The main nutritional components in colored rice grains

Colored rice grains contain rich nutrients. To investigate the differences in nutrient composition among different colored rice varieties, LC-MS non-targeted lipidomics and targeted amino acid profiling were used to study the lipid and amino acid composition in four colored rice grains. The study analyzed the relationship between amino acids, mineral elements, crude protein (CP), crude fat (CF), carotenoids (CAROT), vitamin C (ASA), ATP, total sugar (TS), soluble protein (SP), and metabolites. A total of 505 lipid metabolites were identified. The results depicted that YZ6H had the highest levels of Arg, Asn, Met, Orn, and Try. HN had the highest levels of GABA, His, Lys, Thr, Tyr, Val, and Tau, which were significantly higher than those in YZ6H, YJN818, and YCN1H. PC (16:0/16:1,16:1/18:2,18:1/14:1,18:1/14:0,18:1/18:1,18:0/18:1), TG (16:0/18:3/22:2,22:4/18:2/18:2,16:0/20:2/20:4), and PE(20:4e/15:0) were significantly negatively correlated with GABA, Leu, Lys, Thr, Tyr, Val, Gln, His, and Ile. TG(18:2/17:1/18:2,15:0/18:2/18:2,15:0/18:2/18:3,15:0/16:0/18:2,15:0/18:1/18:2,18:1/17:1/18:2,18:1/17:1/18:1,18:1/10:1/18:1) was significantly positively correlated with Pro and Tau. YZ6H had the highest levels of ASA, SP, TS, CAROT, and ATP content. PG(28:0/18:1), MLCL(14:2/16:0/16:0), Cer(t18:0/26:0+O,d18:2/16:0,t18:0/26:0), and LPC(16:0) TG(20:4e/18:3/20:1) were significantly negatively correlated with SP, CAROT. Hex1Cer(t18:1/24:0+O), MLCL(14:2/16:0/16:0), Cer(t18:0/26:0+O,d18:2/16:0,t18:0/26:0), LPC(16:0), TG(16:0/20:2/20:4,20:4e/18:3/20:1), and DG(18:1/14:0), which are key lipid metabolites involved in the synthesis of nutritional components in colored rice grains.