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

- Temperature-power combinations significantly affected physico-functional properties.
- Pronounced impact of microwave roasting observed on antioxidant and thermal properties.
- Parameter optimization and FTIR analysis aided in development of value added products.

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.