[关键词]
[摘要]
对比分析陈化前后6个不同品种大米淀粉结构与理化性质,结果表明,不同品种大米淀粉的直链淀粉含量、体积平均粒径(D[4,3])、结晶度及糊化起始温度(To)、峰值温度(Tp)、终止温度(Tc)、热焓(ΔH)分别介于17.24%~22.69%、5.74~7.09 μm、16.45%~18.19%、64.77~73.03 ℃、71.73~81.13 ℃、77.17~87.40 ℃、12.62~18.44 J/g之间,陈化后大米淀粉的直链淀粉含量显著(p<0.05)上升,结晶度显著下降,陈化对淀粉晶型及短程有序性无明显影响;陈化对回生前后大米淀粉糊化特性均有明显影响,大米淀粉经回生处理后,To、Tp、Tc及ΔH明显下降;随着温度升高,大米淀粉溶解度与膨胀度明显上升,陈化降低了大米淀粉膨胀度、溶解度和透光率。大米淀粉的直链淀粉含量与其To、To'(回生淀粉To)正相关;大米淀粉的D[4,3]与其To、To'、透光率正相关;大米淀粉结晶度与其To、ΔH、ΔH'(回生淀粉ΔH)正相关。该研究结果可为湖北稻米资源合理利用、陈米资源高效利用及产品开发提供理论依据。
[Key word]
[Abstract]
The structure and physicochemical properties of six different varieties of rice starch before and after aging were compared and analyzed. The results showed that the amylose content, volume mean diameter (D[4,3]), crystallinity, gelatinization on set temperature (To), peak temperature (Tp), conclusion/end set temperature (Tc) and gelatinisation enthalpy (ΔH) of different varieties of rice starch were in the ranges of 17.24%~22.69%, 5.74~7.09 μm, 16.45%~18.19%, 64.77~73.03 ℃, 71.73~81.13 ℃, 77.17~87.40 ℃, and 12.62~18.44 J/g, respectively. After aging of rice starch, the amylose content significantly increased (p<0.05), and crystallinity significantly decreased, with the aging having no significant effect on the starch crystal form and short-range order. Aging had significant effects on the gelatinization characteristics of rice starch before and after retrogradation, and the To, Tp, Tc and ΔH values of rice starch decreased significantly after retrogradation. With the increase of temperature, the solubility and swelling degree of rice starch increased significantly. Aging decreased the swelling degree, solubility and light transmittance of rice starch. The amylose content of rice starch was positively correlated with To and To' (To of retrograded starch), D[4,3] of rice starch was positively correlated with To, To' and light transmittance, and the crystallinity of rice starch was positively correlated with To, ΔH and ΔH' (ΔH of retrograded starch). The results of this research can provide a theoretical basis for rational utilization of rice resources in Hubei, and efficient utilization of old/aged rice resources and product development.
[中图分类号]
[基金项目]
国家重点研发计划项目(2018YFD0301306)