Studying the effect of tomato pomace incorporation on physicochemical, nutritional and storage characteristics of corn-based extrudates using response surface approach

Abstract

PurposeThe present research was envisaged with an aim to optimize the system and the product responses for the development of tomato pomace-incorporated corn-based extrudates employing central composite rotatable design and determine its proximate, lycopene, consumer acceptability and storage studies.Design/methodology/approachLycopene-rich extrudates were developed from corn flour blended with different levels of tomato pomace. The independent extrusion variables, namely, feed composition (95:5 to 75:25), feed moisture (12–20%), screw speed (200–600 rpm) and barrel temperature (125–185 °C), were studied to determine their influence on dependent variables, namely, specific mechanical energy, hardness, water solubility index, lateral expansion, water absorption index, bulk density and color.FindingsAll of the quality parameters were significantly (p < 0.05) influenced by independent variables. The regression models obtained for all the responses showed high coefficients of determination (R2 = 0.85–0.95). The optimum conditions for the development of tomato pomace-incorporated corn-based extrudates were feed composition (90:10), feed moisture (14%), screw speed (300 rpm) and barrel temperature (170 °C). The moisture, fat and carbohydrate contents of the extrudates were significantly reduced, whereas protein, ash and fiber were significantly (p < 0.05) enhanced after the incorporation of tomato pomace. Aluminum laminates were found to be the suitable packaging materials for extrudates for a period of 120 days in comparison to high-density polyethylene packages.Originality/valueAs far as the authors could possibly know, scanty literature exists wherein the tomato pomace has been utilized for the development of lycopene-rich corn-based extruded snacks. Such extrudates with significantly higher fiber and lycopene contents than corn flour will serve as a suitable alternative for the development of shelf-stable ready-to-eat extruded snacks.