Effect of microwave roasting parameters on functional and antioxidant properties of chickpea (Cicer arietinum)

Abstract

Chickpea seeds were roasted at different levels of power (450–900 W) and for different time periods (5–15min) in microwave oven. The effect of roasting process on antioxidant properties and different physico-functional parameters like bulk density (ρb), surface area(S), color, glass-transition temperature, spectral variations in functional groups, water solubility index(WSI), water absorption index (WAI), water absorption capacity(WAC) etc. were analyzed. A significant increment in surface area, redness, yellowness, onset temperature of amylose-lipid complex and water absorption properties of roasted samples was observed with roasting time and power whereas reduction was observed in bulk density (26.43–43.47%), lightness (88.48–54.57), onset temperature for starch gelatinization (69.10–63.6 °C) and oil absorption capacity (1.25–1.04 g/g), water solubility index (0.26–0.14) and foaming properties (26.29–4.21%). Two-fold and three-fold higher antioxidant and phenolic activity, respectively was observed in roasted sample (900 W, 15min) compared to unroasted control sample. Significant increase in total phenolic content (TPC, 8.02–27.87 mg gallic acid equivalents/g) and antioxidant activity (AOA, 22.85–46.69%) was observed after roasting. The total flavonoid content (TFC) significantly decreased (22.89–17.04 mg quercetin equivalents/100 g) after roasting.