Microwave assisted extraction of chitosan from Agaricus bisporus: techno-functional and microstructural properties
Adity Bahndral, Rafeeya Shams, Kshirod Kumar Dash, Pintu Chaudhary, Ayaz Mukarram Shaikh, Béla Kovács
Abstract
Chitosan, a copolymer of glucosamine and N-acetyl glucosamine, is primarily derived from chitin. The present research was conducted to generate and analyze chitosan derived from white button mushroom waste ( Agaricus bisporus ) using microwave assisted extraction. Dried mushroom waste powder was demineralized in diluted acid using 3 M HCl in 1:10 w/v at 540 W for 8 min and deproteinated at 180 W using 10% NaOH in 1:10 w/v for 8 min to remove proteins and lipids. The extracted chitin was deacetylated using 50% NaOH in 1:20 w/v at 360 W to convert it into chitosan. Chitin from the aforesaid process was deacetylated in concentrated alkaline medium at 360 W for 8 min to yield chitosan by converting acetyl groups to -NH 2 groups. The pH and solubility of fresh chitosan were 7.5 and 75%, respectively. Extracted chitosan had maximum 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity of 53.97% and reducing power of 3.58. The microwave irradiation method produced chitosan having degree of deacetylation of 79.94% and crystallinity index of 1.09. The spectra bands confirmed existence of NH 2 , OH, C O, CH, and C N functional groups. The X-ray diffraction analysis of the chitosan sample discovered distinct peaks at 2θ values between 10 and 20 °, indicating its semi-crystalline nature. Graphical abstract for microwave assisted extraction of chitosan from mushroom waste powder.