THE EFFECT OF DIETARY ANTI-OXIDANTS ON THE SHELF LIFE OF PELLET FED SOUTHERN BLUEFIN TUNA (THUNNUS MACCOYII)

摘要

The distinctive and commercially important red colour of farmed southern bluefin tuna (SBT) sashimi meat is primarily due to the myoglobin content of the muscle. Myoglobin is prone to oxidation and browning and the rate of the discolouration is a shelf life indicator routinely used by the consumer as an indicator of quality. The ability to influence the rate of SBT sashimi discolouration has the potential to increase the market acceptability of this product and thereby increase returns to the producer. Anti-oxidants have been used to decrease the rate of muscle browning in beef and the reduced postmortem oxidation rate of lipids in fish Baker, (1997). We have previously demonstrated that increasing the tissue level of vitamins E & C reduces the rateof discolouration in tuna flesh Buchanan and Thomas (2001). In an effort to determine the most cost effective use of anti-oxidants, the current study examines the effect of a higher dietary level of the vitamin E alone, in comparison to a combination ofhigher selenium, vitamin E and C.