Investigation of the usability of chitosan in extending the shelf life of cultivated mushrooms

This study focuses on the preservation of fresh, non-rotten or diseased mushrooms from PEMA mushroom farm by immersion in organic acid solutions with and without chitosan. Mushrooms were sterilized with 0.01% NaOCl and immersed in organic acid solutions (1% citric, acetic, lactic and tartaric acid) containing chitosan (0.5-1-2%). For the control group, organic acid solutions without chitosan were used and the mushrooms were wrapped with polyethylene film and stored at 4°C. These mushrooms were examined daily for 15 days and weight loss, enzymatic activity, antioxidant activity and color characteristics were evaluated. The study shows that chitosan is an effective coating material in extending the shelf life of mushrooms. It is reported in the literature that acetic acid can denature proteins in mushroom tissue, leading to decay, and accelerate lipid oxidation, causing darkening of the color. The thesis covers topics such as factors affecting shelf life, food spoilage kinetics and shelf life extension techniques. Chitosan coating inhibits enzymatic browning by limiting oxygen availability and preserves the visual appeal of mushrooms. Research findings show that the flavor and nutritional values of mushrooms experience a slower decline during storage due to the inhibitory effects of chitosan coating on enzyme activities. Chitosan prolongs the quality and shelf life of mushrooms by inhibiting polyphenol oxidase (PPO) and peroxidase activity. This highlights the potential of chitosan as a natural preservative. The study shows that chitosan coating dissolved in 1% lactic, citric and tartaric acid (0.5-1-2%) forms a protective barrier on the surface of the mushrooms, reducing oxygen supply and inhibiting enzymatic browning processes, thus preserving the visual and nutritional values of the mushrooms and extending their shelf life. For this reason, the coating materials with the highest chitosan ratio (containing 2% chitosan) in 1% organic acid solutions were found to be the most favorable.