Evaluation of Phytoconstituents, Nutritional Quality, and In Vitro Biological Activities of Red Rice Ethanolic Extract from Different Regions of Chiang Rai and Phayao

Red rice, a pigmented rice, is a staple food in Thailand that has beneficial biological properties for the consumer. The objective of this research was to assess the phytochemical composition, macro- and micro-nutritional quality, as well as the anti-glycation and in vitro antioxidant properties of three planting sites located in Chiang Rai and three planting sites located in Phayao. Raw red rice was extracted with 70% ethanol, and the phytoconstituents were evaluated using colorimetric analysis and HPLC techniques. The antioxidant activity, ROS production, lipid peroxidation, and in vitro anti-glycation properties were examined. According to the results, the greatest levels of total phenolic and total flavonoid contents were detected in CRR1 and PYR1. The amounts of fat, protein, fiber, and carbohydrates were comparable in red rice extracts. The PYR3 had the greatest quantities of iron and zinc, whereas the CRR3 had the highest levels of magnesium and potassium. The CRR1 and PYR1 had the highest amounts of vitamin E compounds and γ-oryzanol. Additionally, CRR1 and PYR1 had greater antioxidant capacities in comparison to the other red rice extracts. In the RAW264.7 macrophage cell, it was demonstrated that CRR1 and PYR1 prevented the generation of AGE at higher concentrations and had the strongest inhibitory effects on linoleic acid peroxidation and ROS production. The study's findings offered additional valuable sources of red rice from Chiang Rai and Phayao, giving consumers the option to choose red rice as beneficial for their health.