Study On The Process Of Instant Rice At Room Temperature Storage

Rice was one of the two major staples of our country. While the industrialization degree of metric convenience food was still very low, the demand for convenience food, especially for convenient staple food was increasing. This paper targeted at meeting consumer demand and realizing the large-scale industrial production, investigated the sensory evaluation model, production process and quality improver of instant rice and observed the effects from storage time.The correlation analysis of physicochemical indexes, texture characteristics and sensory evaluation showed that Amylose content of raw rice, the hardness and adhesiveness of instant rice could react the quality of instant rice in a larger degree. And the sensory evaluation based on physicochemical indexes and texture characteristics was proved feasible and effective.The effects of soaking and cooking condition on the quality of instant rice were investigated to select the optimal condition of instant rice. Pseudo-level method of L9(34) orthogonal design results showed that the optimal cooking process was:the rice soaked25minutes at normal temperature water and steamed5minutes at100℃for the first time. And soaked20minutes in normal temperature water and steamed50minutes at105℃in the second time. The gelatinization degree and moisture content of this kind of instant rice could respectively reach90.19%and64.8%.Three additives, including GML, β-CD and SE on the evaluation indexes were optimized using RSM and PC A. Addition of0.08%GML,0.81%β-CD and0.78%SE considered as a quality improver could help obtain the optimum quality of instant rice. The result of Differential scanning calorimetry showed that CD, GML, SE three additives played a certain role in inhibiting the retrogradation of rice starch, and the compound additive was the best.The instant rice aged rapidly under4℃, the Gelatinization degree droped to80.8%after21days storage and corrupted fast at37℃,the microbial counts reached2700cfu/g, which was exceed the standard of1000cfu/g,during the120days storage. Considering from the microbial counts and the Gelatinization degree, the quality guarantee period of instant rice would reach2to3months.