Green and Hybrid Extraction of Chitosan: An Insight Into Sustainable Food and Health Applications

ABSTRACT

Chitosan is a natural polymer found in many products, including food preservatives, packaging, health supplements, and medical items. Traditionally, strong acids and bases are used to remove proteins, minerals, and acetyl groups, but this can harm the polymer and create hazardous waste. This review examines chemical, biological, physical, and combined extraction methods that aim to reduce or avoid steps that generate chemical waste while maintaining high product quality. Chemical extraction usually gives a degree of deacetylation (DD) between 25.25% and 99.5% and a molecular weight (MW) between 22.7 and 865.7 kDa. Hybrid methods yield DD values between 55.3% and 97.7% and MW values between 53.4 kDa and 500 kDa. Hybrid chemical‐biological methods, such as those using enzymes or fermentation, lower the need for chemicals to turn chitin into chitosan. Hybrid chemical‐physical methods, such as microwave or ultrasound, help move materials more quickly and reduce processing time to achieve the desired DD and MW. These results help create a model that links chitosan quality, cost, and production scale in a waste‐to‐wealth approach. This method turns shrimp‐processing waste into chitosan, reduces disposal problems, and supports a circular seafood economy. High‐quality chitosan produced can be used in food and health products, benefiting Malaysia's aquaculture and seafood industries.