Utilization of By-product from Tomato Processing Industry for the Development of New Product

Abstract

Extrusion cooking is recognized as a smart technology for food processors. It is a low cost, high temperature, short-time process. In this the starchy ingredients are input to create a puffed snack. However it contains multiple parameters that need to be rigorously controlled to develop an optimal process. Present study investigated the blends of corn flour, rice flour and tomato pomace (peel and seed), processed in a co-rotating twin-screw extruder and examined the effect of incorporation of tomato byproduct derivatives on final extruded product quality of the ready -to-eat expanded product. Furthermore, the physio-chemical properties, post cooking quality were analyzed for the extruded product. As tomato pomace, corn and rice flour are naturally gluten free, the extruded product would appeal to people who suffer from gluten intolerances, allergies and celiac disease. Dried and milled tomato peel and seed at levels of 0 - 30% and 0 - 5%, respectively were added to the formulation mix. D-optimal mixture design was chosen, which generated 17 combinations; within these combinations, the control formulation existed. The formulations were processed in a twin-screw extruder with a combination of parameters including: solid feed rate kept constant, water feed adjusted to 14%, screw speed of 300 rpm - 350 rpm and process temperatures 30°C to 140°C. It was observed that the addition of tomato pomace significantly increased the crude fiber content and level of protein content in the final product. The expansion ratio, hardness, colour, and overall acceptability varied significantly with respect to tomato pomace addition. Sensory test panel indicated that tomato pomace extrudate could be incorporated into ready-to-eat expanded products up to the level of 30% and it was acceptable. Optimization using D-optimal mixture design suggested that the best formulation extruded product with high desirability was the one consisting of 40% corn flour, 30% rice flour, 25% tomato peel and 5% tomato seed. The results suggest that tomato pomace can be extruded with corn and rice flour into an acceptable and highly nutritious fiber enriched snack food.