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1
Namutebi, Agnes Ssekaalo. "Extrusion processing of sweet potato." Thesis, University of Nottingham, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.247561.
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Yaku, Alexander. "Effects of intercropping sweet potato on the population density of sweet potato weevil, Cylas formicarius (F.) (Coleoptera:Curculionidae)." Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=56673.
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Field experiments were conducted during the 1989 dry season (July to December) at the Manggoapi Farm of the Faculty of Agriculture, Cenderawasih University in Manokwari, Irian Jaya, Indonesia. The objectives of the experiments were to determine the effects of four sweet potato cropping systems on the population density of sweet potato weevils (SPW) and on the diversity of other insects within these agroecosystems.Fewer SPW were found in intercropped sweet potato + corn (2 weevils per kg infected tubers), sweet potato + soybean (21 weevils), sweet potato + corn + soybean (8 weevils) than in monoculture sweet potato (37 weevils); percentage of damaged tubers followed the same trend, ranging from 2.6% to 14.0% in intercropped sweet potato, to 21.9% in the sweet potato monoculture. However, the higher number of SPW and damaged tubers in the monoculture did not reduce yield below that in the intercropped plots.
Insect and spider populations were more diverse in the intercropped sweet potato systems than in monoculture. Number of arthropods increased throughout the growing season. Intercropping may reduce the population density of other insect pests associated with sweet potato and may increase the population density of natural enemies.
3
Leighton, Christina Stephanie. "Nutrient and sensory quality of orange-fleshed sweet potato." Pretoria : [s.n.], 2008. http://upetd.up.ac.za/thesis/available/etd-09222008-114748.
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Byrne, David N., John C. Palumbo, T. V. Orum, and Robin J. Rathman. "Identifying Short-Range Migration by the Sweet Potato Whitefly." College of Agriculture, University of Arizona (Tucson, AZ), 1995. http://hdl.handle.net/10150/221474.
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Populations of the sweet potato whitefly, Bemisia tabaci, have been shown to consist of both migratory and trivial flying morphs. The behavior of these forms as part of the process of short-range migration needed to be examined under field conditions. Insects were marked in a field of cantaloupes using fluorescent dust. During the first growing season traps, used to collect living whiteflies, were placed along 16 equally spaced transects (22.5° apart) radiating out from the field to a distance of up to 0.6 miles. Wind out of the northeast consistently carried migrating whiteflies to traps placed along transects in the southwestern quadrant because cold air drainages dictate wind direction during early morning hours. For this reason, during the second season traps were laid out in a rectangular grid extending 3 miles to the southwest of the marked field. If dispersal was entirely passive or wind directed patterns could be described using a diffusion model. Statistical examination of the data, however, demonstrate that the distribution on all days was patchy. Traps in the immediate vicinity of the marked field caught more whiteflies than the daily median. Large numbers were also collected from around the periphery of the grid. Whiteflies were far less prevalent in the grid's center. As a result, the distribution of captured whiteflies can be described as bimodal. These patterns confirm behavior observed in the laboratory, i.e., a portion of the population are trivial fliers that do not engage in migration and are consequently captured in traps near the field and a portion initially ignore vegetative cues and fly for a period of time before landing in distant traps. This second population comprises the second peak in the model that appeared 1.6 miles from the marked field. On a localized level, 1.6 miles seems to be how far whiteflies move in a day. Earlier studies indicate that whiteflies only fly one day.
5
Dai, Shun. "Preliminary Evaluation of Antioxidant Compounds and Antioxidant Capacity of 15 Cultivars of Sweet Potato (Ipomoea batatas) and Sweet Potato Fries." Ohio University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1533642035567536.
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Collado, Lilia S. "Physical properties and utilization of sweet potato starch and flour." Thesis, Click to view the E-thesis via HKUTO, 1997. http://sunzi.lib.hku.hk/hkuto/record/B42574675.
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Byrne, David N., Erich A. Draeger, and Donna L. Meade. "Effectiveness of Pesticides with Novel Chemistries Against Different Life Stages of the Sweet Potato Whitefly." College of Agriculture, University of Arizona (Tucson, AZ), 1991. http://hdl.handle.net/10150/221441.
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The sweet potato whitefly is an insect whose economic importance is continually expanding as it becomes a more efficient vector, increases its fecundity and broadens its host range. To keep pace with its ability to develop resistance to existing classes of pesticides, we have undertaken a program to examine the effectiveness of pesticides with novel chemistries and novel modes of action. Several have shown themselves to be very effective against the various life stages of the sweet potato whitefly. Once these are incorporated in to our arsenal of pesticides, we hope to be able to manage resistance by prudently using these new materials.
8
Byrne, David N., and William B. Miller. "Examination of the Expansion of the Host Range of the Sweet Potato Whitefly." College of Agriculture, University of Arizona (Tucson, AZ), 1990. http://hdl.handle.net/10150/214480.
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A Florida strain of sweet potato whitefly, Bemisia tabaci (Gennadius), was found to have an expanded range which includes several new food crops. To determine why, we examined how it processes plant nutrients. The amino acid and carbohydrate content of phloem sap from poinsettia and pumpkin and of honeydew produced by the Florida strain were analyzed Honeydews produced by a strain from Arizona feeding on both plants were also analyzed Poinsettia phloem sap contained 15 amino acids; 14 of these were in pumpkin phloem sap. Almost all the same amino acids were in the honeydews produced by the two strains on the two hosts. Carbohydrates in phloem sap and honeydew were common transport sugars, like sucrose. Both honeydews contained trahalulose, a disaccharide not previously associated with insects. Both strains processed phloem sap and honeydew from both plants in the same manner, but the Florida strain produced significantly larger quantities of honeydew; it is therefore assumed to process more phloem sap. Since this strain has access to more phloem sap it also has access to more of the amino acids, which are in short supply in the phloem sap of some plants, allowing it to broaden its range.
9
Byrne, David N., Jackie Blackmer, and Robin Rathman. "Field and Laboratory Evaluation of Migration and Dispersal by the Sweet Potato Whitefly, Bemisia tabaci (Gennadius)." College of Agriculture, University of Arizona (Tucson, AZ), 1994. http://hdl.handle.net/10150/214731.
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Although problems associated with the sweet potato whitefly, Bemisia tabaci (Gennadius), are not as dramatic as they were in 1992. they were still significant in 1993. Laboratory research in 1993 focused on defining the cues that result in migratory behavior, specifically host quality. In addition, field studies were conducted to learn more about timing, direction, and distance flown. Our goal is to develop a predictive model that can be used for forecasting whitefly movement. During our behavioral studies, B. tabaci was presented with two cues that lead to disparate behaviors. More than 70% of the whiteflies we tested ended their flights (within three presentations of the cue) when given a choice between settling on a 'host' (550 nm interference filter) and continued flight. Only 6% of the individuals we tested, demonstrated what would be considered to be true migration Both endogenoous and exogenous factors can play an important role in determining when insects will fly. Finally, although the oogenesis-flight syndrome is thought to be a strong component of insect migratory activity, whiteflies do not appear to postpone egg production until after they have engaged in flight. In the field marked whiteflies were also collected in the most distant of these traps. These field results support our hypothesis that most whitefly movement in the fall in the Yuma Valley is in a SW direction (prevailing winds are from the NE). Within a 3 hr time frame whiteflies can travel as far as 2.2 miles from the source field. We examined the effects of female flight distance and eggload. We found significant differences in the eggload of field collected whiteflies versus whiteflies collected in traps at all distances from the source field. There was no relationship between distance flown and eggload. These results may indicate that dispersing individuals are capable of delaying egg laying until a suitable host plant is located
10
Lim, Soyoung. "Anthocyanin-enriched purple sweet potato for colon cancer prevention." Diss., Kansas State University, 2012. http://hdl.handle.net/2097/13719.
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Doctor of PhilosophyDepartment of Human Nutrition
Weiqun Wang
Anthocyanins are flavonoid pigments that account for the purple color in many plant foods. It has been investigated that anthocyanins’ predominant occurrences in human diet and their health beneficial activities such as antioxidant, anti-inflammatory, and anti-carcinogenetic effects. Based on those scientific evidences, anthocyanins are now recognized as potential therapeutic compounds. Particularly, the chemopreventive effect of anthocyanins has been widely studied by many researchers in nutrition. However, their bioactivities are diverse due to different chemical structures of anthocyanins from different sources. In this study, we discuss the chemopreventive activity of anthocyanins from purple sweet potato. Previously, we selected a purple-fleshed sweetpotato clone, P40, crossbred seeds obtained from the International Potato Center in Lima, Peru. We hypothesized that anthocyanins enriched P40 may provide health beneficial activities in cancer prevention. For the first part of this study, we analyzed nutrient compositions, dietary fiber content, anthocyanins contents, total phenolics contents and total antioxidant activity. Even thought P40 presents similar composition and amount of nutrients with the control cultivars, white-fleshed O’Henry and yellow-fleshed NC Japanese, HPLC-MS analysis confirmed that it possesses much higher anthocyanin content even up to 7.5g/kg dry matter. Also, dietary fiber, particularly soluble dietary fiber content, total phenolics content, and total antioxidant capacity of P40 were significantly higher. For the second part of the study, we tested the potential anticancer characteristic of P40 cultivar in human colonic SW480 cancer cells and in azoxymethane-induced aberrant crypt foci in mice. Treatment with 0 – 40 μM of peonidin-3-glucoside or P40 extract containing corresponding amount of anthocyanins resulted in inhibition of cell growth in a dose-dependent manner. Interestingly, even though the patterns of growth inhibition were similar in the two treatment groups, the cells treated with P40 extract tend to survive significantly less than those treated with peonidin-3-glucoside. Cell cycle analysis confirmed that the growth inhibition was not due to cytotoxicity, but cytostatic mechanism with increased number at the G1 phase of the cell cycle. The cell cycle arrest was also significantly correlated with the anthocyanin contents in P40 cultivar when compared with the white-fleshed O’Henry and yellow-fleshed NC Japanese controls. After Azoxymethane (AOM) or saline injected mice were fed basal AIN-93M diet or diets containing 10~30% of P40, 20% O’Henry or 20% NC Japanese for 6 weeks, aberrant crypt foci (ACF) multiplicity was significantly inhibited by 10~30% P40 diet. Imunohistochemistry results of colonic mucosa showed that the expression level of apoptosis marker, caspase-3, was significantly induced in the mice treated with 10~20% P40 diet. Also, PCNA expression level, which is proliferation marker, was significantly inhibited by the 30% P40 diet. These findings indicated that consuming a purple sweet potato, P40, may prevent colon cancer by modulating antioxidant status, inducing apoptosis, and reducing cell proliferation.
11
Watson, T. F. "Insecticidial Control of the Sweet Potato Whitefly in Cototn." College of Agriculture, University of Arizona (Tucson, AZ), 1992. http://hdl.handle.net/10150/208651.
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Four field experiments were conducted to evaluate efficacy of a number of registered or experimental insecticides against the sweet potato white fly. Several materials gave encouraging results under unusually high population densities. Among the more effective treatments in one or more tests were: Capture, Danitol, NTN 33893, pyriproxyfen and SN 85292, and combinations of Capture +endosulfan, Capture +Ovasyn and Danitol +Orthene.
12
Gawel, N. J., and A. C. Bartlett. "Differentiation of Sweet Potato Whitefly Biotypes Using RAPD-PCR." College of Agriculture, University of Arizona (Tucson, AZ), 1993. http://hdl.handle.net/10150/209572.
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RAPD -PCR was used to detect differences at the DNA level between the A and B forms of B. tabaci. All twenty of the RAPD primers tested distinguished readily between the forms. These primers also distinguished between the forms at the egg and nymph stage. Genetic similarity statistics indicate that these two forms of B. tabaci were no more closely related to each other than to bayberry whitefly (Parabemisia mvricae) or bandedwinged whitefly (Trialeurodes abutilonea). DNA from B. tabaci collected from 11 locations around the world was also analyzed. These insects could be classified into six distinct groups, suggesting there are more than two variant forms of B. tabaci. A comprehensive examination of all variant types of B. tabaci will have to be conducted before a concise definition of the taxonomic relationship between the 'A' and 'B' forms can be determined.
13
Richardson, Kenneth Vincent Austin. "Abiotic stress effects in potato (Solanum tuberosum L.) and sweet potato (Ipomoea batatas [L.] Lam.)." Thesis, University of Reading, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312599.
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Nelson, Merritt, Thomas Orum, Thomas Byrne, Lissy Osama El, Larry Antilla, and Robert Staten. "Preliminary Investigation of Sweet Potato Whitefly Population Dynamics Across Arizona." College of Agriculture, University of Arizona (Tucson, AZ), 1993. http://hdl.handle.net/10150/209537.
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The sweet potato whitefly can have an impact on cotton by reducing yields through direct feeding damage, by transmitting the cotton crumple leaf virus during feeding and by the production of large amounts of sticky honeydew that interferes with the harvesting and ginning process. Data on whitefly populations collected weekly from 938 yellow sticky traps near cotton fields have been entered into a geographic information system (GIS) database. In general, whitefly populations were high near cotton fields in the Yuma area before July 6th. They rose rapidly in central Arizona between July 6th and July 20th. During the month of August, counts continued to rise in central Arizona, particularly in western Pinal County. Populations began to fall during October. Whitefly populations in eastern La Paz County were slower to develop than in other areas in western Arizona. Whitefly populations in Graham and Cochise County were not significant throughout the growing season. Cotton crumple leaf virus was observed in parts of central and western Arizona.
15
Blackmer, Jacquelyn L., David N. Byrne, and Robin J. Rathman. "A Critical Examination of Flight by the Sweet Potato Whitefly." College of Agriculture, University of Arizona (Tucson, AZ), 1992. http://hdl.handle.net/10150/214502.
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In the past we have assumed that sweet potato whiteflies, Bemisia tabaci (Gennadius), were poor fliers with a limited ability to disperse. This assumption was based on the fact that sweet potato whiteflies are extremely small insects (24 -44 μg) and consequently would be subject to desiccation. We also thought small size would limit their capacity to store sufficient energy reserves to sustain flight for long periods of time. Recent experiments have indicated we were wrong on several counts. Data collected in the laboratory using a vertical flight chamber have revealed a number of interesting facts. Of importance is the fact that a portion of the population is capable of sustaining flight for more than 2.5 hours. In a wind-aided situation, this means they can be moved more than 25 miles in a 10 mph wind. Other details of flight behavior are being made clear to us. For example, we found that flight activity is influenced by host plant quality and age of the whitefly. We hope to eventually be able to predict when whiteflies are going to migrate between crops. This will allow growers to make informed decisions concerning planting dates. We are also working in the field to confirm laboratory results.
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Byrne, David N., and Jesse A. Hardin. "Have Distances Traveled by the Sweet Potato Whitefly Been Underestimated?" College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2008. http://hdl.handle.net/10150/215036.
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The importance of the sweet potato whitefly to Arizona vegetable continues to ebb and flow from year to year. Over the last 25 years much of this likely is tied to the invasion by different strains. As we continue to study this insect, an aspect of importance to their management is their ability to disperse. In past studies we have determined how far they are capable of flying in a day’s time, 95% migrate 1.6 miles. We are now investigating their ability to fly multiple days. If they do migrate on more than 1 day, we must readjust our estimates of their influence on surrounding fields.
17
Sedijani, Prapti, of Western Sydney Hawkesbury University, of Science Technology and Agriculture Faculty, and School of Horticulture. "The use of mutagenic agents to increase the protein content and improve the amino acid composition of sweet potato (Ipomea batatas Lam.)." THESIS_FSTS_HOR_Sedijani_P.xml, 1997. http://handle.uws.edu.au:8081/1959.7/647.
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The sweet potato has become a major international crop and it is also the main staple food for many people in the developing world. This crop is desirable as it is high yielding, easy to grow and has a low cost of production. However, the tubers have a low protein content and a low concentration of amino acids, particularly the aspartate amino acid. This has contributed to malnutrition in some areas. To help overcome this problem this study had the aim of producing lines of sweet potato with increased nutritional values. Two varieties, Beauregard and LO322, were selected for study as they have a good flavour and a high beta-carotene content. The conditions for the tissue culture of these varieties were determined by altering the mineral and hormonal composition of the culture medium. Increases in nutritional composition were induced by treating calli with mutagenic agents which included : colchicine, ethylmethanesulphonate, UV radiation and two levels of gamma radiation. Putative mutants with reduced feedback inhibition in the pathways which lead to the synthesis of the aspartate amino acids were selected by placing calli on media containing increasing concentrations of lysine and threonine. During the final stage of the selection process, calli were placed on a medium without the addition of selection agents. The results from the tissue culture study suggest that media, 2, 4-D and explant size affect callus growth. MSMA medium (a modified Murashige and Skoog medium) was the most suitable for growing the callus of Beauregard whilst modified White's medium (MW) was better for the growth of LO322 calli. The most prolific callus growth was exhibited by explants of the cultivar Beauregard when placed on MSMA medium. This combination was used to determine the potential of mutagenic treatments to improve the nutritional qualities of the sweet potato. Results from treatments with mutagenic agents showed that all mutagens used had the capability of increasing the soluble protein content of callus. These treatments also had the capacity to increase the concentration of aspartate and other amino acids. Of the mutagens trialed, a treatment with 500 rad gamma radiation appears to be the most suitable for increasing protein and amino acid concentrations. Therefore, once the conditions for regeneration of shoots from calli have been determined this study suggests that it should be possible to produce lines of sweet potato with increased nutritional values using this agentMaster of Science (Hons)
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Button, Kimberly. "Processing sweet potatoes into french fries." Kansas State University, 2015. http://hdl.handle.net/2097/20496.
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Master of ScienceFood Science Institute - Animal Sciences & Industry
Fadi M. Aramouni
Sweet potatoes are a significant crop and are popular among consumers, particularly as french fries. Because the processing steps of making white potato french fries may be detrimental to the quality of a sweet potato fry, it is important to understand the impact of processing on quality and consumer acceptability. The variety of sweet potatoes can affect the texture, appearance, and consumer preference. Peeling processes have evolved from harsh lye treatments to more quick and efficient methods such as steam peeling. Blanching is one of the most important steps because it deactivates enzymes, including polyphenol oxidase and amylases, that affect texture and appearance. While hot water blanching is used by majority of french fry manufacturers, novel techniques like microwave blanching may be similarly effective and less detrimental to the texture and nutritional composition. Time and temperature of the blanching method can affect the texture and flavor by weakening cell walls and leaching sugars. Drying of sweet potato fries prepares the product prior to frying. Drying drives moisture off and allows the starch on the surface of the fries to gelatinize. Many types of dryers, including vacuum, hot air, and fluidized bed, have been evaluated for the rate of moisture loss and final product texture. Drying should not be done too quickly because case hardening will occur and make the product have a tough and chewy bite. Frying uses oil at elevated temperatures to develop color, flavor, and a crispy external texture. The type of oil, oil temperature, and time of frying will affect the finished product attributes. Low oil temperature may lead to higher oil uptake into the sweet potato fries. Vacuum frying compared to deep fat frying can create sweet potato fries with less darkening and less oil uptake, but this method would be difficult in large scale manufacturing. Opportunities in creating high quality sweet potato french fries are directly related to consumer acceptability and manufacturing capability.
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Soenarto. "Morphological components of yield in sweet potato (Ipomoea batatas (L.) Lam.)." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ61177.pdf.
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Chen, Ren Zhi, and 陳仁治. "Sporamin gene family of sweet potato." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/13404069005623260298.
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Pan, Jyh-Shyue, and 潘志學. "Processing Optimization on Sweet Potato Chips." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/26569216817401051560.
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碩士國立屏東科技大學
食品科學系
91
Sweet potato is one of the major roots crops grown in Taiwan. Sweet potato chip, a kind of of processed products made of sweet potato, has a higher acceptability in the market. Steam is the most common material used in food industry. Proper utilization of its characteristic can save the energy and promote the processing efficiency. Generally, the temperature range of the steam used in food industry is between 100℃~180℃. Yet the steam over this range has been studied for how to develop and utilize. The reheating of saturated steam is called superheated steam, which shows better dry effect than hot air drying. Its advantages showed not only the quick drying rate but also the surface of the food with not to being harden. Besides, the products can have effects such as oxidation-reduction, sterilization and deodorization. Compared with other mediums, superheated steam is the safest material and an ideal medium of directly heating like saturated steam and boiled water do. We use native sweet potatoes（TW66）along with superheated steam as a medium to proceed the experiement.The results showed that optimal conditions by Grey-Taguchi method were A1（thickness；0.2cm）B1（drying time；4 mins）C1（SAPP concentration；0.2﹪）D1（superheated steam 140℃）E1（heating time；9mins）F3（shorting oil）G1（blanching；3 mins）H1（oil coating）.The most significant factor is the temperature of the superheated steam though the analysis of ANOVA to the system .The crude fat of sweet potatoes chips made of superheated steam is between 5.22﹪~7.52﹪, and is lower than the commercial frying sweet potatoes chips, therefore sweet potatoes chips made of superheated steam are safer to our health. Besides, the results of texture profile analysis and scanning electron microscopy（SEM） showed that compared with commercial frying sweet potatoes chips, the ones made of superheated steam have characteristics of porosity and crispness. The storage test of aw、white index、acid value、peroxide value of stored experiement showed that, compared with room temperature（25℃）, sweet potatoes chips stored at low temperature, can avoid the absorption、reduction of oxidation and have shelf life.
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KANG, CHANG-WEN, and 康藏文. "Study on the texture changes during heating process of sweet potato and storage of mashed sweet potato." Thesis, 1987. http://ndltd.ncl.edu.tw/handle/44589608791163029726.
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江翠蓮. "Biochemical study of sweet potato starch phosphorylase." Thesis, 1989. http://ndltd.ncl.edu.tw/handle/91663784694826778763.
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Liao, Ya-Ling, and 廖雅玲. "Reactions of Lipoxygenase Isolated From Sweet Potato." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/77301778840204715133.
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Soenarto. "Sweet potato response to shading and potassium." Thesis, 1994. http://hdl.handle.net/2429/5230.
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A study of the effects of shade and K on sweet potato was conducted to
explore the possibility of the interaction between shade and potassium treatments. The
response of sweet potato plants treated with combinations of four levels of shade and
four levels of K in a factorial experiment was examined by using a split plot design
with whole plots replicated three times. Plant growth analysis, two-dimensional
partitioning analysis and path coefficient analysis were used to evaluate responses of
sweet potato to the different environmental conditions created by the treatments
applied.
The growth of sweet potato plants was more influenced by shade than by K.
The relationships between shade and tuberous root weight were largely influenced by
negative indirect effects. Shade indirectly affected tuberous roots through stem
number, stem length, stem weight and leaf number. These yield components
significantly contributed to tuberous root weight. Potassium linearly contributed to
tuberous root variation, but the contribution of K to tuberous root weight was smaller
than that of shade.
The interaction between shade and K contributed to variation of stem weight
and of stem number, and also contributed to variation in leaf area and in leaf weight.
It is suggested that sweet potato could tolerate 25% shade and under these conditions
the optimum rate of K was approximately 120 kg . h1a of02K. Shade affected yield variation of large tuberous roots through its influence on
total weight of tuberous roots, while K affected yield of large tuberous roots by way
of total number of tuberous roots. The total tuberous root weight and number of
tuberous roots both contributed to the weight variation of large tuberous roots. The
interaction between shade and K significantly affected both of these two yield
components.
The P concentration in tuberous roots and the K concentrations in both leaves
and stems increased with increasing levels of shade. Potassium application decreased
the N concentration in tuberous roots, but increased the P concentration in stems and
the K concentration in both stems and petioles. Leaf starch concentration was not
significantly affected by either shade or K treatments.
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Chen, Ru-Wei, and 陳儒緯. "Quality characteristics of sweet potato leaf bread." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/9d6kjn.
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碩士弘光科技大學
食品科技所
106
Bread is one of the oldest and most popular foods in the world, and sweet potato leaf is a phytochemical-rich food. Brazilian Simon No. 1 sweet potato leaf (SPL) powder was used to substitute 5%, 10%, and 15% (w/w) of wheat flour (protein content 13.50%, ash content 0.48%, and moisture content 13.05%) to manufacture breads, assigned as SP5, SP10, and SP 15, respectively. Proximate compositions (moisture, crude ash, crude fat, crude protein, carbohydrate, and dietary firber), and physical qualities (water absorption percent, particle size distribution, and color), and total phenols contents of SPL powder and wheat flour, the proximate compositions, physical qualities (volume, weight, specific volume, water activity, color and texture), and hedonic qualities of baked breads were evaluated by physicochemical and sensory analyses. Total phenols content and antioxidant property of ethanol (50%) extracts from baked breads were also determined. The crude ash (9.47%), crude protein (19.39%), crude fat (3.02%), dietary firber (50.25%) and water absorption percent (383.93%) of SPL powder were significantly higher than those of wheat flour, whereas moisture (1.17%) and carbohydrate (66.95%) of SPL powder showed a reverse trend. Total phenols (66.58 mg GAE/g extract) and antioxidant properties of freeze-dried SPL powder extracts were higher than those of wheat flour (7.43 mg GAE/g extract). Crude ash (1.07-1.90%), crude protein (8.37-9.15%), crude fat (1.50-2.45%), hardness (201.75-350.26 g), gumminess (147.28-210.16 g), and chewiness (141.39-156.79 g) of baked breads increased with increased SPL powder levels. However, baked bread volume (2725-2075 mL), specific volume (5.28-4.03 mL/g), water activity, crust L*, a* and C* values, crumb L*, H*, WI* values, springiness (0.96-0.73), cohesiveness (0.73-0.60), and resilience (0.29-0.20) showed a reverse trend. Total phenols, scavenging ability and reducing power of baked bread extracts increased with increased SPL powder levels. The hedonic sensory results of control and 5-10% substituted breads were comparable but 15% substituted bread showed lower sensory results. Altogether, SPL powder bread could be developed as a novel food with bioactive component and effective antioxidant activity.
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Leighton, Christine S. (Christina Stephanie). "Nutrient and sensory quality of orange-fleshed sweet potato." Diss., 2007. http://hdl.handle.net/2263/28114.
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Vitamin A deficiency has been recognised as a widespread problem affecting about 750 million people, mostly in developing countries. Mortality due to vitamin A deficiency can be reduced by as much as 23% with improved vitamin A status. Vitamin A's immuneenhancing aspects strengthen the body's defence system against infectious diseases such as measles, malaria and diarrhoea, thus preventing death. Children beyond the weaning age (6 months to 6 years) are most at risk. In South Africa, one in three children has a low vitamin A status, with the rural areas being most affected. Orange-fleshed sweet potato (OFSP) has emerged as a promising plant source with a high beta-carotene content that can make a significant contribution to the vitamin A intake of individuals at risk of vitamin A deficiency. The purpose of this study was to determine the nutrient and sensory quality of OFSP. To this end, the nutrient content of different cultivars of OFSP was determined as well as the sensory characteristics and consumer acceptability was established. During the first phase, four different cultivars of OFSP i.e. Resisto, W119, Jewel and A 15, plus one composite sample, all cultivated by the Agricultural Research Council (ARC)-Roodeplaat, South Africa, were sampled for nutrient analysis. During the second phase (descriptive sensory analysis), four OFSP cultivars and one white-fleshed sweet potato (WFSP) cultivar i.e. Blesbok, were evaluated. A trained sensory panel was used to establish terminology for describing the sensory attributes of the different sweet potato cultivars in terms of its aroma, texture, flavour and aftertaste attributes. Consumer preference (n=180) for OFSP and WFSP was measured by means of a paired preference test. Focus group discussions were conducted to verify findings of the consumer preference test. The results obtained from the nutrient analysis confirmed that OFSP is an excellent source of beta-carotene. A 100 g portion of cooked OFSP can provide up to 6528 ~g beta-carotene, which is approximately 136% of the RDA for vitamin A for children four to eight years. High levels of other nutrients present in OFSP were identified namely vitamin C, calcium and zinc. OFSP further contributes 28% vitamin C, 13% calcium, 15% magnesium and 75.6% zinc of their daily requirements. This study confirms the valuable contribution that OFSP can make as a food-based approach to reduce vitamin A deficiency in individuals at risk. The sensory profiles indicated that OFSP differed from WFSP in colour, flavour and texture. OFSP is generally less moist and subsequently more dense and adhesive compared to WFSP. The latter being more fibrous and less firm than OFSP. Overall OFSP had and earthy aroma which was not typical of WFSP and had a sweeter flavour. The flavour of OFSP was described as similar to that of yellow vegetables such as butternut and pumpkin. Although the different OFSP cultivars had similar characteristics, differences were found in the moist, adhesive and grainy texture attributes as well as the vegetable sweet flavour. Resisto had the sweetest in flavour, with the most dense and pasty texture of the four OFSP cultivars. W119 had the grainiest texture. No significant differences were found in the earthy aroma, sweet potato and yellow vegetable flavour attributes. It can be concluded that in flavour, few differences were found among the OFSP, except in sweetness. OFSP differed primarily from each other in texture. The consumer preference test results showed that overall 85% of respondents preferred the taste of OFSP to that of WFSP, 53% liked the orange colour a lot while 24% liked the colour a little and the remaining 22 % disliked the colour (either a lot, a little, neither like nor dislike). The majority of the consumers (86%) indicated a willingness to buy OFSP. From these results it can be concluded that the taste and colour of OFSP are acceptable to consumers of sweet potato and that it has potential to be successful in the marketplace. Given the high level of consumer acceptability of OFSP, an opportunity exists to address vitamin A deficiency through commercially viable decentralised vine production centres. Such centres could be managed by commercial-, small-scale- and subsistence farmers in South Africa in key sweet potato production areas, with adequate water supply throughout the year. However, availability of commercially produced OFSP in retail sores in recent months, may change this prospect.Dissertation (MConsSci)--University of Pretoria, 2008.
Consumer Science
unrestricted
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Weng, Jian Yu, and 翁健瑜. "Molecular studies of sweet potato trypsin trypsin inhibitors." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/07502071016031478797.
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Xie, Shi Yan, and 謝士彥. "Studies on amylolytic enzymes from sweet potato callus." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/60776806302409207685.
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Yang, Chih-Yuan, and 楊智元. "Studies on Amylolytic enzymes from Sweet Potato Callus." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/26972296416893601671.
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XUE, YI-LING, and 薛亦玲. "Production and application of dehydrated sweet potato granules." Thesis, 1991. http://ndltd.ncl.edu.tw/handle/30659938787544683863.
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Lin, Yi-Chun, and 林怡君. "Study of pretreatments for cryopreservation of sweet potato." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/14627433463369773507.
Full textAbstract:
碩士國立中興大學
植物學系
90
Sweet potato（Ipomoea batatas（L）Lam.）is a tropical plant which is unable to be cold-hardened. To achieve cryopreservation of this plant, We have used osmotic stress to replace the treatment of low temperatures. Suitable osmotic stress induced by 0.3 M sucrose preculture is aimed at enhancing the tolerance to desiccation and freezing of this plant to be cryopreserved. The shoot tips of sweet potato TN68（Ipomoea batatas（L）Lam. cv. Tainung No. 68）were excised from 80-day-old in vitro-grown plantlets and pretreated on solidified MS basal medium supplemented with 0.3 M sucrose for 7 days. The precultured shoot tips were treated with a loading solution（LS）for 60 minutes and then dehydrated with a vitrification solution（PVS2）for 55 minutes prior to a plunge into liquid nitrogen. The post-thaw survival rate of shoot tips was up to 22.2 % . The shoot tips of sweet potato TN57（Ipomoea batatas（L）Lam. cv. Tainung No. 57）were excised from 40-day-old in vitro-grown plantlets and pretreated on solidified MS basal medium supplemented with 0.3 M sucrose for 3 days. The precultured shoot tips were treated with a loading solution（LS）for 60 minutes and then dehydrated with a vitrification solution（PVS2）for 35-75 minutes prior to a plunge into liquid nitrogen. The post-thaw survival rates of shoot tips was up to 87.5-100 % . To understand the action of sucrose in conferring desiccation and freezing tolerance, we analyzed the hydric and biochemical modification in pretreated plantlets. The results indicated that the accumulation of soluble sugar was the main effect that leaded to the decrease of osmotic potential. When the correlation of soluble sugar content and osmotic potential was high, the survival rate of cryopreservation was also high. When the decrease of osmotic potential was large and more rapid and lasting, the survival of cryopreservation was also better. Based on the results shown above, the best pretreatment time was 1-7 days and the shoot tips from young plantlets was better than old plantlets for cryopreservation. What kinds of soluble sugars accumulate after osmotic stress is important. We found that the accumulation of disaccharide can make the survival of cryopreservation to be better.
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Duvivier, Predner, and 杜維耶. "Antioxidant activity of sweet potato (Ipomoea batatas Lam.)." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/58128270701375708065.
Full textAbstract:
博士國立屏東科技大學
熱帶農業暨國際合作系所
97
Sweet potato production and utilization exceeds 133 million tons of tuberous roots annually in the world. It represents the 5th and 7th staple food crop in developing countries and the world, respectively. This study evaluated and compared three sweet potato (Ipomoea batatas Lam.) cultivars: Tainong 57 (TNG57), Tainong 66 (TNG66), and Tainong 73 (TNG73) on the basis of their antioxidant activity (AOA), phenolic and carotenoid contents, and color parameters. The effects of extracting solvent, genotype, part of the root, drying method, fractionation method, storage temperature, and storage duration were tested. The results showed that on average, ethanol and diethyl ether (DE) extracts exhibited the highest total phenolic contents, followed in descending order by acetone, methanol, ethyl acetate (EA), aqueous ethanol (1:1 v/v) and distilled de-ionized water (ddH2O) extracts. The highest AOA, as evaluated by 1, 1-diphenyl-2-picrylhydrazyl (DPPH) assay, were observed in methanol, ethanol, and acetone extracts, followed in descending order by DE, aqueous ethanol, and EA, and ddH2O extracts. Due to its high effectiveness and its relative lower toxicity compared to acetone, DE and methanol, ethanol was chosen for further extractions. Among the three cultivars, TNG73 had on average the highest phenolic content and AOA, followed by TNG66 and TNG57. TNG66 exhibited the highest carotenoid content, while TNG57 and TNG73 showed low content of total carotenoids. The skin samples had, on average, a higher AOA and phenolic content than the flesh samples. Freeze-dried samples had on average higher AOA and phenolic content than the air-dried samples. During the air-drying process, including sun-drying, low temperature air drying (LTD) at 25C, hot air drying (HAD) at 50ºC, and HAD at 75ºC, we observed in the three cultivars significant decreases of the AOA, as evaluated by DPPH, anti-oxidative potency in linoleic acid system model (AOP); and 2,2’-Azino-di-[3-ethylbenzothiazoline-6-sulfonate] (ABTS) assays. The decrease of AOA was attributed to a decrease of total phenolics and total flavonoids. The losses of AOA, total phenolics, and total flavonoids decreased with the increase of the drying temperature and the decrease of the drying time of TNG73 during the air-drying process. However, in TNG57 and TNG66, an increase of the losses of AOA, total phenolics, and total flavonoids during the air-drying process was observed with the increase of the drying temperature associated with a decrease of the drying time. These results indicated that changes in antioxidant components and activities during food drying are genotype-dependant, as the trend of variation was different for the three cultivars. As LTD is time consuming and difficult to scale up, TNG73 was therefore the most suitable for being processed by drying. Low correlations were observed among the three AOA analytical methods. Therefore, their relative goodness of fit was studied using the coefficients of determination (R2) and variation (CV). Based on the results, there was no sufficient evidence to show that one method was better than another. Thus, a single AOA indicator, referred to as AOA relative desirability index (RDI), was computed from the results of DPPH, AOP, and ABTS assays to overcome the problem of lack of correlation among the analytical methods used. For TNG57, the highest RDI value was observed in freeze-dried samples, while the lowest was observed in those treated by sun-drying. Higher correlation of the RDI was observed with carotenoid than with phenolic contents of TNG57. For TNG66, freeze-dried samples showed the highest RDI, followed by sun-dried ones. In LTD, HAD at 50ºC, and HAD at 75ºC, the RDI decreased with the increase of the drying temperature for both TNG57 and TNG66. For TNG73, the highest RDI was observed in freeze-drying, followed by HAD at 75C, then sun-drying, and then HAD at 50C. The samples dried at 25ºC showed the lowest RDI. Both for TNG66 and TNG73, higher correlation of the RDI was observed with phenolic than carotenoid contents. The best air-drying conditions were at 75ºC for 24 h for TNG73, and at 25C for 10 days for TNG57 and TNG66. Three major phenolic compounds, namely, catechin, rutin, and gallic acid were identified in TNG73. Catechin (268.24 mg/kg dry matter) was the highest, followed by rutin (67.06 mg/kg dry matter), and then gallic acid (25.56 mg/kg dry matter), respectively. Comparing with the flesh samples, the skin exhibited higher contents of catechin and gallic acid, but had lower content of rutin. Rutin was the major contributor to the AOA of TNG73, followed by catechin, and gallic acid. In a storage test, the samples stored at room temperature and 4ºC did not show significant difference in the total phenolic content, but the AOA was on average lower at room temperature than at 4ºC. Both the AOA and total phenolics exhibited a general trend of decrease during the storage. The decrease of the total phenolics of the flesh samples was significant after nine-month storage at room temperature and 10 months at 4ºC. For the skin samples, the decrease of total phenolics was significant after 11-month storage both at room temperature and 4ºC. The decrease of the AOA of the flesh samples was significant after five-month storage at room temperature and 10-moonth storage at 4ºC. For the skin samples, the decrease of AOA was significant after 11-month storage both at room temperature and at 4ºC. Results of a pasting profile analysis showed that the peak and final viscosity of the starches isolated from all three cultivars exceeded 495 and 335 RVU, respectively, with a peak viscosity time shorter than 5 min around 80ºC. These results showed that the solid extraction residue of the three cultivars could be processed as gel foods and other food items that require moderate to high gelatinization ability of the raw material. Sweet potato-based puddings, cookies, and cakes prepared in this study supported our findings of the suitability and usefulness of the starches contained in the residue of sweet potato after extraction of antioxidants.
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Liao, Yen-Ying, and 廖晏瑩. "Assessment of Sweet Potato Extract on Immunomodulatory Effect." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/88253104646940773547.
Full textAbstract:
碩士實踐大學
食品營養與保健生技學系碩士班
102
Simon No.1 is one of the white-skinned sweet potato (Ipomoea batatas) that is used as an immunomodulation food and leukemia therapy in the aboriginal tribe. In our previous study, we found sweet potato extract can increase cytotoxic activity of splenocyte NK cell in vitro. Therefore, we investigated the immuneregulatory effect of ethely acetate fraction of Simon No.1 sweet potato (SEA) and Tainong No.66 sweet potato (TEA) in healthy murine model and ovalbumin (OVA)-induced mice model. In healthy mice model, mice were treated with control, low-dose (50 mg/kg BW) or high-dose (200 mg/kg BW) of sweet potato extract every two days for 4 weeks. In OVA-induced mice model, mice were sensitized with OVA (ovalbumin), and then administered with different dosages of control, low-dose (100 mg/kg BW), high-dose (400 mg/kg BW) or dexamethasone (5 mg/kg BW, as a positive control for this study) for 16 days. Our result showed high dose extract of SEA increased interleukin-2, interferon-γ secretion with Con A stimulation; it also increased interleukin-4 and decreased interleukin-5 secretion with LPS stimulation. It seems trend to exhibit increased Th1 and decreased Th2 responses. High dose extract of TEA only significant increased interleukin-4 secretion with LPS stimulation and no different changes in other parameters. It might trend to promoted T helper 2 cell pathway in mice splenocyte. In OVA-induced mice model, SEA treatment significant decreased serum total IgE, OVA-IgE, and increased OVA-IgG2a level with dose manner, it also decreased interleukin-5 level in bronchoalveolar lavage fluid (BALF). TEA treatment significant decreased serum OVA-IgE, OVA-IgG1, OVA-IgG2a level with dose manner and increased interleukin-10 and interferon-γ level in BALF. The pathologic histopathological assay of lung section revealed that high dose of SEA and TEA had less inflammatory cells infiltrated in peribrochial and peribronchiolar regions as compared to the control group. Through the immune response might be different, but SEA and TEA could ameliorate allergic response and airway inflammation. Thus, SEA and TEA have potential to develop as a nutraceutical food.
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PU-MING, HSU, and 許莆明. "Functional study of sweet potato cysteine protease SPCP3." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/54908552076242001363.
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碩士中國文化大學
生物科技研究所
95
We have previously isolated a full-length SPCP3 cDNA, which encodes a putative granulin-containing cysteine protease from sweet potato senescent leaves. Leaf senescence is the final stage of leaf development and has been considered as a type of programmed cell death. In plants the main enzymes involved in this process are papain-type cysteine proteases and Caspase-like proteases. Recently a novel type of cysteine proteases containing C-terminal granulin-like domains were identified and isolated from various plants under different conditions that induce PCD. Granulins are a family of evolutionarily ancient proteins that are involved in regulating cell growth and in stimulating cell division in animals. The physiological role and function of plant novel cysteine proteases containing C-terminal granulin-like domains were not clear. However, several studies concerning its association with programmed cell death during plant development and under stress conditions were described. In this study, we obtained recombinant pBI121 vectors containing different portions of SPCP3 inserts by deletion and recombinant vector technology. Transgenic Arabidopsis plants harboring different SPCP3 portions described above will be produced with Agrobacterium-mediated transformation via floral dip. Morphological analysis in T1 transgenic plants containing full length SPCP3 which that have been charactered expression in mRNA and protein level, which that displayed T1 transgenic plants flowered earlier, the length of siliques is shorter and the degree of senescence of siliques is more evident. These results support that sweet potato SPCP3 is a functional senescence-associated gene and likely plays a role directly in association with senescence.
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Hsin, Cheng-Lin, and 辛政霖. "Research and development of sweet potato ice cream." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/36495722816037968293.
Full textAbstract:
碩士國立高雄餐旅大學
餐飲創新研發碩士學位學程
101
This study aimed to investigate the anthocyanins, total phenols, scavenging ability on DPPH radicals, and consumer market survey of three sweet potato types in Taiwan (Tainung 57, Tainung 66, and Tainung 73). Based on these results, response surface methodology (RSM) was employed in the present work to determine the optimum formula for sweet potato ice cream making. As the data of the survey for the expended behaviors of normal consumers and the acceptability of sweet potato ice cream, results showed as followed: The majority normal consumers were preference for the sweet potato (47.4%), correlative products (50.2%), and ice cream (41.6%). The expectation for the normal consumers in sweet potato ice cream was desiderative (91.9%) and purple particularly (61.7%). The most highly contained value of anthocyanin (254.08 mg GAE/g), total phenols (8.67 mg/100 dry matter), scavenging ability on DPPH radicals, and expecting type was TNG73. By the experimental and the analytic results, this study determined the TNG73 type of sweet potato to be the ingredient of sweet potato ice cream. On RSM, the result which physical properties were 0.95 specific gravity value, 2,349 cps viscosity value, 32.9 g value after melting 60 minutes, 69.13 L value, 5.31 a value, 2.58 b value, 884.96 mg/l total anthocyanins, 130.49 mg/ml total phenols, and 59.5 of scavenging ability on DPPH radicals, was the sample which contained 26% sweet potato, 10 hours mix aging, and 8 minutes frozen time, reached the 3.8 value of disciplined sensory evaluation acceptation by subjects and conjectured the status was the optimum formula for sweet potato ice cream. As the result of the sensory evaluation of consumers for the samples, the average score was 3.74 which more than the sweet potato ice cream at market conditions and performed the significant difference. This study furthermore will raise the suggestion to be the reference for the sweet potato ice cream development and be the local distinguished agricultural product in Taiwan.
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Huang, Yih-Jong, and 黃義忠. "Studies on leaf senescence associated genes in Sweet Potato." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/62697329601158754272.
Full textAbstract:
碩士國立陽明大學
生物化學研究所
87
Leaf senescence is the final stage of leaf development in higher plants. During this stage, senescing leaves recycle their movable nutrients to other parts of the plant. Nuclear genes are known to be involved in the senescence process, recent evidence indicates that leaf senescence is a form of programmed cell death (PCD). Molecular approaches have been recently employed to identify the senescence-associated genes (SAGs).In this thesis, two dimensional gel electrophoresis of proteins and mRNA differential display (DD-PCR) were used to study leaf senescence in sweet potato. By using two dimensional gel electrophoresis, four protein spots were identified to be leaf senescence-specific. They are named Sp30-1, Sp30-2, Sp43 and Sp45 according to the molecular mass estimated on the SDS-PAGE gel. After N-terminal sequencing and database comparison, Sp30-1 and Sp30-2 were found to be members of the cathepsin protein. The identities of Sp43 and Sp45 remain unknown, possibly due to N-terminal blocking. Utilizing DD-PCR method with 3 anchor primers and 12 H-AP primers, 16 differential-displayed cDNA fragments were obtained. These 16 cDNA fragments were first screened with reverse Northern hybridization, and 10 positive cDNA fragments were subjected to cloning. Three cDNA clones including pC20b, pG16-1 and pA15e were confirmed to be senescence-specific by Northern hybridization. pC20b was found to belong to cathepsin B subfamily. Further analysis showed that Sp30-1, Sp30-2 and pC20b are different cathepsin proteins. pG16-1 was found to be a receptor-like serine/threonine protein kinase. pA15e has no homologous gene sequence reported in the GenBank.
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Lin, Hung-Ta, and 林泓達. "Development of a Functional Mixed Drink with Sweet Potato." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/f6y989.
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碩士中國文化大學
生活應用科學系
105
The goal of this study was to develop sweet potato functional mixed beverage products. Sweet potato was used as the main material, and pineapple, wolfberry and walnut were added for sensory and nutritional purpose. The experimental drinks were divided into six groups (200SP, 100SP, 50SP, 200S, 100S, 50S) according to whether adding pineapple (P) and three kinds of sweet potatoes (S). Sensory evaluation, basic composition, and antioxidant activity of the test drinks were to evaluate and analyze. In appearance, the six groups of drinks are pale yellow; as for taste, the addition of the pineapple increased acidity and sweetness, making more changes of the taste. With respect to nutrition, the calories of these drinks are between 182-303 kcal. According to the amount of calories recommended per person per day, the intake of 400 g of this drink can be 10-15% of the daily energy required and it is suitable to be a snack supplement. The result of the general nutrient composition shows that 100S is a high-fat low-carbohydrate drink, 200SP is a high-carbohydrate low-fat drink, and different components offer different consumers to choose from depending on their needs. With regard to anti-oxidation, it is suggested that the antioxidant capacity of drinks and their phenolic content are related to walnut. For the drinks, the appearance, taste, nutrients, and even antioxidant capacity serve as main influencing factors, which can be employed as an important reference for the deployment of related drinks or for alternative materials in the future.
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Yu, Jia Guang, and 余家光. "Studies on sucrose synthase of sweet potato tuberous roots." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/20312758531787764226.
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Lin, Yuh-Lih, and 林育朸. "Studies on Starch Phosphorylase Isozymes from Sweet Potato Callus." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/66524261734832306600.
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CHEN, KE-LIAN, and 陳克廉. "Studies on processing and textural characteristics of sweet potato." Thesis, 1987. http://ndltd.ncl.edu.tw/handle/11097706652259658283.
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Li, Wei-Yu, and 李瑋育. "Utilization of sweet potato cellulosic wastes for producing bioethanol." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/10785793229517354707.
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碩士國立中興大學
食品暨應用生物科技學系
96
Among lots choices of energy crops, sweet potato is considered most suitable for Taiwan. However, currently only the underground starch stem is used for producing bioehtanol, there still 50% sweet potato biomass is not exploited yet. The agricultural waste from currently Taiwan maximum yield sweet potato strain Tainung No. 57 was studied for better bioethanol production. Composition analytical results show the potential that the raw dry material contains approximately 64% carbohydrate and fiber can be used as bioethanol substrate. In this study, sweet potato field waste was used as substrate and processed with quickly pressure release process and ball milling micron treatment. Pretreated substartes saccharified by Trichoderma reesei ATCC 56765 were subsequently fermented by Sacharomyces cerevisiae BCRC 21679 to produce bioehtanol. The saccharified enzymes combination from Trichoderma reesei ATCC 56765 and Aspergillus niger BCRC 21679 improve the glucose yield from 15.7g/L to 20.0g/L. 0.96% enthanol can be acheived from 150 g/L quickly pressure release pretreated substrate through the saccharification (24.4 g/L glucose) and fermentation process. 0.92% enthanol can be harvested from 150 g/L ball milling pretreated micron substrate through the saccharification (22.2 g/L glucose) and fermentation process. However, only parts of the carbohydrate and fiber were utilized in this process. Even though the theoretical yield of ethanol is high, the small amount of fermentable sugar after saccharification stage limited final ethanol yield. Further study on optimized the pretreatment processes, enzyme saccharification and development of pentose saccharification and fermentation should be emphasized to improve the waste utilization.
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Lu, Mu-Han, and 呂牧涵. "Studies on Heat Treatments and Storage of Sweet Potato." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/87161217267068311745.
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碩士國立臺灣大學
生物產業機電工程學研究所
97
It is very general abroad that sweet potato are stored in cold storage. However, in Taiwan, cold storage of sweet potato is rarely seen because of highly decay loss. Therefore, the purpose of this study was concentrated on heating treatments to decrease decay of sweet potato during cold storage. The methods of this study were to use the heat treatments included hot air, hot water and steam to prevent decay. We measured the temperature in 5 mm depth of the surface on sweet potato in heating treatments and also used COMSOL Multiphysics to simulate the process and to predict surface temperature that was undetectable during heating process to insure the effeteness of heat treatments. After heating treatments, sweet potato were stored in cold rooms at 13~15℃ and 85~100%. After storage of 30 and 60 days, decay rates were compared by using statistical analysis program ANOVA. The results showed the decay rates in cold rooms were significantly lower (p<0.05) than that in room temperature. Sweet potato became more decayed and produced fibrous roots in non-treated control during cold storage. Control treatments had much more decay than heat treatments and were also significant (p<0.05) but difference between hot water and steam treatments were insignificant. Steam treatments caused sweet potato became more brownish but still acceptable. Our results indicate that 30 days storage of heat treated sweet potato in cold storage is commercially applicable and the storage life might extent to 60 days if healthy roots are selected.
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Chen, Yu-Chi, and 陳玉琪. "Characterization and Regulation of Ipomoelin Gene from Sweet Potato." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/99547338030313945144.
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博士國立臺灣大學
植物學研究所
91
In order to investigate the functions and applications of wound inducible genes in the plant defense response, sweet potato (Ipomoea batatas cv. Tainung 57) was used as the experimental materials in this study. In the previous study from our laboratory indicated that ipomoelin (IPO) gene from sweet potato was wound- and methyl jasmonate (MeJA)-inducible, but the function and signal transduction of IPO protein was not clear. To understand the basic traits of IPO gene, the full-length cDNA of IPO gene was obtained by screening the cDNA library of the wounded sweet potato leaves. The full-length cDNA of IPO gene contains 720 base pairs, and encodes 154 amino acids. Also, the amino acid sequence of IPO protein showed high homology with those of lectin proteins. Southern blotting assay demonstrated that IPO gene existed two copies within sweet potato. However, IPO gene induced by wounding was only present in sweet potato of Tainung 57 and Tainung 25, but not in Taoyuan 1 or Taoyuan 2. Moreover, IPO gene was not expressed in the wounded leaves of Arabidopsis, tobacco, and tomato. The result of Western blotting assay indicated that the IPO protein was accumulated in the day one after the treatment of wounding, and the maximum accumulation was in the day seven after wounding. To study the function of IPO protein, His-IPO fusion protein was expressed in E.coli BL21(DE3), and two-week-old silkworms were fed the mulberry leaves smeared with His-IPO protein. The feeding experiment showed that His-IPO fusion protein reduces silkworm growth and survival rates. Additionally, the reduction of silkworm growth and survival rates was dosage-dependent. This result demonstrated that IPO protein was one of the defense-related proteins. Furthermore, His-IPO fusion protein agglutinates human blood and this agglutination was inhibited by some carbohydrates. This result further demonstrated that IPO protein was a carbohydrate-binding protein. The regulation of IPO gene in sweet potato was also an important project in this study. IPO gene was induced in both local and systemic leaves of sweet potato after wounding. In addition, IPO gene was induced by MeJA, polygalacturonic acid (PGA), and chitosan (CHI) in sweet potato. Moreover, several factors, including calcium ion influx, calcium release from organelles, biosynthesis of MeJA, and protein dephosphorylation, were involved in the expression of wound-inducible IPO gene, and analyzed by Northern blotting assay and confocal scanning microscope. However, when IPO gene was induced by PGA, protein kinase was involved in the signal transduction pathway. On the other hand, ethylene, a plant hormone, induced large expression of the IPO gene in sweet potato leaves. The signals involved in the ethylene-induced IPO gene expression were via calcium ions influx through high affinity calcium channels into cytoplasma, calcium ions released from organelles, and the activation of protein phosphatase, hydrogen peroxide, and MAPK to promote the expression of IPO gene. In this study, the DNA of IPO gene was cloned and the function of IPO protein was demonstrated to be involved in the plant defense response. Moreover, the regulation of IPO gene was also studied. These data help us understand how the stress-related IPO gene regulated by environmental factors, and further elucidate the complex regulation of gene expression with plants.
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Wang, Yong Liang, and 王永樑. "Studies on soluble acid invertase from sweet potato leaves." Thesis, 1995. http://ndltd.ncl.edu.tw/handle/58553501994194123653.
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Chen, Ying-Ying, and 陳櫻瑛. "Effect of sugar on the quality of sweet potato." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/02744215024452991501.
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碩士國立屏東科技大學
食品科學系所
97
The maior purpose of this study is to research the effects of fructooligosaccarides and sucrose on the quality of sweet potato, include the appearance of sweet potato,Brix, water activity, reducing sugar, and hunter L, a, b, and scanning electron microscop. Using 50 Brix syrup in different cooking times for 3 hours , 3.5 hours, and 4 hours with 100 ℃ of lasting syrup cure, taking samples and doing analysis after 60℃ of hot air dry for 14, 15, and 16 hours, it is about 50~65 Brix that the candy degree does not have obvious difference for cooking time, candy degree steeping the sweet potato through the sucrose after dehydration was evaluated about 5 Brix, the fructooligosaccarides is up 8 Brix, water active has obvious changes, especial for sucrose, and present negative correlation with cooking time and dry time.L values of the sweet potato candied with the fructooligosaccarides is slightly lower that of sucrose, and W.I in candied sweet potato increasing obviously with the fructooligosaccarides for 16 hours, hardness, gumminess and chewinss in candied sweet potato obviously increasing with the fructooligosaccarides concentration.The content of reducing candies of fructooligosaccarides sweet potato is slightly higher than that of sucrose. Scanning electron microscope observe ation indrcated, sucrose the can maintain the organization fullness of candied sweet potato than the fructooligosaccarides. According to sensory evaluation, panelists accept sucrose candied sweet potato easier than that of fructooligosaccarides, and the overall acceptablity was negatively correlated with hardness.
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Yu, Chia-hsin, and 游加興. "Study on Root and Stem Rot of Sweet Potato." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/91041118201157767573.
Full textAbstract:
碩士臺灣大學
植物病理與微生物學研究所
96
Severe root and stem rot of sweet potato was first found in Yong-He and Shu-Lin, Taipei county, in Taiwan in 2006. The disease symptoms include wilting shoot, pale leaf, black stem, root rot and death. The occurrence of this disease can be traced back to at least ten years ago as described by the farmers. The causal agent of root and stem rot of sweet potato is a pathogenic bacterium according to Koch’s postulates. The pathogen was identified as Erwinia chrysanthemi based on the morphology, Gram’s stain test, Bilolog identification, and NGM differential medium test. The pathogen mainly attacked the root and stem and caused black rot of stem base, brown rot of root, and death. The symptoms were similar to those of the bacterial stem and root rot reported in United States, although in United States it majorly attacked the roots. This is the first report of this disease in Taiwan. Four varieties including “Taoyuan#2”, “Tainong#71”, “YongHe# 1” and “YongHe#2” were screened for the disease resistance “YongHe#1” had the highest resistance, while “Taoyuan#2”, “Tainong#71” and “YongHe#2” were sensitive to E. chrysanthemi. Nine bactericides at three concentrations were tested for their control effects on E.chrysanthemi by paper disc diffusion method. Among them, tetracycline has been proven to be the most effective, while oxine-copper＋copper hydroxide, cupric hydroxide, streptomycin sulfate + tetracycline, kasugamycin +copper oxychloride, thiophanate-methyl + streptomycin, streptomycin and validanmycin could inhibit the growth of E. chrysanthemi. However, kasugamycin alone was no effective to control this bacterial disease.
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Li, Yu-Chi, and 李昱錡. "Signal Transduction and Regulation of IbpreproHypSys in Sweet Potato." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/ms62a5.
Full textAbstract:
博士國立臺灣大學
植物科學研究所
105
Hydroxyproline-rich glycopeptides (HypSys) are small signaling peptides containing 18–20 amino acids. The expression of IbpreproHypSys, encoding the precursor of IbHypSys, was induced in sweet potato (Ipomoea batatas cv. Tainung 57) through wounding and IbHypSys treatments by using jasmonate and H2O2. Transgenic sweet potatoes overexpressing (OE) and silencing (RNAi) IbpreproHypSys were created. The expression of the wound-inducible gene ipomoelin (IPO) in the local and systemic leaves of OE plants was stronger than the expression in wild-type (WT) and RNAi plants after wounding. Furthermore, grafting experiments indicated that IPO expression was considerably higher in WT stocks receiving wounding signals from OE than from RNAi scions. However, wounding WT scions highly induced IPO expression in OE stocks. These results indicated that IbpreproHypSys expression contributed toward sending and receiving the systemic signals that induced IPO expression. Analyzing the genes involved in the phenylpropanoid pathway demonstrated that lignin biosynthesis was activated after synthetic IbHypSys treatment. IbpreproHypSys expression in sweet potato suppressed Spodoptera litura growth. In conclusion, wounding induced the expression of IbpreproHypSys, whose protein product was processed into IbHypSys. IbHypSys stimulated IbpreproHypSys and IPO expression and enhanced lignin biosynthesis, thus protecting plants from insects.
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Nurdjanah, Siti Chemical Sciences & Engineering Faculty of Engineering UNSW. "Extraction and characterisation of pectin from Australian and Indonesian sweet potato." 2008. http://handle.unsw.edu.au/1959.4/41424.
Full textAbstract:
Starch residue samples from two Australian sweet potato varieties (Beauregard and Northern Star) and two Indonesian sweet potato varieties (Bis192 and Bis183), and commercial sample of sweet potato starch residue, were studied for their pectins. Pectins were extracted using 0.1M HCl, 0.05M NaOH, 0.1M HCl/0.75%SHMP, and 0.05M NaOH/0.75% SHMP. Hydrolysis of residual starch in the cell wall of sweet potato using heat stable α-amylase and amyloglucosidase was employed prior to pectin extraction to eliminate starch contamination. Pectins were characterised for yield, moisture, ash, galacturonic acid content (GA), degree of esterification (DE), neutral sugars content and molecular weight (MW). Selected pectins were also characterised for their dispersion and gel properties. Pectin with the highest yield was compared to commercial low methoxyl pectin (GRINSTED??YF 450) for its application in milk pudding. The pectin characteristics are dependent on variety and extraction process; however, the extraction methods were dominant. Yields were between 7 and 30 % of the cell wall. Ash varied from 2.9 to 6.8%. NaOH/SHMP extraction gave higher yields and ash contents. Moisture was between 5.5 and 6.7. GA varied from 27 to 80% with the highest found in Bis192 extracted using NaOH/SHMP. DE varied between traceable and 57%. HCl extraction gave higher DE, while NaOH/SHMP caused demethylation. Neutral sugars varied from 10 to 25% where galactose was the predominant sugar, followed by arabinose, rhamnose, glucose and xylose. Pectin MW was very heterogeneous. HCl extraction gave higher MW than the others. Dispersion of sweet potato pectins displayed shear-thinning. Consistency coefficient (K) increased, while flow behaviour index (n) decreased with increasing pectin concentration. HCl-extracted pectins formed stiff sugar-gels at concentrations higher than 2%. The optimum Ca2+ concentration for NaOH/SHMP-extracted pectin gels was 20 mg/g pectin. Pectin with the highest yield and stiffness (Norther Star extracted using NaOH containing SHMP) was used for milk pudding preparation. This pudding had comparable texture to pudding prepared from commercial low methoxyl citrus pectin (GRINSTED??YF 450). Overall, this study demonstrated that pectin from sweet potato starch residue is mainly low methoxyl pectin with possible chemical structure of rhamnogalacturonan I (RGI) that has potential for food applications.
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Ravli, Yagmur 1985. "Improved Vacuum Frying Process for High Quality Sweet Potato Chips." Thesis, 2012. http://hdl.handle.net/1969.1/148101.
Full textAbstract:
Vacuum frying is a promising method for preserving the desired color, texture, and flavor of products with high sugar content. Since most vegetables and fruits degrade when processed with traditional frying, vacuum frying is an excellent alternative to high temperature processing. However, in vacuum frying the product should be pre-treated before frying to obtain a better texture.
The kinetics of oil absorption and oil distribution in sweet potato chips (total, internal, and surface oil content) was studied so that effectiveness of the de-oiling system could be established. An analysis of product quality attributes (PQA) such as moisture content, oil content, microstructure, diameter shrinkage, and thickness expansion, as well as, color, texture, bulk density, true density, and porosity of chips fried at different temperatures (120, 130, and 140°C) was performed to evaluate the effect of process temperature on the product.
The final oil content of the sweet potato chips was 0.178±0.007, 0.178±0.011, and 0.172±0.002 g/g solid for frying temperatures of 120, 130, and 140ºC, respectively. These values were lower (~60% less) than those found in traditionally fried sweet potato chip, which indicates that the de-oiling mechanism is crucial in vacuum frying processing.
It was found that the rate of change in PQAs is greatly affected by temperature; however, the final values of bulk density, true density, porosity, diameter shrinkage, and thickness expansion were not affected by temperature. The texture of the samples was affected by temperature, with the chips fried at 140 degrees C being crispier. In terms of color, the L* and color b* values decreased as temperature increased. While color a* was not affected by temperature.
In this study, a two-stage frying process was also evaluated to improve the flavor and texture of sweet potato chips. First, a basket filled with the sweet potato slices was submerged into the oil under atmospheric conditions. As soon as the potato slices were partially cooked (1 min), the pressure was lowered to 1.33 kPa (vacuum frying stage) and the product fried for 2 more min. The products were fried at 130 degrees C for different interval of times. Starch gelatinization, texture, moisture content, and oil content were evaluated at each time interval. Sensory analysis was accomplished by using a consumer panel with 50 members. The samples were compared with the on-stage frying and atmospheric frying processes.
The two-stage fried chips had better appearance and texture compared to the ones that were only fried under vacuum or atmospheric conditions. The samples were lighter and more yellow than the chips fried under the single-stage process. In vacuum frying, the temperature of the chips does not reach the gelatinization temperature until most of the water is evaporated. Therefore, there is not sufficient moisture content in the product for gelatinization to occur completely. As a result, the product has a glassy texture. In the two stage frying, the atmospheric frying prior to vacuum frying helps the starch to gelatinize thus producing a better product in terms of texture, oil content, and flavor. The atmospheric fried samples were darker in color and had a scorch taste. The degree of starch gelatinization was 21% higher for the two-stage fried samples than the single-stage fried ones.
The application of the dual stage enhances the quality of sweet potato chips, improves consumer satisfaction, and reduces the need for space, cost, and any other needs of blanching pre-treatment to the sweet potato manufacturers.