Ergothioneine accumulated in the catfish muscle by supplementation of Flammulina velutipes extract prevents lipid oxidation, improves color stability, and limits soft structure of the fillet during frozen storage

Abstract

This study aimed to evaluate whether ergothioneine (ESH) accumulated in catfish muscle affected to fillet quality during frozen storage. The fish after fed by feed supplemented 0 to 15% concentrated extract (CE) from Flammulina velutipes for 30 days were filleted and stored at −18 ± 0.2°C for 90 days. The results show that with 10% CE, the highest accumulation of ESH in fish muscle was 21.02 mg/Kg. During preservation, ESH decreased gradually with DPPH. Peroxide and FFA were the lowest value at 1.09 meq/Kg and 0.35% on day 90, respectively. L* achieved lower while a* and b* values were quite stable during the first 60 days. The a* dropped slightly, but the b* and ∆E increased slowest from days 60 to 90. The muscle hardness was more stable during storage. Therefore, high accumulation of ESH in catfish muscle could prevent lipid oxidation, improving color stability, and limit soft structure during frozen storage. Novelty impact statement The Pangasius processing industry in the Mekong Delta depends on the catfish harvest time point and export demand, so it usually needs 1 to 3 months preservation in the freezer in which the quality of the fillet may be changed. The results from this study indicated that the highest ESH accumulation corresponding to 10% CE of F. velutipes supplemented with feed for 30 days feeding showed the most effectiveness during 90 days preservation in terms of limiting lipid oxidation, preventing discoloration, and making the fish structure less soft after thawing from frozen storage. Therefore, the supplementation of F. velutipes during feeding shows a great solution for improving catfish fillet quality during frozen storage.