Structural Characterizations and Digestibility of Debranched Normal Corn Starch Complexed with Fatty Acids

• Main Authors: Zhu, Guan-Pin, 朱冠頻
• Other Authors: Shao, Yi-Yuan
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/t5p2hq

碩士 === 實踐大學 === 食品營養與保健生技學系碩士班 === 106 === Resistant starch is beneficial for controlling and preventing a variety of diseases associated with hyperglycemia. In this study, ALC was prepared by debranching treatment and its structure and digestion characteristics were investigated. The gelatinized starch was debranched by pullulanase to form short chain amylose. ALC were either prepared by gelatinized starch (G-lipids) or debranched starch (D-lipids) with fatty acids including palmitic acid, stearic acid, oleic acid and linoleic acid. Scanning electron microscopy showed that D-lipids particles were smaller than G-lipids. Crystals were obvious in the structure of the complexes either in the form of spherulites which protrude from the surface of the particles or in the form of elongated lamellae, which had cylindrical shape and were closely aggregated in parallel to each other. Confocal laser scanning microscopy showed that both G-lipids and D-lipids could form ALC. Debranched starch was prepared by debranching treatment increased the apparent amylose content from 33.26% to 68.72%, which was consistent with the molecular weight distribution using high performance size exclusion chromatography (HPSEC). The results of complex index showed that D-lipids were significantly higher than G-lipids, and the complex index of ALC prepared by unsaturated fatty acids was higher than saturated ones. The thermal property analysis of rescan showed ΔH of ALC in D-lipids were significantly higher than G-lipids, and the ΔH in D-lipids with unsaturated fatty acid were higher than saturated ones. For the in vitro digestibility, the rapidly digested starch (RDS) of D-lipids was significantly lower than G-lipids, but slowly digestible starch (SDS) and resistant starch (RS) were significantly increased; there was no significant difference in RS content between different ALC of G-lipids and D-lipids. However, C∞, HI (Hydrolysis index) and eGI (Estimated glycemic index) of D-lipids were significantly lower than G-lipids; eGI of G-lipids were lower than Gelatinized starch, indicating the formation of amylose crystals and ALC contributed to reduce eGI. Polarized light microscopy showed a characteristic birefringence pattern with a Maltese cross of NCS. The ALC formed by either long or short chain amylose had both B-type and V-type X-ray diffraction pattern. Relative crystallinity of D-lipids were significantly higher than G-lipids. Complex formation with different fatty acids was no significant difference in relative crystallinity. Debranching treatment contributed to increase the formation of amylose crystals and ALC, and has potential application in food industry in the future.