茶多酚对两种淀粉热力学特性及糊化特性影响的研究

利用差示扫描量热仪(DSC)及快速粘度仪(RVA)研究了茶多酚(TP)对糯玉米淀粉(WMS)及由糯玉米淀粉改性的辛烯基琥珀酸淀粉酯(OSA淀粉)的热特性及糊黏度的影响。结果表明,两种淀粉的糊化温度和焓值随TP添加量的增加而明显降低(p<0.05);4℃下贮存7d,两种淀粉的回生焓值和重结晶随TP添加量增加而降低(p<0.05),添加15%TP的糯玉米淀粉及添加10%和15%TP的OSA淀粉没有出现重结晶及回生焓值;由RVA曲线知,随TP添加量增大,OSA淀粉糊黏度降低,其中添加15%TP的OSA淀粉,其峰值黏度、谷值黏度及终粘度降低最大,而糯玉米淀粉并未呈现一定规律性。以上结果证明,TP能够降低两种淀粉的糊化温度及焓值,抑制淀粉老化,且在一定程度上具有降低淀粉糊黏度的作用。 

Study on the effect of tea polyphenols on thermal and pasting properties of two kinds of starch

The effect of tea polyphenols (TP) on thermal and pasting properties of waxy maize starch and octenyl succinic anhydride starch (OSA starch) was investigated.The gelatinization and retrogradation properties were tested using a Differential Scanning Calorimeter.The pasting properties were assessed by a Rapid ViscoAnalyzer.It showed that the gelatinization temperature and gelatinization enthalpy of these two kinds of starch obviously decreased (p<0.05) with the increasing level of TP.After 7 days storaged at 4℃, the retrogradation enthalpy and recrystallization of these two starches decreased (p<0.05) with the increase of TP content.Waxy maize starch with 15% TP and OSA starch with 10% and 15% TP didn’t appear recrystallization and retrogradation enthalpy after storage of 7 days.The viscosity of OSA starch decreased with the increase of TP, especially when adding 15% TP, the peak viscosity, trough viscosity and final viscosity decreased most while waxy maize starch didn’t show a certain regularity.Coclusion:The overall results demonstrated that TP could reduce the gelatinization temperature and enthalpy, inhibit retrogradation of these two kinds of starch and could reduce paste viscosity of starch to some extent.