Mold Activity, Quality Changes And Analysis Of Volatile Compounds In Stored Corn

The embryo of corn is larger, in the storage process is extremely easy to moisture from the environment, leading to increased seed moisture content, mold vigorous activity, eventually causing its storage stability was reduced. In this paper, Zhengdan958, Xundan 20 and zhongke 4 corn seeds as the research object ,in which have the large cultivation, production and reserves in Central Plains, respectively examined from storage year, the moisture content and temperature and the main quality changes of corn seeds, fungal activities and types of volatile substances, access to the initial data from deterioration of quality during store period of corn, reference for the safe storage and quality analysis of corn.The study on the changes of the corn seeds quality with different storage life showed that: Two varieties maize storage for 3 months increased fungal species,the germination rate all reached more than 96%, and fatty acid value was about 20 units. 27 months storage of maize seeds, slightly difference between two varieties, Xundan 20 germination rate was 74%, lower than Zhengdan 958. fatty acid value was 34.5 units, higher than the Zhengdan 958.two varieties maize in Different storage period,the water-soluble, salt soluble protein content changes little, alcohol-soluble protein fractions content started to decline.The influence of different water content and storage temperature on the corn quality showed that:The quality deterioration of Zhongke4 is faster than the Xundan20 and Zhengdan958 in the same storage conditions.In the storage of low water content, the quality did not change significantly. with the temperature, water content increased, the quality also changed significantly.When the water content rises to 17%, moldy serious Fusarium, glaucum Aspergillus and other fungi in corn have been gradually replaced by Penicillium, Aspergillus niger, white Aspergillus and other fungi.25℃, Zhongke 4 in the stored of 35 days the microbial activity value increased from below 100u to the 1353u. fatty acid value increased 4.2 times higher than the original sample. the seed almost complete loss capacity of germination. Xundan 20 in 20 stored days, water-soluble, salt-soluble and alcohol-soluble protein fractions content started to decline, at 45 stored days decreased by 17%, 18.1% and 25%. There is a greater degree of hydrolysis of protein components, reducing the number of large molecular weight protein, less gray bands, medium and small molecular weight protein brief increase.The detect results of Volatile substances during store period in corn showed that:The high-pressure sterilization of maize inoculated with different fungi, without mold as control was simulated stored at 30℃.The typical volatile substances produced by Pure culture corn were benzene homologue ketones, aldehydes, alcohols, phenols, low molecular ketones, alkanes and some fat and so on. Without mold sterile corn produced more alkanes compared with corn inoculated mold.The volatile compounds produced by corn inoculated with Penicillium more than Aspergillus flavus. 13.5% and 15.5% water content corn was simulated stored at 40℃.The typical volatile substances produced by 13.5% as well as 15.5% water content corn were benzene homologue ketones, aldehydes, phenols, alkanes and some fat and acid and so on. The volatile substances produced by different water content corn were similar,but quantitative differences exist.