A review on valorization of chitinous waste

The accumulation of waste from sea food industries poses hazards to aquatic life and environment. The shells of crustaceans, which constitute a major chunk of the sea food waste, are the source of chitin, a valuable polysaccharide. The physiochemical properties of chitin make it suitable for several applications, viz. in medical science, waste water treatment, food preservation etc. To explore its potential in uncharted domains, it is desired that this polymer is available in abundance. Chitin can be extracted from the marine sea food waste by chemical or biological methods. Owing to the higher efficiency and short processing time of the chemical method in the recovery of chitin from the marine biomass waste, this method has been adopted in industries in spite of its adverse impact on the environment. On the contrary, the eco-friendly biological method is still restricted to the research laboratories. In view of this, we aim to provide an overview on the sources and physico-chemical properties of chitin/chitosan and discuss the methods of their extraction and applications. As the impetus to green technologies in chitin extraction would be beneficial to the environment, this review highlights the advantages of biological methods of chitin extraction over the chemical methods. Though the biological method of chitin extraction offers a wider choice of enzymes or microorganisms in the fermentation processes, it is not without challenges. There is a need to increase the efficiency of the biological process of chitin extraction to make it a key process to harvest the high value biopolymer from marine waste without any damage to the environment and to explore its utility for the welfare of mankind.