Metabolomic Analysis Reveals Insights into Deterioration of Rice Quality during Storage

Abstract

To determine the changes in the quality of rice during storage, this study investigated the comprehensive metabolomic profiles of Nanjing 9108 (typical japonica rice) and Jianzhen 2 (typical indica rice) varieties in China, using metabolomics. A total of 13 categories of 593 metabolites including lipids (134 species), phenolic acids (78 species), flavonoids (70 species), alkaloids (67 species), organic acids (64 species), amino acids and derivatives (64 species), saccharides and alcohols (44 species), nucleotides and derivatives (37 species), vitamins (14 species), lignans and coumarins (9 species), tannins (2 species), terpenoids (2 species), and others (8 species) were identified in both varieties. The result showed significant changes in 204 metabolites in Nanjing 9108, while only 26 were altered in Jianzhen 2 during storage. These metabolites involved 46 metabolic pathways. The TCA cycle, linoleic, and α-linolenic acid metabolic pathways were unique in Nanjing 9108. Finally, the results of quantitative mass spectrometry of 11 metabolites provided insight into biomarkers associated with quality deterioration of rice. This study provides insights into the mechanism of deterioration in the quality of rice during storage.

Storage Drives Alterations of Proteomic and Protein Structural Properties in Rice (Oryza sativa L.)

“…27, 29, 31, 32, and 35) are only related to glycolysis/gluconeogenesis in NJ ( japonica rice), and all of them were up-expressed in NJS. These results corroborate our previous study findings according to which storage increases the sugar metabolism of japonica rice, and accelerates the accumulation of organic acid [ 14 ]. Der Agopian et al [ 43 ] compared the enzyme activity and protein levels related to starch conversion to sucrose in bananas stored at different temperatures.…”

“…Liu et al [ 12 ] found that the changes of glutathione metabolism in rice were closely related to the yellowing of the stored samples. Our previous metabolomics study also found that the glutathione metabolic pathway was enhanced in rice after storage [ 14 ].…”

“…Thus, the large consumption of acyl carrier protein, and the up-regulation of acyl-[acyl-carrier-protein] hydrolase suggested that fatty acids are continuously produced in NJ ( Table 3 , No.10). Lipidomic and metabolomic analyses revealed that the fatty acid metabolism pathway was the most active one in japonica rice after storage [ 14 , 15 , 16 ]. This result also supports our previous finding according to which indica rice was more stable under environmental changes than japonica rice [ 14 ].…”

“…Lipidomic and metabolomic analyses revealed that the fatty acid metabolism pathway was the most active one in japonica rice after storage [ 14 , 15 , 16 ]. This result also supports our previous finding according to which indica rice was more stable under environmental changes than japonica rice [ 14 ].…”

“…The structural properties of fresh and stored rice protein were further investigated based on free sulfhydryl content, number of disulfide bonds, surface hydrophobicity (H 0 ), and Fourier transform infrared spectroscopy (FTIR). This analysis fills the research gap in rice omics (metabolomics and lipidomics) [ 14 , 15 , 16 ] and provides a comprehensive insight into the role of proteins in rice quality deterioration.…”