The effect of different rates of pomegranate (Punica granatum) juice usage in sausing on the physical, chemical, microbiological and sensory quality of pike-perch (Sander lucioperca) marinates

"Pike-Perch", which can be found in various freshwater sources in Turkey, is usually being exported in frozen form. The aim of the study was to determine the effects of marination, as well as using various rates of pomegranate juice on the quality of marinates. In this objective, fresh pike perch fillets were marinated in solution containing 4% acetic acid and 10% salt. Marinates produced with fresh pike perch fillets have been allocated to one of 4 groups sauced with, 100% olive oil (Group control), 75% olive oil and 25% pomegranate juice (Group A), 50% olive oil and 50% pomegranate juice (Group B), 25% olive oil and 75% pomegranate juice (Group C). All groups have been stored at +4oC for 120 days. To determine the quality of fresh pike perch fillets and marinates, physical-chemical analyses (dry matter, ash, fat, protein, salt, pH, acidity, color, total volatile basic nitrogen and thiobarbituric acid), microbiological parameters (total mesophilic aerobic bacteria, total psychrophilic aerobic bacteria, coliform bacteria, lactobacillus bacteria, Staphylococcus-Micrococcus bacteria, yeast and mold, sulphate-reducing bacteria) and sensory analysis were used. Pomegranate juice is found to be decreasing the dry matter, ash, fat, protein and salt in the pike perch marinates. There was not a statistical difference between acidity levels in control and pomegranate juice groups at the end of the storage period. It was shown that pomegranate juice reduces L* (brightness) value, while increasing a* (redness) value. During storage, highest pH values were in control group with no statistical difference between group A (p>0.05), whereas the difference between control and B, C groups were significant (p<0.05). In terms of chemical parameters, usage of pomegranate juice prevented any increase in total volatile basic nitrogen (TVB-N) and thiobarbituric acid (TBA) levels with a significant difference between control and pomegranate juice groups (p<0.05). During storage period, coliform bacteria and sulphate-reducing bacteria was not isolated in any marinate groups. After the marination, total psychrophilic aerob bacteria, yeast and mold numbers were found to 1,5 log cfu/g, but these microorganisms were below the detectable number at the end of the storage period. On the other hand, lactobacillus group and Staphylococcus-Micrococcus bacteria were detected after day 120, group C had the highest counts of 3.61±0.31 and 3.64±0.34 log cfu/g, respectively. Considering the sensory assessments, scores of marinate group A were higher than any other group through storage, but the difference between group A and control was not statistically significant (p>0.05). Even though TVB-N, TBA values and microbiological results showed that marinates still had enough quality to be consumed after 120 days in storage period, sensory assessments concluded that marinates were not suitable for consumption after 90 days. Consequently, it is thought that pike perch has the possibility to be used in marination technology, due to can be economically more valuable. Pomegranate juice, which is used in the sauce of pike-perch marinades, gives flavor, aroma, and color to the product, also supports the preservation of acidic structure in the product and may have positive effects on consumer health with many useful bioactive compounds.