رابطه بين تغييرات شيميايي ماهي كيلكا Clupeonella engrauliformis با افت وزني در طول مدت نگهداري در سردخانه 18- درجه سانتيگراد

An investigation on relationship of chemical indices of kilka (Clupeonella engrauliformis) with weight loss during cold storage at -18°C

We studied the relationship between physical and chemical properties of frozen kilka with weight loss for packed and unpacked products during storage at -18°C. Statistical analysis of the results including variance, Duncan test and ANOVA showed relationships existed between changes in Total Volatile Nitrogen (TVN), Peroxide Value (PV), pH, moisture, organoleptic properties of frozen packed and unpacked kilka with product weight losses during cold storage at -18°C. The statistical treatment of the results showed that weight losses for packed samples in comparison to unpacked one at the level of P<0.01 was significant. The weight losses, changes of TVN, PV, pH and moisture losses for unpacked samples were 1.5, 1.35, 4.5, 1.32 and 1.32 times more in comparison to the packed one, respectively. Also, the statistical analysis of the results showed a correlation between weight losses in unpacked samples of frozen kilka and the measured factors. The results of chemical and physical properties measured for packed samples of frozen kilka during cold storage and their statistical analysis showed a significant correlation P<0.01 between weight losses and the changes in TVN from 7 to 28mg/100gr, PV from 2.28 to 6.01meq/kg, pH from 6.08 to 6.37 and 1.72% loss in the moisture of the samples. According to these results and the organoleptic tests, the shelf life for packed and unpacked frozen kilka in cold storage at -18°C, is recommended 60 and 30 days, respectively.