Mung-Oat snack of high protein content by twin screw extrusion using response surface methodology

Abstract

Mung bean and oat flour were utilized to extrude snacks with high protein content using response surface methodology. Raw material ratio was standardized using NDpCal% to ensure mutual supplementation of essential amino acids such as lysine, methionine, cysteine, threonine and tryptophan. Moisture content ranging between 11% to 20% and barrel temperature 95 °C to 180 °C had shown significant influence on the development of extrudates. Parameters such as moisture content (4.94–6.21%), moisture retention (17.53–59.58%), expansion ratio (2.60–3.82), bulk density (0.021–0.79 g/cm3), water absorption index (4.86–7.53%), water solubility index (18.3–25.2%), water holding capacity (74.65–88.65%) were analyzed. Addition of moisture to feed mixture has significantly affected the expansion ratio, bulk density, water absorption index, water solubility index and water holding capacity (p < 0.05) and coefficient of regression R20.8802, 0.8920, 0.5042, 0.5925 and 0.9197, respectively. Sensory evaluation using 9-point hedonic scale was also conducted.

Keywords

• Essential amino acid
• NDpCal%
• Twin-screw extrusion
• Expansion ratio
• Water absorption index
• Response surface methodology