Production of extruded functional snacks based on resistant starch using waste rice and whey milk

Food waste is a serious problem on a global scale. Rice, being a staple food in the Saudi Arabian diet, is a major contributor to this waste. Current study aimed to harvest advantages of rice waste to produce and develop a new sustainable product. Corn was used as a control, extrusion process was used with leftover rice-based resistant starch (10-40%), chickpea flour (10%). and fortified with whey byproduct (10%). Chemical composition, digestibility, anti-nutritional factors, bioactive compounds, antioxidant activity, amino acids, and physical properties were investigated before and after extrusion. In comparison to control, all formulated samples showed increased levels of resistant starch, proteins, essential amino acids, total phenolic compounds, and minerals. Extruded (E4) showed the highest levels of protein at 10.46%, fiber at 3.45%, resistant starch at 34.38% and lowest energy 364.12 Kcal/100 g. There was no significant change for most of the amino acids by extrusion process. Antioxidant activity increased after extrusion from 24.80 to 32.06 mg TC/g. In conclusion, use of leftover rice-based RS, chickpea, and fortified with whey protein to produce functional food via extrusion will be beneficial to exploit such food wastes, and to avoid their negative impact on the environment.