污泥与醋糟共热解特性及碱金属迁移规律

分别采用热重分析仪、真空固定床反应器和原子吸收光谱研究了污泥与醋糟共热解过程中反应动力学、产物分布和碱金属迁移行为,探究了协同效应及碱金属迁移规律。结果表明,两者共热解过程中存在明显协同效应;与理论计算相比,混合物分解所需的活化能下降了35.38%～29.49%,脱挥发指数比计算低3.5×10-8。协同效应导致气体产率增加,生物炭、液体产率降低;醋糟的存在加速了污泥的脱挥发分析出,提高了气体产物中合成气含量,加大了生物炭中大芳香环的裂解反应,使生物油中酚类和酯类物质含量明显增加;热解终止时,碱金属元素析出量达到79.19%～86.73%。     

Contribution to the Evaluation of Physicochemical Properties,Total Phenolic Content,Antioxidant Potential,and Antimicrobial Activity of Vinegar Commercialized in Morocco

Vinegar is a natural product widely used in food and traditional medicine thanks to its physicochemical properties and its richness in bioactive molecules. However, its direct use by consumers can have complications and undesirable effects. Therefore, this study contributes to investigating the physicochemical and biological properties of eleven vinegars marketed in Morocco. Determination of pH, acetic acid, conductivity, total soluble solids and alcohol content in vinegar was carried out. The polyphenols (TP), flavonoids (TF), and condensed tannins (CT) content was determined, and their antioxidant activities were evaluated using 2,2-diphenyl-1-picryl Hydrazyl (DPPH), Ferric Reducing Antioxidant Power (FRAP) and Phosphomolybdenum Reduction Assay (TAC). Then, the antimicrobial activity was studied against four pathogenic bacteria and two fungal strains, using the disk diffusion and the microdilution method. This study showed a wide range of acetic acid values from 0.65 ± 0.29 to 5.15 ± 0.20%. The high value of TP, TF, and CT in our samples V10, V9, and V4 was 655.00 ± 22.2 µgGAE/mL, 244.53 ± 11.32 µgQE/mL and 84.63 ± 1.00 µgTAE/mL, respectively. The tested strains showed variable sensitivities to the different samples with inhibition zones ranging from 6.33 ± 2.08 to 34.33 ± 0.58 mm. The lowest minimum inhibition concentrations were recorded against Staphylococcus aureus ATCC29213 ranging from 1.95 to 7.81 µL/mL. While Aspergillus niger ATCC16404 showed resistance against all of the analyzed samples. In general, vinegar commercialized in Morocco presents a variable range of products with variable properties. Indeed, must take into account this diversity when using it. A future study is needed to identify the phytochemical composition that will further the comprehension of this variability and contribute to its valorization.     

Fruits Vinegar: Quality Characteristics,Phytochemistry, and Functionality

The popularity of fruits vinegar (FsV) has been increased recently as a healthy drink wealthy in bioactive compounds that provide several beneficial properties. This review was designed in the frame of valorization of fruits vinegar as a by-product with high value added by providing overall information on its biochemical constituents and beneficial potencies. It contains a cocktail of bioactive ingredients including polyphenolic acids, organic acids, tetramethylperazine, and melanoidins. Acetic acid is the most abundant organic acid and chlorogenic acid is the major phenol in apple vinegar. The administration of fruits vinegar could prevent diabetes, hypercholesterolemia, oxidative stress, cancer, and boost immunity as well as provide a remarkable antioxidant ability. The production techniques influence the quality of vinegar, and consequently, its health benefits.     

Authenticating apple cider vinegar’s home remedy claims: antibacterial,antifungal, antiviral properties and cytotoxicity aspect

These are the days when one would go online first seeking home remedies before seeing a doctor. Apple cider vinegar (ACV) is one such popular yet scientifically under-validated remedy. Our results prove the unequivocal antimicrobial activity of ACV to be true at full strength concentrations. However, the activity cannot be generalised because although strong antibacterial activity was observed at 25% concentrations, in terms of antifungal activity, yeasts, especially Candida were found to be less susceptible. The antimicrobial/antioxidant properties are ascertained to the total phenolic contents of ACV, as confirmed by our characterisation of the bioactive compounds and antioxidant activity. When checking for its cytotoxicity, ACV exhibited toxicity even at concentrations as low as 0.7%. These results indicate that there is no question of generalising the idea of ACV usage, instead more in vitro and in vivo validations are necessary in order to precisely weigh the pros and cons of ACV.     

高效液相色谱法测定食醋中的苯甲酸和山梨酸

研究了一种用蒸馏法提取,高效液相色谱法测定食醋中苯甲酸和山梨酸的方法。用蒸馏法提取食醋中的苯甲酸和山梨酸,收集蒸馏液直接进行液相色谱分析。使用的色谱柱为C18柱,流动相为甲醇-乙腈-5 mmol/L柠檬酸缓冲溶液(体积比为10∶20∶70),检测波长为230 nm。苯甲酸和山梨酸标准溶液在0.25~100 mg/L内线性良好,其线性相关系数分别为0.999 9和0.999 8,加标回收率为91.0%~95.2%,测量结果的相对标准偏差为2.46%~3.45%。该方法用于测定食醋样品中的苯甲酸、山梨酸,检测下限均为0.5 mg/L。     

短分离柱胶束液相色谱法同时测定酱油和食醋中的苯甲酸和山梨酸

建立了胶束液相色谱同时测定酱油和食醋中苯甲酸和山梨酸的检测方法。样品经过简单的稀释和过滤后直接注入高效液相色谱仪进行分析。分析柱使用两根串联的色谱保护柱(Zorbax Extend-C₁₈ 柱, 12.5 mm×4.6 mm, 5 μm),胶束流动相为含有2%(体积分数)异丙醇的0.01 mol/L十二烷基硫酸钠-0.01 mol/L醋酸钠(pH 4.9),检测器为二极管阵列检测器,检测波长为235 nm。苯甲酸和山梨酸在3.5 min内完全分离。检测的线性范围为10~100 μ g/mL,相关系数(r)为0.9999。检出限(S/N=3)和定量限(S/N=10)分别为0.04和0.14 μ g/mL。批间和批内精密度均不高于5.2%,高、中、低3个水平的加标回收率为90.5%~103.8%。该方法简单、快速,适用于食品质量监测的日常检测。     

食醋中C_1－C_8脂肪酸及乳酸的气相色谱分析

食醋中Ｃ１－Ｃ８脂肪酸和乳酸与适当过量的四甲基氢氧化铵作用生成季胺盐，用二甲基甲酰胺将其溶解，在室温下与过量溴乙烷完全反应而生成相应的乙酯。生成的乙酯在１０％丁二酸乙二醇聚酯（ＰＧＳ）柱上进行分离。用保留时间定性，用内标法定量。本法操作简便、快速，分离完全，对几种样品的测定结果较好     

Direct determination of mercury in white vinegar by matrix assisted photochemical vapor generation atomic fluorescence spectrometry detection

This paper proposes the use of photochemical vapor generation with acetic acid as sample introduction for the direct determination of ultra-trace mercury in white vinegars by atomic fluorescence spectrometry. Under ultraviolet irradiation, the sample matrix (acetic acid) can reduce mercury ion to atomic mercury Hg⁰, which is swept by argon gas into an atomic fluorescence spectrometer for subsequent analytical measurements. The effects of several factors such as the concentration of acetic acid, irradiation time, the flow rate of the carrier gas and matrix effects were discussed and optimized to give detection limits of 0.08 ng mL⁻¹ for mercury. Using the experimental conditions established during the optimization (3% v/v acetic acid, 30 s irradiation time and 20 W mercury lamp), the precision levels, expressed as relative standard deviation, were 4.6% (one day) and 7.8% (inter-day) for mercury (n = 9). Addition/recovery tests for evaluation of the accuracy were in the range of 92–98% for mercury. The method was also validated by analysis of vinegar samples without detectable amount of Hg spiked with aqueous standard reference materials (GBW(E) 080392 and GBW(E) 080393). The results were also compared with those obtained by acid digestion procedure and determination of mercury by ICP-MS. There was no significant difference between the results obtained by the two methods based on a t-test (at 95% confidence level).     

Polyphenols Extracted from Shanxi-Aged Vinegar Inhibit Inflammation in LPS-Induced RAW264.7 Macrophages and ICR Mice via the Suppression of MAPK/NF-κB Pathway Activation

Shanxi-aged vinegar, a traditional Chinese grain-fermented food that is rich in polyphenols, has been shown to have therapeutic effects on a variety of diseases. However, there has been no comprehensive evaluation of the anti-inflammatory activity of polyphenols extracted from Shanxi-aged vinegar (SAVEP) to date. The anti-inflammatory activities of SAVEP, both in RAW 264.7 macrophages and mice, were extensively investigated for the potential application of SAVEP as a novel anti-inflammatory agent. In order to confirm the notion that polyphenols could improve inflammatory symptoms, SAVEP was firstly detected by gas chromatography mass spectrometry (GC-MS). In total, 19 polyphenols were detected, including 12 phenolic acids. The study further investigated the protective effect of SAVEP on lipopolysaccharide-induced inflammation in RAW264.7 macrophages and ICR mice. The results showed that compared with those of the model group, SAVEP could remarkably recover the inflammation of macrophage RAW264.7 and ICR mice. SAVEP can normalise the expression of related proteins via the suppression of MAPK/NF-κB pathway activation, inhibiting the expression of iNOS and COX-2 proteins, and consequently the production of inflammatory factors, thus alleviating inflammatory stress. These results suggest that SAVEP may have a potential function against inflammation.     

Butyltin compounds in vinegar collected in Beijing: Species distribution and source investigation

Forty-eight vinegar samples including white vinegar,rice vinegar and mature vinegar were collected from several markets in Beijing.Butyltin compounds were determined by headspace solid-phase microextraction coupled with gas chromatography and flame photometric detector after in situ ethylation with sodium tetraethylborate.Butyltin species were detected in sixteen vinegar samples and ranged from 0.012 to 14.10 μg Sn L 1.The detection rate of white vinegar is higher than that of rice vinegar and mature vinegar.Vinegar samples with relatively high butyltin concentration(>1.5 μg Sn L 1) were those stored in plastic bags,indicating that the plastic bag was one of the possible sources of butyltin contamination.This was further confirmed by the leaching experiments of three selected plastic bags,and monobutyltin was detected in the leaching solvents.According to the estimation,the average daily intake of total butyltin compounds through vinegar consumption is about 0.04 ng Sn/kg b.w.,much lower than the Tolerable Daily Intake(TDI) of 100 ng Sn/kg b.w.set by the European Food Safety Authority(EFSA).