A physicochemical characterization of chitin extracted from edible Lithuanian mushrooms

Abstract

Chitin is a biopolymer made from (1→4)-linked N-acetyl-β-D-glucosamine. It can be found in exoskeleton of crustacean, insect and in the cell wall of mushrooms [1]. Chitin is very important biomaterial these days, because of its biodegradable, biocompatible, nontoxicity, antitumor, antioxidant and antimicrobial properties. Chitin has many applications in medicine, cosmetic, biotechnology and other fields [2]. More than 100 000 mushrooms species are known in the World. More than 6000 mushrooms species are described in Lithuania [3]. Till now no studies has been done with Lithuanian mushrooms chitin. In this study the Lithuanian mushrooms chitin was investigated for the first time. The aims of this study were: a) to extract chitin from five edible mushrooms species belonging to four families; b) to evaluate and compare chitin physicochemical properties between these five mushrooms, c) to compare chitin contents of mushroom pileus and stipes. Chitin was extracted from five (Boletus edulis, Leccinum auranticum, Russula vesca, Cantharellus cibarius and Paxillus involtus) edible Lithuanian mushrooms by using a chemical method. Four steps was used to isolate chitin from mushrooms: mushrooms dust bleaching (NaClO), deproteinization (NaOH), demineralization (HCl) and second deproteinization (NaOH). Obtained chitin was characterized by Fourier transform infrared spectroscopy (FTIR) and by scanning electron microscopy (SEM). The results of FTIR showed that all mushrooms chitin are in alpha form and can be used as a potential raw material for chitin production. SEM analysis showed that mushrooms chitin surface was clumped and has no clearly visible nanoporous and nanofibers structure. The chitin contents of pileus and stipes of mushroom bodies were determined and compared. Three mushrooms species (Leccinum auranticum, Cantharellus cibarius, Paxillus involtus) out of total five had higher chitin content in pileus [...]