The effect of feeding with sodium bicarbonate feed on the chemical quality of rainbow trout (Oncorhynchus mykiss) duringcold storage

The effect of sodium bicarbonate (SB) supplementation to fish feed on the quality characteristics of rainbow trout (Oncorhynchus mykiss)under post-harvest cold storage conditions was investigated in this study. Rainbow trout fed with 0, 1M, 2M and 3M SB supplemented diets for 21 days before harvesting were stored at 4oC. The highest post-harvest pH level was observed in the group fed with 2M and 3M SB. TVB-N value was found between 14.88-15.68 mg/100g in fish fed with 1M, 2M and 3M SB supplemented diets, while it was determined as 20.14 mg/100g for control group. On the 13th day of storage, the TVB-N value of the group fed with 3M SB supplemented feed (29.10 mg/100g) was found to be significantly lower than the control group (37.21 mg/100g). At the beginning of storage, similar TBARs values were observed in all groups; howeverthe increase in TBARs in the groups fed with SB supplemented feeds was slower than the control. Sensory scores of trout fed with SB supplemented diets at the beginning of storage were higher than the control group. However, no difference was determined between the groups in terms of shelf life (13 days). The best texture scores were observed in the 3M group throughout the whole storage period. Therefore, it can be concluded that SB addition to pre-harvest rainbow trout feeds can be used as a feed supplements to improve quality of fish flesh. Keywords: Sodium bicarbonate, rainbow trout, pH, cold storage, post-harvest quality