Effect of artificial formaldehyde treatment on textural quality of fish muscles and methods employed for formaldehyde reduction from fish muscles

Abstract

The influence of treatment of three different concentrations of formaldehyde on fish muscles textural quality was determined using spectrophotometric and reverse phase high-performance liquid chromatography (RP-HPLC) methods. The experimental fish treated with 1, 5 & 10 % formaldehyde for 5 min and as a result, the residual content was enhanced to almost 7, 11 and 15 times respectively. The hardness and chewiness of fish muscles increased with increase in formaldehyde concentration and the values increased by 80 and 121 % respectively in the fish treated with 10 % formaldehyde. In order to reduce formaldehyde content in fish, formaldehyde-treated fish was washed in running tap water, saline water and tepid water separately for a period up to 30 minutes and thereby the content got reduced to the acceptable label in 20, 20, and 10 min respectively. Similarly, treated fish was fried for five minutes and content was reduced to acceptable limits. Overall, this study could establish that formaldehyde treatment not only reduced bacterial load but also improved the textural properties of the fish muscles, creating the impression that the fish is fresh. Tepid water washing and frying process were effective in reducing formaldehyde content in fish muscles.