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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.

The aim of this study was to determine the effects of processing on the quality, protein oxidation, and structural properties of yak meat. The cooking loss, Warner–Bratzler shear force, meat color, texture, thiobarbituric acid reactive substance, total carbonyl content (TCC), total sulfhydryl content (TSC), and structural properties of yak meat under frying, drying, and boiling were measured. The results showed that the cooking loss rate, shear force, L* value, hardness, elasticity, and chewiness of yak meat increased (p <.05) and the a* value decreased (p <.05) with increasing central temperature after processing. Fried yak meat at 80°C had the lowest cooking loss rate of 42.21% and the lowest shear force of 50.86 N, which had better textural characteristics, followed by boiling, while the maximum cooking loss rate, hardness, and shear force were 1.40 times, 1.26 times, and 1.2 times that of frying, respectively. The thiobarbituric acid reactive substance was obtained after decoction and peaked at 1.88 ± 0.04 mmol/mg at 60°C. The highest TCC and the lowest TSC were obtained for dried proteins at 80°C. In addition, as the central temperature increased, the helical structure in the protein secondary structure decreased, the disordered structure increased, the fluorescence intensity of myofibrillar proteins decreased, and protein degradation occurred. It was concluded that dried yak meat had the highest protein oxidation and the worst quality, while fried yak meat had the lowest protein oxidation and the best quality. [ABSTRACT FROM AUTHOR]

Based on the data of 281 cities from 2005 to 2016, we constructed difference-in-difference (DID) models to study the impact of national innovative-city-pilot policy on urban innovation from the three dimensions of dynamic effect, heterogeneity, and influence path. The research found that: (1) The innovative-city-pilot policy has significantly improved the level of urban innovation. This conclusion is still valid after a series of robustness tests. (2) The policy does not have a lag effect, but it has a certain dynamic and continuous effect. (3) This policy is more conducive to innovation in provincial capitals or sub-provincial cities, and has little effect on innovation in other cities; there is no significant difference in the policy effects on eastern, mid-western cities, but the average policy effect in eastern cities is slightly higher than in the mid-western cities. (4) The impact mechanism test shows that the pilot policy affects urban innovation through government fiscal expenditures, the degree of urban industrial agglomeration, and the level of human capital. [ABSTRACT FROM AUTHOR]

Based on the panel data of 16 cities in Anhui from 2010–2018, this paper measures the index system of fiscal structure and high-quality economic development in Anhui using the entropy weight method, and empirically analyzes the coordinated development level of fiscal structure and high-quality economic development in Anhui using coupled coordination degree model. The study finds that: (1) the overall structure of Anhui's fiscal expenditure is characterized by "service-oriented and investment-oriented", and there is a phenomenon that contradicts "Wagner Principle", and there are also spatial and temporal differences in Anhui's tax structure. (2) The level of high-quality development of Anhui economy shows a steady upward trend, but is still at a low level. (3) The level of coordinated development of fiscal structure and high-quality economic development is still low, and the overall situation is "on the verge of disorder" or "barely coordinated". (4) Regionally, the overall coordination of fiscal expenditure structure, tax structure, and high-quality economic development in southern Anhui shows a decreasing trend, while the overall coordination in central and northern Anhui shows an increasing trend, so that southern Anhui has been or will be surpassed by northern and middle Anhui, and the growth rate of middle Anhui is faster than that of northern Anhui. [ABSTRACT FROM AUTHOR]

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