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To analyze the metabolic differences in Wangdu peppers, this study employed high-performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC-MS) to detect chemical components and perform non-targeted metabolomics analysis on five different varieties of Wangdu peppers: Yan Jiao (YJ), La Yan (LY), Guo Ta (GT), Yan Jiao 110 (YJA), and Re La (RL). Machine learning was used to classify and identify the differential metabolites screened. First, HPLC was used to measure the content of capsaicin, dihydrocapsaicin, and Vitamin C (VC) in the five pepper varieties. Then, GC-MS was used for non-targeted metabolite analysis of the five peppers. Principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) were employed to identify differential metabolites and metabolic pathways. Machine learning methods were used to identify the different pepper varieties based on the differential metabolites. In the five pepper varieties, Re La had the highest content of capsaicin and dihydrocapsaicin, at 533.897±62.187 μg/g and 264.526±28.532 μg/g, respectively. Yan Jiao had the highest VC content at 146.9±0.029 mg/100 g. OPLS-DA identified 16 differential metabolites, including organic acids such as quinic acid and aconitic acid, which were higher in Yan Jiao, D-sorbitol, which was highest in La Yan, citric acid, D-fructose, D-mannose, and lactic acid, which were most enriched in Guo Ta, D-tagatose and amino acids, which were highest in Yan Jiao 110, and glucose and inositol, which were most abundant in Re La. KEGG pathway enrichment analysis indicated that the differential metabolic pathways mainly included galactose metabolism, fructose and mannose metabolism, the citric acid cycle, starch and sucrose metabolism, glyoxylate and dicarboxylate metabolism, and pyruvate metabolism. Finally, three machine learning methods—random forest (RF), XGBoost, and backpropagation (BP) neural networks were used to classify and validate the differential metabolites of the five pepper varieties. The established classification models achieved accuracies of 100%, 92.9%, and 78.6%, respectively, demonstrating their utility in identifying pepper varieties. These results would provide fundamental data for the quality evaluation, variety improvement, and comprehensive utilization of Wangdu peppers.

Plasma homocysteine (Hcy) is an amino acid causing vascular injury. It is closely associated with endothelial cell injury, vascular smooth muscle proliferation, inflammatory responses, thrombosis and vascular calcification. An elevated level of Hcy may affect normal function of renal vasculature and glomeruli, thereby accelerating the progression of chronic kidney disease to end-stage renal disease. In maintenance hemodialysis (MHD) patients, the incidence of hyperhomocysteinemia (HHcy) is 33 folds that of normal individuals so that it becomes a common yet complex health issue. For accurately identifying HHcy and improving patient prognosis, this review summarized the common causes of HHcy in MHD patients and introduced various preventive and therapeutic measures.

Seven samples of Wuyi rock tea (cv. Shuixian) stored for different times (0, 5, 10, 15, 20, 25, and 30 years) were collected to investigate the effect of storage time on the flavor quality of Wuyi rock tea by the combined use of sensory evaluation, non-volatile and volatile composition analysis and chemometrics methods. The results showed that the transformation of the flavor quality of Wuyi rock tea during storage was divided into three stages: 0–5, 10–15, and 20–30 years. As the storage time increased, the taste gradually transformed from mellow to stale, and a sour taste appeared at the middle stage of storage and then faded away at the late stage. The aroma gradually changed from flowery and fruity to aged, woody and herbal. A significant decrease in the content of tea polyphenols, catechins-like and theaflavins and an increase in the content of soluble sugars were the major reasons for the taste changes. Changes in the contents of 15 characteristic volatiles, including indole, trans-nerolidol, dihydroactinidiolide, hotrienol, α-terpineol, methyl salicylate, β-ionone, and (Z)-hexanoic acid-3-hexenyl ester, were the key factors affecting the aroma changes. This study provides a scientific reference for the storage and consumption of Wuyi rock tea.

In this study, the main components of the extract of (Lithocarpus litseifolius folium extract, LLFE) were analyzed,and the anti-oxidative stress and anti-aging effects of LLFE on C.elegans were evaluated using Caenorhabditis elegans (C.elegans) as a model to explore the possible mechanisms of action.The results showed that LLFE contained 52.84±1.45 mg/g of total phenols, 380.74±15.12 mg/g of total flavonoids, 470.36±5.84 mg/g of total sugars and about 6.00% of dihydrochalcone compounds, with phloridzin 52.76±0.71 mg/g, phloretin 1.64±0.06 mg/g and trilobatin 4.88±0.01 mg/g. LLFE (0.25, 1.25 mg/mL) also significantly extended the mean lifespan of C.elegans under oxidative and heat stress conditions (P

In this study, non-targeted metabolomic research was conducted using gas chromatography-mass spectrometry (GC-MS) on Laba garlic at different storage times to explore the signature metabolite changes during storage. Multivariate statistical analysis was used to screen out the significant metabolites of Laba garlic at different storage times. Further, the deep learning support vector machine recursive feature elimination (SVM-RFE) algorithm was used to determine its landmark metabolites, and enrichment analysis of the pathways of its landmark metabolites was carried out. A total of 57 different metabolites were screened out (VIP≥1, P

In order to compare the change trend of fermented garlic broth by different strains in the fermentation process, the chemical and physical index of total phenol, titratable acid, methanol, ethanol, and hydroxyl radical scavenging capacity during the fermentation process were determined, then the types and content of organic acid was analyzed by high performance liquid chromatography. The taste of fermented garlic broth at different fermentation time was analyzed by electronic tongue. The results showed that the total phenols and titratable acids of fermented garlic broth prepared by different strains (Saccharomyces cerevisiae and Lactobacillus plantarum) showed an upward trend during the fermentation process. The content of six organic acids (tartaric acid, malic acid, lactic acid, acetic acid, citric acid, succinic acid) was measured in fermented garlic broth, among which the content of malic acid and lactic acid was relatively high. The taste response value of fermented garlic broth prepared by Lactobacillus plantarum had a large change in the early stage of fermentation. The value of sourness response rapidly increased to 9.21±0.03 after 4 days of fermentation, and the value of saltiness response rapidly decreased to −21.11±0.01 after 4 days of fermentation. The scavenging capacity hydroxyl radicals and the content of methanol, ethanol showed a trend that firstly increasing and then keeping in a steady state. The hydroxyl radical scavenging ability for fermented garlic solution was 99.88%±0.05% after 80 days of fementation by Lactobacillus plantarum. The ethanol content produced by Saccharomyces cerevisiae fermentation was higher, while the content of methanol produced by fermentation of Lactobacillus plantarum was higher. Considering the comprehensive evaluation of the effects of strains on the quality of fermented garlic broth, Lactobacillus plantarum was more suitable for garlic fermentation than Saccharomyces cerevisiae, methanol content was within the safe range. This research would provide a theoretical study for the research and development of garlic fermentation products.

A two-step fermentation method was used to prepare Hovenia dulcis Thunb Huangjiu, its physical and chemical indexes were tested, and its antioxidant capacity was evaluated. To explore the reasons for its antioxidant, the total phenols and total flavonoids in soaked and fermented Hovenia dulcis Thunb Huangjiu were compared, and the differences in the content of the main active ingredients dihydromyricetin and myricetin were further analyzed by high-performance liquid chromatography. The results showed that Huangjiu fermented with Hovenia dulcis Thunb (HFH) belonged to special type semi-dry Huangjiu. It had medicinal aroma, improved bitterness and astringency, and better taste. Its VC milligram equivalents on DPPH, ABTS, OH free radical scavenging ability and reducing power were 0.727, 33.60, 9.07 and 0.823 mg VC/mL, which were higher than those of Huangjiu. After comparison, it was found that the total phenol content of HFH was 1120.20 mg/L, which was significantly higher than that of the soaked type (P

A new type of gas-liquid cylindrical separator with baffle inside was designed, and the CFD method was used to simulate the flow fields of new cylindrical separator and the general cylindrical separator. The properties of these two kinds of separator were compared, such as distribution of velocity vector, liquid volume fraction and turbulent dissipation rate. Meanwhile, to investigate the performance and influencing factors of the two separators, experiments were carried out under the condition of cold model. It is revealed that the experimental data is in good agreement with the simulation results, which verified the feasibility and correctness of the numerical simulation method. Analysis results also show that, though the pressure drop of the new type separator was a little higher than that of the general one, the new type of gas-liquid cylindrical separator has the advantages of high separation efficiency and broad operating conditions, which is of great value to the modification and industrial application of the gas liquid separator. [ABSTRACT FROM AUTHOR]

Solid-holdup, which is significant to the design and optimization of reactor, is an important parameter to assess solid suspension in stirred tank. In this work, solid-holdup in gas-liquid-solid system was measured by detected hydrophone signals combined with the partial least squares (PLS) analysis. It was revealed that a characteristic frequency band of hydrophone signals representing the particle motion was in accordance with the results of FFT analysis. A regression model between solid-holdup and hydrophone signal was built up. Comparing the real values with predicted results, it shows that the correlation coefficient (R) is larger than 0.89, the average relative deviation (ARD) is less than 1.02% and the root mean squared error of prediction (RMSEP) is less than 1.73%. Good precision of the prediction model has been verified. It is concluded that hydrophone is feasible for determining solid-holdup in stirred tank and it have the merit of being sensitive and accurate. [ABSTRACT FROM AUTHOR]

Phosphorous modified high silica ZSM-5 catalysts were synthesized by infusion method. XRD BET and NH3-TPD results showed that phosphorous compounds were loaded uniformly on the surface of catalyst and de-aluminated pore surface was observed. The strong acids of phosphorous modified catalyst decreased and the weak acids increased. It also revealed from the results of methanol to propylene reaction that the phosphorous compounds in high silica ZSM-5 catalysts could suppress the hydrogen transfer reaction and increase the propylene selectivity. But the activity of catalysts would decrease rapidly when the phosphorous was over-loaded. [ABSTRACT FROM AUTHOR]

The criterion of dividing the electrostatic potential signal in three characteristic scales is established by Hurst analysis of the wavelet decomposed signals. For bubbling fluidization, energy percent of meso-scale component is highest, which confirms that the electrostatic signals mainly reflect the action of bubbles. Furthermore, energy profiles of three components vary with the radial distance of the bed. It is also found that micro-scale and meso-scale components are sensitive to the flow regime transition. [ABSTRACT FROM AUTHOR]

Fourier-transform (FT) Raman spectra were measured for 7 kinds of different polypropylene copolymers and the assignments of all Raman bands were made through a detailed analysis. Ultimately, by choosing 2 700-3 100 cm(-1) as the characteristic spectral, partial least squares (PLS) regression models were set up for xylene solubles content, ethylene content and ethylene content of xylene solubles in polypropylene copolymers. The values of correlation coefficient (r) between predicted results and actual values were all greater than 0.94, and the values of average relative error (ARE) were all less than 5%. The second PLS factor was also analyzed in this paper, and it was concluded that the original information of the sample was accurately extracted by using PLS regression. This paper offered a kind of possibility for on-line measurement of xylene solubles content, ethylene content and ethylene content of xylene solubles in polypropylene copolymers.

Ethylene content in polypropylene was studied by Raman spectrum, combined with partial least squares (PLS) method. The comparison between Raman spectra for polyethylene and polypropylene was carried out, and the spectra between 50 and 600, 600 and 1600, and 2700 and 3100 cm(-1) were analyzed respectively. The models for ethylene content prediction were built, while the model based on 50-3600 cm(-1) spectra gave the best performance. The experiment indicated that Raman spectrum gave the similar predictive results as the near infrared (NIR) spectrum; the values of correlation coefficient (r), relative average deviation (RAD) and root mean square error (RMSE) between predictive results and actual values were 0.995, 2.65% and 0.319, respectively. According to PLS analysis, the loadings of factor 1 could reflect the relationship between the composition of polypropylene molecular chain and ethylene content, and ethylene content had a positive correlation with CH2 content, but a negative correlation with content of CH3, C-H, and C-C. The results indicated that it was feasible to detect the ethylene content in polypropylene by Raman spectrum.

Quantitative determination of polyvinyl chloride (PVC) concentration by Raman spectrum was studied in the present work. According to partial least squares (PLS) analysis, it was found that scores of PLS factor 1 were proportional to the concentrations of the sample solutions. Meanwhile, the loadings of factor 1 could reflect the contents of PVC and cyclohexanone simultaneously. The PLS regression model for PVC concentration prediction was built. The values of r and root mean square error (RMSE) between predictive results and actual values were 0.9963 and 2.775, respectively. The Raman characteristic peaks of PVC and cyclohexanone were found, including the C-Cl bond for PVC (620 and 695 cm(-1)) and the alicyclic ketone for cyclohexanone (1709 cm(-1)). By using internal standard method, another model for PVC concentration prediction was established, and the values of r and RMSE were 0.9941 and 3.151, respectively. The results indicated that it is feasible to use Raman spectrum to detect the PVC concentration, which is of significant importance to PVC recycling.