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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 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.)

In order to investigate the effect of curing time on the edible quality and oxidative characteristics of compound low-sodium yak meat products, in this experiment, complex low-sodium yak meat was selected to investigate the effects of curing time (12, 18, 24, 30 and 36 h) on the edible quality and oxidative characteristics. The results showed that prolonging the curing time significantly reduced the cooking loss (P

To investigate the changes in the quality of yak meat at different dry aging times (7, 14, 21, 28 and 35 d), in this study, sensory evaluation, texture analysis, and GC-IMS were employed to investigate the changes in texture and flavor of yak meat during different dry aging periods. Additionally, PLS-DA was utilized to identify the characteristic flavor compounds. The results showed that the dry aged 35 days sample exhibited the highest comprehensive score, with intact soft tissue structure and a favorable overall acceptability of aroma. The dry aging time had significant effects on the hardness, chewability, and adhesivity of yak meat (P

This study aimed to examine the impact of different low-sodium formulations on the quality and oxidative properties of yak meat products. Yak foreleg meat was utilized as the primary raw material, and various proportions of potassium chloride (KCl) and sodium pyrophosphate were incorporated to partially replace sodium chloride (NaCl) during the marination process. The objective was to assess the effects of these low-sodium composite salts on yield, edible quality, lipid oxidation, and protein oxidation of yak meat in sauce, while also determining the optimal ratio of composite substitutes for sodium salts. The findings revealed that an increasing substitution of sodium pyrophosphate and KCl resulted in a significant increase in product yield (P

In order to improve the effect of microwave thawing on yak meat quality, this paper mainly adopted four different intermittent microwave thawing methods to determine and analyze the indicator changes of the nutritional quality of yak meat and peroxide-value (POV), superoxide dismutase (SOD), total volatile base nitrogen (TVB-N), thiobarbituric acid reactants (TBARS). The results showed that the thawing loss of yak meat in mode 1 (heat 10 s and stop10 s as a cycle) was less, higher protein and fat content among the several thawing methods, and the hardness, viscosity and chewiness of yak meat were the smallest, which dates were 2612.115 g, 1771.18 N and 878.63 mJ respectively, with a shear force of 69.59 N and pH of 5.9. At the same time, the freshness preservation effect was better. Compared with room temperature thawing, the mode 1 reduced the degree of fat oxidation of yak meat, its POV and TBARS were 9.45 mmol/kg and 0.36 mg/kg respectively. But there was no significant data difference between SOD activity and TVB-N and other thawing methods (P>0.05). Therefore, choosing the mode 1 to thaw, which could greatly reduce the damage of yak meat caused by thawing in terms of basic quality.

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 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.)

This study aimed to investigate the effects of nitric oxide (NO)-mediated hypoxia-inducible factor-1α (HIF-1α) on the glycolysis and tenderness of postmortem yak muscle and its regulatory mechanism. In this study, Yak Longissimus dorsi was injected with 0.9% saline (control), 200 μmol/L S-nitrosoglutathione (GSNO), 200 μmol/L GSNO + 100 μmol/L YC-1 (HIF-1α inhibitor) or 200 μmol/L GSNO + 50 μmol/L PD98059 and aged, and NO level, HIF-1α, mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) pathway activation, glycolysis-related enzyme activities, and shear force of muscle were analyzed at different aging time points (3, 6, 9, 12, 24 and 72 h). The results revealed that NO levels in the GSNO group were significantly higher than those in the control group during 3–72 h (P < 0.05), reaching a peak at 6 h. ERK1/2 and p-ERK1/2 expression levels were higher in the GSNO group than the control and GSNO + PD98059 groups during 3–72 h (P < 0.05), reaching a peak at 24 h. HIF-1α expression level in the GSNO group was significantly higher than that in the control and GSNO + YC-1 groups (P < 0.05), peaking at 12 h. Hexokinase (HK), pyruvate kinase (PK) and lactate dehydrogenase (LDH) in the GSNO group reached their maximum values at 9, 12 and 12 h, respectively (P < 0.05) and were significantly higher than those in the control group; at 3, 12 and 72 h, the glycolytic potential in the GSNO group was significantly higher than that in the two other groups (P < 0.05); at 6, 9 and 72 h, the pH in the GSNO group was significantly lower than that in the other groups (P < 0.05). In addition, shear force and hematoxylin and eosin (HE) staining were used to assess the tenderness of yak meat. Shear force, myofiber cross-sectional area and diameter were lower and the space between myofibers was higher in the GSNO group than in the two other groups. In conclusion, during the early period of postmortem aging, NO mediates the MAPK/ERK signaling pathway, thereby activating HIF-1α expression and upregulating HK, PK and LDH activity, accelerating the rate of glycolysis of and reducing pH, and ultimately improving the tenderness of yak meat. The results of this study may serve as a potential regulatory mechanism for regulating the tenderness of yak meat and provide a theoretical basis for improving the theoretical system of glycolysis and tenderness during postmortem aging.

Copyright of Food & Fermentation Industries is the property of Food & Fermentation Industries 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 China Condiment is the property of China Condiment 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.)

Objective: Analyze the differences in mineral element content in yak meat from Leiwuqi County, Changdu City, Tibet. Methods: This study focused on 431 yak meat samples from Leiwuqi County, Xizangchang City, including (Kamado Township, Leiwuqi Township, Yiri Township, Changmaoling Township, Gangse Township, Sangdo Township, Binda Township, Shangka Township, Jiasangka Township, Jiduo Township). The contents of K, Na, Ca, Mg, Se, Sr, Mn, Zn and Fe in yak meat were determined by microwave digestion ICP-MS. The difference of mineral element content in yak meat from different regions and parts were analyzed. Results: There were extremely significant differences in mineral elements in different parts of the meat of similar Uqi yaks (P

The digestibility of myofibrillar proteins (MP) extracted from yak meat cooked to different internal temperatures of (40, 50, 60, 70 and 80 ℃) was determined during in vitro gastrointestinal digestion, and total carbonyl content, total sulfhydryl content and Schiff base content before and after digestion were measured. Ultraviolet (UV) absorption spectroscopy, endogenous fluorescence spectroscopy and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) were used to investigate the oxidation and digestion patterns of yak meat proteins during gastrointestinal digestion. The results showed that total protease hydrolysis of MP from yak meat cooked to 60 ℃ was the highest after simulated gastric and intestinal digestion (88.64%). The rates of pepsin hydrolysis and total protease hydrolysis of MP from yak meat cooked to 80 ℃ decreased by 34.10% and 22.47%, respectively, and the rate of trypsin hydrolysis increased by 75.34% compared with MP from raw yak meat. The total carbonyl content after simulated gastric and intestinal digestion increased by 81.42% and 77.40%, respectively, and the total sulfhydryl content decreased by 30.02% and 36.43%, respectively, compared with raw MP. With an increase in cooking temperature, the Schiff base content gradually increased, the UV absorbance was significantly enhanced, and the endogenous fluorescence intensity was significantly reduced. The SDS-PAGE patterns showed that the protein bands were severely degraded and even disappeared after digestion. It was found that the digestibility of MP from yak meat cooked to 60 ℃ was the highest. The degree of protein oxidation in yak meat cooked to 80 ℃ was the strongest and increased during gastrointestinal digestion.

In order to explore the difference in flavor among yak leg meat roasted at different temperatures, sensory evaluation, gas chromatography-ion mobility spectrometry (GC-IMS), relative odor activity value (ROAV), partial least squares-discriminant analysis (PLS-DA), and principal component analysis (PCA) were used in this study. The results showed that the samples roasted at 240 ℃ for 7 min had the highest (E) sensory evaluation score. A total of 82 compounds were identified by GC-IMS, including 15 aldehydes, 12 alcohols, 24 lipids, 14 ketones, 7 heterocycles, 3 olefins, and 7 other compounds. The total amount of these compounds in sample E (240 ℃) was the highest, followed by samples D (180 ℃) and C (120 ℃). The total amount of these compounds in sample F (300 ℃) was lower than that in sample E (240 ℃). The key flavor compounds of roasted yak meat were ethyl 2-hydroxypropanoate, 4-methylguaiacol, 2-acetyl-1-pyrroline, 5-nonanone, ethyl salicylate, 1-propanol, (E,E)-2,4-heptadienal, 1-penten-3-one, (E)-2-heptenal, linalyl acetate, butanol-D, methional-M, 2-ethyl-6-methylpyrazine, 4-hexen-1-ol, (Z)-4-decenal, 2,4-heptadienal, 2-phenylethanol, and ethyl butyrate. Sample E had roasted meat-like, fatty, flowery and fruity aromas, which was the best among these five samples. The flavor of samples C and D was lower than that of sample E, having nutty, toasty, sweet and smoked aromas.

Copyright of Shipin Kexue/ Food Science is the property of Food Science 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 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 Shipin Kexue/ Food Science is the property of Food Science 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 Modern Food Science & Technology is the property of Editorial Office of Modern Food Science & Technology 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.)

Sarcoplasmic proteins (SP) derived from yak meat were oxidized by malondialdehyde (MDA) at different concentrations. The effects of lipid oxidation on physicochemical properties and color stability of SP were investigated by evaluating side-chain amino acid oxidation, protein structure and color of SP and the oxidation status of myoglobin (Mb). The results showed that after MDA oxidation, the a* value, b* value, C* value, and deoxymyoglobin and oxymyoglobin contents of SP significantly decreased (P < 0.05), and the L* value, metmyoglobin content, and ferrylmyoglobin concentration significantly increased (P < 0.05), indicating that MDA oxidation lowered color stability. The contents of carbonyl groups and dimeric tyrosine, the fluorescence intensity of SP-MDA adducts, and the relative contents of β-helix and β-turn significantly increased (P < 0.05), and total sulfhydryl content, surface hydrophobicity, intrinsic fluorescence intensity, and the relative contents of α-helix and random coil significantly declined (P < 0.05). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed blurred expansion of small molecule bands and the formation of macromolecular aggregates, suggesting that MDA promoted the oxidation and aggregation of SP. Pearson correlation analysis revealed significant correlations between MDA oxidation and physicochemical properties and color stability of SP (P < 0.05). This study reveals that MDA alters the structure of SP by directly oxidizing it or mediating Mb oxidation, causing cross-linked aggregation of SP and reducing its color stability.

In order to study the effects of L-Lys on the quality characteristics and protein oxidation of yak meat induced by MDA. In this study, MDA was used as the simulated oxidation system, and yak meat were used as the research objects. The changes of edible quality, lipid oxidation, protein oxidation and muscle histological characteristics during storage were measured after yak meat treated with different concentrations of L-Lys and MDA. The results showed that 10 mmol/L L-Lys could reduce the increase of pH caused by MDA, alleviate the excessive increase of hardness and chewiness, and significantly inhibit the conversion of oxygenated myoglobin into high iron myoglobin, thereby increasing the L* value and a* value (P

The current study aimed to investigate the difference of volatile compounds in Qinghai Yushu yak. In this experiment, brisket, round, tenderloin, bottom round of yak was taken as the research object, the electronic nose, electronic tongue intelligent detection combined with the solid-phase microextraction-gas chromatography-mass spectrometry method (SPME-GC-MS) to analyze the flavor, the principal component analysis (PCA), the cluster analysis (CA) and correlation analysis (Pearson) of yak meat. The results showed that the taste intensity of electronic tongue was significantly different, the taste of different parts of yak meat was significantly different, and the taste of sample HT was better than that of other samples. The principal component analysis results of electronic nose showed that HT, HB and QT were close to the X axis, and the odor characteristics were similar. A total of 57 volatile compounds were detected in yak meat, including aldehydes (12 kinds), alcohols (11 kinds), hydrocarbons (11 kinds), acids (5 kinds), ketones (3 kinds), and other miscellaneous sulfur compounds (15 kinds). Among them, the results of PCA-GC-MS showed the contents of benzaldehyde, nonaldehyde, 2-ethyl-1-hexanol, m-xylene, allyl methyl sulfide and 2-acetylpyrrole in the bottom round of yak were significantly different from those in other parts, indicating that the flavor of bottom round of yak was significantly different from that in other parts which was the same as the results of electronic nose PCA showed that data analysis. The results would provide a theoretical basis and a data reference for the processing technology and flavor characteristic identification of yak in the future.

In order to clarify the synergistic effect of different concentrations of arginine and different concentrations of chitosan on the quality of yak meat during postmortem aging and its potential mechanism, in this study, different concentrations of arginine and different concentrations of chitosan were injected into yak meat to determine their effects on the quality of yak meat during postmortem aging. The results showed that the combination of 0.4%~0.8% arginine and 1.0% chitosan could significantly increase the pH value, reduce the L*, b* values, metmyoglobin and cooking loss of yak meat during postmortem aging, and increase a* value and oxymyoglobin (P0.05). Histological observation showed that the compound treatment was more conducive to the integrity and fullness of muscle cells, and reduced the water channel. In summary, the combination of different concentrations of arginine and different concentrations of chitosan improved the quality of postmortem yak meat during aging to a certain extent, improved its meat color stability and reduced cooking loss, promoted tenderization, and made muscle cells more complete and fuller, but it promoted fat oxidation and protein oxidation as a whole. The specific reasons and related mechanisms need to be further explored.

The effects of adding different levels (0.01%, 0.05% and 0.10%) of banana flower extract (BFE) versus dibutylated hydroxy toluene (BHT) on protein oxidation in naturally fermented yak meat sausages were investigated. lys The carbonyl content, Schiff base content, total sulfhydryl content, active sulfhydryl content, surface hydrophobicity, dimeric tyrosine content, endogenous fluorescence intensity and solubility of myofibrillar proteins (MPs) from fermented yak meat sausage were measured at different fermentation times, and the secondary structure and composition of MPs were characterized by Fourier transform infrared (FTIR) spectroscopy, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The results showed that compared with the blank control, the addition of BFE decreased the carbonyl group content, Schiff base content, surface hydrophobicity, dimeric tyrosine content and endogenous tryptophan fluorescence intensity of MPs, and increased the total sulfhydryl group content, active sulfhydryl group content and solubility. FTIR spectroscopy showed that the addition of BFE improved the reveal the more stability of the secondary structure of MPs. SDS-PAGE showed that BFE reduced the diffusion of myosin heavy chain and had a protective effect on myosin. This study showed that BFE inhibited protein oxidation in naturally fermented yak sausage, and this effect was positively correlated with BFE concentration, being most pronounced at 0.10% BFE concentration.

Copyright of China Condiment is the property of China Condiment 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 Shipin Kexue/ Food Science is the property of Food Science 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 Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality 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.)

To explore the effect of different levels of lipid oxidation on the structural and functional properties of myofibrillar protein (MP) in yak meat, the oxidation of side-chain amino acids, structure, rheological characteristics, and emulsion stability of MP incubated in the presence of different concentrations (0, 0.1, 1, 5, 10 and 20 mmol/L) of malondialdehyde (MDA) were measured. The results showed that with an increase in MDA concentration, the contents of carbonyl group, MDA-MP adducts and dimeric tyrosine and the relative content of β-turn in MP overall increased, while total sulfhydryl content, surface hydrophobicity, endogenous fluorescence intensity, and the relative contents of α-helix and β-sheet decreased. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) results indicated gradual loss of myosin heavy and light chains, implying that interaction with MDA could induce MP oxidation and cross-linked aggregation and result in structural transition from an ordered to a disordered state. In addition, moderate oxidation (with MAD concentration < 10 mmol/L) increased the storage and loss moduli and improved the gel quality of MP; however, excessive oxidation (with MAD concentration ≥ 10 mmol/L) led to serious aggregation of MP and a decrease in the storage and loss moduli as well as a decrease in the emulsion stability and color deterioration. In conclusion, MDA oxidation can promote the oxidation of MP, and alter the structural and functional properties.

To investigate the effects of freezing-thawing times on the collagen properties and the yak meat quality. The changes of shear force, pH, thawing loss, cooking loss, color difference, texture, collagen content and solubility, enzyme activity and microstructure of yak meat were analyzed on different freezing-thawing times. The results showed that with the increase of freezing-thawing times, the shear force of yak meat decreased by 59.72%, moreover，the collagen solubility, β-galactosidase and β-galacturonase activity, thawing loss, cooking loss and b* value of yak meat increased significantly (P

To investigate the effect of high-pressure processing (HPP) on the quality of yak meat, yak meat was processed under pressure at 200, 400, and 600 MPa for 480 seconds, respectively, and the sensory, pH, microorganism, color, protein, and lipid oxidation of yak meat stored at 4 °C for 0, 4, 8, 12, and 16 days was determined. The results showed that HPP significantly lowered the total number of colonies and total volatile basic nitrogen (TVB-N) during storage (P

Copyright of Shipin Kexue/ Food Science is the property of Food Science 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 Shipin Kexue/ Food Science is the property of Food Science 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 Shipin Kexue/ Food Science is the property of Food Science 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 Shipin Kexue/ Food Science is the property of Food Science 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 Shipin Kexue/ Food Science is the property of Food Science 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.)

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.)

Copyright of Shipin Kexue/ Food Science is the property of Food Science 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 Journal of Southern Agriculture is the property of Journal of Southern Agriculture 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 objective of this paper was to research the law of moisture migration, and to investigate the correlation between moisture status and the histological structure and texture during the processing of dried yak meat. The semimembranosus of the healthy and disease-free male yaks when they were from 3 to 4-year-old under natural grazing was selected to remove the fascia and fat on its surface and cut into the strips with cross-section of 2 cm × 2 cm. At the same time, the meat was hung on the wire and kept a distance of 1-2 cm between 2 adjacent pieces of meat in a dark and naturally ventilated place in Xiahe County, Gannan Prefecture, Gansu Province. The temperature was from -10 to -15°C and the relative humidity was from 50% to 75% there. The samples were collected to analyze the changes of indices during natural drying of 60 d. Moisture ratio of dried yak meat was analyzed by the direct drying. Moisture activity and moisture status were evaluated respectively using the water activity meter and the low field nuclear magnetic resonance (LF-NMR). The change of texture characteristics of dried yak meat was measured by texture analyzer and the histological structure of dried yak meat was observed by hematoxylin eosinstaining. The results showed, during the 60 days of drying, moisture ratio decreased by about 60.27%. The final water activity reached about 0.308 and decreased by about 66.73%. On the 30th day, the peak integral area, which is immobile water content, decreased by about 98.12%, and no peak appeared after 40 days. With the reduction of moisture ratio, myofibril cross-sectional area, muscle fiber diameter and distance between muscle fibers were significantly decreased (P<0.05) respectively by about 42.65%, 67.15% and 61.22%. The hardness, cohesiveness, gumminess and chewiness were significantly increased (P<0.05), and among them, the chewiness that best represents the taste of dried meat increased by 1 229.16 g. However, the springiness and resilience decreased significantly (P<0.05) during the whole process.The change of immobilized water shows a significant negative correlation with changes in hardness, cohesiveness, gumminess, and chewiness，and have a significant positive correlation with springiness and resilience. Moreover, the decrease in distance between muscle fibers, diameter of myofibers and cross-sectional area of myofibers was negatively correlated with changes in hardness, cohesiveness, gumminess, and chewiness significantly, but have a significant positive correlation with changes in springiness and resilience. It shows that the immobile water in yak meat expands and evaporates continuously. It causes the contraction and aggregation of the muscle fiber of yak meat, which leads to the change of its textural properties in the process of natural freezing and drying. The results can provide a reference for the mechanism understanding of moisture migration and product quality control in the processing process of traditionally dried yak meat. [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.)

There are more than 16 million yaks in China, which accounting for about 95% of total amount in the world. The yak beef could be a new resource for meat industry in China with high protein, low fat and unique flavour. However, the commercial potential of yak beef is limited because of the poor tenderness of yak beef. The aging could be a simple and effective method to improve tenderness of beef especially prolonged aging time more than 14 d. In order to investigate the prolonged aging time on quality traits of yak meat, the pH value, tenderness (WBSF, Warner Bratzler shear force), water holding capacity (WHC, including cooking loss and press loss) and chroma (L*, a* and b*) of M. longissimus dorsi removed from yak within postmortem 2 h were determined during 21 d aging after vacuum packaging, and the changing patterns of quality traits of yak beef were analyzed through standardization of variables and kinetic model. It was found that there were significant variations during 21 d aging for quality traits (P<0.05) except b* value. The main variation of pH values during postmortem aging occurred in 3 d of early postmortem, while yak beef aging for 21 d did not have a lower pH value than those aging for 7 d. The aging of 7 d decreased the WBSF by 43 N, but the average WBSF of yak beef aging for 7 d still higher than 50 N. The WBSF of yak beef aging for 21 d was lower to 30 N, which was 47% significantly lower than that aging for 7 d (P<0.05). The cooking loss of yak beef significantly increased from 40.4% to 51.5% when aging time was prolonged from 7 d to 21 d (P<0.05), while the prolonged aging of 21 d did not have a significant effect on press loss of yak beef (P>0.05). The L* value significantly decreased with aging time during early aging of 7 d (P<0.05), but there was no significant difference on L* value between yak beef aging for 21 d and 7 d (P>0.05). However, a* value (redness) of yak beef significantly increased with prolonged aging time, and a* value of yak beef aging for 21 d was 32% higher compared to that aging for 7 d (P<0.05). Meanwhile, the changing pattern of quality traits of yak beef with significant change during aging was also investigated through standardization of variables and kinetic model analysis. It was found that the quadratic function had best predicting performance on quality traits of yak meat with coefficients of determination R2 ranged from 0.90 to 0.98, through comparing fitting degree of linear, exponential and quadratic functions. The changes of pH value, shearing force, press loss and L* were characterized by the convex function with negative second derivative, while cooking loss and a* value were characterized by the concave function with positive second derivative. It shows that the prolonged aging can be beneficial to improvement of tenderness, but has adverse effects on water holding capacity and meat color. Conclusively, different quality traits have different changing patterns and vary on different phases of aging. [ABSTRACT FROM AUTHOR]