Extraction and characterisation of starch from cassava (Manihot esculenta) agro-industrial wastes

Abstract

This study has investigated the potential of extracting starch from cassava agro-industrial wastes, namely, cassava peel and bagasse, as a non-edible source and has developed an extraction method to maximise the starch extraction from these sources. Obtained extracts were characterised and their properties were compared with that of commercial cassava starch. The results demonstrated that cassava peel starch yield (30 ± 2 % wt.) was significantly higher than that from bagasse (8 ± 1 % wt.). Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) analyses revealed that starches extracted from cassava peels, bagasse and commercial starch had very similar morphology and functional groups. Main crystalline phase, α-amylose dihydrate identified by X-ray diffraction (XRD) in peel, bagasse and commercial starches were 98.3(2) %, 98.5(1)% and 100% respectively. The highest percentage (by weight) of crystallinity phases: quartz (0.33%) and whewellite (1.53%) were detected in peel and bagasse starches respectively. Cassava peel and bagasse have been proven to be potential alternative sources of starch, and the excellent properties exhibited by the starch extracted from these sources suggest their potential applications as biodegradable food packaging matrices, as an alternative to the commonly used commercial cassava starch.