Effect of Extrusion on the Nutritional, Antioxidant and Microstructural Characteristics of Nutritionally Enriched Snacks

The aim of this work was to investigate the effect of extrusion cooking on the nutritional, antinutritional, antioxidant activity and structural properties of snacks. An increase in protein, fiber and total carbohydrate content was observed. The overall mineral content of extruded product increased by increased availability of minerals due to destruction of antinutritional properties. The antinutritional properties such as tannin and phytic acid content of extruded sample observed were 0.38 and 5.02 mg/g, respectively, which was lower than the raw ingredients. Thus, nutritional quality was maintained by extrusion through destruction of antinutritional components. A significant (P ≤ 0.05) decrease in the antioxidant activity as compared with the raw ingredients, except that of rice, was observed, and a significant (P ≤ 0.05) decrease in the total phenolic content as compared with the raw ingredient, except that of rice and pea, was observed. Scanning electron microscopic structure showed compactness of extrudate as compared with control extrudate. PRACTICAL APPLICATIONS: The purpose of this study was to investigate the effect of extrusion process on the nutritionally enriched extruded products prepared using ingredients such as oat and dried green pea and fenugreek. This type of study has not been extensively studied. The effect of extrusion process on its nutritional, structural, total antioxidant and phenolic content has revealed improvement in the nutritional profile by extrusion cooking. Destruction of antinutritional properties by extrusion thus maintains the nutritional quality. Increased overall antioxidant activity has greater influence on its storage. Because of heat sensitivity, phenolics decrease by extrusion cooking, and structural studies revealed the compactness of extrudates as compared with control.