Fish is an important source of animal protein. However, its quality deteriorates quickly due to factors such as microbial activity, oxidative reactions, and self-enzymatic activity, especially with rising temperatures. This can be problematic as the freshness of fish greatly affects its acceptability to consumers. Inadequate preservation facilities and long transportation distances can further contribute to a decline in quality by the time the fish reaches the market. To tackle this problem, traders frequently turn to the use of formalin, a 37% solution of formaldehyde, as an economical preservative. However, it is important to note that formalin possesses harmful and carcinogenic properties, and it can readily permeate fish tissues. Traders may immerse the entire fish in formalin, inject it into the body cavity, or spray a mixture of formalin and water on the surface while displaying the fish in retail markets. It is believed that formalin significantly influences post-mortem changes, affecting the physical, biochemical, and nutritional components of fish flesh or the entire fish. While fish preserved with formalin have a longer shelf life compared to other methods, it is important to note the presence of formalin in edible fish poses health risks.

Dr. Bibha Kumari has completed her PhD in Zoology from Magadh University, Bihar, India, and has more than 17 years of teaching and research experience. At present, she is the President-Elect of the Asian Pacific Chapter of the World Aquaculture Society. She has published more than 15 papers in reputed journals and reviewed more than 35 articles for international journals. Also serving as an editorial board member of repute.