Dissertations / Theses on the topic 'Sweet potatoes – Storage'

Biofortified orange-fleshed sweetpotato (OFSP) is being promoted to tackle vitamin A deficiency, a serious public health problem affecting children and pregnant/lactating women in sub-Saharan Africa. The aim of the study was to quantify and understand the factors influencing carotenoid losses in dried OFSP. Losses were determined in chips after drying and storage. A preliminary study demonstrated that carotenoid levels were not significantly different following either solar or sun drying. Carotenoid loss after drying was generally correlated with high initial moisture content and high carotenoid content in fresh sweetpotato roots. Losses of pro-vitamin A were less than 35% in all cases. Flour made from OFSP could therefore be a significant source of provitamin A. In contrast, storage of chips at room temperature in Uganda and Mozambique for four months resulted in high losses of pro-vitamin A (ca. 70-80% loss from the initial dried product). Low-cost pre-treatments, such as blanching, antioxidants and salting, did not reduce carotenoid losses during storage. Enzymatic catabolism of b-carotene in dried OFSP was considered unlikely because of low peroxidase activities at low water activities and the loss of peroxidase activity during storage. To understand further the factors causing the losses, dried sweet potato chips were stored under controlled conditions of temperature (10; 20; 30; or 40ºC), water activity (0.13; 0.30; 0.51; 0.76) or oxygen (0 [under nitrogen]; 2.5; 10 or 21% [air]). Oxygen was the main cause of degradation followed by temperature. An Arrhenius kinetic model was used to show that carotenoid breakdown followed first order kinetics with an activation energy of 68.3kJ.mol-1 that was in accordance with the literature. Experimental observations fitted well with data predicted by the kinetic model. The formation of the volatile compounds,b-ionone; 5,6-epoxy-b-ionone; dihydroactinidiolide; b-cyclocitral that were clearly related to the degradation of b-carotene, helped further understand breakdown patterns of b-carotene.

Alternaria leaf petiole and stem blight is an important disease of sweetpotato (Ipomoea batatas (L.) Lam.) causing yield losses in both landraces and improved cultivars. The most important species causing economic yield loss in Uganda are Alternaria bataticola and A. alternate with A. bataticola the most aggressive and widely distributed. The study was conducted to: i) establish farmer-preferred sweet potato attributes, production constraints and Alternaria leaf petiole and stem blight awareness; ii) evaluate Ugandan sweet potato germplasm for Alternaria leaf petiole and stem blight resistance; iii) determine the mode of inheritance of resistance to Alternaria leaf petiole and stem blight and storage root yield components of sweet potato through estimation of the general combining ability (GCA) of the parents and the specific combining ability (SCA) of the parents for each cross; and iv) determine the adaptability and farmer acceptability of selected F1 genotypes across environments. The participatory rural appraisal was conducted to establish farmer preferences and production constraints revealed that farmer preferred sweet-potato traits were high yield, sweetness (taste), early maturity, high dry mass, resistance to pests and diseases, and in-field root storability after maturity. A majority of the farmers considered Alternaria leaf petiole and stem blight a serious production constraint causing yield loss of over 50%. The main control measures against the disease were roguing of infected plants, spraying with fungicides, use of healthy planting materials and planting resistant genotypes. Thirty sweet potato land races and improved cultivars were evaluated for Alternaria blight severity; yield, dry mass, harvest index, sweetpotato weevil (Cylas spp.) damage and sweetpotato virus disease at two sites (Namulonge and Kachwekano) over three seasons (2010B, 2011A, 2011B) under Alternaria inoculum and fungicide spray treatments. Landrace Shock was more resistant to Alternaria blight than Tanzania, the resistant check. Genotypes NASPOT 1, NASPOT 7, New Kawogo and Dimbuka were the most susceptible. Thirty two F1 families were generated from 16 parents in two sets in a North Carolina II mating scheme. The families were evaluated at two sites using a 5 x 7 row-column design with two replications. There were significant (P<0.05) differences among the families in Alternaria blight severity. Both GCA and SCA mean squares (MS) for Alternaria blight were highly significant (P<0.001) but the predominance of GCA sum of squares (SS) for Alternaria blight at 67.4% of the treatment SS versus 32.6% for SCA SS indicated that additive effects were more important than the non-additive effects in controlling this trait. For the yield components, the GCA MS were significant (P<0.05) and accounted for more than 60% of the treatment SS except for percentage dry mass composition where SCA SS accounted for 53.0% of the treatment SS implying that non-additive genetic effects were slightly more important than additive for this trait. Some parents that had desirable high, negative GCA effects for Alternaria blight produced families with undesirable positive SCA effects and the reverse was also true. This implied that the best parents should not be chosen based on GCA effects alone but also on SCA effects of their best crosses. The promising F1 genotypes selected from previously evaluated crosses together with one Alternaria blight resistant check (Tanzania) and one susceptible check (NASPOT 1) were evaluated at three sites (Namulonge, Kachwekano and Serere) using a randomised complete block design with three replications. Scientists and farmers evaluated the agronomic performance and also quality traits of the genotypes before and at harvest. Genotypes G14, G16, G24, G29, G49, G59 and G69 were the most stable across the sites for low Alternaria blight severity and can, therefore, be recommended for further evaluation under both low and high disease pressure areas. Genotypes G67, G13, G14, G24, G29 and G53 were the most high yielding and stable across the sites and were therefore the most widely adapted. In the participatory selection, before harvest and at harvest, Spearman’s rank correlation of the scientists and farmers’ mean ranking of the genotypes at each site was positive and significant. This indicated that the scientists in the study were capable of selecting for farmer preferred traits.
Thesis (Ph.D.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.

碩士
國立屏東科技大學
熱帶農業研究所
88
Leafy sweet potato is becoming a popular health vegetable in recant years. The quality of the vegetable can be ensured through proper storage; thus, the quality and physiological characteristics of harvested leafy sweet potatoes are the major objectives of this research. This study employed different agronomy features of leafy sweet potatoes Taoyuan No. 2 variety and line C83L20 for comparing their physiological and quality responses under storage. Factors considered for comparisons were packing, storage temperature, and harvest time. Comparing these factors will enable the understanding of their effects on the shelf-life of leafy sweet potato. Results showed that the water content, dry weight, vit.C content, soluble sugar and chlorophyll contents of the leafy sweet potatoes, which were packed and then stored, were higher than that of non-packed control, but less changes in color were observed in all tested varieties. The water content, dry weight, vit.C content, soluble sugar and chlorophyll contents of leafy sweet potatoes that were subject to pre-cooling prior to the analysis were higher than those not subjected to pre-cooling, but less color changes were observed as compared to the untreated. It is suggested that packing and pre-cooling before storage improve storage quality in leafy sweet potatoes. The water content, dry weight, vit.C content, soluble sugar content, starch content, chlorophyll contents, and protein content decreased with the increase of the storage time and temperature. Under high temperature conditions（20℃, room temperature） the EFEase activity, ethylene production, respirator rate, and protease content were higher as compared to that of the low temperature（5℃, 10℃）. Conversely, the water content, dry weight, vit.C content, soluble sugar content, starch content, chlorophyll content, and protein contents were higher under low temperature than that of high temperature. Pre-cooling, packing, and storage under low temperature could inhibit physiological changes and maintain the quality of leafy sweet potatoes. It indicated that storage under high temperatures accelerated the senescence process; thereby, reducing the storage life of leafy sweet potatoes. Leafy sweet potatoes harvested in the afternoon had higher dry weight and soluble sugar content than those harvested in the morning. Conversely, the levels of water content, vit. C and chlorophyll were higher in leafy sweet potatoes harvested and than stored in the morning than those harvested in the afternoon and than stored. Also, the leafy sweet potatoes harvested in the afternoon showed more serious yellowing on leaves than those harvested in the morning. The temperature at harvest had significant effects on the shelf-life of leafy sweet potatoes. It showed that pre-cooling enhanced the quality of leafy sweet potatoes under storage. After one week of storage, the water content, dry weight, vit.C content, carbohydrate content, soluble protein content and color of leafy sweet potato harvested in the morning, then that harvested in the afternoon and subjected to the same treatments packed, and than stored under low temperature at 5℃-10℃ appeared to be better.

碩士
文化大學
生物科技研究所
83
Peroxidase is believed to play an important role in lignin synthesis, IAA oxidation, detoxification of Ｈ2Ｏ2 and is also known to have close relationship with shoot and root initiation, leaf formation, senescence ,internode elongation, and pathoqenetic infection etc. In this experiment, five treatments including control, middle or late stage flooding, and middle or late stage drought were performed on 7 sweet potato cultivars. The effects of flooding and drought stresses on leaf peroxidase zymograms and activity and the relationship of zymogram agronomic traits were investigated. Peroxidase zymogram variations were noted among 7 varieties. At least 15 anodal bands and 3 cathodal bands were observed. Varietal differences were most pronounced at the A4 zone (A13-A15 bands). Variation in band intensity was also observed at cationic bands. Drought and flooding treatments affected on band intensity especially in A12-A7 bands. SAS analysis indicated treatments and genetic background had significant effects on peroxidase activity and protein content. In general, drought tended to decrease protein contents while increase peroxidase activity. Flooding had similar effects but was not as distinct as drought. When flooding at the middle stage of growth period, plants had the ability to recover growth. However, drought treatment performed much worse than flooding. Investigations on agronomic characters revealed drought treatment at the late stage of growth period had the worst effects on fresh weight of tops, fibrous roots and storage roots. Of the storage root, dry matter content was lowered by both treatments, sugar content by flooding and stard by drought. Leaf peroxidase zymogram also has significant relationship with fresh weights of tops, fibrous roots, and storage roots, dry matter, protein and starch contents of storage root. Leaf peroxidase zymogram has the potential to be an early selection indicator of sweet potato breeding.

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.

碩士
台北海洋科技大學
食品科技與行銷系碩士班
106
This study uses Purple-Sweet potato as material. Study on raw powder and cooked powder made from different processing methods. Each of the raw materials for the processing of raw material and cooked powder is made of 12%, 18%, 24% of different proportions of materials for the manufacture of steamed bread products. Screening the best product conditions with the commercially available steamed bread for the control group. We have three months storage test with different packaging materials. (Foil bag, Vacuum bag, PP packaging material) Product quality assessment and testing items include microorganisms, color, water activity, etc. It is expected that the use of sweet potato utilization value will be applied to the development of new products in the market.

碩士
國立屏東科技大學
農園生產系所
95
Abstract Student ID:M9411014 Title of thesis:Studies of phenolic compounds and storage life of sweet potato (Ipoma batatas (L.)Lam) tuberous roots during storage Total page :115 Name of Institute:National Pingtong University of Science and Technology Department of Plant Industry Graduate date:2007.06.20 Degree Conferred:M. S. Name of student:Shi-Long Zheng Adviser:Dr. Ming-Shaiun Guu The contents of abstract in this thesis : This study is to take the varieties of edible sweet potato in the market as research materials; the studies processe will be divided into three parts:(1) edible quality of sweet potato during storage (2) the effect of curing and temperature treatment on the storage life of sweet potato and (3) phenolic acid on the storage life on sweet potato so as to investigate how to preserve their original qualities and decrease damage while they are in the storage. Tainong No.57, Tainong No.66 and purple sweet potatos were selected to be stored for four months in room temperature with natural ventilation and low temperature separately in order to study the quality change of root tuber during storage for different varieties of sweet potato. The results indicated that for the three varieties of sweet potato, that had, the lower sprouting percentage and lower rotting percentage, lower fresh weight loss percentage, and that with increasing the storage time. The results also showed that dry weight, moisture content, starch content, total sugar content, non-reducing sugar content, reducing sugar content, total phenolics content, antioxidation, superoxide anion of scavenging vanillic acid content, caffeic acid content, ferulic acid content, and sinapic acid content decreased by prolonging the storage time. Sprouting perentage, rotting percentage and fresh weight loss in low temperure were lower than room temperature, but dry weight, motisture content, starch content, total sugar content, non-reducing sugar content, reducing sugar content, total phenolic content, antioxidation, supenoxide anion of scavenging, vanilic acid content, caffeic acid content, ferulic acid content and sinapic acid were higher in low temperature. The only exception was p-coumaric acid, the content increased with storage time. For the carotenoide content variation in different varieties of sweet potato during storage period, the purple sweet potatos showed higher of carotenoide content when stored in low temperature than in room temperature, the Tainong No.57 and Tainoung No.66 showed in the opposite results. For all the three varieties, the carotenoide content decreased with prolonging the storage time, and the phenolics content is higher in their periderm than in stele. The purple sweet potatos stored in room temp had higher flavonoids content than those stored in low temperature. In these testing materials, the purple sweet potato also showed lowest sprouting percentage, rotting percentage, antioxidation, yet highest total phenolics content, superoxide anion of savenging, caffeic acid content, ferulic acid content, sinapic acid content, and p-courmaric acid content Tainong 57 showed the highest in starch content , the total sugar content, sprouting percentage , and the rotting percentage; on the other hand , the dry weight, the vanillic acid content, the coffeic acid content, the sinapic acid content, and the p-aacourmaric acid content showed the lowest. The Tainong No.66 had the highest carotenoide content among all the testing materials, Thevariety showed highest flavonoids content and ferulic acid content among all the testing materials stored in room temperature. By selecting Tainong No.57 as testing material, while comparing the storage life between the condition of low temperature and room temperature after curing treatment, the results showed that stored in room temperature had the highest sprouting percentage, rotting percentage, fresh weight loss percentage, sample being curing and stored in low temperature obtained lower, and stored in the low temperature achieved the lowest; while none of sprout occurred in low temperature storage. The low temperature storage showed the highest in dry weight, moisture content, polysaccharide content, total phenolics content, peroxidase activity, vanillic acid content, caffeic content, p-courmaric acid content, sinapic acid content, and ferulic acid content, the curing and stored in low temperature followed the next higher, the next was the curing and stored in room temperature, room temp showed the lowest. The total phenolics content in a different storing treatments decreased along with increasing storage time. In addition, the polysaccharide content, the peroxidese activity, and the phenol acid also changed in relation to the different store treatments and different storage times. In the different storing process of the sweet potato root tuber, the study showed that the phenol acid content, was highest for the ferulic acid content, next was the vanillic acid, caffeic acid, sinapinic acid, p-coumaric acid, orderly. In order to investigate the phenol acid on the storage life of sweet potato , the study had conducted by applying different concentration of ferulic acid and the vanillic acid treatment on Tainoung No.57 , and performed a comparation between low temperature storage and room temperature storage. The result showed when in a low temperature storage environment had the lowest sprouting percentage; next was in the phenol acid storing treatment, and stored in room temperature showed highest; sprouting percentage decreased with increasing the concentration of the ferulic acid and the vanillic acid. While comparing the different storing methods, storing sweet potato in low temperature environment revealed the highest in the fresh weight, the moisture content, the polysaccharide content, the total phenolics content and the peroxidase activity except the result of total phenolics content in the condition that the tuber root treated by 3200 ppm ferulic acid ; the next was phenolic acid treatment, the lowest was room temperature. In phenolic acid treatment all various component contents increased along with the increasing concentration of ferulic acid and vanillic acid . For the sweet potato root tuber treated by ferulic acid at various concentration, no rotten showed in a 4 month storage time. On the other hand , when applying the vanillic acid at the concentration of 800 ppm , the rotting percentage of sweet potato root tuber was the highest. In addition, the sweet potato root tuber were not getting rotten when using vanillic acid treatment at the concentration other than 800 ppm.

碩士
國立屏東科技大學
農園生產系所
99
Sweet potato (Ipomoea batatas L.) is an important industrial raw materials of food and food crops in subtropical and tropical regions. The root is very rich in nutrients, and its extracts have antioxidant, scavenging free radicals and other effects and can also be as functional food use. The major problem of sweet potatoes are the short storage life and reduction of food quality during storage because of the deterioration and infection of disease of the tuberous roots. The appication of chitosan film on fresh fruits asnd vegetables is an innovation technology in posthavest handling which will reduce the respiration rate and ethylene production, delay ripening, decrease water loss, increase shiny peel texture and reduce perishable fruits and vegetables. The objective of this study is to investigate the effect of chitosan application on the storage time of fresh sweet potato roots and evaluate the efficiency of prolonging the shelf life. The experiments are divided into three parts: (1) chitosan treatment on the storage life of sweet potatoes. (2) chitosan treatment on the antioxidant properties of sweet potato tuberous roots during storage and (3) chitosan treatment on the metabolism of phenylpropanoid in sweet potato tuberous roots during storage. The first part, tuberous root of sweet potato cultivars TNG 57 and TNG 66 were treated with 1% and 5% chitosan, applied as solution immersion of the whloe tuberous root and spraying on the peel. The results showed that 5% chitosan treatment inhibited germination of sweet potato root, reduced sprout number, fresh weight loss and decay rate. Immersion and spraying of chitoasn treatment in the roots during storage would maintain the flesh firmness, increase color performance, delay the decrease of starch, total sugar and soluble protein content and inhibit α-amylose and invertase activities. The second parts, cultivars TNG 57 and TNG 66 were treated with 1% and 5% chitosan solution, immersion and spraying on sweet potato peel. The results showed that both the peel and the flesh of sweet potato got the highest total flavonoid content, DPPH and ABTS radical scavenging capacity. But the reduction and superoxide anion scavenging capacity wouled not be influenced. The application of 5% chitosan treatment induced the increment of peroxidase activity and glutathione reductase activites, thus increased the total glutathione content and inhibited the lipid oxidation of MDA. The third parts, cultivars TNG 57 and TNG 66 were treated with 1% and 5% chitosan solution, immersion and spraying and stored for eight weeks. The results showed that the phenylalanine ammonia lyase(PAL) activity was highest at the founth week’s storage. The lignin, total phenolic compounds and chlorogenic acid content increased, coffeic acid did not change significantly. In conclusion, treatment of 1% and 5% chitosan solution, either immersion or spraying, has positive effect on sweet potato tuberous roots. The shelf life is extended and the food quality is improved.

碩士
東海大學
食品科學系
98
The aim of this study were to screen the sweet potato leaves with high carotenoid content and high antioxidant activity from different varieties, and to study their storage stability in the form of freeze-dried powder. At first, total carotenoids (TC) and total phenolic compound (TPC) were analyzed for all kinds of sweet potato leaves from Tainung No. 57 (TN57) , Tainung No. 66 (TN66) , Tainung No. 71 (TN71) , purple varieties (purple), yellow varieties (yellow) and Dilaw. The result indicated that TN57 had highest content of TC and TPC, which were 142.59 μg/g fresh weight and 2938.22 μg GAE/g fresh weight, respectively. Antioxidant activity test also showed that TN57 had highest trolox equivalent antioxidant capacity (TEAC) of 7770.62 μg trolox/g fresh weight. The effects of growing period of TN57 on TC, TPC and antioxidant activity were investigated. The result indicated that TN57 had highest TC of 144.79 μg/g fresh weight and TPC of 3452.41 μg GAE/g fresh weight at growing period of 2nd and 3rd month, respectively. The highest TEAC was also observed at growing period of 2nd month. According to the above results, TN57 was selected and cultivated for two months, and then its leaves were collected and freeze dried. Finally, storage stability of the freeze-dried powder was investigated. The result showed that the best conditions to store lutein and zeaxanthin in the powder were 4℃ in the dark. The decrease of TC was mainly affected by light then by temperature.

博士
國立中興大學
農藝學系
91
The goal of our research was focused on the development of storage root in sweet potato(Ipomea batatas) during spring and fall growth seasons. The experiments were divided to four primary parts , the results are summarized as follows: 1.Eight sweet potato varieties from abroad and domestic countries were used in the present study , we planted the seedlings in both spring and fall seasons , to realize the developnant of vine-leaf and storage root in two growth seasons . The results showed that the leaf area index , leaf dry weight , petiol dry weight and stem dry weight in spring season were higher than those of parameters in fall season at middle and late growth stages , the storage root weight and harvst index in the fall season were higher than those parameters in the spring season , it revealed that the proper balance between sink and source could obtain higher amount of storage root yield , and the harvest index(HI) is a good indication to represent the yield of storage root. The variety of TNG66 had higher HI in both spring and fall seasons , but TNG57 only had higher HI in fall season , and lower HI in spring season. 2.We used two sweet potato varieties , TNG57 and TNG66 , as the experiment materials to do the extended study for the enzyme activity, which affects the accumulation of storage root.The results showed that there were no significant difference for sucrose content on the storage root of two varieties in two growth seasons ,but the SS and AGPase activity of TNG57 in fall season were significantly higher than those parameters in spring season , the TNG66 had higher SS and AGPase activity in both spring and fall seasons. Therefore , the variety of TNG66 had higher glucose content , storage root fresh weight and starch content in both spring and fall seasons , but the TNG57 only had higher glucose content ,storage root fresh weight and starch content in fall season , and had low glucose content ,storage root fresh weight and starch content in spring season . As a result , the SS and AGPase might be the primary key enzyme for the formation of storage root. 3.The four self and reciprocal grafted combinations were used to study the influence of source and sink relationship to the yield of storage root.The results showed that the grafted combination with high sink capacity variety(TNG66)as stock got a higher storage root fresh weight and starch content , it explained the contribution of sink strength to storage root yield. On the other hand , the grafted combination with high source potential and poor sink capacity variety(TNG57)as stock could not get higher storage root fresh weight and starch content , it also proved the previous assumption that the proper balance between source and sink relationship could obtain higher storage root yield. 4.Three different hybrid combinations with high or low storage root yield were used to investigate the genetic behavior of vine-leaf and storage root traits, The results showed that the F1 of nine traits (vine-leaf dry weight，storage root fresh weight，storage root dry weight，starch content，storage root mean weight，SS activity ，AGPase activity，glucose content and sucrose content) had the phenomenon of transgressive segregation and heterotic effect at two crop seasons. Reciprocal difference were significant for all the traits , it means there was maternal effect between the male and female parent . The estimated gene pair were between 4-9 pairs for all nine traits., it indicated the multiple gene controlled the genetic behavior for all nine traits, consequently , the heritability of all the traits were only between 10-60% . The phenotypic and environmental correlation coefficients among storage root weight and sturage root mean weight ,SS activity in both spring and fall seasons showed highly significantly positive correlation , and the phenotypic and environmental correlation coefficients between storage root mean weight and the number of root showed highly significantly negative correlation in both spring and fall seasons . Therefore , the SS activity，proper balance between storage root mean weight and the number of root are the good indication of selecting high storage root yield in both spring and fall seasons .

碩士
國立中山大學
生物科學系研究所
101
Sweet potato cysteine proteases SPAE and SPCP2 exhibited high amino acid sequence identities with seed vacuolar processing enzyme (VPE) and papain-like cysteine protease, respectively, which have been demonstrated to play important roles in association with seed globulin storage protein degradation. Transgenic Arabidorpsis suggested that SPAE and SPCP2 also play important roles in association with seed storage protein degradation. Therefore, the study was focused on whether SPAE and SPCP2 participate in the degradation of storage root trypsin inhibitor (TI) during sprouting. In sweet potato, the major trypsin inhibitor degradation began 3 weeks after sprouting, and became significant 4 weeks later in sprouting storage roots. The reduction of trypsin inhibitors was significant and much earlier at the outer flesh near the skin than that at the inner flesh. The degradation of trypsin inhibitors was also the most significant at the outer flesh nearest to the sprout of the storage root. An inverse correlation between the distance away from the sprout and the trypsin inhibitor degradation was observed. Gene expression of SPAE and SPCP2, but not SPCP3 and SPCP1, increased in the flesh 3 weeks after sprouting and were significantly enhanced 4 weeks later in sprouting storage roots. In vitro degradation assay showed that exogenous application of SPAE or SPCP2 fusion proteins to the crude extract from outer flesh of two-week old sprouts significantly promoted storage trypsin inhibitor degradation. The denatured SPAE/SPCP2 or SPCP3 fusion proteins did not affect trypsin inhibitor degradation. Based on these results, SPAE and SPCP2 participate with specificity in trypsin inhibitor degradation during storage root sprouting.

碩士
國立嘉義大學
農藝學系研究所
106
In this study, three varieties of sweet potato, TNG 57, TNG 66, and TNG 72, were used as materials for spring planting from Feb. 2016 to Sep. 2016 in the farm of Yizhu township, Chiayi County. Two treatment, integrated pest management(IPM) and physical control management(PCM) were used, and it was harvested at 120 days, 150 days and 180 days after planting. The sweet potato roots were treatmented with different temperatures (25°C, 20°C, 15°C) and months of storage (1 month, 2 months, 3 months, 4 months, 5 months, 6 months), during the storage period, the root quality (germination rate, dry matter rate, sweet potato ant image hazard rate, soft rot rate, water loss rate) were investigated, and the contents of the general compositions (moisture, ash, crude fat, crude protein and starch) of the roots at the optimum harvest stage were analyzed. The results show: In 2016, when the planting days longer, sweet potato weevil damage increased in both of the pest treatment of two growing seasons for three varieties. TNG 66 and TNG 72 has a lower rate of sweet potato weevil damage than TNG 57. In Two-pest management, TNG 57 has increase in the tuberous yield/plot after 150 and 180 days of planting, as well as TNG 66 and TNG 72. TNG 66 and TNG 72 have higher yields than TNG 57 in spring cropping. TNG 57 has higher yield than TNG 66 and TNG 72 in fall cropping. The optimum harvest period for three varieties is 150-180 days in spring, and the optimum harvest period for three varieties in fall is 150 days. In IPM, three variety with the same harvest period has lower rate of sweet potato weevil damage than the PCM. In two pest management methods, there are lower rates of sweet potato weevil damage than in spring, and three varieties of the same management period have higher block area and root yield than the PCM. In fall crop, stem length, fresh leaves weight, tuberous root diameter, tuberous root length was significantly higher than fall crops. For tuberous yield/plot in fall, both TNG 57 and TNG 66 were less than 120 days after planing, , and fall harvesting for 180 days. In the case of the spring crops, the TNG 72 crops in the spring crops have a higher tuberous yield/plot, and the three crops in the fall crops have more roots and higher tuberous yield/plot than the spring crops. The change of germination rate is affected by storage temperature, storage time and variety; the change of dry matter rate is affected by storage temperature, water loss rate, different harvest days, period crops and varieties; the change of sweet potato weevil damage(Cylas formicarius) rate is affected by storage temperature and different harvest days, cropping, different management methods in the field, variety disease resistance; Soft rot(Rhizopus stolonifer) rate changes affected by storage temperature, different harvest days, variety disease resistance; water loss rate changes affected by storage temperature, storage time, variety. The two phases were used in the same harvest period and different management methods. With the increase of storage month, the three roots were stored at 20 °C and 15 °C with lower germination rate, dry matter rate, weevil damage rate and water loss rate; storage at 20 °C and 15 °C can delay germination time, reduce Sweet potato weevil damage and root loss. After 6 months of storage at the same storage temperature, the germination rate of TNG 57 in IPM and PCM increased slightly from 120 days to 180 days after planting, TNG 66 and TNG 72 was exactly opposite. After 6 months of storage at the same storage temperature, there was no significant difference in the germination rate of IPM and PCM from 120 days to 180 days after planting in the same storage temperature, storage time, period and harvest period. After 6 months of storage at the same storage temperature, dry matter rate of TNG 57 in the IPM and PCM at 20 °C and 15 °C increased slightly from 120 days to 180 days after planting. The dry matter rate of TNG 66 and TNG 72 decreased slightly from 120 days to 180 days after planting. The dry matter rate of TNG 72 increased slightly from 120 days to 180 days after planting. The three varieties in fall crops were stored at the same storage temperature for 6 months. The dry matter rate of IPM and PCM increased significantly from 120 days to 180 days after planting. As the planting days goes by, dry matter rate of TNG 72 is higher than TNG 57 and TNG 66 in spring crop, and TNG 57 had a higher dry matter rate than TNG 66 and TNG 72 in fall crop. After storage at 20 °C and 15 °C for 6 months, the numbers of sweet potato ant in IPM and PCM for three varieties were not significantly different from 120 days to 180 days after planting. After three months of storage at the same storage temperature, the damage rate of weevil damage rate in IPM and PCM increased slightly from 120 to 180 days after planting at 25 °C, and there was no significant difference between 20 °C and 15 °C. After three months of storage at the same storage temperature, the spring crop of all varieties had higher rates of weevil damage rate than fall crop. When the planting days increased to 180 in spring crop, TNG 66 and TNG 72 had higher rates of weevil damage rate than TNG 57. And TNG 57 had a higher rate of weevil damage rate than TNG 66 and TNG 72 in fall. When planting days increased to 180, there was no significant difference in the soft rot damage rate of the three varieties in spring crop. In fall crop, TNG 66 has a higher soft rot rate than TNG 57 and TNG 72, as planting days increased. After storage at 20 °C and 15 °C for 6 months, water loss rates of the three varieties in the IPM and PCM increased slightly from 120 days to 180 days after planting. TNG 66 was compared with TNG 57 and TNG 72 in high water loss rate, as planting days increase in both crops. The results showed that in the spring of 2016, both spring and fall crops were stored at 25°C for 4 months in the two management areas. After being stored for 4 months at 25°C, the roots showed lack of value due to corruption, so there was no relevant data for 5 months and 6 months. Three varieties at two management areas in spring storaged at 25°C for 4 months; after storaged at 20°C and 15°C for 6 months, the roots had higher ash content and crude protein content at 25°C, and had higher moisture content, crude fat content and starch content at 20°C and 15°C. The content of moisture,ash, crude fat, and crude protein increased as storage time increased, but the starch content decreased as storage time increased; There was no significant difference between different storage temperature and months with two-processes (IPM and PCM) in the general composition of the roots with three varieties. Between different storage temperature and months, TNG 57 with IPM had lower ash content and crude fat content than PCM, but it had higher crude protein content and starch content; TNG 66 with IPM had lower ash content, crude fat content and crude protein content than that with PCM, but it had higher starch content; TNG 72 with IPM had lower crude protein content than that with PCM, but it had higher ash content, crude fat content, and starch content. In fall, the treatments of two management areas with three varieties were stored at 25°C for 4 months; after storaged at 20°C and 15°C for 6 months, the roots had higher moisture content and crude protein content at 25°C and higher ash content, crude fat content and starch content at 20°C and 15°C. The moisture content, ash content and crude protein content increased as storage time increased, but the crude fat content and starch content decreased as storage time increased. There was no significant difference about the two-processes (IPM and PCM) in the general composition of the roots with three varieties between different storage temperature and months in moisture, crude fat, crude protein, and starch content in the tuber roots, but ash content with IPM decreased as storage time increased, and ash content with PCM increased as storage time increased. Between different storage temperatures and months, TNG 57 with IPM had lower ash, crude protein and starch content than PCM, but it had higher crude fat content; TNG 66 with IPM had lower ash, crude fat, and starch content than PCM, but it had higher crude protein content; TNG 72 with IPM had lower ash, crude fat, crude protein content than PCM, but it had higher starch content.

碩士
台北醫學院
生藥學研究所
90
Trypsin inhibitors (TIs), the major root storage protein of sweet potato, were purified from different cultivars of Tainong 57 and Tainong 65 of sweet potato (Ipomoea batatas [L.] Lam) roots by trypsin-Sepharose 4B affinity column. By series of in vitro tests, including DPPH radicals and hydroxyl radicals scavenging activity assays, reducing power test, anti-superoxide radicals assay, anti-human low density lipoprotein (LDL) oxidation test, protections against hydroxyl radical- mediated DNA damages and peroxynitrite medialed dihydrohodamine oxidation, it was showed that TIs exhibited antioxidant and antiradical activities compared with positive controls. Modifications of cysteine residues by iodoacetamide or tryptophan residues by NBSI (N-bromosuccinimide) in TIs, it was showed that tryptophan residues contributed greatly and cysteine residues partially against hydroxyl radicals; however, cysteine residues contributed largely DPPH radical scavenging activities. Using TIs as materials for pepsin, pronase E or pepsin successively by chymotrypsin hydrolysis, it was showed that all of the hydrolysates still had antioxidant activity against DPPH radicals, anti-human LDL oxidation activity and protections against hydroxyl radicals mediated DNA damges. The peptides distributions of hydrolystates were separated by Sephadex G-50 column. Each fraction was determined for hydroxyl radical scavenging activities. It was showed that the small molecular fractions still had activities against hydroxyl radicals.

碩士
國立屏東科技大學
農園生產系所
99
Sweet potato (Ipomoea batatas (L.) Lam) is the main tuberous roots crop that grown in tropics and subtropics area. In Taiwan when properly stored, it will still be available for several months after harvest. However, the deterioration of storage life in sweet potato is effected by several factors which includes: weight loss, decay and sprouting which are reducing the quality and nutrient values. In this study three major objectives were: The first, to investigate the effect of different coating materials on the storage life of sweet potato. The second, to understand the effect of different times of chitosan coating different times on the storage life of sweet potato. The final, to determine the phenolic content of chitosan coating times on the storage of sweet potato. The results of first study showed that the treatment of 5 % chitosan＋0.75 %calcium gluconate coating 1 or 5 min on Tainong 57 lead to the sprouting percentage, sprout number, sprout length, rotting percentage, percentage of fresh weight loss and color change lower than the control. But the coating treatments had the higher starch content, sucrose content, fructose content and glucose content. The activies of amylase and invertase were increased. The enzyme activites increase may delay by coating. The results of second study showed that coating two times or three times of 5 % chitosan＋0.75 % calcium gluconate for 5min depressed sprouting percentage, sprout number, sprout length, rotting percentage, percentage of weight loss, color change, amylase activity and intervase activity which were significantly lower than the control. Starch content, sucrose content, fructose content and glucose content of coating treatment were significantly higher. The results of third study showed that the caffeic acid and chlorgeic acid content increased with storage time. The treatment with 5 % chitosan＋0.75 %calcium gluconate coating lead to significant higher caffeic acid and chlorgenic acid content than the control. The two time and three time treatments of 5 % chitosan＋0.75 %calcium gluconate coating would cause the caffeic acid and chlorgenic acid content significant higher than the control and one time treatment in stored eight weeks. The chitosn coating treatment could reduced the penolic acid content in the final storage time.

碩士
中國文化大學
生物科技研究所
97
The objective of the research was to study variations of polysaccharides in storage roots of different sweet potatoes. Three varieties of sweet potatoes, Tainung (TN) 57, Tainung 10 and Japanese Satsumahikari (as control), were stored in growth chambers at 15℃and 25℃ for 12 weeks. Samples were also stored at 15℃ under 4 different lights, red (660nm), blue (435nm), red and blue, and white (400nm ~700nm, as control) for 12 weeks. Beta-amylase activity and contents of soluble polysaccharide (fructose, sucrose, glucose and maltose), total carbohydrate and starch were analyzed every week. Meanwhile, sprouting and cold injure (15℃) were recorded weekly. Three samples of each treatment were analyzed for the above mentioned chemical and physiological parameters and statistically calculated by ANOVA using SAS. The results show that total carbohydrate content started accumulation at second week at 25℃resulting in sprouting and increasing of maltose content. The activities ofβ-amylase were not augmented by increasing total carbohydrate and maltose contents as well as decreasing starch content. The increased activities ofβ-amylase might come from the inductions of sucrose and lights, followed by digesting starch into maltose. Therefore, activities ofβ-amylase may not be an indicator for low-sugar content breeding in the sweet potato. Fructose content of TN57 and glucose content of TN10 were positively correlated under red light and blue light, respectively. The content of glucose was increased as fructose increased because sucrose was hydrolyzed and became fructose and glucose. The contents of fructose and sucrose as well as glucose and fructose of TN10 were negatively and positively correlated, respectively, under 15℃. These results indicate that lower amount of sucrose digested from starch was accompanied by increasing higher values of fructose and glucose. Therefore, fructose and glucose may inhibit sprouting of storage roots and use as a selection index for long-term storage of storage roots of sweet potato.

碩士
國立屏東科技大學
農園生產系所
101
Sweet potato (Ipomoea batatas (L.) Lam) is one of the most versatile food crops in the world. The climate in Taiwan is suitable for growing sweet potato, which is also served as an excellent functional food due to the roots’ richness in fiber, starch and nutrients. One particular variety, Simon, is known for its high functional purposes. However, there still lacks of enough published articles about the starch properties of Simon variety sweet potato in Taiwan. Therefore, this research utilized sweet potato (Ipomoea batatas (L.) Lam) cv. Simon to explore starch properties within its roots.The main objectives were to understand the quality variations and physicochemical properties in starch at different harvest time of storage root. And, to investigate root starch physicochemical properties under different process treatments. Finally, to compare starch physicochemical properties of different size storage root. The results showed that different harvest time treatments expressed linear increment in their moistness, ash, starch and amylopectin contents in sweet potato storage root. The five-month cultivation produced poor agronomic and starch physicochemical characteristics. In comparison, sweet potato planted for six months produced better root quality in weight, firmness, color, and β-amylase activity, physicochemical property, cold water solubility, water binding capacity, swelling power, solubility and degree of gelatinization. When under different process treatments no significant differences in cold water solubility of all samples were found. The analyses of root content showed lower ash and higher total starch under drying treatment. The amylase, β-amylase, swelling power, gelatinization temperature range, and turbidity of baked-dried sweet potato starch was considerably lower than freeze-dried and heat-dried starch. In comparison, the starch under freeze-dried showed higher swelling power, gelatinization, turbidity, and lower water binding capacity and solubility than the heat-dried starch. The experiment also showed that in different size sweet potato roots no significant differences could be found on total starch content, water binding capacity, and solubility. In this study, King size sweet potato had higher amylopectin content and turbidity as compared to other sizes of the sweet potato. Small sized sweet potatoes showed highest level of gelatinization, lowest level of ash content and turbidity. The amylose content in small sized sweet potato was high but did not showed significant difference from other sizes except big-sized ones. Moreover, the level of β-amylase activity was similar to the king-sized but higher than other sizes. The minimal sweet potato had the highest cold water solubility and lowest swelling power and gelatinization among all root sizes. In conclusion, starch physicochemical properties of the sweet potato cv. Simon root were significantly affected by harvest time, processed treatment and storage root size. The best way was : root harvest time was when the crops grew for six months then freeze-dried or heated dried which would had better starch qualities and physiochemical characteristics. Further, sweet potatoes with small roots had better physicochemical properties in starch.

Sweetpotato (Ipomoea batatas (L.) Lam.) is a root crop well established throughout the world's tropical and sub-tropical regions. Despite sweepotato's importance, it has been under-researched relative to many other major crops. The main objective of this thesis is to contribute to a fuller understanding of the genetic and physiological factors underlying the production of sweetpotato storage roots for human consumption. The sweetpotato genome is diverse and subject to high levels of natural somatic mutation. Applying the AFLP (amplified fragment length polymorphism) technique allowed a direct comparison of inter and intra-cultivar DNA (deoxyribonucleic acid) base sequence variation. Analysis of the variation indicated that although sweetpotatoes are clonally propagated, clones show a lack of genetic fidelity to their source. Further, the level of genetic variation within the cultivar 'Owairaka Red' indicated the continuing emergence of distinct new strains. Plant field establishment represents the interaction of both propagation and growth phases of storage root production. A range of establishment techniques were investigated in a field trial under commercial conditions. Sprouts cut from seed roots and held for six days rather than immediate planting improved establishment as measured by growth, at little expense. Plug raised plants also improved establishment, while potentially reducing the degree of intra-cultivar genetic variation. Plant carbohydrate partitioning in three cultivars, 'Beauregard', 'Beniazuma' and 'Owairaka Red' was examined by field trial over the period of storage root growth. While cultivars differed in the proportions of dry matter partitioned to leaf, stem and root organs, the cultivar specific ratios of leaf to stem dry weight were relatively stable over time. Total storage root dry weight increased with time for all cultivars, but the distribution of storage root grades by size was cultivar specific. Within the storage roots % dry weight increased over time in all cultivars, but total sugar concentration only increased for 'Beauregard' and 'Beniazuma'. Finally, a storage root disorder called 'brown centre' curtails the temperate growing season so was investigated using low temperature storage and a field trial with various nutrition regimes. The disorder was found to be associated with susceptible germplasm, high soil nitrogen and harvest time.