Investigation of the effects of some propolis-containing packaging types on shelf life of foods

In this thesis, the effect of different applications of propolis solutions on the shelf life of foods was investigated. In this context, the surface of vacuum bags, stretch films and sealed bags, which are frequently preferred in the food industry, were coated by spraying the propolis-ethyl acetate solution. Red meat and cheddar cheese, which are among the consumption foods with high added value, were placed in these packages and kept in refrigerator (4 °C) conditions for 30 days for red meats and 90 days for cheddar cheese. In the study, it was also studied to spray propolis-propylene glycol solution directly on the product surfaces. As a result of all these processes, physical, chemical, microbiological and sensory analyzes were performed on red meat and cheddar cheese samples. First of all, it was determined that the highest phenolic compound amount of propolis used in the study was CAPE with 27.523.4 μg / g. Antibacterial activity analysis was performed on Escherichia coli (ATCC 8739) and Staphylococcus aureus (ATCC 6538P) bacteria with various concentration values in order to determine the appropriate concentration for the coating of selected packages and foods. It has been determined that the optimum concentration is 10% propolis-ethyl acetate for packages and 10% propolis-propylene glycol for direct spraying. It was determined that there was a statistically significant difference (p˂0.05) in the pH values of red meat and cheddar cheese, whose pH and water activity were analyzed on certain days, but there was no statistically significant difference (p˃0.05) in the water activity values. In general, it was determined that the pH values of the samples in the packages covered with propolis were lower. A statistically significant difference (p˂0.05) was found in the results of microbiological analyzes (total mesophil aerobic bacteria, Enterobacteriaceae, Pseudomonas and lactic acid bacteria count) applied to red meat samples and cheddar cheeses. It was determined that the bacteria counts of the samples kept in packages covered with propolis were lower than those of uncoated packages. It was determined that the sample in the vacuum bag with propolis had the best results. According to the sensory analysis carried out on the cheddar cheese, when the general taste scores of cheddar were examined, it was seen that the cheddar sample kept in a vacuum bag with propolis had the highest score.