用RVA仪分析玉米淀粉的糊化特性

摘要

以玉米淀粉为原料,利用RVA(快速黏度分析仪),研究了不同浓度玉米淀粉以及在同一浓度下氯化钠、蔗糖以及转速对淀粉糊化特性的影响,并且在此基础上将RVA糊化程序改为多重RVA程序,然后观察对淀粉的特性的影响.结果表明:随着玉米淀粉溶液浓度的增加,起始成糊温度降低,淀粉糊的热稳定性降低,凝胶性增强.随氯化钠浓度增大,起始成糊温度逐渐升高,到达峰值时间有所延长,热稳定性明显提高,但凝胶性降低.当蔗糖浓度增加时,淀粉成糊温度、峰值黏度、最低黏度和最终黏度都随之增加,热稳定性增强,冷却过程中淀粉糊形成凝胶的能力减弱.玉米淀粉在多重RVA程序中,淀粉胶体反复形成并且溶解.添加油脂后的玉米淀粉的黏度曲线的变化是复杂的,由淀粉和油脂之间的相互作用引起,油脂的水溶性以及淀粉颗粒与蛋白质的关系影响着它们的相互反应.%With maize starch as raw material, a rapid viscosity analysis system (RVA) was used to study the pasting properties of maize starch under different concentrations and the effects of sodium chloride, sugar and rotation rate of RVA on the gelling property of the starch under the same concentration. Then, the RVA gelling process was changed to a repeated RVA process and then the properties of the starch were observed. It was concluded that the initial gelling temperature decreased, the thermal stability of the starch paste decreased and the gelling property increased with the increase of starch concentration. With increase of the mount of sodium chloride, the initial gelling temperature increased gradually, the peak time was postponed and the thermal stability was improved obviously, but the gelling property decreased. With the increase of sugar concentration, the gelling temperature, peak viscosity, minimum viscosity and final viscosity of the starch increased together, the thermal stability was improved and the gelling capability of the starch during the cooling process weakened. Gels of the starch formed and melted reproducibly during repeated heating and cooling in the RVA. It was observed that the change in the multiple cycle viscosity traces when lipid was added to the starch was complicated, which was caused by mutual interaction between the lipid and the starch. The said mutual interaction was subject to the relation between the lipid water solubility and starch kernel and the protein.