Effect of bleeding on lipid oxidation and quality changes of Asian seabass (Lates calcarifer) muscle during iced storage

Lipid oxidation, microbial load and fishy odour development in the slices of bled and un-bled Asian seabass during 15. days of iced storage were comparatively investigated. Bled samples showed the lower peroxide value (PV) and thiobarbituric acid-reactive substances (TBARS) throughout the storage period (P<0.05). Bleeding effectively lowered the total haem and non-haem iron contents in Asian seabass slices. The release of non-haem iron was pronounced in the un-bled samples during the storage. Solid phase micro-extraction coupled with gas chromatography and mass spectrometric (SPME-GCMS) analysis revealed that the bled samples stored in ice for 15. days contained the lower amount of volatile compounds. Heptanal, the major volatile compound detected in the un-bled samples, was four-fold higher than that of bled counterparts. The contents of aldehydic compounds, including hexanal, octanal, nonanal and nonenal were also higher in the former. Bled samples had the lower fishy odour, compared with the un-bled counterparts during storage (P<0.05). The lower total viable counts (TVC) and psychrophilic bacterial counts (PBC) were observed in the bled samples, in comparison with the un-bled ones (P<0.05). Thus, bleeding was a potential means in retarding lipid oxidation, fishy odour development, and microbial growth of Asian seabass slices during storage in ice.