米饭质构特性测定方法的研究(Ⅲ)——米饭质构测试的最佳条件探讨

A Study on Determination of Texture Characteristics of the Cooked Rice( Ⅲ)——Optimum Conditions for Determination of Texture Characteristics of the Cooked Rice

摘要用天津小站米（粳米）和南充顺心大米（籼型杂交稻米），参照GB／T15682-2008米饭样品制备方法制作米饭样品，并利用质构测试仪采用TPA模式对米饭样品的质构特性进行测定，主要通过单因素试验考察了压缩程度和压缩速度对米饭硬度测定值的影响，并通过正交试验探讨了米饭质构测定的最佳测试条件。结果表明：在压缩程度为50％条件下，不同压缩速度的米饭硬度测定值的变异系数为2．8％～7．7％；压缩程度、压缩速度、米饭样品制作与测试温度、放置时间对硬度测定值都有高度显著（P〈0．01）的影响，各因素对米饭硬度测定值的变异幅度大小无影响。以米饭硬度测定值变异幅度为指标的米饭质构测定的最佳条件为：米饭放置时间90min、米饭样品制作与测试温度20℃、压缩程度50％、压缩速度50mm／min。

The cooked rice was produced from different kinds of rice （Tianjin Xiaozhan Rice （japonica rice） and Nanchong Shunxin rice （ indica hybrid rice） ） according to GB/T 15682--2008 method, and the texture charac- teristics of the cooked rice were determined by a food texture analyzer and the TPA model, in order to investigate the impact of the degree of compression and crosshead speed on determination of the cooked rice hardness through single factor experiment, and the optimum condition through the orthogonal experiment. The results show that the coefficient of variation of different compression speeds was between 2.8%~ 7.7% under 50% compression degree; The influ- ence of degree of eompression, erosshead speed, storage time and temperature of production and determination on measured hardness values was highly significant （P 〈0.01 ）, and all the factors had no effect on the variation range of the measured hardness values. According to the variation range of the measured hardness values, the optimum con- dition is： 90 min storage time, 20 ℃ temperature of production and determination, 50% compression degree, and 50 mm/min crosshead speed. Key words cooked flee, texture eharacteflstics, determination method, degree of compression, compression speed