Fractionating Chitin and Coproducts from Pleurotus ostreatus Mushrooms

Abstract A large amount of wasted mushroom stems are accumulated yearly by the mushroom industry. To reduce this waste, we have proposed a fractionation method to isolate several useful coproducts such as β-glucans, lipids, Vitamin D, polyphenols, and proteins before producing chitin from oyster mushrooms using reusable organic solvents. The extracted β-Glucans, polyphenols, and proteins were confirmed by 3,5-dinitrosalicylic acid (DNS), Folin-Ciocalteau, and bicinchoninic acid (BCA) assays respectively. Extracted lipids were analyzed by gas chromatography-mass spectrometry (GC-MS) and chitin was characterized by Fourier-transform infrared spectroscopy (FT-IR) and powder X-Ray diffraction (XRD). The crystallinity index of the extracted chitin was 71.2% when compared to 85% for crustacean chitin. The reduced crystallinity in mushroom chitin was due to the presence of some β-glucans. Overall, the reported fractionation method uses less solvent and provides a greener alternative to producing chitin when compared to the conventional methods of using a large quantity of harsh chemicals harmful to the environment. Further, fractionating several coproducts while producing chitin will reduce the total processing cost.