Pangasius Catfish Feeding with Flammulina velutipes Extract Decreases the Disease Ratio, Prevents Lipid Oxidation, Structure Damage and Color Changes during Cool Preservation

The effect of dietary supplementation of Flammulina velutipes concentrated extract (CE) on catfish fillet quality under cool preservation was evaluated. The catfish were fed by feed supplementing with 0% to 15% CE during the growth phase. After 30 days, the fish were filleted and stored at 4 ± 0.2°C for 7 days. The results showed that with 10% CE, the fish produced the best growth performance from 605 to 1106 g, corresponding to the lowest disease rate of 1.5%. Ergothioneine in muscle reached the highest value at 20.63 ± 1.35 mg/Kg. During the preservation, ergothioneine, 2,2-Diphenyl-2-picrylhydrazyl (DPPH) and lipid decreased slightly while free fatty acid (FFA) increased gradually until day 7. Peroxide and thiobarbituric acid reactive substances increased slowly after 7 days to 0.90 and 0.55 mg/Kg MDA, respectively. The b* value and total color variation (∆E) showed the slowest increase of −0.21 ± 0.67 and 46.85 ± 0.97, respectively, while the a* value decreased gradually during storage. pH decreased slightly on day 1, then increased to 6.4 ± 0.2 on day 7. The fillet was firmer on day 1, then decreased gradually in all treatments. Therefore, an increasing ergothioneine in catfish muscle leads to higher growth performance with a low disease rate and helps to prevent lipid oxidation, improving color and structural stability.