The changes in texture and sweetness of steamed storage roots of sweetpotato cultivars induced by the storage of raw roots at low temperature in relation to cell structure and starch metabolism
The changes in texture and sweetness of steamed storage roots during the storage of raw roots for 8 weeks at 5-7 ℃ (the low temperature) were investigated compared with the storage at 13-16℃ (the normal temperature) about 3 cultivars with different storability,Beniazuma Tamayutaka and Kokei No. 14 in relation to cell structure and starch metabolism. The storage of raw roots of Beniazuma and Tamayutaka at the low temperature remarkably decreased the starch content and induced rapid change in the texture of steamed ones,while Kokei No. 14 roots did not show these changes by the same storage treatment. The cell structure of steamed roots after the storage for 4 weeks at the low temperature was different between Tamayutaka and Kokei No. 14 . The activity of a-amylase largely increased during 1-4 weeks of storage at the low temperature only in Beniazuma and Tamayutaka ,not in Kokei No. 14 ,suggesting the relation of this enzyme to the different changes in texture of steamed root during the storage at low temperature. On the other hand, the sweetness of steamed roots of the three cultivars moderately increased by the storage at low temperature. However, the changes in activity of P-amylase could not completely account for this increase in sweetness. HPLC analysis revealed the rapid and drastic increase in sucrose content in the steamed root after the storage at the low temperature. The metabolism from starch or other carbohydrate to sucrose is thought to play important roll in the changes in texture and sweetness of steamed root.
amylase cell structure low temperature sucrose starch content storage sweetness sweetpotato texture
Yoshiyuki Nakamura Toshikazu Kuranouchi Akiko Ohara-Takada Toshirou Fujita Ichie Kouda Toshiaki Matsuda Tom Kumagai
National Institute of Crop Science,National Agriculture and Food Research Organization (NARO) 2-1-18 Col. of Agriculture,Ibaraki University,3-21-1 Chuo,Ami-machi,Inashiki-gun,Ibaraki 300-0393 Japan
国际会议
徐州
英文
704-710
2010-11-27（万方平台首次上网日期，不代表论文的发表时间）