Effects of low temperature (LT, 20 °C) combined with nitrogen-modified atmosphere (MA, 95% N₂) storage (LT + MA) on quality, microstructure, and metabolome characteristics of high moisture content (15.5%) during 180 days of storage were investigated to explore a potential preservation technique for high moisture rice. The results showed that after 180 days of storage, the fatty acid value, malondialdehyde content, and amylose content of rice under LT + MA storage were 53.33%, 72.93%, and 91.85% of those under conventional storage (CS, conventional atmosphere, 30 °C, RH 65%), respectively. The color, pasting properties, and scanning electron microscopy (SEM) of the LT + MA treatment were found to be markedly superior to those of the CS treatment. In addition, the differential metabolites sucrose, trehalose-6P, trehalose, 3,7-Di-O-methylquercetin (DMQ), rutin, and vitexin 2″-O-rhamnoside (VOR) were screened to assess for sensitivity to changes in storage conditions. The study demonstrated that the LT + MA effectively suppressed the escalation of FAV, MDA content, and amylose content. In addition, it was observed to inhibit the deterioration of color and pasting properties while concurrently maintaining the polygonal shape of rice starch granules. Furthermore, the differential metabolites of non-targeted metabolomics indicated that the LT + MA group exhibited superior efficacy in retarding rice aging.

Rice storage under suboptimal conditions leads to rapid quality deterioration. In this study, effects of low-temperature (LT, 20 °C) combined with nitrogen-controlled atmospheric conditions (NCA, 95%) on physicochemical properties, nutrient, mycotoxins and metabolites of rice during 180 d storage were comprehensively evaluated, to explore a potential preservation technique for rice. The LT + NCA treatment significantly inhibited the accumulation in free fatty acid value, malondialdehyde and electrolyte leakage, while maintaining higher catalase activity, lower amylose content and better pasting properties (higher breakdown, lower final viscosity and setback). Crucially, mycotoxin accumulation remained within safe limits across all groups, with LT + NCA showing the lowest levels. Metabolomics analysis identified 653 metabolites, with LT + NCA significantly modulating pathways related to carbohydrate metabolism (e.g., promoting raffinose accumulation while inhibiting the pentose phosphate pathway) and amino acid metabolism (enhancing glutathione metabolism and suppressing arginine biosynthesis). These metabolic rearrangements reduced oxidative damage, stabilized membrane integrity, and preserved cooking quality. Therefore, LT + NCA could be a superior strategy for delaying oxidative stress, maintaining nutritional and cooking quality, and ensuring the safety of stored rice.