Effect of artificial aging on wheat quality deterioration during storage

The quality of wheat deteriorates naturally during long-term storage. In this study, to evaluate the quality changes of stored wheat, an artificial aging treatment was applied to accelerate the deterioration of wheat grain. The germination rate, free fatty acid content, malondialdehyde (MDA) content, and embryo and endosperm microstructures were examined in the wheat cultivars Zhengmai-103 and Zhengmai-379. In both wheat cultivars, seed germination almost completely ceased during storage for 10 months, whereas the contents of free fatty acids and MDA increased significantly. The variance analysis results showed that the accelerated deterioration process had significant effects on the free fatty acid, MDA, and superoxide radical contents. Further, the storage time was well correlated with the germination rate, free fatty acid content, and MDA content, and there was significant correlation between the free fatty acid and MDA contents (p < 0.05). However, there was no significant correlation between the superoxide radical content, which decreased in the later stages of storage, and the above indicators. Scanning electron microscopy observations revealed that artificial aging resulted in blurring of the interstitial space in the embryo cells of wheat seeds, looser binding between the protein matrix and starch granules in the endosperm, and increased exposure of starch granules, which have some protein fragments on their surfaces. The insights obtained in this study about the quality deterioration of stored wheat can potentially be applied to the development of improved wheat cultivars.