|關鍵字： 甘藷；癒傷；酚酸；sweet potato；curing；phenolic acid
|摘要： 本研究以目前市售的食用甘藷品種為材料，試驗分三部分(一)甘藷貯藏期間食用品質， (二)癒傷與溫度處理對甘藷貯藏壽命的影響及(三)酚酸處理對甘藷貯藏壽命的影響；研究探討如何延長甘藷塊根貯藏期間的品質，減輕貯藏過程損失。 為探討不同甘藷品種在貯藏期間塊根品質變化，以台農57號 (黃肉)，台農66號 (紅皮黃肉)及紫藷 (紫皮紫肉)為材料，分別經室溫(26℃)通風與低溫(15℃)貯藏4個月，試驗結果顯示供試三品種萌芽率、腐爛率、鮮重損失率，隨貯藏時間增加而增加；乾重、水分、澱粉、總糖、非還原糖、還原糖及總酚類化合物含量，以及抗氧化性、捕捉超氧陰離子能力、香草酸、咖啡酸、阿魏酸、芥子酸含量卻隨貯藏時間增加而減少。另外低溫貯藏較室溫貯藏有較低萌芽率、腐爛率及鮮重損失率，但卻有較高乾重、水分、澱粉、總糖含量，非還原糖含量、還原糖含量、總酚類化合物含量、抗氧化性、捕捉超氧陰離子能力、香草酸含量、咖啡酸含量、阿魏酸含量、芥子酸含量。香豆酸含量雖在低溫貯藏較高，但隨貯藏日數增加而增加。 不同品種甘藷在貯藏期間的類胡蘿蔔素含量表現，紫藷在低溫較室溫貯藏有較高含量，台農57號與台農66號則相反；供試三品種類胡蘿蔔素含量皆隨貯藏時間增加而減少。各品種的各種酚酸含量在周皮部較皮層、中柱層部位高。 紫藷在室溫貯藏較低溫貯藏有較高的類黃酮含量。供試材料中紫藷表現最低萌芽率、腐爛率、抗氧化性、捕捉超氧陰子能力，總酚含量、清除DPPH能力、咖啡酸含量、阿魏酸含量、芥子酸含量、香豆酸含量卻最高。 台農57號在試驗材料中表現有最高澱粉含量、總糖含量、萌芽率、腐爛率；但乾重、香草酸、咖啡酸、芥子酸含量、香豆酸含量最低。 台農66號在試驗材料中有最高的類胡蘿蔔素含量，在室溫貯藏之供試材料中亦表現最高類黃酮含量及阿魏酸含量。 以台農57號品種為材料，經由癒傷處理後分別以室溫與低溫貯藏比較其貯藏壽命。試驗結果顯示室溫貯藏有最高萌芽率、腐爛率、鮮重損失，癒傷室溫貯藏表現其次、癒傷低溫貯藏次之、低溫貯藏最低；而低溫貯藏並未表現萌芽情形。乾重、水分含量、多糖含量，總酚含量、過氧化酶活性、香草酸含量、咖啡酸含量、香豆酸含量、芥子酸含量、阿魏酸含量以低溫貯藏最高，其次為癒傷低溫貯藏、癒傷室溫貯藏次之、以室溫貯藏最低。 不同貯藏處理之總酚含量隨貯藏日數增加而減少；多糖含量、過氧化酶活性及酚酸含量因不同貯藏處理，在貯藏時間有不同變化；但甘藷塊根在貯藏過程之不同酚酸含量，以阿魏酸含量最高，依序為香草酸、咖啡酸、芥子酸、香豆酸。 將不同濃度阿魏酸及香草酸處理台農57號甘藷品種，並以室溫貯藏及低溫貯藏為對照組，探討酚酸對甘藷貯藏壽命之影響。結果顯示甘藷塊根萌芽率以低溫貯藏最低，其次為酚酸處理，室溫萌芽率最高；萌芽率隨阿魏酸及香草酸處理濃度增加而減少。除3200 ppm阿魏酸處理之總酚含量外，在不同貯藏處理之甘藷塊根在低溫貯藏表現最高鮮重、水分含量、多糖含量、總酚含量及過氧化酶活性；其次為酚酸處理，以室溫貯藏最低；在酚酸處理中，各成分含量皆隨阿魏酸及香草酸處理濃度增加而增加。甘藷塊根經阿魏酸不同濃度處理，在貯藏4個月內皆無腐爛發生。而香草酸800 ppm濃度處理甘藷塊根，在貯藏期間腐爛率最高，其他香草酸濃度處理甘藷塊根亦無腐爛情形發生。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.