浸泡处理对大米淀粉糊化特性及流变特性的影响

为了研究大米的浸泡处理对大米淀粉性质的影响,本文采用快速粘度分析仪(RVA)及流变仪研究了不同浸泡时间对大米淀粉的糊化特性和流变特性的影响。RVA曲线表明,随着浸泡时间的延长,大米米粉的峰值黏度和崩解值都有显著提高(p<0.05),最终黏度和回生值先上升后下降,糊化温度有所降低。流变实验表明,经过浸泡处理的大米淀粉的屈服应力、剪切应力及表观黏度均高于未经处理的大米淀粉;随着浸泡时间的延长,大米淀粉悬浊液的G'_max、G'_{95 ℃}、G'_{25 ℃}、tanδ_{G'25 ℃}和K'_G都呈现减小趋势,表明浸泡处理可以显著影响大米淀粉凝胶强度,提高其稳定性。

Effect of Soaking Treatment on the Gelation Properties of Rice Starch

In order to study the effect of soaking treatment on the gelation properties of rice starch, the effects of different soaking times on the gelatinization and rheological properties of rice starch were investigated by means of rapid viscosity analyzer (RVA) and rheometer. The RVA curves showed that the peak viscosity and the breakdown of rice flour increased significantly with the soaking time (p<0.05), and the final viscosity and setback first increased and then decreased, and the gelatinization temperature decreased. Rheological experiments showed that the yield stress, shear stress and apparent viscosity of rice starch after soaking treatment were higher than those of untreated rice starch. With the prolongation of soaking time, the G'max, G'_95℃, G'_25℃, tanδ_25℃ and K'_G showed a decreasing trend, which indicated that soaking treatment could significantly affect the strength of rice starch gel, and improve the stability of the gel.