Extraction of Betacyanin and Betaxanthin Pigments from Red Beetroots by Chitosan Extracted from Shrimp Wastes

Abstract

Red beetroot as the main source of natural red dye is rich in betalain pigments, which are divided into betacyanins and betaxanthins with antioxidant, antimicrobial and antiviral activity. In this study, chitosan as a deacetylated derivative of chitin, non-toxic, biodegradable and biocompatible polysaccharide, was extracted from shrimp wastes by demineralization, deproteinization and deacetylation processes. The extracted chitosan was characterized by SEM and FTIR analyses. The weight efficiency of chitosan from shrimp wastes and the degree of deacetylation were 26.25 and 86%, respectively. The extracted chitosan was used to betacyanin and betaxanthin adsorption from red beetroots. Betacyanin and betaxanthin adsorption experiments were conducted based on a rotatable central composite design and analyzed using response surface methodology for three independent factors, initial solution pH (3–7), initial concentration (50–150 mg/L) and adsorbent amount (0.01–0.05 g). The optimum adsorption capacity for the betacyanin and betaxanthin pigments were 144.15 and 114.50 mg/g, respectively. The chitosan extracted from shrimp wastes could be used as a proper and available adsorbent for adsorption of betacyanin and betaxanthin pigments from beetroot plant.