Analysis of Mould Volatile Substances and Quality during Rice Storage

Four common moulds(Aspergillus niger,Aspergillus flavus,Aspergillus oryzae and Penicillium chrysogenum)were inoculated with rice for 28 d to determine the appearance quality,enzyme activity,gelatinization characteristics and volatile substance changes of different rice before and after mildewed. The results showed that the growth rate of Aspergillus oryzae,Aspergillus flavus and Aspergillus niger grew faster. The overall quality of the mildewed rice changed a lot when roughness and the rate of whole mildewed rice decreased,and the imperfect grain increased significantly,which result in the quality of mildewed rice was lower than the national third-grade rice paddy requirement. Moreover,the enzyme activity of rice was significantly affected after mildewed,which led to an increase in the content of the direct starch and a rancid smell. The overall quality of the rice was bad. It was found that the mycelium of rice infected by moulds still adhered to the surface of rice,though it was treated by shelling and grinding by SEM. The volatile matter changed during the storage of rice infected with moulds. The relative content of rice lipids infected by Aspergillus niger was 3.45%~11.89%,which was reduced by about 2.38%~4.00% compared with the control group. The relative content of hydrocarbon in rice infected by Penicillium chrysogenum was 54.45%~72.45%,which increased by 0.24%~3.44% compared with the control group. This experiment would provide a theoretical basis for the study of preventing mildew contamination in rice storage in China,and comprehensively and effectively reduces the waste of mildew contaminated rice to food.