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

Abstract

Summary 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 °C to 120.5 ± 1.28 °C and T m from 89.1 ± 1.51 °C to 158.7 ± 1.37 °C, 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.