Is utilization of mushroom derived chitin and chitosan a viable path towards a circular bioeconomy?

Abstract In keeping with the transition to a circular bio-economy, chitin as the second most abundant biopolymer and its soluble derivative chitosan are increasingly used to create diverse multifunctional materials. In this work the feasibility of chitin and chitosan derived from mushroom sources as a sustainable, renewable, non-animal, less polluting and energy demanding alternative to crustacean or insect chitin was investigated. A systematic analysis of the structure, morphology, thermal properties of chitin and chitosan derived from: Agaricus bisporus, Pleurotus ostreatus, Pleurotus eryngii, Boletus edulis, Chantarellus cibarius and Cyclocybe aegerita using short alkali and mild acetic acid treatment is presented. The classification artificial neural network concept was applied to measured far infrared reflection spectra of mushroom powder, mushroom derived chitin and chitosan enabling identification of the chitin and chitosan origin. Depending on the fungal species and source (whole, stipes, fresh or dry) chitin and chitosan yields were 8.66%–15.66% and 5.8%–50.4%, while crystallinity degrees were 30.45–58.20 and 34.18%–65.32%, respectively. The chitin N-acetylation degree was 62.95%–95.84%, while the chitosan de-acetylation degree was 85.89%–96.14%. Noticeable β-glucan presence was detected in C. aegerita, P. eryngii and P. ostreatus chitin samples emphasizing the specific advantage of mushroom derived chitin for applications requiring improved flexibility and toughness. Though the antioxidant potential of 6.6–30.2 mg TE g −1 of derived chitosans was relatively low, strong antimicrobial potential of chitosan was noted against B. cereus and L. monocytogenes . The obtained results show that mushroom derived chitin and chitosan have a wide application potential and represent a viable path towards achieving a circular bio-economy.