Emine Özpolat

Effects of water extract of propolis on fresh shibuta (Barbus grypus) fillets during chilled storage

The present study examined the effects of water extract of propolis on the chemical, microbiological and sensory quality in vacuum-packed fresh shibuta (Barbus grypus) fillets during storage at 2°C. Treatments in the study included the following: control (P0) without extract of propolis, 0.1 (P1), 0.3 (P3) and 0.5 (P5) % (v/w) the water extract of propolis, respectively. After 24 days of storage, the total volatile basic nitrogen (TVB-N) values were 57.76, 44.66, 42.23 and 36.5mg/100g, and total viable counts (TVC) were 8.9, 8.3, 7.96 and 6.95logcfu/g, for water extract of propolis additions of 0.1 (P1), 0.3 (P3), 0.5 (P5) and 0 (control; P0) % (v/w), respectively. The highest acceptable TVB-N value was adopted as 30 mg/100g, corresponding to shelf lives of 9, 15, 18 and 21 days for P0, P1, P3 and P5, respectively. Addition of 0.1% water extract of propolis extended the products shelf-life by approximately 6 days, whereas the 0.5% water extract of propolis resulted in a significant shelf-life extension of the shibuta fillets, i.e. by approximately 12 days, according to sensory data, as compared to the control sample.

Determination of Lipid Peroxidation and Fatty Acid Compositions in the Caviars of Rainbow Trout and Carp

ABSTRACT In this study, roes obtained from carp (Cyprinus carpio carpio) that were caught in Keban Dam Lake (Turkey) and cultured rainbow trout (Oncorhynchus mykiss) were processed as caviar, and the products were stored at + 4 C°. Lipid peroxidation and the compositions of fatty acids of these products were assessed during production and storage period. The result of fatty analyses showed that palmitic acid (16:0), stearic acid (18:0), palmitoleic acid (16:1), oleic acid (18:1), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), which are all essential fatty acids, were determined in the caviars of the roes obtained from rainbow trout and carp. According to results of chemical analyses, there were no significant differences in thiobarbituric acid reactive substances (TBARs) between rainbow trout and carp caviars (p > 0.05), but malondialdehyde (MDA) levels were found to be statistically significant (p < 0.01). It can be concluded that caviars obtained from both rainbow trout and carp roes are rich in fatty acids and take a part in a balanced and healthy diet.