EFFECT OF DIFFERENT PROCESSING METHODS ON POLYPHENOLIC CONTENT AND ANTIOXIDANT ACTIVITY OF BROAD BEANS (VICIA FABA)

Objective: The effects of processing on total phenolic components and antioxidant activity in commonly consumed broad bean was investigated. Methods: The raw and processed samples were extracted with 70% methanol and analysed for antioxidant components and antioxidant activity. Results: Processing of legumes caused decrease in total phenolic content when compared to the raw samples. However, the dry heating caused remarkable increase in tannin contents (6.98 plus or minus 0.53 g TAE/100 g extract). The flavanoid and beta carotene content was significantly reduced on processing of samples. Raw sample of D. lablab was found to possess the highest DPPH (73.5 plus or minus 2.5%), Reducing power (4.9 plus or minus 0.68 mg ascorbic acid/gm) and Iron chelating capacity than other samples. Conclusion: Maximum retention of antioxidant activity was observed in dry heated samples. Higher correlation was found between phenolic content and chelating capacity (r2=0.945) but a poor correlation with DPPH. Moreover, the content of tannins gave good correlation (r2=0.745-0.913) with Iron chelating and DPPH assays.