Development of extruded snack from food by-products: a response surface analysis

Response surface methodology was used to investigate the effects of extrusion conditions including the moisture content of blend (12-18%), barrel temperature (150-175C), screw speed (200-280 rpm) and change in feed composition on the product characteristics of the snack food developed from rice grit in combination with durum clear flour, partially defatted hazelnut flour (PDHF) and fruit wastes. The blend was made up of rice grit (67%), durum clear flour (8-20%), PDHF (5-15%) and fruit waste (3-7%). The response variables were radial expansion ratio, color, and textural and sensory properties of the extruded snacks. Increasing the PDHF content caused a decrease in the radial expansion ratio, hardness and lightness of the snacks. The textural properties and color of produced snacks were affected by the fruit waste addition. Increasing the moisture content and decreasing the temperature caused an increase in the expansion ratio for most compositions. The extruded snacks with lower PDHF content had the highest levels of overall acceptance in the sensory panel. There was no significant effect (P < 0.05) of fruit waste addition on the sensory properties of the snacks. Large amounts of side products of the food industry, in particular fruit and vegetable waste, evolved during production (most of which cause environmental pollution), preparation and consumption of foods. Because of this, it is necessary to collect and use these wastes for the production of new foods, which is important from the point of environmental pollution and a country's economy. This study aimed to produce a ready-to-eat, puffed and value-added snack food by using the side products of various food industries. Durum clear flour of macaroni production, partially defatted hazelnut flour of hazelnut oil production and fruit wastes of various fruit juice production might be evaluated as the components of the extruded snack food product. The contribution of the present work is to propose an alternative technology for the utilization of food-processing wastes for the development of a useful, value-added extruded food product.