Changes in quality characteristics and metabolites composition of wheat under different storage temperatures

The quality variation of wheat post harvesting is strongly affected by storage temperature. Low temperature storage can alleviate the quality deterioration in wheat after harvest. However, the mechanism regarding metabonomics analysis between different storage temperatures in postharvest wheat remains poorly understood. Here, we analyzed the changes in wet gluten content, fatty acid values, Catalase (CAT) activity, alpha-amylase activity, pasting properties changes, as well as the differentially expressed key metabolites in wheat, stored at 15, 20, and 30 °C for 180 days. In our study, wheat storage, processing, and edible quality remained steady at 15 °C and 20 °C storage temperatures, and wheat quality drastically degraded at 30 °C. Through non-targeted metabolomics analysis, carbohydrate metabolism, fatty acid metabolism, amino acid metabolism, and nucleotide metabolism pathways were proven to be involved in wheat storage. Specifically, gamma-glu-cys and 4-trimethylammoniobutanoic acid were up-regulated; adenine, l-gluconic acid, linoleic acid, 13(s)-HPODE, 9(s)-HPODE, 9-OxoODE, n-acetyl-l-glutamic acid, and trans-2,3-dihydroxycinnamate were down-regulated at 15 °C and 20 °C. These substances helped maintain the stability of cellular structures within the wheat kernel. The study's findings revealed the low-temperature impact mechanism on high moisture wheat from the perspective of metabolite changes. This may provide a scientific basis for the efficient preservation of wheat.