Qualitative detection of formaldehyde in challani fish obtained from selected fish markets of Nagaon, Assam, India

Abstract

Preservatives are used to increase the shelf life of any product for a very long time, yet they are extremely detrimental to human health when used in food. The use of preservatives like formaldehyde by fishermen and fish merchants for prolonged preservation of fish during sales and transportation has recently become problematic and threat to human health. Therefore, the goal of the current investigation was to determine the presence of formaldehyde in the fish sold at fish markets in Nagaon, Assam. The present investigation indicates the contamination of fish with formaldehyde in the local fish markets of Nagaon district. The fish that show the presence of formaldehyde are imported (challani) and out of the whole fish sample collection (challani/imported), Labeo rohita, Catla catla indicates the highest positive result, with 35.96% and 48.44% respectively from the 114 Labeo rohita to 64 Catla catla samples. Additionally, the results for Ompok pabda, Pangasius pangasius, Hilsa ilisha, and Piaractus brachypomus are all positive, with Hilsa ilisha showing a positive result of 100% from their whole sample collection. However, the local fish like Labeo gonius, Cirrhinus reba, Ctenopharyngodon idella, Cirrhinus mrigala, and Hypophthalmicthys nobilis fish species have shown 100% negative results for formalin detection, indicating that their samples are formalin-free. Since formaldehyde is harmful to human health, better methods and techniques should be adopted for the preservation of fish for commerce and storage. Strict regulations should be put in place to limit the use of these hazardous chemical substances.