Antioxidant Potential and FTIR Profiling of Red Rice (Oryza sativa L.) Grown in Himachal Pradesh

Abstract

Red rice is a variety of rice that possesses a red coat of bran. The aspect that makes such rice different is that, although the rice undergoes extensive milling, it still retains the red residue in the outermost layer. It is well recognised that red rice has a high level of phytochemicals and exhibits strong antioxidant properties. The objectives of this research were to evaluate the phytochemical content, antioxidant capacity, and FTIR characterisation of red rice collected from different districts of Himachal Pradesh. Phytochemical composition indicated that there were statistically significant differences (P<0.05) in total phenolic content (TPC), total flavonoid content (TFC), and total anthocyanin content (TAC) among the red rice samples. Kaluna (72.48±1.45 mg GAE/g) had the highest TPC, while the TFC was recorded in Jattoo (15.10±1.25 mg QE/g). The total anthocyanin content (TAC) varied from 0.37 ± 0.05 to 1.36 ± 0.03 mg/g, with Jattoo having the highest anthocyanin content. Gocha exhibited the highest total antioxidant activity (76.32±2.42 mg AAE/g), while HPR-2795 showed the highest DPPH radical scavenging activity (91.70±0.40 %) with the lowest IC₅₀ value. Matali demonstrated the highest reducing power, highlighting its superior antioxidant potential. The FTIR spectra of red rice identified various functional groups linked to proanthocyanidins. The results highlight the nutritional and functional importance of red rice from Himachal Pradesh, demonstrating its potential as an antioxidant-rich functional food for enhancing health and reducing the chances of chronic diseases.