Study Of Storage Stability And Storage Method Of Lightly Milled Rice

Rice is one of the major food crops in the world,there are more than 100 countries around the world produce rice. The grain output of rice has been occupied one third of the world’s. Nearly half of the world’s population made rice as the staple foods. In recent years, food problem is becoming increasingly acute, due to the reduction of the world cultivated land area and growth of world population. The traditional rice processing not only results in a large amount of waste, but also makes rice nutrient loss in the machining process. Lightly milled rice can balance the nutrition of brown rice and the taste of highly milledrice, reducing the waste of rice in rice processing. However, lightly milled rice retains more lipid and biological active enzyme in the processing, then makes the storage stability of lightly milled riceis not the same as brown rice and highly milled rice.This paper studied the storage stability of brown rice(0% degree of milling), lightly milled rice(5% degree of milling) and highly milled rice(10% degree of milling); also, using high-handed sterilization pan to inactivate lipase lightly milled rice(5% degree of milling), moreover, investigates the effect of thermal stabilization on physical and chemical properties of rice with different moisture(15% and 30%); furthermore, explores the influence of different storage methods on storage stability of lightly milled rice. The conclusions are as follows:(1) Due to the different processing methods of lightly milled rice, it makes the lightly milled rice retained a large number of biological active enzyme and lipids, especially the starch-lipids. It makes lightly milled ricethat be more easily to rancidity in storage and difficult to storage than brown rice and highly milled rice as well. Enzyme activity is one of the important factors in the process of lightly milled rice rancidity, vacuum packing method cannot effectively solve the storage problem of lightly milled rice.(2) For the rice in different moisture levels, the lipase could be inactivated effective through the ways that conducting the condition of 120℃ or disposing within 5min. Comparing with high-moisture heat treatment, low-moisture heat treatment shows much less influence on the color characters of rice(whiteness, chroma and difference of total color) and texture characters(hardness and stickiness). Due to the fact that under the low-moisture, heat treatment makes mild effects on microstructure and diffraction pattern of starch in rice grains.(3)Both 4℃ storage and heat treatment can better maintain the quality of the lightly milled rice appearance and better control the rancidity of lightly milled rice, also, slow down the light to the deterioration of rice milling, and reduce the speed of deterioration of lightly milled rice. Besides, the effect of heat treatment is better than 4 ℃ refrigerating. For the lightly milled rice, its storage effect seems low-impact in vacuum packing after heat treatment. The order of the storage effect:Heat treatment storage≈Vacuum heat treatment storage>4℃storage>Ordinary storage.