pictorial” flower seed mixes are often used because they are designed using cultivars and non-native species to provide more colourful and longer-lasting flower displays. Although these seed mixes are effective in providing a high density of large colourful flowers, over an extended season, their value for biodiversity, and in particular the floral rewards they provide for flower-visitors, is largely unknown. The overall aim of my thesis was to assess and improve the value of these new urban habitats as forage resources for flower-visiting insects. My approach was to quantify and compare floral reward provision and insect visitation between meadows grown from three exemplar commercial pictorial flower meadow seed mixes (called Marmalade Annual, Short Annual and Cornfield Annual). I also compared these standard commercial mixes with corresponding ‘nectar-enriched’ formulations, which were designed by increasing the proportional seed weight contribution of selected species predicted to produce high quantities of nectar within each mix. To compare floral rewards and visitation between meadows grown from these seed mixes, I set up a field experiment in Sheffield, UK, using a complete randomised block design with six replicate blocks, each with six 25 m2 plots sown with one of the six seed mix treatments. My first objective was to quantify the floral nectar and pollen rewards provided by each flowering species recorded in the meadows (on the scale of a single flower or inflorescence). My second objective was to use these data to quantify the floral rewards provided per unit area by replicate meadows of different seed mix treatments, testing whether enrichment of seed mixes is an effective method of increasing floral nectar sugar rewards. My third objective was to corroborate/correct my morphology-based flower-visitor identifications using DNA barcoding to screen for misidentifications and morphologically cryptic species. I then used these DNA barcode-based identifications to assess whether there are systematic biases in the structure of flower-visitor networks constructed using molecular taxon identifications compared to traditional morphology-based taxon identifications. My fourth objective was to quantify patterns of insect visitation to meadows, testing whether meadows of different seed mix types attract different flower-visitor assemblages. Meadow floral composition surveys revealed that contamination by unintended horticultural species was widespread across replicate seed mix treatments, with contaminants likely germinating from a seed bank laid down during a failed attempt at this experiment the previous year. Contamination particularly affected Marmalade mixes, mainly because the common contaminant species were often also components of the Short and Cornfield mixes. For example, contaminants contributed on average about a third of nectar sugar mass or pollen volume per unit area in Marmalade mix meadows. Hence, contamination fundamentally undermined the internal validity of seed mix treatments, reducing the ability to directly attribute meadow level patterns in floral rewards or flower-visitors to seed mixes. As result, examination of patterns of floral resource provision and insect visitation were more informative at a species scale. In terms of patterns of insect visitation, Centaurea cyanus received 91% of bumblebee visits, 88% of honeybee visits and 29% of hoverfly visits, whilst T. inodorum received 27% of hoverfly visits. Patterns of bumblebee and honeybee visitation indicated preferential visitation to floral units of Centaurea cyanus. Although this species produced high quantities of nectar sugar mass and pollen volume, this did not differentiate it from other Asteraceae, such as Glebionis segetum, Rudbeckia hirta and Coreopsis tinctoria, which all produced high quantities of both floral rewards. Hence, it is likely that floral traits not measured in this study, such as nectar accessibility (‘nectar-holder depth’) or concentration/volume characteristics (which can affect accessibility due to constraints imposed by feeding morphology), drove patterns of preferential visitation in bumblebees and honeybees to C. cyanus. Given that in the absence of contamination there would have been very few bumblebee or honeybee visitors to Marmalade mix meadows, aesthetically designed pictorial meadows can fail to jointly provide benefits for people and some important flower-visiting insect taxa. DNA barcoding did not change specimen identifications for most morphotaxa. However, splitting and/or lumping processes affected almost one third of morphotaxa, with lumping of morphotaxa the most common type of change. This was in part because males and females from sexually dimorphic species were often separated by morphological identification. These DNA barcode-based changes to visitor taxonomy resulted in consistent minor changes in network size and structure across replicate networks. Lumping of morphotaxa decreased taxon richness, reducing the number of unique links and interaction diversity (the effective number of links). Lumping also increased flower-visitor generality, reducing plant vulnerability and increasing overall network connectance. However, taxonomic changes had no effect on interaction evenness or network specialisation. Thus, for this well-studied fauna, DNA barcode-based flower-visitor networks were systematically biased toward fewer taxa and links, with more generalist visitors and specialist plants. Given that many tropical faunas have more species and are less described than in Britain this pattern may not be replicated in other studies. Further studies in contrasting plant-pollinator communities are required before generalisations can be made about systematic biases between networks constructed using morphological versus molecular data. Overall, meadows grown from annual pictorial flower meadow seed mixes provide abundant floral units per unit area of meadow and are a valuable alternative to traditional horticultural flower beds or amenity grasslands in high profile urban contexts. Nevertheless, care must be taken during design of seed mixes and selection of mixes for planting to ensure that species in the mix provide suitable floral resources for an array of flower-visitors, including bees. This would be aided by the integration of informative measures for candidate species of floral rewards or visitor types and visitation rates during seed mix design.

Across the world, people feed birds to interact with nature. A variety of feeder types have been developed over the years to target a broad bird community. Attracting nectarivorous birds to gardens using supplementary nectar feeders is a popular human activity across the globe, but few studies have explored its effects on birds and the plants they pollinate. Nectar feeders may have positive effects, facilitating the urban adaptation of nectarivorous birds, and supplementing their diets when floral resources are scarce. However, supplementary feeders may also lure birds away from indigenous vegetation, affecting the rate of visits to bird-pollinated plants, with consequences for seed set. This study is the first to investigate the effect of nectar feeders on an African plantpollinator mutualism. Given that many plant species in the fynbos biome are bird pollinated, this study was conducted in residential gardens and natural vegetation along the urban edge of the Cape Peninsula, South Africa. I carried out a feeding experiment with a matched paired design to answer two main questions: (1) Do nectar feeders affect bird abundance and distribution ranges? If so, (2) do these affect their visitation rates to bird-pollinated plants? I conducted bird surveys to compare relative bird abundance and local distribution patterns for three feeding guilds (i.e., nectar-specialists, nectar-opportunists and non-nectarivores) between feeder and control treatments (Chapter 2). I then tested whether the presence of nectar feeders in gardens affected sunbird visitation rates to two bird-pollinated Erica species (Erica plukenetii subsp. plukenetii and Erica abietina subsp. atrorosea) in the neighbouring vegetation compared to control sites (Chapter 3). In chapter 2, I found that nectar feeders attracted higher densities of avian nectarivores (but not non-nectarivores) to gardens relative to natural vegetation, and decreased their densities in the neighbouring fynbos, even when floral abundance in the neighbouring vegetation was high. In chapter 3, I found that the consequent changes to sunbird distribution patterns (the main pollinators of ericas) seemed to have no influence on visitation rates to E. abietina, but decreased visitation to E. plukenetii flowers within 300 m of gardens with feeders. Thus, nectar feeders may have positive effects for birds themselves by reducing their urban sensitivity but may also have negative effects on the surrounding fynbos ecosystem. Given that nectar feeders appear to compete with the flowers of E. plukenetii, and perhaps those of other birdpollinated species, supplementary feeding may inadvertently threaten bird-plant pollination networks. This issue is particularly concerning in biomes such as the Cape Floristic Region where many bird-pollinated plants occur near urban edges.

Fundação de Amparo a Pesquisa no Estado do Rio Grande do Sul
This study aimed to determine the details of the offer and quality of floral resources in Bauhinia forficata Link, native species of Seasonal Deciduous Forest in Rio Grande do Sul, and how they influence the attraction and interaction with the flower visitors and other plant species. It sought to further determine the ecological mechanisms that are established from the plant interactions / animal that can be used as a theoretical basis for the creation of ecological restoration strategies. The work was conducted in the municipality of Santa Maria, central region of Rio Grande do Sul. Were selected 11 matrices based on the environmental quality of the fragments their surroundings and morphophysiological and phytosanitary characteristics of individuals, of which was evaluates the phenology, volume and concentration of nectar instanding crop (NID), pollinic viability, suitability for autogamy, floristic diversity of the surrounding areas, diversity, intensity and behavior of diurnal and nocturnal flower visitors and ditrophic networks of plant-pollinator interaction. The variables were tested by comparison of means, Principal Component Analysis (PCA) and correlation analysis. The average volume of NID observed for the species was 40.3 μl and the mean concentration was 0.265 mg / μl. The average pollen viability was 81.43%, and the species has proved unfit to autogamy. The average number of floral visitors was 18.24 per matrices and the average intensity of interaction was 59.94%. Were accounted for 730 floral visitors belonging to 29 morphospecies, 657 at the diurnal monitoring and 73 at nocturnal monitoring. The main order observed was Lepidoptera. The suborder Rhopalocera was the most abundant between diurnal visitors (30.43%), and the suborder Heterocera the most abundant among the nocturnal visitors (50%). Proved to be effective pollinators of Bauhinia forficata the bumblebee (Hymenoptera) morphospecies, gray-moth (Pyrgus sp.) (Lepidoptera: Heperiidae) and orange-black-butterfly (Helyconius sp.) (Lepidoptera: Nymphalidae). The functionally effective pollination systems for Bauhinia forficata in the study area are the Psychophily (butterflies) and Melittophily (bumblebees). In the analysis of floristic diversity were found 34 species, the Shannon diversity index ranged between 1.46 and 2.43 between plots. The Bauhinia forficata species, Acacia velutina and Strychnos brasiliensis have the greatest relative densities, respectively, 10.97%, 10.42% and 8.78%. It can be concluded that both the supply and quality of resources influence at the attraction of visitors, as the interaction of visitors with flowers interfered at the availability of resources. The quantity, quality and plasticity of the offered floral resources, the generalist attraction of visitors, the time and intensity of flowering, the inability to autogamy and geitonogamy, high rates of pollen viability and the high degree of connectance of ditróficas webs, are responsible for initiate important ecological mechanisms between this and other ecosystem agents, being them: compensation mechanisms, of species coexistence, induction of gene flow and competition and partilhamento of the resources. These results demonstrate that Bauhinia forficata is an important energy source for the diet of a wide range of pollinators and acts as an inducer of ecological processes and gene flow in the study area.
O presente estudo teve por objetivo determinar as características da oferta e qualidade dos recursos florais em Bauhinia forficata Link, espécie nativa da floresta Estacional Decidual do Rio Grande do Sul, e a forma como estas influenciam na atração e na interação com os visitantes florais e com as demais espécies vegetais. Buscou-se ainda determinar os mecanismos ecológicos que se estabelecem a partir das interações planta/animal que possam ser utilizados como base teórica para a criação de estratégias de restauração ecológica. O trabalho foi conduzido no Município de Santa Maria, região central do Rio Grande do Sul. Foram selecionadas 11 matrizes com base na qualidade ambiental dos fragmentos de seu entorno e nas características morfofisiológicas e fitossanitárias dos indivíduos, das quais se avaliou a fenologia, volume e concentração de néctar instantaneamente disponível (NID), viabilidade polínica, aptidão à autogamia, diversidade florística das áreas adjacentes, diversidade, intensidade e comportamento de visitantes florais diurnos e noturnos, e teias ditróficas de interação planta-polinizador. As variáveis foram testadas por comparação de médias, Análise de Componentes Principais (PCA) e análise de correlação. O volume médio de NID observado para a espécie foi de 40,3 μl e a concentração média foi de 0,265 mg/μl. A viabilidade polínica média foi de 81,43%, sendo que a espécie demonstrou ser inapta à autogamia. O número médio de visitantes florais foi 18,24 por matriz e a intensidade média de interação foi 59,94%. Foram contabilizados 730 visitantes florais pertencentes a 29 morfoespécies, sendo 657 no monitoramento diurno e 73 no monitoramento noturno. A principal ordem observada foi Lepidoptera. A subordem Rhopalocera foi a mais abundante entre os visitantes diurnos (30,43%) e a subordem Heterocera a mais abundante entre os visitantes noturnos (50%). Demonstraram serem polinizadores efetivos da Bauhinia forficata as morfoespécies mamangava (Hymenoptera), mariposa-cinza (Pyrgus sp. (Lepidoptera: Hesperiidae) e a borboleta-laranja-preta (Helyconius sp. (Lepidoptera: Nymphalidae)). Os sistemas de polinização funcionalmente efetivos para Bauhinia forficata na área de estudo são a Psicofilia (borboletas) e a Melitofilia (mamangavas). O grau de conectância total das teias ditróficas foi de 53,47% para as redes de visitantes diurnos e de 44% para as redes de visitantes noturnos. Na análise da diversidade florística foram encontradas 34 espécies, o índice de diversidade de Shannon variou entre 1,46 e 2,43 entre parcelas. As espécies Bauhinia forficata, Acacia velutina e Strychnos brasiliensis apresentaram as maiores densidades relativas, respectivamente, 10,97%, 10,42% e 8,78%. Foi encontrada correlação entre a concentração do néctar e diversidade florística, entre volume de néctar e diversidade de visitantes e entre a viabilidade polínica e volume e concentração do néctar. Pode-se concluir que tanto a oferta e a qualidade dos recursos influenciaram na atração dos visitantes, quanto a interação dos visitantes com as flores interferiu na disponibilidade dos recursos. A quantidade, qualidade e plasticidade dos recursos florais ofertados, a atração generalista de visitantes, a sincronia e intensidade de floração, a inaptidão à autogamia e geitonogamia, as altas taxas de viabilidade polínica e o alto grau de conectância das teias ditróficas, são responsáveis por desencadear importantes mecanismos ecológicos entre esta e os demais agentes do ecossistema, sendo eles: mecanismos de compensação, de coexistência de espécies, indução do fluxo gênico e de competição e partilhamento de recursos. Tais resultados demonstram que Bauhinia forficata é uma importante fonte energética para a dieta de uma vasta gama de polinizadores e atua como indutora dos processos ecológicos e do fluxo gênico na área de estudo.

Bumblebees are a group of valuable pollinators that are declining all over the world. The main reason is believed to be habitat loss due to the changes in agriculture. The changes in agriculture influence the structure of the vegetation and flower abundance, which are of great importance to the abundance of bumblebees. The aims of this study were to get a better understanding of bumblebees and what preferences they might have regarding vegetation height and flower abundance in semi-natural grasslands. This study is based on data collected by a Swedish national environmental monitoring program in 2006-2010. Data on twelve bumblebee species were analysed using a generalized linear model based on the dependent variables of occurrence/ non-occurrence. The target variables used in the analysis were flower abundance, vegetation height and standard deviation of vegetation height. The species-wise analyses mostly showed no or weak positive relationships between the bumblebee occurrence and the three target variables. Grouping the species-wise results into ecologically meaningful guilds and analysing them did not increase the explanatory power of flower abundance or vegetation characteristic, but vegetation height showed significant (positive) results in relation for the forest dwelling species and the species group non-parasite and parasite. The results of this study were considerably weaker than expected. Flower abundance and variation in vegetation height could not explain the occurrence of bumblebees. However, the results of this study show that vegetation height is of importance to the occurrence of bumblebees. Bumblebees in general seem to prefer a higher vegetation height. Based on the findings of this study I would recommend a low intensity of grazing in semi-natural grasslands.

Orientador: Flávio Luís Schmidt
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: O mercado de sucos prontos para beber é recente no Brasil, está em constante ascensão e nossos consumidores ainda encontram limitação nos sabores disponíveis nos supermercados. A mangaba é um fruto do Cerrado com características sensoriais promissoras, porém, ainda com consumo pouco difundido. Este trabalho teve por objetivos estudar características físicas e químicas dos frutos in natura; avaliar o processamento do fruto na forma de polpa, néctar e de uma bebida fantasia adicionada de esferas com polpa de mangaba; e estudar a viabilidade econômica de uma unidade processadora de frutos do Cerrado. Os frutos foram obtidos das regiões sudeste e norte do Estado de Goiás. Quatro formulações de néctares, com variação do conteúdo de açúcar (12 e 14oBrix) e uso de hidrocolóide (0 e 0,01% p/p de goma gelana) foram elaboradas e submetidas a teste de aceitação em dois diferentes potenciais mercados consumidores: Campinas ¿ SP e Urutaí ¿ GO. Como uma metodologia diferenciada da apresentação de bebidas, a polpa de mangaba foi gelificada na forma de esferas e incorporada em uma bebida fantasia elaborada com água, açúcar, goma gelana, citrato de sódio, lactato de cálcio e benzoato de sódio, a qual também foi submetida a teste de aceitação. Os extratos brutos dos frutos, polpa e néctar de mangaba foram avaliados quanto à capacidade antioxidante in vitro através dos métodos 2,2 diphenil-1-picrylhydrazil (DPPH); trolox equivalent antioxidant capacity (TEAC) e oxygen radical absorbance capacity (ORAC). As mangabas apresentaram grandes oscilações de formato, tamanho e massa, sendo a textura e o teor de sólidos solúveis os principais parâmetros indicativos de maturação. O rendimento em polpa de 77% é interessante para a agroindústria, porém, o despolpamento reduziu o conteúdo de ácido ascórbico em 64%. O tratamento térmico da bebida aumentou o volume de sedimento, porém, obteve-se uma excelente estabilização com 0,01% de goma gelana. As quatro formulações de néctares não diferiram significativamente (p>0,05) para os atributos avaliados em ambos os mercados consumidores testados. A bebida com esferas de polpa de mangaba teve boas médias de aceitação assim como intenção de compra positiva. O estudo da viabilidade econômica da unidade produtora de néctares mostra taxas internas de retorno, de 39,54% e 83,02% sem e com financiamento respectivamente, superiores às taxas de juros vigentes para implantação de projetos agroindustriais, sendo o payback do projeto com financiamento mais atrativo (2,4 ano)
Abstract: The ready to drink juice market is new in Brazil and it is still growing, even juice flavors in the supermarket being limited. Mangaba is a fruit from Cerrado with promising sensory characteristics, but still not widespread among consumers. This work aimed to study some characteristics of fresh fruits, methodologies for the processing of pulp, nectar and pulp based ready to drink beverage, and to evaluate the economic feasibility of a fruit processing unit. Fruits were purchased from the north and southeastern State of Goiás. Four formulations, varying sugar content (12 e 14oBrix) and hydrocolloid (0 e 0,01% p/p de gellan gum) were prepared and subjected to acceptance test in two potential consumer markets, Campinas - SP and Urutaí ¿ GO. As a different approach to the production of beverages, mangaba pulp was gelled in the form of spheres and incorporated into a pulp based ready to drink beverage prepared with water, sugar, gellan gum, sodium citrate, calcium lactate and sodium benzoate, which was also subjected to an acceptance test. Crude extracts of fruits, pulp and nectar were evaluated for antioxidant capacity in vitro by the methods 2,2 diphenil-1-picrylhydrazil (DPPH), trolox equivalent antioxidant capacity (TEAC) and oxygen radical absorbance capacity (ORAC). Mangaba showed large fluctuations in shape, size and mass, and the main parameters indicative of maturation were texture and soluble solids. The high pulp yield (77 %) is interesting for agribusiness, however, the pulping process reduced 64% of the ascorbic acid content. Mangaba nectar had good physical stability and when it was exposed to heat treatment the volume of sediment increased, however, an excellent stabilization was obtained adding 0.01% gellan gum. Formulations of nectars did not differ significantly for the attributes evaluated in both consumer markets. The pulp based ready to drink beverage had good acceptance as well as positive purchase intention. The study of the economic feasibility of a fruit processing plant showed internal rate of return of 39.54 % and 83.02 %, respectively for projects with and without funding, and an attractive pay back of 2,4 years with funding
Doutorado
Tecnologia de Alimentos
Doutora em Tecnologia de Alimentos