Metabolic insights into the mechanism of soybean reddening during storage

BACKGROUND: Soybean reddening during storage and transportation has caused great concern due to the serious economic loss. However, the mechanism of reddening has not been clearly elucidated. In this study, metabolomics was employed to investigate the reasons for soybean reddening during storage. RESULTS: The results of multivariate statistical analysis showed that the metabolite level of red soybean was significantly different from that of normal soybean. The differentially expressed metabolites were mainly enriched by biosynthesis of secondary metabolites and amino acid metabolism. Metabolism analysis showed that the biosynthesis of cyanidin and betalains was enhanced in reddening soybean. In addition, it was found that phenolic and flavonoid compounds decreased, while quinones, furans and 5-hydroxymethylfurfural increased in reddening soybeans compared to normal soybeans. CONCLUSION: The upregulation of cyanidin and betalains was the main reason for soybean reddening. Besides, the oxidation of phenols and flavonoids, as well as Maillard reaction, also contributed to the color change. © 2024 Society of Chemical Industry.