OPTIMIZATION OF CARROT POMACE POWDER INCORPORATION ON EXTRUDED PRODUCT QUALITY BY RESPONSE SURFACE METHODOLOGY

Rice and gram flour mix with carrot pomace powder (CPP) was used for the extrudates under study. Response surface methodology was used to analyze the effect of die temperature (65-125C), feed rate (2.5-8.5 g/s), feed moisture (10-30%, w.b.) and CPP (1.5-15.5%) on extrudate moisture, expansion index, bulk density and sensory characteristics of extrudates. Regression equations describing the effect of each variable were obtained. Die temperature was observed to be the most effective (P < 0.05) process variable to affect the selected responses, followed by change in feed moisture and CPP. Overall acceptability (OA) of the experimental samples ranged from 3.4 to 7.9 for the selected process variables. An optimization of process variables using regressed equation was attempted for maximum desirability in responses. Optimum incorporation level of CPP was found to be 5%, with OA score of 7.4. The study demonstrated that an acceptable extruded product can be prepared by CPP incorporation. PRACTICAL APPLICATIONS Extrusion is a widely used processing technology in many ready-to-eat cereal-based snacks. A lot of work has been done on cereal-based extrusion along with pulse supplementation for improved protein quality. The present study also takes its basis from such previous studies. Innovative approach in this study involves utilization of a by-product through incorporation of carrot pomace powder (CPP) in pre-extrusion mix. Furthermore, a polynomial model is established for each process variable, and CPP incorporation is optimized for the desired quality of extrudates.