Integrated quality assessment and pigment profiling in colored rice varieties

Colored rice, available in black, red, purple, and yellow, and green varieties, is recognized for its high nutritional value and potential in modern health-conscious diets. This study systematically evaluated the quality attributes and pigment profiles of diverse colored rice germplasm resources. Principal component analysis revealed that pasting properties, total phenolic content, total flavonoid content, antioxidant capacity, and sensory characteristics were the primary determinants of quality across all colored rice accessions. Furthermore, comprehensive metabolic profiling using UHPLC-MS/MS identified 818 metabolites across 20 pigment extracts, including flavonoids, anthocyanins, phenolic acids, alkaloids, terpenes, and organic heterocyclic compounds. Notably, 11 anthocyanins—predominantly cyanidin-3-glucoside, cyanidin-3-galactoside, cyanidin-3-rutinoside, and malvidin-3-glucoside—along with 3 proanthocyanidins, were identified as the major bioactive components. These findings provide a robust scientific basis for the functional characterization and nutritional evaluation of colored rice, facilitating the future conservation, genetic improvement, and industrial utilization of these valuable germplasm resources.