In this study, antibacterial and antifungal properties of four medlar extracts obtained using four different solvents, ethanol, methanol, acetone and water, were investigated. The disk diffusion method was used to determine the antimicrobial effects of the extracts. In addition, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and minimum fungicidal concentration (MFC) values were determined. The antibacterial effect of the pure water extract of medlar on S. aureus bacteria was found to be high (11.46 mm). In addition, the MIC and MBC values of the pure water extract were determined as 35.15 and 23.39 µg/mL for S. aureus bacteria. When the antifungal effect was examined, the antifungal effect of the pure water extract of medlar against P. crysogenum was found to be high (14.00 mm). The MIC and MFC values of the pure water extract of medlar are 23.43 and 11.72 µg/mL for P. crysogenum, respectively. Therefore, it was concluded that the pure water extract had the highest antimicrobial effect.

This study investigated the microbiological, physicochemical, textural, and sensory characteristics of ayran and kefir samples produced from milk treated with different doses of UV-C radiation. For this purpose, raw milk was passed through a UV-C column at three different flow rates (15, 30, and 45 mL/min), and irradiated with doses of 72, 36, and 24 J/mL, respectively, corresponding to the flow rate. Samples produced from milk pasteurised by thermal treatment were used as the control group. This research indicated that UV-C treatment effectively reduced the microbial load in milk to a level comparable to that achieved through conventional pasteurisation. A reduction of 2.15 log cfu/mL in total aerobic mesophilic bacteria count was achieved, while total coliform group bacteria counts were decreased to an undetectable level. Samples produced from milk treated with UV-C showed lower pH and higher titration acidity (% lactic acid). Furthermore, the organic acid content was higher in these samples. Lactic acid, the main organic acid, levels in the ayran and kefir samples were measured at their highest as 11,951.51 mg/kg and 12,989.34 mg/kg, respectively, in the UV45 sample with a radiation dose of 24 J/mL. The treatment of UV-C resulted in a minor change in the colour and textural properties of the samples. Nonetheless, this change was not significant enough to influence consumer acceptance. The application of UV-C to raw milk, depending on the radiation level used, can enhance the fermentation process in the production of ayran and kefir. This study showed that the application of UV-C has improved the quality of drinkable fermented milk products. This research has shown that, while reducing nutritional losses caused by thermal processing, microbial safety is obtained at an approximate value similar to pasteurisation. As a result, UV-C application decreases the loss of dietary compounds and provides an alternative method for microbial inactivation.

In this research, the suitability of tench (Tinca tinca L., 1758) for the production of fish cake and changes in nutrient components were determined. The supplied fish materials were minced followed by forming into fish cakes with the addition of various additives. Chemical and organoleptic analyzes of the minced fish and fish cakes were made. Also, thiobarbutyric acid (TBA), total volatile basic nitrogen (TVB-N), pH parameters were determined and total mesophilic aerobic bacteria (TMA), total psychophilic bacteria (TPA), coliform group bacteria, and yeast-mold counts were performed in fish cakes on the 1., 4., 7. and 10. days of the storage at 4 ± 1 °C. According to the organoleptic analysis findings, the fish cakes obtained from tench were considered suitable for consumption. TBA, TVB-N, pH values, and microbiological analysis results of storage have shown that deterioration occurs as storage time increases. Especially the changes after the 7th day of storage are statistically significant (p<0.05). As a result of the research, it is concluded that fish cakes made using tench can contribute to the economy. It was determined that the obtained fish cakes which were stored at 4±1° C maintained the good quality parameters until the 7th day while they deteriorated after the 10th day of the storage.