Effects of Feeding Regimes and Postmortem Aging on Meat Quality, Fatty Acid Composition, and Volatile Flavor of Longissimus Thoracis Muscle in Sunit Sheep

Abstract

The effects of different feeding regimes on antioxidant activity, meat quality, fatty acid composition, lipid oxidation, and volatile matter production in the longissimus thoracis (LT) of Sunit sheep at 0, 24, 48, 72, and 96 h postmortem were investigated. The results showed that the activity of antioxidant enzymes, tenderness, water retention, and percentage of unsaturated fatty acids were significantly higher in the pasture-fed sheep (PF) than in the concentrate-fed sheep (CF) (p < 0.05). During postmortem aging, antioxidant activity, water retention, and the proportion of unsaturated fatty acids decreased in the PF and CF (p < 0.05), while malondialdehyde (MDA) content, the proportion of saturated fatty acids, and the content of flavor substances resulting from fat oxidation increased. After 24 h of LT muscle aging, the pH and shear force of the meat started to increase and the color stabilized. The differences between shear force values and lipid volatile flavor substance content of sheep meat under different feeding regimes disappeared with increasing aging time. PF had better oxidative stability and fatty acid composition. Postmortem aging changed the oxidative stability of sheep meat, thus affecting meat quality and fatty acid composition and consequently meat flavor composition, while aging also eliminated to some extent the differences caused by feeding regimes.

Physicochemical Characteristics, Selected Lipid Content and Protein Bioactive Compounds of Lamb Meat Depending on Aging Time and Muscle Type

“…An increase in fat can decrease collagen content, which was also observed in the present study [44] Although the study found no significant differences in the content of SFA, MUFA, PUFA fatty acid groups and in the content of the main isomer of C18:2 cis-9, trans-11 linoleic acid either between fresh and aging meat or between the muscles studied, it should be noted that meat after aging in both GM and LL muscles was characterized by an increase in SFA content and a decrease in MUFA and PUFA (Table 3). A similar variation in fatty acid content during aging was obtained by Yang et al [11] in a study of m.l.d. muscle in Sunit sheep subjected to different feeding regimes.…”

“…Decreasing pH values in lamb meat with aging up to 35 days were recorded by Gramatina et al [13] in a study comparing the quality of beef, lamb and pig meat. A significant reduction of this parameter, but during 0 and 24 hours after slaughter, was recorded by Yang et al [11] in LT muscle of Sunit sheep, which the authors explained by the accumulation of lactic acid during the process of anaerobic glycolysis. In this studies, there was no effect of muscle on the pH value either in fresh meat and after 7 and 14 days of aging.…”

“…Color is a key indicator of meat quality for consumers, who consider meat color to be the main criteria for judging whether meat is fresh or not, which does not go unchallenged in the decision to buy it [33]. One of the factors influencing changes in meat color may be the storage method and aging period [11] The darkening of meat expressed by a higher saturation of readness and an increase in Chroma values in gluteus medius muscle along the aging period obtained in the present study was confirmed by Yang et al [11] analyzing changes in quality parameters in lamb meat from 0 to 96 hours. Likewise, Abdullach and Qudsieh [7] reported a significant increase in a* value with a slight decrease in L* value after 7 days aging of meat compared to fresh meat in Awassi lambs.…”

“…Many studies have shown that breed, age at slaughter, the feeding system and related muscle development and the proportion of different types of muscle fibers determine important meat characteristics for the consumer, such as color, tenderness, juiciness or intramuscular fat content, as well as the presence of biologically active ingredients [3][4][5][6][7][8][9][10][11]. The quality of the meat is also affected by physiological, biochemical and metabolic changes that occur during meat aging.…”

Advances and applications in water retention technology for meat and meat products: Status and future research directions

“…The cooking loss rate of the longissimus thoracis muscle in the concentrate-fed was significantly higher than that in the pasture-fed. (Yang et al, 2022) Finishing pigs A 2 9 2 factorial arrangement with two levels of valine and two levels of isoleucine constituted four dietary treatments Drip loss and cooking loss increased at higher levels of valine in the feed, and high levels of isoleucine reduced meat drip loss (Xu et al, 2020) Crossbred pigs Addition of different types and levels of selenium to feed for feeding, respectively…”