Probing a best suited brown rice cultivar for the development of extrudates with special reference to Physico-chemical, microstructure and sensory evaluation

Abstract

Seven Pakistani brown rice cultivars (KS-282, SB, C-9, SUPRI, PK-386, IRRI-9 and IRRI-6) were investigated as an alternative raw material to develop directly expanded extrudates. Results indicated that bulk density remained constant in all rice cultivars, whereas SUPRI presented a higher length-breadth (LB) ratio and lower thousand kernel weight and starch content than other cultivars. Amylose content was higher in KS-282, C-9 and IRRI-9 and lowest in SB. SUPRI rice extrudates produced optimum expansion and crispiness with reduced hardness, piece and bulk density. Scanning electron micrographs showed more cell pockets and evenness in porosity per unit area in SUPRI brown rice extrudates, indicating more porous and crispier extrudates. It is also evidenced from the micrographs that cavities were evenly distributed and less ruptured in SUPRI brown rice. Consequently, SUPRI extrudates exhibited better microstructure, crispiness (No. of peaks 9), and porosity (0.838 ± 0.009) along with minimum piece density (0.038 ± 0.001 g/cm3) and hardness (17.85 ± 1.05 N). Conclusively, low amylose rice cultivar (SUPRI) perform better as substitute raw material for extrudates development.