Studies of different saccharides on retrogradation of taro starch and on stability of taro starch gel

• Main Authors: I-Ping Hung, 洪憶萍
• Other Authors: Chiun-Chuang R. Wang
• Format: Others
• Language: zh-TW
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/90947658282158413097

碩士 === 靜宜大學 === 食品營養學系 === 87 === The properties of this study were to investigate nine different sugars on retrogradation of taro starch and on stability of taro starch gel. Several techniques, included differential scanning calorimetry (DSC) , scanning electron microscope (SEM), texture analyzer, and dynamic rheometer, were applied in this study . The results showed that the gelatinized temperature (To, Tp, Tc) of the taro starch were increased with addition of sugars. Moreover, gelatinization temperature increased with the increase of sugar concentration. Ribose added gel was found to decrease retrogradation enthalpy. In presence of sucrose and maltose (5%∼10%), retrogradation was retarded in the initial period (1 day).All sugars-added gels increased retrogradation enthalpy of taro starch except 5∼10% sucrose and maltose at early stage (0∼1day). Maltodextrin-added gel increased retrogradation enthalpy significantly during 28 days storage. The water activity of taro starch gel with sugars (xylose, glucose, fructose, galactose, sucrose, maltose or maltodextrin) were decreased comparing with control gel. Water activity of taro starch gel decreased with the increases of sugars concentration. The SEM results showed that the development of microstructure of taro starch gel become denser in the initial 12 hours after gelling. However, taro starch gel with sugars addition retarded the development of amylose network during storage. The development of network of taro starch gel slowered with increases of sugars concentration. However, the addition of maltodextrin resulted in the rapider development of network than mono- and disaccharide starch gel. The results showed that the firmness of taro starch gel were decreased when high concentration solution(40%) of xylose, glucose, galactose, sucrose or maltose were added into gel. In presence of sucrose (5%), the firmness decreased of taro starch gel. However, maltodextrin-added(0∼20%) increased the firmness of gel during 28 days storage. In the system of 10% taro starch gel( taro starch :solution = 1 : 9), the rheological properties including storage that the storage modulus (G’) and loss modulus (G”) of taro starch gel were increased but tanδ was decreased from to 28 days. The results showed that the storage modulus (G’) of taro starch gel with sugars addition were lower than control gel, except maltoextrin, during storage . The addition of xylose, glucose, fructose, galactose, sucrose, maltose, and maltodextrin in taro starch gel increased degree of retrogradation with the extent of starage time. Higher sugars concentration addition resulted in the higher degree of retrogradation in taro starch gel.