INVESTIGATION OF QUALITY CHARACTERISTICS OF RESTRUCTURED BEEF STEAKS PRODUCED BY USING TRANSGLUTAMINASE AND DIFFERENT PROTEIN SOURCES
Project no. 29559 · Status: Kapanmış (Yayın bekleniyor) · 2023
Summary
<p>In this thesis, it was aimed to compare the effects of the use of plant and animal protein sources on the binding properties and oxidation reactions of beef steaks restructured using microbial transglutaminase (MTG) under different pre grinding conditions (in cubed and flake form), to examine the effects on the technological and sensory properties of these products and to observe the oxidation processes occurring in proteins due to the use of MTG. In the study consisting of two different trials; in Trial I, the use of pumpkin seed protein (KCP) and whey protein (PSP) together with MTG in restructured steak products using beef prepared in cubed form as raw material, and in Trial II, the effects of the use of the same protein sources together with MTG on technological quality, lipid-protein oxidation and sensory properties in restructured steak products prepared with beef prepared in flake form were investigated. In the restructured beef steaks produced in Trial I, the addition of microbial transglutaminase and different protein sources led to an increase in ash content. During the storage period, the L* value of the samples to which KCP was added decreased, while the other samples had similar L* values at the beginning and end of storage. The water holding capacity of the samples to which PSP was added was found to be higher than the samples containing KCP. The use of MTG alone or in combination with KCP and PSP caused a decrease in protein solubility. Hardness, springiness, stickiness, gumminess and chewiness values of the enzyme-treated ix sample groups were higher than the control group. Low TBARS values were observed in the groups containing pumpkin seed and whey protein during storage. Carbonyl content increased during storage in all groups, whereas sulphydryl content showed a decreasing tendency, and enzyme and added protein sources were not found to be effective on protein oxidation. It was determined that the surface hydrophobicity values of the sample groups containing MTG decreased. In sensory evaluations, the restructured sample groups received acceptable scores, and FTIR, SDS and TEM images revealed findings supporting the textural development of the restructured beef steaks. In the restructured beef steaks produced in Trial II, the addition of microbial transglutaminase and different protein sources resulted in a reduction in ash content. In colour analysis, pumpkin seed protein increased the lightness and yellowness values, while all colour parameters decreased during the storage period. TBARS and carbonyl values increased during storage, while sulfhydryl groups decreased. A decrease in surface hydrophobicity values was observed with the addition of microbial transglutaminase. TEM and FTIR images revealed that the protein particles formed a dense network structure and the microstructure exhibited a firmer binding. In the sensory evaluation, the experimental groups were generally acceptable and it was found that the restructured groups of samples obtained better results in terms of appearance compared to the control group. Microbial transglutaminase was found to reduce protein solubility and promote polymer formation by covalent bonds, which was confirmed by the decrease in MHC band density in SDS profiles. In conclusion, the effects of the use of microbial transglutaminase and different protein sources on product quality in restructured beef steaks produced with different formulations and parameters were examined and it was concluded that these methods offer an economical alternative to consumers by formulating reduced salt and trimmed meat with enzymes and different protein sources. </p>