Effects of acid hydrolysis and defatting on crystallinity and pasting properties of freeze-thawed high amylose corn starch |
| |
Authors: | Hyun-Jung Chung Hyo-Young Jeong Seung-Taik Lim |
| |
Institution: | a Graduate School of Life Sciences and Biotechnology, Korea University, 5-1 Anam-dong, Sungbuk-ku, Seoul 136-701, South Korea b Foods R & D Center, CJ Corporation, Seoul 152-050, South Korea |
| |
Abstract: | Paste of defatted and/or mildly acid-hydrolyzed high amylose corn starch was freeze-thawed, and then the starch was isolated by vacuum drying for the analysis in crystallization and pasting properties. X-ray diffraction pattern and differential scanning calorimetric analysis showed that the crystallinity of the freeze-thawed starch was increased as the degree of hydrolysis increased. The diffraction pattern revealed B- and V-crystals with patterns with diffraction peaks at 17, 20, and 23–25° (2θ), which were developed by amylose recrystallization during the freeze-thawing. The crystal melting enthalpies, for dual endothermic transitions above 100 °C, which resulted from the melting of amylose–lipids complex and amylose double helices were raised by the treatment. The isolated and dried starch formed a paste by aqueous heating under the ambient pressure, and its paste viscogram exhibited substantially higher resistance to shear-thinning, and rapid setback upon cooling. Acid hydrolysis, however, reduced overall paste viscosity, possibly due to the increased crystallinity. Enzyme-resistant starch content in the acid hydrolyzed starch was increased by the freeze-thawing, but not by acid hydrolysis. It was slightly increased by defatting. |
| |
Keywords: | Freeze-thawing Acid hydrolysis High amylose corn starch Resistant starch |
本文献已被 ScienceDirect 等数据库收录! |
|