تاثیر روش های کشتار بر کیفیت ماهی قزل آلای رنگین کمان (Oncorhynchus mykiss) طی نگهداری در دمای 4 درجه سانتیگراد

In this study the effect of different slaughter methods were examined on the quality of rainbow trout during 12 days storage in refrigerator. Treatments were included choked (suffocated) the fish out of water (control), blows to the head with a mallet, cut the base of gill and abdominal drain and the use of water and ice and then hit in the head with a mallet. Peroxide value in abovementioned treatments were increased from 0.96 to 11.03, from 0.92 to 10.60, from 0.86 to 10.20 and from 0.88 to 10.40 meq/kg during storage at 4 ºC, respectively. There were significant differences (P<0.05) in peroxide value (PV), thiobarbituric acid (TBA) and free fatty acid (FFA) content between different slaughter treatments during storage in refrigerator. Slaughter treatments had significant effect on bacterial loading. Lower mesophilic and TVC count during storage period was observed in use of water and ice and then hit in the head treatment followed by cut the base of gill and abdominal drain treatment. All treated samples reached to 7 logCFU/g at day 9. The result showed that gill based amputation treatment had best impact on the quality of rainbow trout during storage period.