芋艿淀粉的功能特性

Functional characteristics of taro starches

该文采用场发射扫描电子显微镜分析芋艿淀粉颗粒形态结构,采用快速黏度分析仪、差示扫描量热仪、流变仪分析淀粉糊化特征,采用体外酶解消化法分析淀粉消化特征。结果表明,温岭芋艿淀粉颗粒(3~5μm)明显大于奉化芋艿头和芋艿子淀粉颗粒(0.5~2μm),形状也较奉化芋艿淀粉规则,粒表面呈褶皱状并有裂纹;芋艿淀粉的糊化黏度参数数值均为温岭芋艿>奉化芋艿子>奉化芋艿头;温岭芋艿淀粉糊化峰值温度(80.3℃)显著低于奉化芋艿淀粉(83.3~84.3℃),但热晗值(18.3 J/g)则显著高于奉化芋艿淀粉(12.5~14.8 J/g),温岭芋艿回生淀粉糊化吸收热晗值(3.2 J/g)显著低于奉化芋艿(6.2~6.7 J/g);在低温和高频条件下,芋艿淀粉动态模量参数值相对较高,且芋艿淀粉动态模量参数值与直链淀粉含量大小有关,即:温岭芋艿>奉化芋艿头>奉化芋艿子;芋艿淀粉中绝大部分为快消化淀粉(60%),并含有一定量的慢消化淀粉和抗性淀粉。

Granular morphology and functional characteristics of starches of Fenghua taro,Fenghua seed taro and Wenling taro were analyzed by field emission scanning electron microscope,rapid viscosity analyzer,differential scanning calorimeter,rheometer,and in vitro enzymatic digestion method.Results showed that the starch granules of Wenling taro(3-5μm)were larger than those of Fenghua taro and Fenghua seed taro(0.5-2μm),and the shape was more regular than that of Fenghua taro starch.Wrinkles and cracks on the surface of taro starch granules were observed when taro starches were magnified at 30000 times.The values of pasting viscosity of taro starches were as follows:Wenling taro>Fenghua taro>Fenghua taro.The peak temperature of gelatinization of Wenling taro starch(80.3℃)was significantly lower than that of Fenghua taro starch(83.3-84.3℃),however,the enthalpy of gelatinization of Wenling taro starch(18.3 J/g)was significantly higher than that of Fenghua taro starch(12.5-14.8 J/g).Moreover,the enthalpy of gelatinization of retrograded Wenling taro starch(3.2 J/g)was significantly lower than that of retrograded Fenghua taro starch(6.2-6.7 J/g).Furthermore,the dynamic moduli was relatively higher at lower temperature and higher frequency conditions,and was positively correlated with amylose content.The rapidly digestible starch accounting for>60%in taro starches,and the rest were slowly digestible starch and resistant starch.