Evaluation of the Effect of Feed Composition and Extrusion Process Variables on Physicochemical, Textural, Visual and Sensory Properties of Puffed Corn Snacks Containing Flaxseed

The production of extruded products enriched with oilseeds and nuts can be welcomed by producers as a new product in addition to helping to nourish consumers. But the production of a product with appropriate characteristics requires the examination of the effect of process conditions on the properties of the produced product.In this study, the effect of feed composition, feed moisture content and screw speed variables investigated on the physicochemical, textural, visual, acoustic and sensory properties of peanut puffed snacks produced by the extrusion process. For this purpose, the peanuts mixed with corn grits at a ratio of 7, 14 and 21 percent and water added to the mixture to reach a moisture content of 12, 15 and 18%. Then, the resulting mixture extruded at screw speeds of 120, 150 and 180 rpm, at 140 °C, with a die diameter of 2.5 mm. In the next step, the required tests performed to determine the intended properties of all produced samples.The results showed that increased moisture content of the feed increased water absorption, particle density, hardness, L*, b* and appearance and color scores in sensory evaluation and decreased water solubility and a* of the samples. Also, increasing the screw speed led to increase in the water solubility, a* and sensory evaluation scores (appearance, texture, flavor and overall acceptance) and reduced radial expansion, hardness, L* and b*. Increasing the ratio of peanut in the produced samples increased particle density, hardness and a* and reduced radial expansion, porosity and L* of the samples. In order to produce the optimum sample with the highest expansion ratio and brightness and the lowest hardness and density, which contains 14% peanut, the screw speed and feed moisture content calculated respectively for 120 rpm and 13.20% respectively.