Preparation of Chitosan from Agaricus bisporus Brown Stems and Studying some Its Physicochemical and Functional Properties

Abstract

The stems of the brown Agaricus bisporus mushroom, which were obtained from the Al-Wadq mushroom farm / Baghdad, The chemical composition of the mushroom stems was estimated as the proportions of the mushroom components: moisture, protein, fat, ash, carbohydrates (91, 2.8, 0.25, 0.88, 5.07)% respectively. Chitin was extracted from the stemsof A. bisporus brown mushrooms by chemical method using 2 M sodium hydroxide solution and 2% acetic acid. The percentage of chitin extracted from mushroom stems was 13.8%. Chitosan was prepared from the stems of A. bisporus brown using a 50% sodium hydroxide solution at a temperature of 100°C for 3 hours, and the percentage of chitosan in mushroom stems was 10.5%. The chitosan under study was identified using Fourier Transform Infra-Red (FTIR). The degree of deacetylation of chitosan produced from the stems of A. bisporus brown was 83%. The viscosity of mushroom stems chitosan was 40cP. When the viscosity was estimated by dissolving chitosan in 1% acetic acid solution, the molecular weight of mushroom stems chitosan was 46.922 kDa. The stems chitosan was distinguished by its high solubility in 1% acetic acid solution, reaching 90%.