Novel insights into rice deterioration for nitrogen controlled atmosphere and re-aeration storage based on no-targeted metabolomics

Nitrogen controlled atmosphere (N-CA) was widely used to keep grains from pest infestation. However, there was few studies on the grain quality changes during re-aeration after N-CA storage, i.e. N2-re-aeration storage (NRAS). In this paper, quality changes of two varieties of rice (Oryza sativa L.) during NRAS was investigated. Moreover, a non-targeted metabolomics approach was employed to reveal the mechanisms of rice quality changes after NRAS. Compared with rice in conventional storage (CS), fatty acid values (FAVs) and malon-dialdehyde (MDA) contents of rice showed slower increase rates in NRAS before re-aeration (0-60 days), while displayed faster increase rates after reaeration (60-150 days). And NRAS had no obvious effect on pasting and texture properties of rice. Additionally, metabolisms that are sensitive to changes in storage atmosphere are screened out, such as glycine, 4-aminobutyric acid, gluconic acid, sorbitol, gamma-linolenic acid and stearidonic acid. This work provided a new insight into the mechanisms of rice quality changes after NRAS and helped reserve corporation develop storage policy for rice storage.

Automated summary

This paper investigated the quality changes of rice during nitrogen-controlled atmosphere storage and subsequent re-aeration storage. The results showed slower increases in fatty acid values and malon-dialdehyde contents before re-aeration, but faster increases after re-aeration. Pasting and texture properties of rice were not significantly affected by re-aeration storage. Metabolites sensitive to changes in storage atmosphere, such as glycine, 4-aminobutyric acid, gluconic acid, sorbitol, gamma-linolenic acid, and stearidonic acid, were identified. This study provided new insights into the mechanisms of rice quality changes after re-aeration storage.