Effect of maceration, ultrasound, and microwave-assisted method of extraction on antioxidant activity and phenolic profile of free, esterified, and bound phenolics of Tulaipanji rice.

The present work was designed to investigate the effect of maceration, ultra-sound, and microwave-assisted extraction on free, esterified, and bound phenolics of Tulaipanji rice (Oryza sativa L.) flour. Antioxidant activity was measured by DPPH, ABTS, SOD, and reducing power assays. HPTLC analysis was performed for identification and quantification of phenolics in different extracts. Total phenolic (TPC) and total flavonoid contents (TFC) were found significantly high (p < 0.05) in microwave-assisted extraction of bound phenolics compared with other methods. Microwave-assisted extracts showed highest DPPH radicals, ABTS radicals, SOD, and reducing power activity. Further, Pearson's correlation study exhibited a significant positive correlation within % yield, TPC, and TFC. Significant negative correlation was found within % yield, TPC, TFC, and antioxidant activity. The study found that extractive value, antioxidant activity, and phenolic contents varied with the extraction methods. Microwave-assisted extraction technique showed the best performance for extraction as compared to other methods. [ABSTRACT FROM AUTHOR]