There are limited reports about the effect of different heat treatments on the quality and flavor of Black Tibetan sheep meat. The current study examined the effect of pan-frying, deep-frying, baking, and boiling treatment on the quality of Black Tibetan sheep meat; the amino acid, fatty acid, and volatile flavor compounds (VFCs) were investigated by a texture analyzer, ultra-high-performance liquid chromatography (UHPLC), gas chromatography (GC), and headspace-gas chromatography-ion mobility (HS-GC-IMS). The key VFCs were identified through orthogonal partial least squares discrimination analysis (OPLS-DA), and variable importance projection (VIP) values. In addition, Pearson’s correlations between meat quality parameters and key VFCs were examined. The sensory scores, including texture, color, and appearance, of baked and pan-fried meat were higher than those of deep-fried and boiled meat. The protein (40.47%) and amino acid (62.93 µmol/g) contents were the highest in pan-fried meat (p < 0.05). Additionally, it contained the highest amounts of monounsaturated and polyunsaturated fatty acids, such as oleic, linoleic, and α-linolenic acids (p < 0.05). Meanwhile, pan-fried and deep-fried meat had higher amounts of VFCs than baked meat. The OPLS-DA similarity and fingerprinting analyses revealed significant differences between the three heat treatment methods. Aldehydes were the key aroma compounds in pan-fried meat. Importantly, 3-methylbutyraldehyde and 2-heptanone contents were positively correlated with eicosenoic, oleic, isooleic, linoleic, α-Linolenic, and eicosadiene acids (p < 0.05). To sum up, pan-fried Black Tibetan sheep meat had the best edible, nutritional, and flavor quality.

To explore the influence of cooking methods on the flavor parameters of Tibetan sheep, various techniques such as atmospheric-pressure (AP), high-pressure (HP), atmospheric-pressure high-pressure (APHP), and high-pressure atmospheric-pressure (HPAP) cooking were tested. The results indicated that APHP and HP cooking yielded the best sensory qualities, accounting for 26.15% and 25.51%, respectively. The HP group had the highest amino acid content at 34%, enhancing the meat’s sweet taste due to alanine, glycine, arginine, and methionine. Among 40 detected fatty acids, the order of saturated fatty acid (SFA), monounsaturated fatty acid (MUFA), polyunsaturated fatty acid (PUFA), and n-6/n-3 content was AP > APHP > HPAP > HP (p < 0.05). An electronic tongue and nose identified aroma components across the four cooking methods. Similarities in aroma were observed among the samples after cooking, while significant differences were found in the aroma components between the AP group and the other three cooking methods (p < 0.05). The gas chromatography–ion mobility spectrometry (GC–IMS) and gas chromatography–mass spectrometry (GC–MS) analyses of the meat in the four groups indicated that there were significant differences in volatile compounds among meat cooked with different methods (p < 0.05), with 56 and 365 flavor compounds detected by the two analytical techniques, respectively. Moreover, the GC–MS results indicated that the flavor substance content in the HP group accounted for 30.80% among these four sample groups. This comprehensive analysis showed that high-pressure steaming could significantly improve the flavor quality of Tibetan sheep, providing a theoretical basis and empirical reference for the optimization of pre-treatment conditions and the processing of Tibetan sheep.

Characterization of the structure and pharmacological activity of Berberis dasystachya Maxim., a traditional Tibetan medicinal and edible fruit, has not yet been reported. In this study, central composite design (CCD) combined with response surface methodology (RSM) was applied to optimize the extraction conditions of B. dasystachya oil (BDSO) using the supercritical carbon dioxide (SC-CO₂) extraction method, and the results were compared with those obtained by the petroleum ether extraction (PEE) method. The chemical characteristics of BDSO were analyzed, and its antioxidant activity and in vitro cellular viability were studied by DPPH, ABTS, reducing power assay, and MTT assay. The results showed that the maximum yield of 12.54 ± 0.56 g/100 g was obtained at the optimal extraction conditions, which were: pressure, 25.00 MPa; temperature 59.03 °C; and CO₂ flow rate, 2.25 SL/min. The Gas chromatography (GC) analysis results showed that BDSO extracted by the SC-CO₂ method had higher contents of unsaturated fatty acids (85.62%) and polyunsaturated fatty acids (57.90%) than that extracted by the PEE method. The gas chromatography used in conjunction with ion mobility spectrometry (GC–IMS) results showed that the main volatile compounds in BDSO were aldehydes and esters. BDSO also exhibited antioxidant ability in a dose-dependent manner. Moreover, normal and cancer cells incubated with BDSO had survival rates of more than 85%, which indicates that BDSO is not cytotoxic. Based on these results, the BDSO extracted by the SC-CO₂ method could potentially be used in other applications, e.g., those that involve using berries of B. dasystachya.

This study aimed to examine the effects of oats cultivated in saline and non-saline environments on the meat quality and muscle metabolism of Qinghai Tibetan sheep. First, targeted and untargeted metabolomics were used to examine oat quality and metabolites. Second, sheep muscle quality and metabolites were analyzed. Finally, a combined examination of the quality of the oats and their metabolites, as well as that of the muscles, was compared with saline oats. This study hypothesizes that, compared with non-saline environments, soil salinization can improve the nutritional quality of oats, thereby enhancing the meat quality and muscle metabolism of Qinghai Tibetan sheep. Saline-grown oats were shown to have higher levels of crude protein, crude fat, free amino acids, and simple sugar. The meat quality of the sheep fed on saline oats was higher due to free amino acid and carbohydrate metabolism, resulting in improved texture, color, water-holding capacity, and cooked meat percentage, with lower steaming loss. The findings of this study confirm the hypothesis that salinization improves Tibetan sheep meat quality by optimizing oat composition, providing a reference for agricultural and animal husbandry production in saline areas.

Background: Intramuscular fat (IMF) is a key determinant of meat sensory quality, but the effects of rumen-protected betaine (RPB) on IMF deposition in Tibetan sheep remain unclear. Methods: Sixty male, 3-month-old Tibetan lambs (Initial weight 17.72 ± 1.36 kg) were randomly assigned to a control (basal diet, n = 30) or RPB supplementation (basal diet supplemented with 0.08% RPB, n = 30) for 90 d. Results: Transcriptomic and lipidomic analyses revealed that RPB modulated glycerophospholipid metabolism-related genes (DGKI and AGPAT1) and altered lipid profiles, including PC (16:0/20:5) and PC (16:0/16:0). RPB increased T-AOC and SOD activities and decreased MDA content (p < 0.05). Intramuscular adipocyte area and diameter increased, while density decreased (p < 0.05). LC-MS/MS analysis showed that unsaturated fatty acids C14:1, C17:1, and C22:4 were significantly increased (p < 0.05). Muscle fiber density in the longissimus dorsi increased, whereas shear force, cooking loss, hardness, and chewiness were reduced (p < 0.05). MYH1, MYH2, and MYH7 expression were upregulated by 2.05-, 1.89-, and 2.73-fold, respectively. Conclusions: In summary, dietary RPB supplementation was associated with increased IMF deposition, which may contribute to improved meat quality, potentially through modulation of glycerophospholipid metabolism.

Castration is a vital technical practice in Tibetan sheep farming on the Qinghai-Tibet Plateau. It reduces fighting among rams, making it easier to manage the herd while they are grazing. However, the impact of castration on the quality of Tibetan sheep meat and muscle metabolites is unclear at present. On this basis, this study examined differences in meat quality and metabolites between castrated (BTC) and non-castrated (BTN) Black Tibetan sheep using targeted and non-targeted metabolomics. Compared with the BTN group, the meat from the BTC group showed reduced drip loss and increased cooking loss, as well as higher levels of elasticity, chewiness and cohesiveness (P < 0.05). The levels of 11 amino acids, total amino acids, total umami amino acids, 23 fatty acids, SFA, PUFA and MUFA were significantly higher in the BTC group than in the BTN group (P < 0.05). A total of 34 differentially abundant metabolites were identified between the two groups, with uric acid, vitamin C, malate, glutamine and oleic acid being all upregulated in BTC. Purine metabolism, metabolic pathways, bile secretion, the phosphotransferase system, glyoxylate and dicarboxylate metabolism, pyrimidine metabolism, and ABC transporters were the key metabolic pathways associated with meat quality in the castrated group. In conclusion, there are certain differences in meat quality and muscle metabolites between BTC and BTN. Castration can affect meat quality characteristics to a certain extent.