Physicochemical, microbiological and sensory characteristics of snacks developed from broken rice grains and turmeric powder

Abstract

The aim of the present study was to develop extruded snacks from broken rice grains (BRG) and turmeric powder (TP). Different levels of substitution of BRG by TP (0%, 2%, 4%, 8% and 10% w/w) were used. Snacks were processed in a single-screw extruder with three heating zones (41, 61 and 84 °C, respectively), using a helicoidal grooved extrusion sleeve, a 4 mm (diameter) matrix, 3:1 screw compression ratio, screw rotation of 3600 × g and a feed rate of 335 g min−1. Snacks were evaluated for their physicochemical, microbiological and sensory characteristics; as well as for the chemical composition, phenolic compounds and the antioxidant capacity of the selected savoury snack formulation. The selected snack, with the physical characteristics closest to the traditional corn product, was obtained with 6% substitution of BRG by TP and was constituted by 7.76% protein, 4.78% lipid, 5.84% dietary fibre, 75.3% available carbohydrates, and 174.75 mg gallic acid equivalent per100 g and 6.52% of DPPH• scavenging capacity. The selected snack was shown to be feasible, once TP is an ingredient that aggregates sensory (colour and taste), nutritional (dietary fibres and total energy value) and functional (antioxidants) values to the BRG-based snack, being an alternative for the production of gluten-free snacks.