The Effects of Sequential Environmental and Harvest Stressors on the Sensory Characteristics of Cultured Channel Catfish (Ictalurus Punctatus) Fillets.

Abstract

Stress during fish culture alters physiological homeostasis and affects fillet quality. Maintenance of high-quality seafood is important to ensure the production of a marketable product. This study assessed how sequential stressors affect the sensory and quality characteristics of catfish (Ictalurus punctatus) fillets. Three stress trials were conducted where temperature (25 or 33 °C) and dissolved oxygen (DO, approximately 2.5 or >5 mg/L) were manipulated followed by socking and transport stress. After each stage of harvest (environmental stress, socking, and transport), fillet yield, consumer acceptability, descriptive evaluation, cook loss, tenderness, and pH were evaluated. Fillet yield decreased with increasing severity of environmental stress. Fillets from the severe stress treatment (33 °C, approximately 2.5 mg/L) received the highest acceptability scores (P < 0.05). Control fillets (25 °C, >5 mg/L) were the least acceptable (P < 0.05). Increased intensity of less favorable flavor attributes commonly associated with catfish resulted in the differences in acceptability among treatments. As fish progressed through the harvest event, cook loss decreased, tenderness increased, and pH increased, indicating that stress induced textural changes. The data suggest that although environmental stress results in slight changes in flavor attributes, its effects on acceptability are minor with fillets from all treatments still liked (>6 on a 9 point scale). Socking and transport were identified to positively affect textural characteristics of catfish fillets. Although the effects observed were not likely to negatively impact consumer acceptance, a strict management plan should be followed to maintain consistency in the product and avoid changes in stressors that might alter quality more drastically.