Pearl millet based pasta: optimization of extrusion process through response surface methodology

This study investigated the influence of extrusion operating condition [barrel temperature (BT) (50-90 °C), feed moisture content (FM) (25-35%, w.b.), feeder speed (FS) (8-16 rpm) and screw speed to feeder speed ratio (SS:FS) (8-12)] on quality of pearl millet pasta [cooking time (CT), cooking loss (CL), hydration capacity (HC), swelling capacity (SC), hardness, springiness (SP), chewiness (CH) through response surface methodology (CCRD design)]. The results indicated that raising BT and FM reduced CT, CL, but increased HC, SC, hardness, SP, CH of pearl millet based pasta. HC, SC, hardness, SP and CH of pasta were increased as FS and SS:FS increased, whereas, CT and CL showed decreasing trend. The optimum operating conditions for pear millet based pasta was obtained at BT of 70 °C, FM of 30% (w.b.), FS of 12 rpm and SS:FS ratio of 10 with low CT (≤ 5.25 min), CL (≤ 7.45%) and high HC (≥ 2.30 g g^-1), SC (≥ 3.14 ml g^-1), good hardness (≥ 11.11 N), SP (≥ 1.24 N) and CH (≥ 6.09 N mm).