Evaluation of physical and chemical properties of citric acid industrial waste

Abstract

© 2019, Springer Nature B.V. This study aimed to evaluate physical and chemical properties and nutritive values of citric acid by-product (CABP) from cassava and to compare its properties with those of cassava root meal (CRM). The physical properties analyzed were color, bulk density, angle of repose, particle size distribution, and ultrastructure morphology. The chemical properties were determined using proximate analysis. Regarding the physical results, the CABP’s color was darker, and its bulk density was greater by approximately 64.18% than those of the CRM (p < 0.05). The CABP’s angle of repose was significantly lower (p < 0.05) with a freer flow, and the particle size was classified as small with fewer polygonal starch granules but more than the CRM. Regarding the chemical composition results, the CABP contained 0.71% citric acid with pH 4.68 whereas crude protein, ether extract, crude fiber, and gross energy were 6.11%, 2.39%, 18.26%, and 3588.10 kcal/kg, respectively. CABP showed greater and significantly different crude proteins and ether extracts but less gross energy than the CRM (p < 0.05). The results imply that the CABP could be an alternative energy source and used as a CRM substitution in animal feed formulation.