Effect of Artificial Formalin Treatment on Fish Muscles Textural Quality and Different Formalin Lessening Techniques from Muscles

Abstract Many countries have reported formalin contamination for extending the shelf life of fish. As a reason, the current study was performed to understand the influence of three different concentrations of formalin on fish muscles quality and thereafter, some formalin lessening techniques were also assessed. The experimental fish treated with 1%, 5% & 10% formalin solutions for 5 min and as a result, the residual content enhanced to almost 7, 11 and 15 times respectively compared to fresh fish. The solubility and water holding capacity of muscle protein were found to be decreased significantly with increase in formalin concentration. The hardness of fish muscles increased with increase in formalin concentration and the value increased by 80% in the fish treated with 10% formalin. Similarly, the chewiness of muscles increased by 16–121% compared to untreated fish. Moreover, the total bacterial load on fish muscles also reduced markedly. In order to reduce formalin content in fish, formalin-treated fish was washed in running tap water, saline water and tepid water separately up to 30 minutes and thereby the content got reduced to the acceptable label in 20 min, 20 min, and 10 min respectively. Similarly, treated fish was fried for five minutes and content was reduced to acceptable limits. From the results, it was observed that formalin treatment not only reduced bacterial load but also impacted the texture of the fish muscles, creating the impression that the fish is fresh. Tepid water washing and frying process were effective in reducing formalin content in fish muscles.