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This study is aimed to observe changes in fatty acid profiles by time of flight secondary ion mass spectrometry (ToF-SIMS) in breast muscle tissues of broilers. Four different groups were identified. The source of fat in group I was soy oil (rich in linoleic acid, ω-6), group II received linseed oil (ω-3), and the third group was fed a mixture of the two mentioned oils. Broilers in the control group were fed with beef tallow, used in mass commercial production. The results reveal that the use of vegetable oils in animal nutrition determines the lipid profile of fatty acids. ToF-SIMS measurements showed that the lipid profile of muscle fibers and intramuscular fat reflect the composition of fats used as feed additives. In both structures, the ratio of ω-6/ω-3 fatty acids, which is most favorable for human health, was found in the groups in which a mixture of vegetable oils and a supplement of linseed oil were used., (© 2019 John Wiley & Sons, Ltd.)

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.

This study evaluated the effect of ageing time (45 min, 24 h, 96 h and 168 h) on desmin degradation pattern, meat quality and muscle fibre traits in longissimus lumborum (LL) and adductor (AD) muscles of 28 Polish Landrace fatteners slaughtered at 105 kg body weight. The results indicate that the rate of desmin degradation depends on pH and type of muscle, and thus on muscle fibre composition. In AD muscle, characterized by significantly higher pH45, pH24 and shear force values, lower drip loss, significantly higher percentage of type I and IIA oxidative fibres, and lower percentage of type IIB glycolytic fibres, desmin degradation is slower than in LL muscle. The rate of desmin degradation is also associated with its localization in muscle fibre. Regardless of muscle type, in all muscle fibres desmin was degraded more rapidly within, rather than at the periphery of the fibres. Additionally, levels of intact desmin and drip loss during postmortem meat storage contribute significantly to a reduction in the diameter of three fibre types analysed in AD and LL muscles 24 h postmortem and of type IIB fibres in AD muscle 96 hpostmortem. Furthermore, the decrease in the level of intact desmin is paralleled by a cumulative increase in drip loss and a decrease in shear force at 45 min, 24 h and 96 h postmortem.

In 54 Puławska pigs and 60 Polish Large White pigs (PLW), slaughtered at 30 and 100 kg body weight, carcass and meat quality of m. longissimus lumborum were studied. Analysis revealed that in both examined body weight groups, hot carcass weight, carcass yield percentage, meat content, and weight of ham and carcass ham percentage were significantly lower and backfat thickness higher for Puławska pigs compared to PLW pigs, while PLW pigs exhibited significantly longer carcasses, greater loin eye area, and, in the case of lighter pigs, smaller proportion of loin in the carcass. Muscles of Puławska pigs, in the lighter group, had higher IMF content and a* value, while in the heavier group they exhibited higher pH(45), pH(24) and a* values, lower L*, drip loss, WHC, and thermal loss compared with PLW pigs. PLW pigs had higher WB and hardness values and more glycolytic muscles characterised by higher TNF., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Changes in the structure and properties of the intramuscular connective tissue, muscle fibre size, collagen content and meat tenderness of m. longissimus lumborum during growth was studied in 45 Polish Large White (PLW) pigs slaughtered at 90, 150 and 210 days of age. The results show that the endomysial sheath in m. longissimus lumborum consists of collagen fibrils of wavy appearance which run in all directions and form a loose network. The arrangement of collagen fibrils in the endomysium and perimysium becomes denser and more regular with increasing age of pigs. In addition, the increase in endomysium and perimysium thickness was paralleled by a significant increase in muscle fibre diameter, as well as an increase in shear force value with chronological aging. In contrast, the percentage of collagen area in muscle structure and the amount of total collagen and amount of soluble collagen decreased gradually with age of pigs. In conclusion, the structural changes in the arrangement of collagen fibres in the architecture of intramusclular connective tissue, as well as the decrease in soluble collagen content in m. longissimus lumborum during growth of pigs are important factors influencing shear force value, and thus raw meat tenderness.

Carcass, meat quality and muscle fibre traits of m. longissimus lumborum were studied in 61 Zlotnicka Spotted (ZS) pigs and 35 commercial crossbred (Polish Large White x Polish Landrace) pigs. The animals received organic feed ad libitum and were slaughtered at 210 days of age. The current findings indicate that both slaughter weight and cold carcass weight were significantly lower, and backfat thickness higher for ZS pigs compared to commercial pigs, while the commercial pigs exhibited longer carcasses and greater area, height and width of the loin eye. No significant differences were found in IMF content between the analysed groups. Moreover, the percentage of type I fibres was higher and their diameter was larger in m. longissimus lumborum of ZS compared to commercial pigs, whereas the opposite occurred for type IIB fibre percentage and diameter, and that concurred with markedly higher pigment content and higher pH(u), redness (a*), plasticity values, and significantly lower drip loss, WHC--loose water, and colour lightness (L*) values in ZS pigs than those found in commercial pigs. Also, sensory assessment of raw meat confirmed that m. longissimus lumborum of ZS pigs was characterized by more favourable colour and less exudative meat.

The influence of RFLP-BsrI polymorphisms at the ghrelin gene locus on carcass, meat quality parameters and muscle fiber characteristics of longissimus lumborum was studied in 168 barrows of the Polish Landrace breed. Analysis revealed a high frequency of the 1 allele (0.60) with the frequencies of the 11, 12 and 22 genotypes being 0.45, 0.30 and 0.25, respectively. The most favorable parameters of meat traits were characteristic of pigs with the 22 genotype, together with a higher carcass and loin weight and lower thermal loss compared to 12 heterozygotes. The highest fat content was found in pigs with the 11 genotype, which had the highest abdominal fat weight and mean backfat thickness. Meanwhile, the 12 heterozygotes were characterized by the largest loin eye areas, highest lightness (L*) and yellowness (b*) values, and lowest redness (a*) values, as well as the greatest hardness and chewiness and largest diameter of type IIB muscle fibers compared to the other genotypes., (Copyright © 2011 Elsevier Ltd. All rights reserved.)