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Textural defects (including syneresis and poor consistency) often occur in yogurt gels produced from yak milk. In this research, the synergistic effects of transglutaminase (TGase) and heating pH on the textural properties of acidified yak skim milk gels, as well as the related mechanism of action, were investigated. The pH values of yak skim milk were adjusted to 6.3, 6.7, and 7.1, respectively. The samples were heated at 80°C for 30 min and then cooled to 42°C. After treatment with different contents of TGase (0, 3, and 10 U TGase per gram proteins), the samples were acidified with glucono-delta-lactone. For a given TGase content, the final storage modulus (G′) of gels was positively related to the heating pH, whereas the opposite trend was observed for the gelation time. This effect was obvious between pH 6.3 and 6.7. At a definite heating pH value, the final G′ of the gels was highest at 3 U TGase per gram proteins. The highest water holding capacity and firmness value were observed in gels prepared using pH 7.1 and 3 U TGase per gram proteins. In the samples treated with 3 U TGase per gram proteins (preheating pH 7.1), more rigid network structures were seen in the gel than 0 or 10 U TGase per gram proteins. Therefore, adjusting the heating pH values and TGase contents is an effective way of improving the textural properties of yak milk gels.

The objective of the present study was to produce antioxidant hydrolysate from Tibetan egg white protein hydrolyzed with papain, and to investigate the effect of added papain egg white hydrolysate (PEWH) on the quality characteristics and amino acid profiles of yak milk yogurt. A response surface methodology (RSM) was utilized to analyze the effects of hydrolysis time (X1), the ratio of enzymes to substrates, and enzyme dosage (X3) on the superoxide anion radical (O2&minus, ) scavenging activity of hydrolysates. The predicted maximum value of O2&minus, scavenging activity (89.06%) was obtained an X1 of 2.51 h, X2 of 4.13%, and X3 of 4500 U/g of substrate, almost approaching the experimental value (88.05 &plusmn, 1.2%). Furthermore, it was found that the addition of PEWH to yak milk can enhance acidification, sensory score, the number of lactic acid bacteria (LAB), and the amino acid content in yak milk yogurt. The results suggested that PEWH displayed an exceptional potential to be developed as a functional food ingredient that could be applied during the manufacturing process of yak milk yogurt.

In recent years, Tibetan pig breeding and meat processing have developed rapidly. However, the basic physiological and biochemical characteristics of Tibetan pork have not been systematically explored. The present study conducted a high-throughput analysis of the tenderloin (longissimus dorsi) proteome of the Tibetan pigs and performed a functional annotation and bioinformatics analysis of the identified proteins. Based on offline two-dimensional liquid chromatography fractionation and MS/MS identification, a total of 1,723 proteins were identified in the tenderloin of Tibetan pigs. Gene ontology analysis and pathway enrichment analysis revealed that the proteins involved in respiration (oxidative phosphorylation, glycolysis/gluconeogenesis, citric acid cycle, and pyruvate metabolism) and protein synthesis and metabolism (proteasome, amino acid biosynthesis, endoplasmic reticulum protein processing, and ribosomes) were significantly enriched, indicating that the energy production and protein metabolism are the most important physiological processes in Tibetan pig tenderloin. Practical applications The in-depth mapping of the tenderloin (longissimus dorsi) proteome of the Tibetan pigs gives a panoramic perspective at the protein molecular level and provides important information on the mechanisms of postmortem muscle physiology and meat quality formation. Furthermore, the development of Tibetan pork storage and processing technologies would also benefit from the characterization of the biochemical properties of Tibetan pork.

In the present study, a tandem mass tag-labeled quantitative proteomic analysis was performed to compare the differences in protein profiles between Tibetan pig (TP) tenderloin and Yorkshire pig (YP) tenderloin. A total of 171 proteins were identified as differentially abundant proteins (DAPs) from 1448 quantified proteins. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) database pathway analyses revealed that upregulated DAPs in the TP tenderloin were mainly involved in energy production, muscle contraction, immunity and defense, while downregulated DAPs were mainly involved in glutathione metabolism. These DAPs and the pathways they participate in were related to meat characteristics. TP tenderloin has a deeper color and higher pH, but lower water content and cooking loss. This study provides insights into the mechanism underlying the differences in protein profiles between TP and YP tenderloins. The findings can provide a better understanding of the formation mechanism for Tibetan pork edible quality.

Taking refined flour, matsutake powder, and highland barley powder as main raw materials, this experiment studied the optimal formula of matsutake highland barley biscuit. Besides, single factor experiment was carried out for the amount of highland barley powder, white granulated sugar, and shortening. Then, the response surface optimization analysis was made on crispness and sensory score of the biscuit. The experiment indicates that taking the refined flour as the base 100 g (100%), the formula of 20% highland barley powder, 25% white granulated sugar, and 26% shortening can bake crisp biscuit with complete shape, pure flavor and high quality.

The Five-hundred-meter Aperture Spherical radio Telescope (FAST) is currently under construction at a Karst depression in the Guizhou province of China. The active reflector of the telescope is composed of 4395 triangular panels laid on a cable-net structure. The aperture of the spherical surface is 500 meters, with open angle of about 110~120 degrees. Acting as the nodes of the reflector, the joint of these panels are adjusted by 2235 down-tie cables drawn by actuators. The RMS error of the parabola reflector is expected to be 5mm. To form the parabola shape of the reflector, for each of the actuators, a minimal working stroke of 950mm is required, with maximal speed of 1.6mm/s at the load of 50kN. Considering the elastic deformation of the down-tie cable and other factors, a positioning error within 0.25mm is required for the actuators. In this paper, the base formula for the motion of a general actuator at a typical observation time is studied analytically. The results are used to estimate the control error of the actuators and the pointing error of the whole reflector. Based on the designed error budgets, a statistical method is employed to estimate the overall surface error of the parabola reflector. The overall surface error is a comprehensive result of the panel design error, panel fabrication error, thermal deformation error, panel wind load induced error, cable-net error, installation error, measurement and control error etc. The results may be used as a reference in the measurement and control of the active reflector when in operation.

Upon its completion, the Five-hundred-meter Aperture Spherical radio Telescope (FAST) will be the largest single dish radio telescope ever in the world. The construction has been initiated in March 2011 in Guizhou province of China. The whole construction process is expected to be completed in September 2016, with duration of 5.5 years. With an aperture of 500 meters and an illumination aperture of 300 meters, the active reflector is one of the most important parts of FAST. The reflector is composed of a ring beam, a cable net and thousands of panels, tie-down cables, actuators and anchors. For the observation process of source switching and source tracking, the parabola shape of the reflector is achieved by drawing back of the tie-down cables by the actuators. The motion performance and the reliability of the actuators are of great importance to the telescope. In this paper, the motion models of the actuators are analyzed for the observation process of source switching and source tracking. Several design schemes are proposed, including mechanical and hydraulic design. The electric, mechanical and hydraulic characteristics of these designs are discussed. Related experimental studies are performed to investigate the electric and mechanical performances of these actuator prototypes. Based on the analysis and test results, a final type of actuator will be optimally concluded to meet the requirements of the reflector of FAST.