Study On Storage And Preservation Technology Of Rice

Rice is a kind of major foods in China. It is necessary for each country to store adequate rice to ensure the elementary living and the food safety. Aging ,pest and mould are problems in the processing of storage. Aiming at the main problems in the processing of storage, this study chose the Xiao Zhan Dao rice 1#,3#,5#as material, adopted the method of integrating standard gas adjusting with Spontaneous gas adjusting, researched the influence factors such as water content,temperature,humidity and gas component which affect the quality and the aging of rice, put forward the best method of preservation and the parameters, investigated the characteristics of materials using in food packing and the effects of preservation in the same time, and provides the basic data for the preservation.The results showed that:⑴ The water content is the most important factor in preservation. The lower it is, the slower the rice becoming worse. It must not exceed the water content of 14% when store the rice for long time in a routine condition.⑵ Low storage temperature is in favor of controlling the breath of rice, restraining the free fatty acid,total acid,reducing sugar and viscosity. The better temperature of preservation is under 15℃.⑶ The components of the gas have prominent effect on restraining the aging and mold of the rice. The higher concentration of CO2, the better result it got. The water content is higher than 16%, and the concentration of CO2 should higher than 80%, then it can not occur the high CO2 damage in fruit and vegetable; the result is the same as vacuum packing and gas flushing.⑷ There is more effect for packing material in preservation. General PE is not fit for vacuum packing and gas flushing. Thickness,the quality of material and the quantity of packed are all influence the water content in the processing of storage. The coefficient of vapour permeance is higher, the change of water content is more obvious.⑸ Preservation film is the important element of the preserve technology. There is a obvious influences caused by the film material and film thickness on rice quality. Packing with PE, the more thickness it is, the more fast aging and mold it got; Packing with PVC,there is little effect on rice fatty acid; Film thickness is less than 0.08mm.The result is best using compound film. But PVC is better for the storage of the high water content rice, the film between 0.05mm and 0.08mm,the quantity of 5 kg；The drier rice is better preserved in PE than PVC,film thickness 0.05mm, the quantity of packed 2.5-5kg. Added antimicrobial and TiO2 is more available to restrain the mold.