Impact of added enzyme-treated bran on the techno-functional properties of puffed-extruded sorghum snack

Abstract

Dietary fibre intake is crucial for improving human health and reducing the prevalence of diet-related non-communicable diseases. This study determines the effect of the enzyme (Viscozyme®L: a cocktail of cell wall degrading enzymes including arabanase, cellulase, β-glucanase, hemicellulase and xylanase) hydrolyzed fibre on the techno-functional properties of puffed-extruded sorghum snacks made from sorghum flour. Sorghum flour and sorghum flour mixed with untreated bran, water-incubated bran, and enzyme-treated bran were extruded using a twin-screw extruder. The puffed-extruded snacks from sorghum flour with 2-hour enzyme-treated bran showed similar expansion ratios to snacks from sorghum flour without bran. The expansion ratios of the without-bran snacks (2.80) and enzyme-treated bran-added snacks (2.77) were significantly (P<0.05) higher than those made with untreated sorghum bran (1.87). A higher expansion ratio usually results in a lighter, crispier texture and a more attractive appearance of puffed-extruded snacks, which consumers often prefer. The enzyme treatment also increased the water solubility index and decreased the water absorption index compared to snacks with untreated bran. This study explores the potential of using an enzyme-treated sorghum bran to manufacture puffed-extruded snacks comparable to those made with sorghum flour.