Metabolomics and transcriptomic profiles reveal membrane lipid metabolism being an important factor of sliced taro browning

Abstract

Cut-surface browning poses a prominent concern when it comes to the storage and consumption of sliced taro. This study evaluated the browning development of sliced taro during cold storage and investigated the underlying browning mechanisms through metabolomics and transcriptomic analyses. Metabolomics analysis revealed a consistent increase in the abundance of metabolites, specifically linolenic acid and its derivatives, as well as hydroperoxides, during the aggravated browning process, suggesting the degradation of membrane lipids, as linolenic acid is a major structural composition of cell membranes. Transcriptomic analysis showed that differentially expressed genes having upregulated expression during the browning process were enriched in the α-Linolenic acid metabolism pathway. Weighted gene co-expression network analysis identified two highly correlated modules with taro slice browning during storage, and genes showing a positive correlation were also enriched in the α-Linolenic acid metabolism pathway. Taken together, these findings indicate that the degradation of membrane lipids during taro browning and the loss of membrane compartmentalization might be key factors contributing to sliced taro browning. Additionally, the upregulation of LOX genes and increased protein activity, along with elevated levels of MDA during browning development, further validate the correlation between membrane lipid peroxidation and taro browning. Overall, this study contributes to our knowledge of the browning mechanisms in fresh-cut foods, providing valuable insights for future research and potential strategies for mitigating browning in sliced taro under cold storage conditions.