Value Addition to Food Industry By-Products and Wastes (Deoiled Rice Bran and Banana Peel) by Optimizing Pellets' Formulation Using Response Surface Methodology: Characterisation and Classification by PCA Approach

Abstract

This study aimed to optimize the pellets formulation (deoiled rice bran (DOB), banana peel powder (BPP) and plasticizers viz. cashew nut shell liquid (CNSL) and glycerol). The maximum hardness and bulk density as desirable responses were obtained for pellets having 100g DOB, 100g BPP, 12% of CNSL and 12% glycerol. Specific mechanical energy during extrusion was higher (85.565 kJ/kg) for pellets containing CNSL. On the basis of Hausner ratio (1.068-1.070), pellets were classified as free flowing. Pellets with CNSL were found durable and more shelf-stable. Scanning electron micrographs revealed that the intermolecular interactions of pellets containing CNSL were better with smoother surface and minimum voids as compared to pellets containing glycerol. Thermal properties revealed that pellets with glycerol had reduced glass transition temperature as compared to pellets with CNSL owing to higher polymer mobility in glycerol. Significant correlations were observed among physical, mechanical, aerodynamic, and functional properties of pellets. Practical Applications Banana peels are obtained in excess amount which gets accumulated in bulk. Therefore, value addition to banana peels by developing pellets can be a better option. Characterization of the durability (engineering, functional, aerodynamic, thermal and morphological) will provide an insight of the quality attributes of the pellets during various processing operations (handling, transportation, injection molding). These pellets can be further injection molded products into various products e.g., biodegradable planters.