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In order to develop a purine-reducing functional yak yoghurt, Lactobacillus paracasei 259 and commercial starter was used as the fermentation strain in this experiment. The inoculation amount of yak yoghurt strain was optimized by single factor experiment, and the quality changes of yak yoghurt during post-ripening period and storage period were observed. Gas chromatography-mass spectrometry (GC-MS) was used to analyze the changes of flavor substances during post-ripening period and storage period, and the purine-lowering activity of yak yoghurt was determined by high performance liquid chromatography (HPLC). The results showed that the post-ripening time of yak yoghurt was 24 h, the sensory score was the best when the inoculation amount of Lactobacillus paracasei 259 was 5%, the number of viable bacteria was 3.1×108 CFU/mL, the acidity was 96°T, and the inhibition rate of xanthine oxidase (XOD) was 51.51%. Yak yogurt with 5% inoculum of Lactobacillus paracasei 259 had a viable bacterial count higher than 107 CFU/mL during 28 d of storage, and the acidity was lower than 105.4°T. With the increase of storage time, the pH and water holding capacity decreased gradually, and the sensory quality, hardness, cohesion, viscosity, consistency and XOD inhibitory activity increased first and then decreased. The main flavor substances in yak yogurt after ripening were alcohols, esters, ketones, aromatic heterocycles and sulfur compounds. The acids increased at storage period compared to the post-ripening period. The relative content and quantity of alcohols were the highest, which gave the yogurt a fruity, floral and sweet flavor. The degradation of inosine and guanosine in yak yogurt during the storage period firstly increased and then decreased, up to 84.6% and 86.5%, respectively. It can be seen that yak yogurt fermented by Lactobacillus paracasei 259 is of better quality, inhibits xanthine oxidase activity, effectively degrades inosine guanosine, and has good potential for application in the prevention and adjunctive treatment of hyperuricemia.

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.

Hyperuricemia (HUA) is a metabolic disease arising from abnormal purine metabolism. It contributes to an increased risk of kidney damage. The present study aimed to investigate the uric acid (UA)-lowering effects of Lactobacillus paracasei 259 isolated from yak yogurt and explore its underlying mechanisms. Our results revealed that L. paracasei 259 decreased the UA levels in rats and inhibited the serum activities of xanthine oxidase. In addition, L. paracasei 259 reduced the levels of pro-inflammatory cytokines (tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6) in the kidney and altered the expressions of UA transporters (ABC transporter 2 (ABCG2), PDZ domain containing 1 (PDZK1), urate transporter 1 (URAT1), and sodium-phosphate cotransporter type 4 (NPT4)) to near normal levels. Moreover, it increased the abundance of beneficial bacteria in the gut and recovered the gut microbiota composition, promoting the production of short-chain fatty acids (SCFAs). These findings suggested that L. paracasei 259 can potentially be used to decrease UA levels, repair kidney damage, regulate gut microbiota, and alleviate HUA.

To improve the storage stability and bioavailability of traditional yak ghee, sodium alginate and CaCl2 were used as composite wall materials in this experiment, and yak ghee microcapsules were prepared using the sharp hole method. The optimal ghee microcapsule process parameters were determined using single factor experiment and orthogonal test with embedding rate as an index. Differential scanning calorimeter (DSC), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), and laser particle size analyzer were used to determine the physicochemical properties of ghee microcapsules. Finally, the characteristics of ghee microcapsule release and storage stability in gastroenteric fluid were investigated. The results showed that when the sodium alginate concentration was 1.5%, the CaCl2 concentration was 2.5%, the core to wall mass ratio was 1.5:1, the emulsification temperature was 50 °C, and the curing time was 30 minutes, the maximum encapsulation rate of microcapsules was 89.41%. The water content, solubility, angle of repose and average particle size of the microcapsules were 5.25%, 57.22%, 20.6° and 929.773 µm, respectively. After microencapsulation, thermal stability of ghee improved. In the release test, microcapsules were released at rates of 11.52% and 96.44% in stomach and intestinal liquids. Microcapsules had a substantially longer shelf life than yak ghee.

In order to study the antioxidant activity of Tricholoma matsutake polysaccharides (TMP), its antioxidant capacity in vitro was investigated using superoxide anion radical (O2－·) scavenging capacity, total reducing capacity and ABTS radical scavenging capacity as indicators; and then the mouse model of ethanol oxidative damage was established, and the antioxidant activity of Tricholoma matsutake polysaccharides in vivo were measured by measuring alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (AKP) in the serum of mice and the activity of catalase (CAT), malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in the liver. In vitro antioxidant results showed that Tricholoma matsutake polysaccharides had better scavenging ability on superoxide anion free radical and ABTS free radical, and the scavenging rate reached 56.67% and 96.60% when the concentration was 1 mg/mL. However, the total reducing ability of Tricholoma matsutake polysaccharides was not obvious. When the concentration was 1 mg/mL, the absorbance value could reach 0.163. Animal experiment results showed that after four weeks of continuous gastric administration, compared with the model control group, Tricholoma matsutake polysaccharides could significantly reduce ALT, AST and AKP viability in mice serum (P

In order to improve the oxidation resistance of traditional yak ghee, extend the shelf life, the yak ghee was embedded in gum Arabic and gelatin by complex coacervation method to prepare yak ghee microcapsules. The optimal preparation technology was obtained via single factor and orthogonal experiment with embedding rate as an index, and the physical and chemical properties, morphology structure, stability and properties in simulate gastrointestinal digestion were also investigated. The results showed that the best parameters of yak ghee microcapsules were as follows: Core-to-wall ratio was 1:1.5, mass fraction of wall material was 1.5%, complex coacervation pH was 4.2, the complex coacervation temperature was 40 ℃, and encapsulation efficiency of microcapsules was 81.39%. The average particle size, moisture content, solubility and angle of repose were 19.728 μm, 3.62%, 96.48% and 37.7°, respectively. Scanning electron microscope and fourier transform infrared spectroscopy showed that the surface of yak ghee microcapsules was smooth, the morphology was irregular, and yak ghee was successfully embedded in wall materials. Differential scanning calorimeter and thermogravimetric analysis proved that yak ghee microcapsules possessed good thermal stability. In addition, the release of yak ghee microcapsules could be controlled in simulated gastric and intestinal fluid, and the release rate in simulated intestinal fluid was 99.74%. Storage experiments exhibited that microencapsulation could slow down the oxidation rate of yak ghee and prolong the shelf life. This study will help provide theoretical basis for improving the bioavailability of yak ghee.

Non-Saccharomyces (NSc) yeasts have great potential in improving wine qualities. In this study, two NSc and two Saccharomyces cerevisiae (Sc) samples were tested on their performance of mono-inoculated and composite culture in the fermentation of Chunjian citrus wine. The cell count, Brix degree, total sugar, total acidity, alcohol level, pH value, color intensity (CI), and tonality were determined to evaluate the contribution of NSc to the quality of citrus wine in the mixed fermentation. Volatile compounds were analyzed by HS-SPME-GC-MS, and sensory evaluation was carried out. During the 9-day fermentation, the mixed-culture wine exhibited a higher cell concentration than the pure culture. After the fermentation, mixed-culture wine specifically decreased the concentrations of unfavorable volatile compounds, such as isobutanol and octanoic acid, and increased favorable volatile compounds, including ethyl octanoate, ethyl decanoate, and phenylethyl acetate. The quality category of the citrus wine was improved compared with the Sc mono-inoculated wines, mainly in regard to aroma, retention, and sweetness. The study shows that the mixed fermentation of NSc and Sc has positive impacts on reducing alcohol level and total acidity and increasing CI. The present work demonstrates that the mixed fermentation of NSc and Sc has enormous beneficial impacts on improving the quality of citrus wine.

The purpose of this study was to investigate the construction of curcumin encapsulated nanocomposite based on bovine serum albumin (BSA) could be a potential strategy to improve the ripening quality of yak cheese. The moisture, ash, crude protein, crude fat, pH value, pH4.6 acetate buffer soluble nitrogen, 12% trichloroacetic acid solution soluble nitrogen, thiobarbituric acid reactant, acid value and sensory index of yak milk cheese were determined. The results showed that the presence of curcumin-BSA nanocomplex could significantly improve the moisture and protein content of yak milk cheese (P

In order to study the effects of freezing-thawing times on the quality characteristics of frozen mutton. After freezing and thawing repeatedly for 0, 1, 3, 5 times and then refrigerated at 4 ℃ for 1, 3, 5, 7 days, the nutritional quality, edible quality, texture characteristics and lipid oxidation degree of Oula Tibetan mutton were determined. The results showed that with the increase of freeze-thaw times, the nutritional quality of Tibetan mutton deteriorated significantly, the moisture content and protein content decreased significantly (P < 0.05); The overall eating quality of Tibetan mutton decreased significantly, especially after 5 freeze-thaw cycles, the color stability and water holding capacity decreased significantly (P < 0.05), the tenderness decreased slightly, but the change was not significant, and the meat hardness and chewiness decreased, while the viscosity, elasticity and adhesiveness increased; Meanwhile, peroxide value (POV) and thiobarbituric acid value (TBARS) reached the maximum after 5 freeze-thaw cycles (P < 0.05), indicating that the degree of lipid oxidation increased with the increase of freeze-thaw cycles; At the same time, the longer the cold storage time, the worse the meat quality. The above results showed that the increase of freeze-thaw cycles had a great impact on the meat quality, and the repeated freeze-thaw phenomenon should be avoided in the actual production, processing and transportation of meat.

The objective of this study was to investigate the potential application of a mixed-mode solar dryer to Qula dehydration in the Qinghai-Tibet Plateau of China. A three-factor five-level central composite rotatable design (CCD) of the response surface methodology (RSM) was employed to evaluate the influences of drying process variables on quality attributes in terms of lipid oxidation [peroxide (POV) and thiobarbituric acid reactive substance (TBARS)] and Maillard reaction (5-hydroxymethylfurfural, 5-HMF). The impact of drying temperature (30–50 °C), material thickness (5–15 mm), and wind velocity (0.4–1.4 m/s) on the color, POV, TBARS, and 5-HMF of Qula were studied. Optimum operating conditions were found to be a temperature of 43.0 °C, material thickness of 11.0 mm, and wind velocity of 1.0 m/s based on the minimum of POV, TBARS, and 5-HMF. In this condition, the values of POV, TBARS, and 5-HMF were 0.65 meq/kg, 0.516 mg/kg, and 4.586 mg water/L, respectively, which are significantly lower than for drying of Qula by open sun-drying (p < 0.05). Compared with open sun-drying, the drying time of Qula by solar drying was shortened by 61.5%. The results indicate that the mixed-mode solar dryer is a feasibility drying technology for Qula and could effectively improve the quality of products.

The incineration process in waste-to-energy plants is characterized by high levels of inertia, large delays, strong coupling, and nonlinearity, which makes accurate modeling difficult. Therefore, an intelligent modeling method for the incineration process in waste-to-energy plants based on deep learning is proposed. First, the output variables were selected from the three aspects of safety, stability and economy. The initial variables related to the output variables were determined by mechanism analysis and the input variables were finally determined by removing invalid and redundant variables through the Lasso algorithm. Secondly, each delay time was calculated, and a multi-input and multi-output model was established on the basis of deep learning. Finally, the deep learning model was compared and verified with traditional models, including LSSVM, CNN, and LSTM. The simulation results show that the intelligent model of the incineration process in the waste-to-energy plant based on deep learning is more accurate and effective than the traditional LSSVM, CNN and LSTM models.

This study compares the prevention effects of Shuidouchi with different fermentation times on constipation in mice. Shuidouchi is a short-time fermented soybean product. By improving its processing technology, it can incur better biological activity and become a health food. The Shuidouchi-treated mice were evaluated using constipation-related kits, quantitative polymerase chain reaction (qPCR), and Western blot assays. After the mice were fed 72-h-fermented Shuidouchi (72-SDC) for 9 d, the defecation time to excrete the first black stool was lower than that of the control and 24-SDC and 48-SDC groups, but was much higher than that of the normal group. The gastrointestinal (GI) transit of the small intestine of the 72-SDC group was higher than that of the control and the 24-SDC and 48-SDC groups, but lower that of the normal group. Meanwhile, 72-SDC could significantly increase the levels of ghrelin, endothelin-1 (ET-1), vasoactive intestinal peptide (VIP), and acetylcholinesterase (AchE) in the serum of constipated mice compared to the levels in mice in the control group. Moreover, 72-SDC could raise c-Kit, stem cell factor (SCF), glial cell-derived neurotrophic factor (GNDF), neuronal nitric oxide synthase (nNOS), and endothelial nitric oxide synthase (eNOS) messenger RNA (mRNA) and protein expression levels, and reduce transient receptor potential cation channel subfamily V member 1 (TRPV1) and inducible nitric oxide synthase (iNOS) expression levels in small-intestinal tissue compared to the levels in the control group. Meanwhile, 72-SDC also raised ghrelin mRNA expression in gastric tissue and transient receptor potential ankyrin 1 (TRPA1) mRNA expression in colon tissue compared to the control group mice; these effects were stronger than those of 24-SDC and 48-SDC. Shuidouchi has good preventative effects on constipation and performs best when fermented for at least 72 h.

This paper presents an electrochemical seismic sensor in which paraylene was used as a substrate and insulating layer of micro-fabricated electrodes, enabling the detection of seismic signals with enhanced sensitivities in comparison to silicon-based counterparts. Based on microfabrication, paralene-based electrochemical seismic sensors were fabricated in which the thickness of the insulating spacer was 6.7 μm. Compared to silicon-based counterparts with ~100 μm insulating layers, the parylene-based devices produced higher sensitivities of 490.3 ± 6.1 V/(m/s) vs. 192.2 ± 1.9 V/(m/s) at 0.1 Hz, 4764.4 ± 18 V/(m/s) vs. 318.9 ± 6.5 V/(m/s) at 1 Hz, and 4128.1 ± 38.3 V/(m/s) vs. 254.5 ± 4.2 V/(m/s) at 10 Hz. In addition, the outputs of the parylene vs. silicon devices in response to two transit inputs were compared, producing peak responses of 2.97 V vs. 0.22 V and 2.41 V vs. 0.19 V, respectively. Furthermore, the self-noises of parylene vs. silicon-based devices were compared as follows: −82.3 ± 3.9 dB vs. −90.4 ± 9.4 dB at 0.1 Hz, −75.7 ± 7.3 dB vs. −98.2 ± 9.9 dB at 1 Hz, and −62.4 ± 7.7 dB vs. −91.1 ± 8.1 dB at 10 Hz. The developed parylene-based electrochemical seismic sensors may function as an enabling technique for further detection of seismic motions in various applications.

A monolithic electrochemical micro seismic sensor capable of monitoring three-axial vibrations was proposed in this paper. The proposed micro sensor mainly consisted of four sensing units interconnected within flow channels and by interpreting the voltage outputs of the sensing units, vibrations with arbitrary directions can be quantified. The proposed seismic sensors are fabricated based on MEMS technologies and characterized, which produced sensitivities along x, y, and z axes as 2473.2 ± 184.5 V/(m/s), 2261.7 ± 119.6 V/(m/s), and 3480.7 ± 417.2 V/(m/s) at 30 Hz. In addition, the vibrations in x-y, x-z, and y-z planes were applied to the developed seismic sensors, leading to comparable monitoring results after decoupling calculations with the input velocities. Furthermore, the results have shown its feasibilities for seismic data recording.

Electrochemical seismic sensors are key components in monitoring ground vibration, which are featured with high performances in the low-frequency domain. However, conventional electrochemical seismic sensors suffer from low repeatability due to limitations in fabrication and limited bandwidth. This paper presents a micro-fabricated electrochemical seismic sensor with a force-balanced negative feedback system, mainly composed of a sensing unit including porous sensing micro electrodes immersed in an electrolyte solution and a feedback unit including a feedback circuit and a feedback magnet. In this study, devices were designed, fabricated, and characterized, producing comparable performances among individual devices. In addition, bandwidths and total harmonic distortions of the proposed devices with and without a negative feedback system were quantified and compared as 0.005–20 (feedback) Hz vs. 0.3–7 Hz (without feedback), 4.34 ± 0.38% (without feedback) vs. 1.81 ± 0.31% (feedback)@1 Hz@1 mm/s and 3.21 ± 0.25% (without feedback) vs. 1.13 ± 0.19% (feedback)@5 Hz@1 mm/s (ndevice = 6, n represents the number of the tested devices), respectively. In addition, the performances of the proposed MEMS electrochemical seismometers with feedback were compared to a commercial electrochemical seismic sensor (CME 6011), producing higher bandwidth (0.005–20 Hz vs. 0.016–30 Hz) and lower self-noise levels (−165.1 ± 6.1 dB vs. −137.7 dB at 0.1 Hz, −151.9 ± 7.5 dB vs. −117.8 dB at 0.02 Hz (ndevice = 6)) in the low-frequency domain. Thus, the proposed device may function as an enabling electrochemical seismometer in the fields requesting seismic monitoring at the ultra-low frequency domain.