Dissertations / Theses on the topic 'Yogurt cheese'

Dissertation 'consists of a selection of 71 publications produced over the period 1975-2001, which were drawn from the more complete list of 198 original research papers, review articles and books published over the same period' -- declaration.
Thesis (PhD Food Sc )--Stellenbosch University, 2001.
ENGLISH ABSTRACT: One of the curious facts about the food industry is that many of the processes in use today were being practised, in some form or other, by the Roman legions as they marched across Europe and beyond. Certainly they were familiar with the basic techniques of fermentation, and much current research into fermented foods is concerned with understanding the fundamental nature of these traditional processes, and how the individual stages in a particular fermentation can be better controlled. Recent developments in the dairy industry have tended to reflect this pattern and, over the years, my research group has done much to support the expanding markets for yoghurt and similar fermented milks. Our evaluation of the polysaccharide-producing characteristics of starter cultures, for example, encouraged yoghurt manufacturers to match physical properties to the perceived demands of consumers, and most culture suppliers followed this lead by labelling their products with precise designations as to their potential for imparting viscosity to a retail item. Similarly, my group was the first to record the unique physical properties of the concentrated yoghurt, labneh, C 230 g 1-1 total solids) that had been made for hundreds of years by draining whey from natural yoghurt hanging in a cloth or animal-skin bag. This detailed analysis of the product facilitated the application of ultra-filtration to natural yoghurt to generate a product with a quality that matched traditionallabneh and, today, factories in the Middle East, Greece and elsewhere are using modern membrane-filtration plants to satisfy a growing market demand. Our success in publicising the attractive properties of concentrated yoghurt encouraged me to devote time to yet another 'historical' concept, namely the apparent 'health benefits' derived by small communities in Eastern Europe from consuming kefir and koumiss. In the West, the flavour and texture of these latter products have never been accepted, but employing similar cultures to produce 'health-promoting' bio-yoghurts opened an entirely new avenue for research. As clinical evidence in support of the prophylactic and therapeutic properties of Lactobacillus acidophilus and a species of Bifidobacterium became available, so it became apparent that the therapeutic advantage that accompanies the regular ingestion of 'bio-yoghurts' depended on the survival of these microfloras over the stipulated shelf-lives of the retail vehicles. However, no laboratory medium was immediately available for the simultaneous enumeration of Lb. acidophilus and Bifidobacterium along with the yoghurt cultures, i.e. Streptococcus thermophilus and Lactobacillus delbrueckii sub-sp. bulgaricus. Designing such a medium became a priority for one of my students, and, even today, the procedures that he derived are being used by consumer groups that monitor the performance of the major dairy companies in England. If the improved quality of yoghurts and 'bio-yoghurts' had a major impact on consumer perceptions of fermented milks, the food sector in England gradually became aware of an even more dramatic change in consumer attitudes. Thus twenty years ago, cheese meant 'Cheddar' but, following a 'deluge' of television publicity about the attractions of 'exotic' catering, housewives began demanding mozzarella and mascarpone for lavish desserts, Feta to sprinkle over salads and Halloumi to grill or fry. In turn, exporting countries like Italy, Greece and Cyprus came under intense pressure to increase supplies of top quality products. Local manufacturers soon realised, however, that there was little information available concerning the scientific basis to the procedures employed to make some of these traditional cheeses, and my research group was selected by Funding Agencies in Greece and Cyprus to act as a focus for a series of studies of Feta and Halloumi cheese. The need to eliminate pathogens from the storage brines of Feta cheese without killing the yeasts and bacteria associated with maturation became an important consideration for exporters, and one of my students exploited a novel procedure employing furocoumarins and long-wave ultra-violet light to achieve the desired selective inactivation. At present, the economics of commercial application are somewhat dubious but, as soon as cheap, synthetic, non-toxic furocoumarins become more readily available, the system may well merit re-evaluation. We did confirm, however, that the metabolic activities of the yeasts and bacteria typically isolated from storage brines are essential for flavour development in Feta cheese, and that similar microfloras are instrumental in the development of the important charactistics of traditional Halloumi cheese. In particular, a new species of lactic acid bacterium, Lactobacillus cypricasei, was isolated from samples of the traditional ovine cheese, but whether or not the species has a unique role(s) in the maturation process remains an open question. Clearly there is still much to learn but, if the activities of my reseach group have added just a little to the scientific background essential for future studies of cheese and fermented milks, then their completion will have been worthwhile.
AFRIKAANSE OPSOMMING: Een van die merkwaardigste feite omtrent die voedselindustrie is dat baie van die prosesse wat vandag gebruik word, in een of ander vorm deur die Romeinse magte gebruik is toe hulle deur Europa marsjeer het. Basiese fermentasie tegnieke was aan hulle bekend, en heelwat huidige navorsing oor gefermenteerde voedsel is gemik daarop om die fundamentele natuur van hierdie tradisionele prosesse te verstaan en hoe die individuele stappe in 'n spesifieke fermentasie beter beheer kan word. Onlangse ontwikkelinge in die suiwelindustrie reflekteer hierdie patroon, en my navorsingsgroep het oor die jare heelwat gedoen om die groeiende markte vir joghurt en soortgelyke gefermenteerde melk te ondersteun. Ons evaluasie van die polisakkariedproduserende eienskappe van suursels het byvoorbeeld joghurtvervaardigers gehelp om fisieke eienskappe daar te stel wat verbruikers tevrede sal stel. Meeste verskaffers van kulture het hierdie voorbeeld gevolg deur hul produkte so te etiketteer dat duidelik gewys word watter potensiaal dit het om viskositeit aan die finale produk te verleen. Verder was my groep die eerste om die unieke fisiese eienskappe van die gekonsentreerde joghurt, labneh (230 g 1-1 totale vastestowwe) te bepaal, wat vir honderde jare gemaak is deur die wei van natuurlike joghurt te dreineer deur dit in "n materiaal- of diervelsak te hang. "n Gedetailleerde analise van hierdie tradisionele produk het bygedra tot die gebruik van ultrafiltrasie op natuurlike joghurt om "n produk te gee met dieselfde kwaliteit as tradisionele labneh. Vandag gebruik fabrieke in die Midde Ooste, Griekeland en elders moderne membraan-filtrasie aanlegte om in die groeiende vraag na die produk te voorsien. Ons sukses met die bekendmaking van die aantreklike eienskappe van gekonsentreerde joghurt het my aangespoor om tyd te spandeer aan nog 'n sogenaamde "historiese" konsep, naamlik die skynbare gesondheidsvoordele van klein gemeenskappe in Oos-Europa wat kefir en koumiss verbruik. In die Weste is die smaak en tekstuur van hierdie produkte nooit werklik aanvaar nie, maar om soortgelyke kulture te gebruik om "gesondheidsbevorderende" bio-joghurt te produseer, het 'n hele nuwe navorsingsveld daargestel. Soos kliniese bewyse van die terapeutiese en voorkomende voordele van Lactobacillus acidophilus en 'n spesie van Bifidobacterium bekend gemaak is, het dit duidelik geword dat die terapeutiese voordele wat saamgaan met die gereelde inname van "bio-joghurts", afhang van die oorlewing van hierdie mikroflora oor die gestipuleerde rakleeftyd van die kommersiële produkte. Geen laboratorium medium was egter onmiddellik beskikbaar vir die gelyktydige telling van Lb. actdophilus en Bifldobacterium tesame met die joghurt kulture Streptococcus thermophilus en Lb. delbrueckii sub-sp. bulgaricus. Die ontwikkeling van so 'n medium het een van my studente se prioriteit geword, en selfs vandag word die prosedures wat deur hom ontwikkel is, gebruik deur verbruikersgroepe wat die optrede van groot suiwelmaatskappye in Engeland monitor. lndien die verbeterde kwaliteit van joghurts en bio-joghurts 'n groot impak gehad het op verbruikers se persepsie van gefermenteerde melk oor Wes-Europa heen, het die voedselsektor in Engeland bewus geraak van selfs 'n meer dramatiese verandering in verbruikers se houding. Twintig jaar terug het kaas "Cheddar" beteken, maar na 'n stortvloed televisie advertensies oor die aanloklikheid van eksotiese geregte, het daar by huisvroue 'n vraag ontstaan na Mozzarella en Mascarpone vir nageregte, Feta oor slaai en Halloumi om te bak of te braai. Italië, Griekeland en Siprus wat hierdie produkte uitgevoer het, het onder kwaai druk gekom om groter hoeveelhede, top-kwaliteit produkte te lewer. Plaaslike vervaardigers het gou agtergekom dat min inligting beskikbaar was oor die wetenskaplike basis van die prosedures wat gebruik word om hierdie tradisionele kase te maak en my navorsingsgroep is deur befondsingsagentskappe in Griekeland en Siprus genader om studies te doen oor sekere aspekte van die vervaardiging van Feta en Halloumi kaas. Dit het vir beide in- en uitvoerders belangrik geword om die patogene te elimineer uit die soutoplossing waarin Fetakaas gestoor word, sonder om die giste en bakterieë wat rypwording aanhelp, te dood. Een van my studente het 'n innoverende prosedure ontwikkel wat furocoumarins en lang-golf-ultra-violet lig gebruik om selektiewe inaktivering te kry. Op die oomblik is daar effense onsekerheid oor die ekonomiese implikasies van die kommersiële toepassing, maar sodra goedkoop, sintetiese, nie-toksiese furocoumarins geredelik beskikbaar word, moet die sisteem weer geëvalueer word. Ons het egter bevestig dat die metaboliese aktiwiteite van die giste en bakterieë in die stooroplossing noodsaaklik is vir geurontwikkeling in Feta kaas en dat soortgelyke mikrofloras instrumenteel is in die ontwikkeling van die belangrike karaktereienskappe van tradisionele Halloumi kaas. 'n Unieke melksuurbakterium, Lactobacillus cypricasei, is uit monsters tradisionele skaap Halloumi geïsoleer, maar of hierdie spesie 'n unieke rol speel in die verouderingsproses is nog 'n ope vraag. Duidelik is daar nog baie om te leer, maar indien my navorsingsgroep se aktiwiteite slegs 'n klein bydrae gemaak het tot die wetenskaplike agtergrond wat essensieel is vir toekomstige navorsing, was die voltooiing daarvan die moeite werd.

Orientador: Adriana Zerlotti Mercadante
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
Made available in DSpace on 2018-08-21T07:45:45Z (GMT). No. of bitstreams: 1 Xavier_AnaAugustaOdorissi_D.pdf: 4199257 bytes, checksum: b4a79d65bfa255c2e573658b211002e9 (MD5) Previous issue date: 2012
Resumo: Apesar dos carotenoides estarem amplamente distribuídos nos alimentos de origem vegetal, a sua adição a produtos alimentícios de elevado consumo se torna cada vez mais frequente, visto as inúmeras evidências sobre os benefícios destes pigmentos para a saúde humana. Assim, esse trabalho teve por objetivo o desenvolvimento e a validação de métodos para extração e quantificação de carotenoides em iogurte desnatado e em queijo Prato, ambos adicionados de corante contendo luteína, a fim de verificar a estabilidade deste carotenoide durante o armazenamento refrigerado destes produtos na ausência e na presença de luz (1000 lux). Para o queijo Prato, também foi verificado o efeito do tipo de embalagem na estabilidade da luteína, empregando embalagens plásticas transparentes e pigmentadas de cor vermelha. Além disso, a bioacessibilidade in vitro da luteína adicionada ao leite e ao iogurte desnatado, semidesnatado e integral foi avaliada para estimar a fração de luteína adicionada que pode ser absorvida pelo organismo humano, após o consumo destes produtos. O método desenvolvido e validado para determinação da luteína em iogurte incluiu a extração dos carotenoides com tetraidrofurano em vortex, seguida de centrifugação, partição dos extratos para éter etílico/éter de petróleo (2:1) e quantificação espectrofotométrica dos carotenoides em etanol. O método apresentou linearidade na faixa estudada (1,41¿13,42 µg/g, coeficiente de determinação 0,9938),limites de detecção e quantificação de 0,42 µg/g e 1,28 µg/g, respectivamente, baixo desvio padrão relativo (3,4 %) e recuperação variando entre 95 e 103 %. Este método foi empregado para avaliar a estabilidade de luteína adicionada em iogurte desnatado, onde foi verificado que, na concentração adicionada (aproximadamente 10 µg luteína/g iogurte), o carotenoide manteve-se estável durante os 35 dias de armazenamento refrigerado, independentemente das condições de iluminação. O método validado para iogurte não foi eficiente para a extração de carotenoides de queijo Prato, e por isso, um novo método foi desenvolvido e validado. A extração dos carotenoides do queijo Prato foi realizada em almofariz, utilizando acetato de etila como solvente extrator e hyflosupercel como adjuvante de extração. O novo método desenvolvido para queijo Prato demonstrou linearidade na faixa de 0,05 a 1,15 mg/g, com coeficiente de determinação de 0,9984. Os limites de detecção e quantificação foram de 0,02 e 0,06 mg/g, respectivamente, o desvio padrão relativo de 2,85 % e os valores de recuperação variaram entre 93 e 98 %. Na aplicação deste método para monitorar a estabilidade de luteína durante o armazenamento do queijo Prato, constatou-se que não houve alteração dos níveis deste carotenoide durante 56 dias de armazenamento refrigerado. Os queijos armazenados na presença ou ausência de luz, embalados em embalagem transparente ou pigmentada, mantiveram seus níveis de luteína praticamente constantes e não apresentaram diferenças entre si. A análise da bioacessibilidade in vitro da luteína adicionada em leite e iogurte demonstrou que as amostras de leite semidesnatado e integral, assim como o iogurte integral, apresentaram índices de bioacessibilidade entre 19 e 21 %, semelhantes aos já relatados na literatura para alimentos naturais e formulados. Além disso, durante a digestão in vitro foi constatada a hidrólise de cerca de 85 % dos ésteres de luteína presentes na formulação do corante luteína, provavelmente devido à ação da lipase pancreática. Os resultados deste estudo mostram que os métodos desenvolvidos produziram resultados confiáveis na análise de luteína adicionada em iogurte desnatado e queijo Prato, e que os níveis de luteína se mantiveram constantes durante o armazenamento dos produtos, nas condições estudadas. Além disso, do ponto de vista de bioacessibilidade, entre o leite e iogurte adicionados de luteína, apenas aqueles com maiores teores de gordura (leite semidesnatado e integral e iogurte integral) mostraram-se bons veículos para adição de luteína.22:00 1/11/2012
Abstract: Although carotenoids are widely found in foods from vegetable origin, their addition to food products of high consumption becomes increasingly common due to the abundant evidence about the benefits of these pigments to the human health. Thus, the aim of this work was to develop and validate methods for the extraction and quantification of carotenoids from skimmed yogurt and "Prato¿ cheese added lutein colorant in order to verify the stability of this carotenoid during refrigerated storage in the dark and in illuminated environment (1000 lux). The effect of packaging on the stability of lutein was also determined in the Prato cheese by using transparent and red pigmented plastic packaging. In addition, the in vitro bioaccessibility of lutein added to skimmed, semi-skimmed and whole milk and yogurt was evaluated to estimate the fraction of the added lutein that can be absorbed by the human body after the intake of these products. The method developed and validated for the determination of lutein in yogurt comprised the extraction of carotenoids with tetrahydrofuran by vortexing, followed by centrifugation, partition of the extract to diethyl ether/petroleum ether (2:1) and spectrophotometric quantification of the carotenoids in ethanol. The method was linear in the tested range (1.41 to 13.42 µg/g, coefficient of determination 0.9938), the limits of detection and quantification were 0.42 µg/g and 1.28 µg/g,respectively, the relative standard deviation (3.4 %) was low and the recovery ranged from 95 to 103 %. This method was employed to evaluate the stability of the yogurt with lutein colorant addition, and at the used concentration (ca. 10 mg lutein/g yogurt), the carotenoid was stable during the 35 days of refrigerated storage, regardless the illumination conditions. The method validated for yogurt was not efficient to extract the carotenoids from Prato cheese, and therefore a new method was developed and validated. The carotenoid extraction from Prato cheese was carried out in a mortar with ethyl acetate and hyflosupercel, as an extraction enhancer. The new method developed for Prato cheese was linear in the range from 0.05 to 1.15 mg/g, with a coefficient of determination of 0.9984. The limits of detection and quantification were 0.02 and 0.06 mg/g, respectively, the relative standard deviation was 2.85 % and recovery values ranged between 93 and 98 %.By applying this method to determine the stability of lutein during the storage of Prato cheese, no modifications were observed in the levels of carotenoids during the 56 days of storage. The lutein contents remained constant and no differences were observed regardless the illumination conditions or package type. The analysis of the in vitro bioaccessibility of lutein from milk and yogurt with addition of lutein colorant showed that semi-skimmed (21 %) and whole milk (19 %), and whole yogurt (21 %) had bioaccessibility values similar to those reported in the literature for natural and formulated foods. Furthermore, about 85% of the esters present in the lutein colorant were hydrolized during the in vitro digestion, probably due to the action of the pancreatic lipase. The results showed that the developed methods produce reliable results for the analysis of lutein added to skimmed yogurt and Prato cheese, and that lutein levels remained constant in these products during the storage, under the studied conditions. Moreover, regarding bioacessibility, only the milk and yogurt with lutein colorant samples with high fat content (whole and skimmed milk and whole yogurt) showed to be good vehicles for the addition of lutein
Doutorado
Doutora em Ciência de Alimentos

Щерба, Л. В. Проєктування цеху з переробки молока у фермерському господарстві на 100 корів : випускна кваліфікаційна робота : 181 «Харчові технології» / Л. В. Щерба ; керівник роботи В. М. Челябієва ; НУ "Чернігівська політехніка", кафедра харчових технологій. – Чернігів, 2021. – 94 с.
Основною метою даної роботи є проектування сучасного виробничого цеху на фермерському господарстві з виготовлення молочної продукції. У роботі висвітлено основні проблеми розвитку молочної промисловості в Україні, наведені статистичні дані, щодо кількості поголів’я великої рогатої худоби та підприємств з переробки молока; наведені основні розрахунки продукції заданого асортименту та технологічна схема напрямків переробки сировини, основні нормативні характеристики, яким має відповідати вхідна сировина та готова продукція, описані загальні технологічних операцій при виготовленні продукції запроектованого асортименту та технологія виробництва, відповідно до апаратурно-технологічної схеми; наведені передумови для впровадження НАССР на виробництві, визначені та обґрунтуванні критично-контрольні точки. Також у роботі висвітлені питання промислової санітарії, заходів щодо охорони навколишнього середовища та організація охорони праці під час виробництва.
The main purpose of this work is to design a modern production plant on a farm for the manufacture of dairy products. The paper highlights the main problems of development of the dairy industry in Ukraine, provides statistics on the number of cattle and milk processing enterprises; the basic calculations of production of the set assortment and the technological scheme of directions of processing of raw materials, the basic normative characteristics to which the input raw materials and finished goods should correspond, the general technological operations at manufacturing of products of the designed assortment and production technology according to the hardwaretechnological scheme are given; the preconditions for the implementation of HACCP in production are given, the critical control points are defined and substantiated. The paper also covers issues of industrial sanitation, environmental protection measures and the organization of labor protection during production.

2 pp.
Originally published: 2002
If drinking milk or eating foods made from milk, like cheese, yogurt, or ice cream, upsets your stomach then you may be lactose intolerant. Some people make too little lactase, so lactose from milk is not absorbed. There are alternatives to obtain the daily calcium if you are lactose intolerant.

Introdução - Evidências recentes de estudos clínicos e epidemiológicos sugerem uma relação inversa entre o consumo de alimentos lácteos e inflamação, demonstrando a relevância do tema para Saúde Pública diante de sua possível atuação na redução do risco cardiovascular. Objetivo - Avaliar a associação entre consumo de alimentos lácteos e marcadores inflamatórios em uma amostra representativa de adultos residentes no município de São Paulo. Métodos - Trata-se de um estudo com delineamento transversal, de base populacional, que utilizará dados bioquímicos (coleta de sangue) e de consumo alimentar (Recordatório Alimentar de 24 horas e Questionário de Frequência Alimentar) provenientes de 269 indiviÍduos de ambos os sexos e idade entre 19 e 59 anos participantes do ISA Capital - 2008/2009. Resultados - Após ajustes de idade e sexo, o consumo total de lácteos demonstrou correlação inversa com as concentrações séricas de homocisteína e interleucina-8. O tercil de maior consumo de iogurte esteve significativamente associado com menores níveis de interleucina-8, fator de necrose tumoral-, homocisteína, triglicérides e VLDL-colesterol e maiores da leptina quando comparado ao tercil de menor consumo (p<0,005). Os queijos com menor teor de gordura apresentaram seu consumo inversamente associado às concentrações de interleucina-8, proteína quimiotática de monócitos-1 e triglicérides e positivamente com HDL-colesterol e leptina, apesar de também correlacionados ao fator de necrose tumoral- e adiponectina (p<0,005). Os grupos do leite e queijos em geral também estiveram associados com alguns marcadores inflamatórios. Conclusões - O maior consumo de iogurte e queijo light parece modular o sistema imune em favor à um menor estado inflamatório, demonstrando-se independentemente associado à reduzidas concentrações de diversos marcadores anti-inflamatórios. Futuros estudos de suplementação poderão confirmar estes achados, caracterizando o benefício do consumo de lácteos.
Introduction - Recent evidence from clinical and epidemiological studies suggest an inverse relationship between dairy consumption and inflammation, which demonstrates the relevance of the subject to Public Health considering its possible role on reducing cardiovascular risk. Objective - To investigate the association between dairy products consumption and circulating levels of inflammatory biomarkers among a representative sample of Brazilian adults from São Paulo City. Methods - The data come from a cross-sectional population-based study, Health Survey for São Paulo (HS-SP). All individuals aged 20 to 59 included in this research gave out completed food consumption information (24-hour dietary recall and Food Frequency Questionnaire) and blood sampling analysis totalizing a 269 subjects sample. Results - After age and gender adjustments, total dairy consumption exhibited an inverse relation with both homocysteine and interleunkin-8. A higher consumption of yogurt was significantly associated with lower levels of interleukin-8, tumor necrosis factor-, homocysteine, triglycerides and VLDL-cholesterol and higher of leptin (p for trend 0.005). Light cheese consumption was inversely associated with concentrations of interleukin-8, monocyte chemoattractant protein-1 and triglycerides and positively with HDL-cholesterol and leptin, despite of being also correlated with tumor necrosis factor- and adiponectin. Milk and cheese also presented significant associations with some inflammatory biomarkers. Conclusions - A higher consumption of yogurt and light cheese seems to modulate immune system in favor of a lower inflammatory status, being independently associated with reduced concentrations of various anti-inflammatory biomarkers. Further research is required to attests these findings, featuring the benefits of dairy consumption.

There is accumulating evidence on differences in the link between types of dairy products and cardio-metabolic health, but inconsistent findings limit the field. In my PhD project, I undertook an epidemiological investigation comprising inter-related but distinct themes evaluating aspects of nutritional, molecular and genetic epidemiology to advance scientific understanding. I undertook research to describe dairy consumption patterns over time by evaluating nationally-representative data of the United Kingdom National Diet and Nutrition Survey. I observed significant time trends for specific dairy types and groups, which were different among different groups of people e.g. adults younger than 65 years or elderly people. Using data from the large Fenland (n~12,000) and EPIC Norfolk (n~25,000) studies, I investigated associations of total and types of dairy consumption with markers of metabolic risk and adiposity as potential pathways to cardio-metabolic disease. The analyses showed differential associations of dairy types and groups mainly with markers of adiposity and lipidaemia. I explored the potential of objective markers to assess dairy consumption, by examining metabolomics profiles and blood fatty acids to identify a set of biomarkers predicting dairy consumption and prospective associations of the identified biomarkers with type 2 diabetes risk. I was able to develop and validate metabolite scores reflecting consumption of some dairy products and observed inverse associations between some of these scores and type 2 diabetes incidence. I analysed genetic determinants of dairy consumption, using a genome-wide association study in the UK Biobank (n~500,000) and identified single nucleotide polymorphisms predicting milk, cheese and total dairy consumption. Overall, this PhD work contributed towards (1) a more precise description of dairy consumption patterns in the UK, (2) hypothesis formulation for potential biological pathways linking to cardio-metabolic disease, (3) discovery of metabolite scores as potential dairy biomarkers and (4) hypothesis formulation for potential genetic predictors of dairy consumption.

Le travail a ete aborde dans deux directions: sur laits individuels on a cherche a determiner les correlations eventuelles entre les caracteristiques physico-chimiques du lait et la viscosite du gel lactique; sur laits de melange, il s'est agit d'apprecier l'influence de certains parametres technologiques sur la consistance et la viscosite du gel lactique. Les parametres etudies ont ete: la concentration du lait (augmentation de la teneur en matiere grasse et de la teneur en matiere seche non grasse), les traitements prealables appliques au lait (refroidissement a 40**(o)c et degres de chauffage plus ou moins severes) et la technologie de la coagulation (temperature d'incubation, ph de fin de culture et temperature et vitesse de refroidissemnt). A ete egalement etudiee, sur lait de melange, l'aptitude du lait de chevre au developpement des bacteries du yaourt. Les resultats obtenus permettent de degager un certain nombre de conclusions claires. Le lait de chevre presente une grande variabilite de composition et d'aptitude a la formation d'un gel acide. L'analyse par regression multiple progressive montre que la viscosite du gel est fonction de la teneur en caseine totale et de la proportion de caseine alpha s avec lesquelles elle est correlee positivement; elle est egalement influencee par la taille des micelles et le rapport calcium soluble/calcium total avec lesquels elle est correlee negativement. Pour ameliorer la consistance et la viscosite du gel acide, il faut utiliser de preference un lait frais, augmenter sa teneur en extrait sec total (par addition de poudre et de matiere grasse) chauffer a 80-85**(o)c pendant 10 a 30 minutes, refroidir a 45**(o)c et incuber a cette temperature jusqu'a obtention d'un ph de 4. 3. Une fois ce ph atteint, il faut refroidir rapidement et stocker a 4**(o)c afin d'eviter l'evolution du ph. Le lait de chevre presente une cinetique d'acidification par les bacteries du yaourt differente de celle du lait de vache