Effects of cooking on phytochemical and antioxidant properties of pigmented and non-pigmented rare Indian rice landraces

Abstract

Ever since a positive correlation between rice consumption and reduced risk of developing chronic diseases was recognized, numerous researches on native indigenous rice landraces have been carried out. In the present investigation, ten pigmented and non-pigmented rare Indian rice landraces were analyzed for their total phenolic content (TPC), total flavonoid content (TFC), total protein, total anthocyanin, and antioxidant potential. Three different parameters in raw, cooked, strained cooking water were taken into consideration and phytochemical analysis revealed that pigmented rice varieties displayed higher levels of bioactive compounds as compared to the non-pigmented cultivars. Higher TPC (398 ± 0.23 mg GAE/100 g), TFC (1308 ± 0.04 mg QE/100 g), total anthocyanin (13.36 ± 0.00 mg/100 g), total protein (2590 ± 0.03 mg/100 g), total antioxidant activity (316 ± 0.03 mg AAE/100 g) was recorded with the pigmented varieties. A strong correlation was found between the antioxidant activity and the phenolic, flavonoid content in pigmented rice cultivars. Further, the phytochemical composition and antioxidant activities in cooked rice and strained cooking water were lower as compared to raw. Among the tested landraces, navara was found to be superior in terms of higher phytochemical contents and antioxidant activity. Our study revealed the various health-promoting properties of pigmented rice over non-pigmented rice. It was also found that pressure cooking without straining away the water would be ideal to retain the nutrients and pigmented rice can alleviate numerous health disorders upon regular consumption.