Comparative Assessment of Gill Cut and Water Perfusion Bleeding Methods on Freshness, Microbiological Stability, and Textural Properties of Asian Seabass (Lates calcarifer) Slices During Refrigerated Storage

Bleeding enhances fish quality by removing blood, which acts as a pro-oxidant and provides nutrients for microbes. However, the effects of bleeding techniques on freshness, quality, and fishy odor of Asian seabass remain unclear. Therefore, the effects of gill cut (GC) and water perfusion (WP) bleeding on slices during 12-day refrigerated storage were investigated. Freshness was retained in bled samples, particularly GC, as indicated by lower K-values during storage. Protein oxidation was higher in WP than GC samples, as shown by higher carbonyl content in the former during the storage. This coincided with lower sulfhydryl content, except during day 3–6 in which there was no difference between both samples. Similar fishy odor intensity between GC and WP was observed during storage, except GC showed lower intensity on day 6, whereas unbled samples (UB) exhibited higher intensity through the storage. Pearson correlation and principal component analysis (PCA) confirmed relationship among bleeding methods, microbial growth, and quality changes. Boxplot analysis supported the results by showing variation in quality indicators among treatments. GC therefore preserved freshness, retarded microbiological and biochemical changes, and retained textural properties. GC tended to reduce fishy odor formation more effectively than WP, particularly at intermediate storage stage.