Effect of Formaldehyde on the Gel Forming Ability of Fish Meat

Abstract

The gel forming ability of dorab meat and washed dorab meat with the addition of 0, 25, 50, 75, 100, 200, 300, and 500 ppm of formalin solution was determined. Three levels of heating: (1) 40^oC 30 min, (2) 90^oC 30 min, and (3) 40^oC 30 min followed by 90^oC 30 min were used for heating fish meat gel. The SDS-PAGE analysis was also carried out. The results showed that gel force, deformation and gel strength of dorab meat were higher than washed dorab meat with and without formalin addition at all heating temperatures (P>0.05). After the addition of formalin solution, the gel force, deformation and gel strength of fish meat gels decreased at all heating temperatures. The addition of formalin at ≥100 ppm affected the gel forming ability of washed dorab meat. Their gel strength was lower than 200 g.cm and formalin smell could be perceived. The fish gels heated at 40^oC and 40^oC/90^oC provided higher gel properties than those heated at 90^oC. According to a SDS-PAGE analysis, the protein patterns of samples without the formalin solution correlated to their gel forming ability. Samples with 100, 200, 300, 500 ppm formalin solution showed the loss of myosin heavy chain and actin bands at 90^oC. It seemed likely that formaldehyde affected not only the gel forming ability of myofibrillar proteins but also the conformation of these proteins.