Relationship between Pectic Substances and Strand Separation of Cooked Spaghetti Squash--Part 2. Changes in Firmness, Histological Structure and Pectic Substances during Soaking in Pectin Extractants  

作　　者：Kayoko Ishii Ai Teramoto Hiroko Kuwada Chihiro Nakazaki Yuri Jibu Mayumi Tabuchi Michiko Fuchigami 

机构地区：[1]Department of Nutrition and Life Science, Fukuyama University, Fukuyama, Hirosima-ken, 729-0292, Japan [2]Department of Health and Nutrition, Kanto Gakuin University, Yokohama, Kanagawa-ken, 236-8501, Japan [3]Department of Nutritional Science, Okayama Prefectural University Soja, Okayama-ken, 719-1197, Japan

出　　处：《Journal of Food Science and Engineering》2014年第5期228-235,共8页食品科学与工程（英文版）（美国）

摘　　要：The flesh of spaghetti squash separates into strands when cooked. The purpose of this paper is to investigate the cause of strand separation （during cooking） by soaking for 24 h at 35 ℃ in solutions with three kinds of pectin extractant. The changes in strand separation, firmness, histological structure and the pectin of flesh during soaking in 0.01 N HCI solution （pH 2.0）, 0.035 M ammonium oxalate solution （pH 4.0） or 2% sodium hexametaphosphate solution （pH 4.0） were investigated. When flesh was soaked in the HCI solution, the separation into strands and removal of calcium and magnesium were greater than that soaked in other pectin extractants. High methoxyl pectin was extracted by soaking in HC1 solution （pH 2.0） due to removal of polyvalent cations. This result shows that high methoxyl pectin glues strands together in the flesh of spaghetti squash. The shape of the cells which constituted strands was round; on the other hand, that of cells surrounded strands was elongated. When cooked in boiling water or soaked at pH 2.0, the shape of the former cells was maintained, but the latter cells, which contributed to adhesion between strands, broke down. Thus, the flesh separated into strands. When flesh was boiled for 15-30 min, pectin degraded and dissolved in the cooking solution; consequently, the flesh separated into strands and also the middle lamella of cell walls of strands separated. However, pectin remaining in strands maintained their crispness.

关 键 词：Spaghetti squash PECTIN texture histological structure strand separation SOAKING pectin extractant. 

分 类 号：TS972.118[轻工技术与工程] TS255.5