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Copyright of Science & Technology of Food Industry is the property of Science & Technology of Food Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Simple Summary: Yaks are a major economic source for people in the Tibetan Plateau region. Yaks are rich in nutrients, but their low fat content is not conducive to the large-scale promotion of yak meat, so the study of the mechanism of yak lipid deposition is beneficial to the marketing of yak meat. In this paper, the results of transcriptome sequencing analysis of yak liver showed that it could be determined that the expression levels of genes associated with partial lipid deposition were significantly up-regulated during yak fattening. In addition, this study found that the tenderness of yak meat improved during this process. Fattening significantly affects fat deposition in yaks, which may be realized through its effects on lipid metabolic pathways. Therefore, studying the mechanism of lipid deposition in yaks and fattening yaks will improve the quality of yak meat. Yak meat is nutritionally superior to beef cattle but has a low fat content and is slow-growing. The liver plays a crucial role in lipid metabolism, and in order to determine whether different feeding modes affect lipid metabolism in yaks and how it is regulated, we employed RNA sequencing (RNA-seq) technology to analyze the genome-wide differential gene expression in the liver of yaks maintained under different raising systems. A total of 1663 differentially expressed genes (DEGs) were identified (|log2FC| ≥ 0 and p-value ≤ 0.05), including 698 down-regulated and 965 up-regulated genes. According to gene ontology (GO) and KEGG enrichment analyses, these DEGs were significantly enriched in 13 GO terms and 26 pathways (p < 0.05). Some DEGs were enriched in fatty acid degradation, PPAR, PI3K-Akt, and ECM receptor pathways, which are associated with lipid metabolism. A total of 16 genes are well known to be related to lipid metabolism (e.g., APOA1, FABP1, EHHADH, FADS2, SLC27A5, ACADM, CPT1B, ACOX2, HMGCS2, PLIN5, ACAA1, IGF1, FGFR4, ALDH9A1, ECHS1, LAMA2). A total of 11 of the above genes were significantly enriched in the PPAR signaling pathway. The reliability of the transcriptomic data was verified using qRT-PCR. Our findings provide new insights into the mechanisms regulating yak meat quality. It shows that fattening improves the expression of genes that regulate lipid deposition in yaks and enhances meat quality. This finding will contribute to a better understanding of the various factors that determine yak meat quality and help develop strategies to improve yield and quality. [ABSTRACT FROM AUTHOR]

This study investigated the differences in meat quality during postmortem aging of yak meat from different altitudes as well as the relationship between the release of hypoxic factor HIF‐1α and meat quality. The results showed that the HIF‐1α increased with altitude but during aging process, there was an initial increase before a subsequent decrease (p <.05). Moreover, significant increases were showed in glycolytic potential, a* value, pH, HIF‐1α mRNA expression, HIF‐1α protein expression and shear force with altitude (p <.05). Additionally, the b* value, L* value, water holding power and MFI decreased significantly (p <.05). HIF‐1α was shown, by PLS‐DA method analysis, to be the main protein marker for differences in the quality during aging time of meat from three altitude groups. HIF‐1α protein expression was high correlated with glycolytic potential, pH value, meat color, tenderness and water holding capacity during postmortem aging. The results demonstrated that HIF‐1α is a novel marker protein that influences meat quality in yak from different altitudes and that HIF‐1α‐mediated glycolytic pathway was key to the meat quality during postmortem aging. Practical applications: Yak meat has the advantages of high protein, low fat, good amino acid and fatty acid composition, so the nutritional value of yak meat is in line with the current best‐selling beef with less fat in domestic and foreign markets. But consumers often think that the meat tenderness of yak meat is worse than that of beef and improving the quality of yak meat was worthy of attention specifically. This study investigated the differences in meat quality during postmortem aging of yak meat at different altitudes and the relationship between hypoxic factor HIF‐1α release and meat quality. [ABSTRACT FROM AUTHOR]

The work aimed to study the effect of four drying methods, namely constant temperature hot air drying (HD), microwave drying (MD), hot air microwave drying (HMD), and gradient hot air drying (GHD), on quality characteristics of dried yak meat. The analyses of physicochemical, textural, flavor, and sensory characteristics were carried out based on these four drying methods. The results revealed that microwave dried yak jerky exhibited better color and received the highest sensory score. Hardness of samples were affected by the drying methods, which showed significant differences. There were 21 free amino acids (FAAs) detected in dried yak samples. The samples treated by microwave drying showed the highest total free amino acid content (73.30 mg/100 g) and the EUC value was significantly higher than other methods, indicating the sample displayed greater flavor. A total of 153 volatile compounds were identified in dried yak meat samples, primarily including aldehydes, ketones, and esters. Moreover, the sensory evaluation indicated that the drying methods could significantly affect on color, flavor, and overall acceptability of different samples. Microwave drying samples scored higher than other drying methods. Overall, considering aspects of quality, time savings, and energy efficiency, microwave drying of yak jerky emerges as a more satisfactory option. This study could provide important theoretical support for the application of drying methods to improve the quality of yak jerky and enhance production efficiency. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The effects of papain and high-pressure processing (HPP), applied separately or in combination, on the tenderization of yak meat were studied regarding texture, water-holding capacity (WHC), cooking loss (CL), pH, and color. When papain was used alone, both the papain concentration level and treatment time could affect the tenderization. The maximal shear force (MSF) of yak meat was decreased by 46.85% and the WHC was increased by 9.93% when 80 U/mL papain was injected into yak meat and then incubated at 55 °C for 120 min. However, the color was significantly deteriorated. When the HPP treatment was performed alone, the MSF of yak meat displayed an initial decrease followed by an increase as the processing pressure or treatment time rose. Although an improved tenderizing effect was achieved at 250 MPa/15 min, leading to a MSF decline of 49.27% and a WHC increase of 10.50%, the meat turned white. Applying treatment sequences of an HPP and papain combination can significantly influence the tenderization effect. Optimal tenderization was obtained by the injection of papain (80 U/mL) and incubation at 55 °C for 30 min followed by HPP at 50 MPa/15 min (Pap → HPP). Results from this process indicated that the MSF of yak meat was decreased by 46.30% and 50.27%, respectively, compared to the separate applications of both HPP (50 MPa/15 min) and papain (80 U/mL, 30 min) treatments. Meanwhile, no significant color change was detected. The microstructure of yak meat was analyzed following the application of different treatments. Results suggest that the meat treated with Pap → HPP exhibited larger spacing and more damaged cells than untreated meat or the sample subjected to other treatments. These findings provided a possible explanation for the specific tenderization result when exposed to the combined treatments. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Animal Science is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: Yak meat is of good quality with fine texture, high protein and low fat content, and rich in amino acids compared with that of cattle, and it lacks anabolic steroids or other drugs. In general terms, however, the meat yield of yak is relatively low compared with that of the cattle. In order to prevent possible adulteration of yak meat with cattle meat, based on the sequence of mitochondrial 12S rRNA gene, a multiplex PCR-based approach was proposed for rapid identification of the meat from yak and cattle using three primers designed in this work. Through the combinatorial usage of three primers with a single reaction set, two fragments of 290 and 159bp were amplified from the cattle meat DNA, whereas only a fragment of 290bp was obtained from the yak meat DNA. Using the assay described, satisfactory amplification was accomplished in the analysis of raw and heat-treated binary meat mixtures of yak/cattle with a detection limit of 0.1% for cattle meat. The technique is fast and straightforward. It might be a useful tool in the quality control of yak meat and meat products. [Copyright &y& Elsevier]