The effects of olive oil usage as a beef fat replacer on the protein oxidation of beef and turkey sucuks produced by different methods

In this thesis, it was aimed to investigate the effect of different fat/oil combination (100% beef fat, 85% beef fat + 15% olive oil, 70% beef fat + 30% olive oil and 55% beef fat + 45% olive oil) and determine the specific protein oxidation products, the relationship between lipid and protein oxidation and the changes in product quality and bioavailability related to protein oxidation progress in fermented and heat-treated beef and turkey sucuk. Sucuk production is a process consisting of fermentation, ripening and/or heat treatment. Proteolytic and lipolytic reactions occurring in proteins during production significantly affect the flavor and texture of the product. For this reason, as oxidation reactions occurring in proteins during production steps has a great importance on overall quality of final product, it becomes considerable to analyse the reactions at each stage of the production. Due to different specific factors in protein oxidation progress, it is a fact that the variables like meat type, fatty acid composition and production techniques could highly affect oxidation mechanism. For investigation of different specific oxidation products particular to variables, three different trials have been organized in this thesis. Accordingly, fermented beef sucuk at 1st trial, fermented turkey sucuk at 2nd trial and heat-treated turkey sucuk at 3rd trial will be produced using different lipid compositions and the progress of protein oxidation and its effects on product quality will be investigated in sucuk dough, after fermentation and/or heat-treatment steps, in final product and during storage. According to analysis results, heat-treated sucuk samples were found to be more sensitive to lipid and protein oxidation compared to fermented sucuks. In addition, it was concluded that the meat used during the production also had an effect on the oxidation of the product. Peroxide and carbonyl values of sucuks produced from turkey meat were found to be higher. Decreasing in the bioavailability of the sucuk samples was observed during production steps and storage period. No stable change in the amount of specific protein oxidation products which were AAS (α-aminoadipic semialdehide) and GGS (γ-glutamic semialdehide) was observed. This may be related to a one-to-one conversion of semialdehydes. In addition to all these results, using of olive oil d as an animal fat substitute in the formula causes change in the the quality and oxidation properties of sucuk samples .