Study of cholesterol and vitamin E levels in broiler meat from different feeding regimens by TOF-SIMS

The quality of chicken meat, which is one of the most widely consumed meats in the world, has been the subject of research and studies for many years. There are several ways to improve the quality of this type of meat, including changing the concentrations of individual molecular components. Such important components of meat are inter alia, cholesterol, vitamin E, and some fatty acids such as ω-3 and ω-6. Manipulation of ingredient levels may be achieved by enriching chicken feed with elements of different types such as vegetable oils, garlic, or selenium. Thus far, various biochemical and biophysical methods have been used to study quality of different meat types, especially broiler meat. Here, the authors demonstrate the use of high-resolution time-of-flight secondary ion mass spectrometry (TOF-SIMS) mass spectrometry to assess how variations in animal nutrition affect concentrations of specific lipids in the meat, such as cholesterol and vitamin E. In the presented experiment, there were four different dietary treatments. Feed for animals in the first group was supplemented with soy oil in 50%, the second group's feed was supplemented with linseed oil in 50%, a combination of these two oils in the proportion of 44%:56% was used for the third group, and in the reference group, animals were fed with beef tallow. From each group, four individuals were selected for further analysis. Positive and negative ion mass spectra were generated from the pectoralis superficialis muscle tissue of the left carcass side of each one animal. Using TOF-SIMS with a bismuth cluster ion source (Bi3 (+)), and based on characteristic peaks for cholesterol in the positive mode and vitamin E in the negative mode, the authors have illustrated the relationship of these lipids levels to the various feeding regimens. Simultaneously, the authors characterized the varying dependences on the concentrations of measured lipids in fat and muscle fibers. The cholesterol concentration in muscle fibers was the lowest in the group fed with soybean oil and the highest in reference group IV (tallow feed). In the fatty region, the highest level of cholesterol was found in the third group. The highest concentrations of vitamin E were found in the fibers of the first group and the fat region of the second group. The obtained results show that SIMS imaging is a useful approach for assessing changes in lipid concentrations in the meat tissue from animals on different diets and provides a foundation for future research.