Effects of extrusion parameters on the physicochemical properties of mung bean–brown rice extrudate for new product development

Abstract Mung beans and brown rice, in the ratios of 60:40 and 70:30, were studied for a wholesome extruded snack by evaluating the effects of extrusion conditions (die temperatures of 100 and 110 °C and screw speeds of 300 and 350 rpm) on extrudates’ key quality properties, i.e., colour values, water absorption index (WAI), expansion ratio (ER), textural properties, bulk density (BD), water-soluble index (WSI), oil absorption capacity (OAC), and antioxidant properties. Results showed that changes in die temperature and screw speed significantly (p < .05) increased protein (15.63–17.61%), ash (1.84–2.50%), crude fat (0.84–1.16%), ∆E (28.56–30.72), ER (2.48–3.36), WSI (21.28–35.37%), hardness (15.46–24.02 N), and DPPH free radical scavenging activity (65.23–72.95%) and total phenolic content (60.7–99.6 mg gallic acid equivalent/100 g) of extrudates. In contrast, an increase in die temperature and mung bean ratio decreased BD (0.22–0.12 g/cm3), OAC (0.99–0.79 g/g), and WAI (5.46–4.72 g/g), respectively. It indicated that mung bean and brown rice combinations produced new nutritious extruded snacks, contributing to food nutrition improvement and diversification.