Co-extrusion of pearl millet-whey protein concentrate for expanded snacks

摘要

A study was conducted to develop pearl millet-based extruded snacks with whey protein concentrate (WPC) to enhance its acceptability and nutritional value. Pearl millet grits (841 μ) was extruded with different levels (0%, 2.5%, 5.0% and 7.5%) of WPC at constant feed rate (10.5 kg h~(-1)) and moisture content (14%). Addition of whey protein at 7.5% level significantly (P < 0.05) increased T_g from 75.1 ± 0.26℃ to 120.5 ± 1.28℃ and T_m from 89.1 ± 1.51℃ to 158.7 ± 1.37℃, which resulted in less expanded and harder extrudates. The expansion index of extrudates was negatively correlated (P < 0.05) with protein (r = -0.940), bulk density (r = -0.949), hardness (r = -0.971) and breaking strength (r = -0.921), while positively correlated (P ≤ 0.05) with overall acceptability (OAA; r = 0.988). Keeping in view the nutritional, textural and consumer's acceptability, incorporation of 5% WPC in pearl millet grits (841 μ) was recommended for preparation of acceptable expanded snacks.