Effects of edible films containing oleoresin on shelf life and baking quality of chicken meat

In this study, it was aimed; to obtain edible films with antibacterial properties by adding the spice oleoresin, to extend the shelf life of chicken meat by wrapping with the obtained film, to provide flavor migration from films to meat and to cook chicken meat wrapped with the film for providing softer and more delicious products and to develop an alternative product existing PET bags that sold under the name of the oven bag. The study was conducted in three stages. In the first stage, the edible films were produced by casting method from film solutions prepared from sodium caseinate and sodium caseinate - starch mixture by adding oregano and cumin oleoresin. The volatile components content, antimicrobial, mechanical, visual and thermal properties of the produced films were determined. Also the water vapor permeability and water solubility were found. In the second stage wrapped chicken meats with edible films were stored at 4°C and growth of total coliform and psychrophilic aerobic bacteria in the chicken meat, the changes in pH, colour and the weight loss were determined during storage. The final stage wrapped chicken meat with edible film was cooked at 200 ° C for 30 minutes. The cooking loss and colour changes of roasted chicken meat was found. Shear force and shear energy values were determined with texture analyzer device and MORS set of knife by cutting test. The sensory evaluation was done to determine chicken meat flavor and softness. GC-MS analysis revealed that the films produced from sodium caseinate-starch mixture was more successful than sodium caseinate films as an oleoresin carrier. Edible film samples containing oleoresin did not show any antibacterial effect against strains of Escherichia coli ATCC 35218 (Gram -) and Staphylococcus aureus ATCC 43300 (Gram +). From mechanical properties, tensile strength values of the sodium caseinate based films (4.39-4.99 MPa) were higher than sodium caseinate-starch mixture films, however the percent elongation values of the films have not been affected from polymer types that was used in the film production. Also water solubility and water vapor permeability values of sodium caseinate based films were higher than sodium caseinate - starch mixture based films. In microbiologically, it was not observed any difference between the wrapped chicken meats with edible films and control groups during storage. However significant differences were determined in pH and water loss values. The pH of the control group chicken meat have started to increase after the third day of storage, and reached to 7.84 at the end of the tenth day. pH values of the wrapped samples with films were not considerably changed during storage, even at the end of the tenth day, their pH values were found near to the first day of pH value, that was 6.74. Cooking process with wrapped edible film, decreased cooking loss, shear force and shear energy values of chicken meats about 20-35%, 40% and 30% respectively. In sensory evaluation, baked chicken meats wrapped with films were evaluated as more tender and delicious by the panelists. Especially, the most delicious meats were the meats baked in the films containing oleoresin. In addition, the aroma migration was detected to chicken meats from films containing oleoresin. This thesis, the first research in this area, showed that edible films significantly improved cooking quality of the chicken meat and edible films could be alternatively used as synthetic oven bags.