Effect of Extrusion Processing Parameters on Antioxidant, Textural and Functional Properties of Hydrodynamic Cavitated Corn Flour, Sorghum Flour and Apple Pomace‐Based Extrudates

Abstract

Corn flour, hydrodynamic cavitated sorghum flour and apple pomace blend was extruded to investigate the effect of extrusion processing on total phenolic content (TPC), antioxidant activity (AA) along with some selected textural and functional properties. Box-Behnken design was applied for three levels of apple pomace ratio APR (10, 20 and 30%), feed moisture FM (25, 30 and 35% wb), extrusion die temperature T (80, 110 and 1408C) and screw speed SS (100, 150 and 200 rpm) as extrusion parameters. Extrusion cooking at higher APR and low T and SS increased the TPC and AA. Expansion ratio, brittleness, crispness and water solubility index of extrudates were increased while hardness and water absorption index decreased compared to that of control extrudates. Starch digestibility and dietary fiber were also observed to be increased after extrusion. At optimum conditions of 30% APR, 25% wb FM, 1328C T and 108 rpm SS, TPC and AA of extruded products were 120.1 mg GAE/100 g DW and 308.7 mmol TE/100 g DW, respectively, whereas those found in control blend were 123.2 mg GAE/100 g DW and 258.9 mmol TE/100 g DW, respectively. Major phenolic acids in extruded products were derived by caffeic acid followed by salicylic acid and ferulic acid. PRACTICAL APPLICATIONSExtruded products with improved phenolic content, antioxidant activity, textural and functional properties with higher inclusion of apple pomace were obtained. This process for incorporation of sorghum (underutilized cereal) and apple pomace (industrial waste) into human diet to produce nutritious, healthy and gluten free snacks for celiac disease patients has greater potential.

Optimization of Extrusion and Ultrasound-Assisted Extraction of Phenolic Compounds from Jizi439 Black Wheat Bran

“…Extrusion has been reported to increase TPC and AA of snacks made from beans [29] or wheat bran [23]. It could potentially improve sensory acceptance and nutritional properties of many food products, including rice, sorghum, apple pomace [30]. Our study showed that the optimized extrusion processes should be 110 • C for the third heating block temperature, 25% feed water content, and 140 rpm screw speeds.…”

Low‐cost healthy extrudates of rice and bhimkol (Musa balbisiana, ABB) formulated through linear programming

“…Increase in feed moisture showed reduced expansion of extrudates. Earlier studies reported that increase in feed moisture reduces expansion and provides a dense product (Borah, Mahanta, & Kalita, ; Lohani & Muthukumarappan, ). Figure c showed reduced bulk density for higher barrel temperature.…”

“…Extrudates were found to have dietary fiber content of 3.46 g/100 g and protein content of 8.15 g/100 g, respectively (Table ). Lohani and Muthukumarappan () reported significant increase in fiber content of extrudates made of corn, sorghum, and apple pomace blend. Extrudate formulation was found to have glycemic index of 83.38 g/100 g, respectively.…”

Extrusion processing of raw food materials and by-products: A review

“…Although, addition of 10 % fruit or vegetable pulp provided additional advantage in terms of nutrition and structure to the products, maximum expansion was reported for both rice and maize products which contained banana pulp (Jain et al, 2013). Higher apple pomace levels in extruded products from corn flour and hydrodynamic cavitated sorghum flour, in combination with low die temperature and screw speed, led to increased total phenolic content and antioxidant activity (Lohani and Muthukumarappan, 2016). Improved products with higher phenolic content, and enhanced antioxidant activity, textural and functional properties were obtained at higher apple pomace levels.…”