柠檬酸缓冲液对蒸谷米色泽及品质特性的影响

采用不同pH的柠檬酸缓冲液浸泡稻谷，以纯水浸泡的蒸谷米为对照组，考察了不同处理组蒸谷米的色差、加工品质、感官评价、体外消化、热力学特性和质构特性的变化，并进行了相关性分析。结果表明：低pH浸泡液预处理后，蒸谷米色差有显著变化，其中pH 4浸泡液颜色最浅，相对纯水浸泡的蒸谷米，其L^*值增加了5.27;消化结果显示，样品淀粉消化率随pH降低而降低，其中pH 3组淀粉消化率最低，其eGI值降低了11.83%,抗性淀粉增加了29.06%;加工品质结果显示，pH对出米率无显著影响，但随着浸泡液pH降低整精米率有所降低、爆腰率有所上升；感官评价和质构特性结果表明，蒸谷米的食用品质随着pH的降低先上升后下降。综合结果表明，适当低pH浸泡液预处理对蒸谷米的色泽、体外消化特性、感官品质具有一定的改善作用。

Effects of citric acid buffer on color and quality characteristics of preboiled rice

Rice was soaked in citric acid buffer with different pH values, and preboiled rice soaked in pure water was used as the control group. The changes of color difference, processing quality, sensory evaluation, in vitro digestion, thermodynamic properties and texture properties of preboiled rice in different treatment groups were investigated, and the correlation was analyzed.The results showed that pretreatment with low pH soaking solution, the color difference of steamed rice changed significantly, and the color of pH4 soaking solution was the lightest. Compared with preboiled rice soaked in pure water, its L* value increased by 5.27.The digestion results showed that the starch digestibility of the sample decreased with the decrease of pH value. The starch digestibility of pH3 group was the lowest, its eGI value decreased by 11.83%, and the resistant starchincreased by 29.06%;The processing quality results showed that the pH value had no significant effect on the rice yield, but with the decrease of the pH value of the soaking solution, the milled rice rate decreased and the crack ratio increased; The results of sensory evaluation and texture characteristics showed that the edible quality of preboiled rice firstly increased and then decreased along with the decrease of the pH value. On the whole, it could be summarized that appropriate low pH soaking solution pretreatment could improve the color, in vitro digestion and sensory characteristics of preboiled rice.