Effect of Process Conditions on Physico-Chemical and Sensory Properties of Fish-Cereal-Based Extruded Snack-Like Products

To establish the effect of barrel temperature, screw speed, total moisture and fish flour content on the expansion ratio, bulk density, porosity and water solubility index of the fish-based extrudates, response surface methodology was adopted in this study. Rice and corn flour was used as starch. The experiments were optimized using five-levels, four-factor central composite design. Analysis of variance was carried to study the effects of main factors and interaction effects of various factors and multiple regression analysis was carried out to explain the variability. Sensory acceptability study was conducted to select best products. The expanded materials obtained at 100–110C with feed material containing 15–20% fish flour and 14–18% moisture had the best properties. The study showed that expanded products produced using rice, corn and fish flour under conditions that induced the maximum expansion, had the best acceptability. PRACTICAL APPLICATIONS Changes in extrusion conditions especially, barrel temperature, screw speed, moisture and fish flour are observed to have significant effects on the physical properties of extruded ready-to-eat snacks. In order to derive optimal conditions, the response surface methodology was followed. The model developed can be used for designing of extrusion conditions for getting extrudates with desirable physical characteristics.