CANADIAN JOURNAL OF CHEMICAL ENGINEERING
·
2018
·Vol. 96
·期 11
·2443-2449
·
IF 1.265
Jiaming Xue,Zuoxiang Zeng,Weilan Xue,Huayu Yang
The kinetics of the esterification between benzoic acid and isoamyl alcohol has been studied using p -toluenesulphonic acid as a catalyst. The conversion of the benzoic acid was determined by following the concentration of water measured with a Karl Fischer titrator. The effects of the reaction temperature, catalyst concentration, and initial acid to alcohol molar ratio on reaction kinetics have been examined. A five-step assumption was proposed to describe the reaction mechanism for the formation of isoamyl benzoate. And the kinetic model derived from the proposed mechanism can fit well with experimental kinetic data of the esterification, which indicates that the proposed mechanism is reasonable. The nonideality of the liquid reaction mixture has been considered and the activity coefficients of all components were estimated by the UNIFAC model. The reaction rate constants from 353.15 K to 383.15 K have been determined through the least square method. Meanwhile the activation energy and the standard enthalpy change of reaction in the presence of p -toluenesulphonic acid were calculated to be 50.45 kJ/mol and −3.75 kJ/mol respectively.
研究领域:
化学工程
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催化化学
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DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2017
·
IF 2.323
Feng Zhou,Lei Zhong,Changxu Chen,Ye Li,Chunjian Xu
Isobaric vapor–liquid equilibrium (VLE) data for binary systems of isoamyl alcohol + dimethyl sulfoxide (DMSO) and isoamyl acetate + DMSO, and the ternary system of isoamyl alcohol+ isoamyl acetate + DMSO at 101.33 kPa were measured by a modified Rose-Williams equilibrium still. The binary experimental data were checked by Herington method and a Van Ness test to verified thermodynamic consistency. The ternary VLE data was checked by Van Ness test. The experimental measurements of the binary systems were correlated by Wilson, nonrandom two-liquid (NRTL) and universal quasichemical (UNIQUAC) activity coefficient models with minor deviation. The ternary VLE data predicted by the obtained correlation parameters fit well with the experimental data. The experimental results indicate that the relative volatility between isoamyl alcohol and isoamyl acetate is changed obviously with the addition of DMSO as an entrainer at 0.50 mass fraction, which shows DMSO is an effective solvent for the separation of isoamyl alcohol and isoamyl acetate mixture in extractive distillation.
研究领域:
化学工程
·
热力学
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DOI
高影响因子
JOURNAL OF THERMAL SPRAY TECHNOLOGY
·
2024
·Vol. 33
·期 4
·1205-1219
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IF 3.2
Xu Kaichun,Han Mengjie,Xu Jinyong,Zheng Zichen,Wu Kaidi,Yu Zexin,Liao Hanlin,Zhang Chao
The development of one-step deposition technology for metal oxide-based coatings is significant for the rapid fabrication of gas sensors. Gas sensors based on LaFeO 3 were fabricated by solution precursor plasma spraying (SPPS) strategy. Through a comparative analysis of material composition and cross-sectional morphology, we have determined the optimal spray distance (8 cm), ensuring the highest level of thickness uniformity in the coating (17.13 ± 0.34 μm). Furthermore, the influence of the number of passes on coating morphology and gas sensing performance was investigated. The optimal gas sensor possessed a higher response to isoamyl alcohol (236 at 25 ppm) at 250 °C. Meanwhile, excellent selectivity, repeatability, long-term stability (431.6 ± 9.2 at 60 ppm for 20 days), and a low limit of detection (144 ppb) were obtained. The superior low-concentration (< 25 ppm) gas-sensing performance should be ascribed to the loose porous morphology with uniform thickness and the higher surface activity of the optimal coating. Moreover, the practical experiment demonstrated the application potential of the sensors for monitoring wheat mildew. This work may provide a direction for the characteristic gas detection of wheat mildew and a successful case for the deposition of LaFeO 3 coating by SPPS.
研究领域:
材料科学
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传感器技术
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表面工程
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分析化学
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食品质量监测
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DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2021
·
IF 2.694
Bingjie Huo,Xiaomin Qiu,Hongru Zhang,Yaning Zhang,Jingwei Yang,Zhaoyou Zhu,Yinglong Wang,Jun Gao
Isoamyl butyrate is a common food additive. Water will be generated by esterification reaction in the process of its formation. Cyclohexane, n-hexane, and n-heptane are often selected as entrainers to remove water and promote the reaction. In this work, the vapor–liquid equilibrium data of the binary systems of isoamyl alcohol + isoamyl butyrate, cyclohexane + isoamyl butyrate, n-hexane + isoamyl butyrate, and n-heptane + isoamyl butyrate were determined by using a modified Rose vapor recirculating-type equilibrium still at 101.3 kPa. Fredenslund test and Van Ness point test methods are used to verify the thermodynamic consistency of the experimental vapor–liquid equilibrium data. In addition, three classical activity coefficient models, Wilson, NRTL, and UNIQUAC, were used to fit the isobaric vapor–liquid equilibrium data of four binary systems. The binary interaction parameters were obtained by regression of experimental data.
研究领域:
化学工程
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物理化学
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DOI
高影响因子
FOOD CHEMISTRY
·
2020
·
IF 6.306
Hailong Sun,Shuangping Liu,Jieqi Mao,Ziwei Yu,Zhijie Lin,Jian Mao
Although huangjiu is a popular alcoholic beverage in China, the occurrence of quick-intoxication suppresses huangjiu consumption and impedes development of the huangjiu industry. In this study, the Cryprinus carpio intoxication model was used to compare the differences in intoxication effect of alcoholic beverages and to assess the impacts of huangjiu components on intoxication for the first time. Exposure to huangjiu led to the most rapid physical imbalance of C. carpio , followed by red wine and Western liquor. Higher alcohols, biogenic amines and aldehydes could cause physical imbalance of fish by themselves, and synergistic effects were observed when combined with ethanol. 2-Phenylethanoland and isopentanol had the greatest positive effect on huangjiu intoxication, followed by histamine and phenethylamine. No synergistic effect was observed between individual aldehydes and ethanol. Identification of these impactful huangjiu components provides a new perspective on the establishment of more rigorous control on the quality and flavor of huangjiu.
研究领域:
食品科学
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饮料化学
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水生毒理学
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DOI
PubMed
高影响因子
FLAVOUR AND FRAGRANCE JOURNAL
·
2023
·
IF 2.6
Yanru Chen,Yin Wan,Wenqin Cai,Xiaming Che,Hong Peng,Guiming Fu
Higher alcohols (phenylethyl alcohol and isoamyl alcohol), as the crucial aroma compounds, have been found to associate with the sensory properties of various alcoholic products. The Ehrlich and Harris pathways are the main pathways for yeast to produce phenylethyl alcohol and isoamyl alcohol during the brewing process of alcoholic products, whereas the specific changes of the Ehrlich and Harris pathways in Wickerhamomyces anomalus under ethanol stress are still unclear. In this study, W. anomalus NCU003 with a high capacity for aroma compound production was treated with ethanol stress at different concentrations (3%, v/v, 6%, v/v and 9%, v/v) to study the effects on the expression levels of genes and metabolite content in the Ehrlich and Harris pathways. The results found that ethanol stress inhibited the production of phenylethyl alcohol and isoamyl alcohol, and the content decreased with the increase of ethanol concentrations. In the meantime, the up-regulation of ARO1 , CS , ARO8 , Leu1 , BAT2 and ilvs family genes in the Ehrlich and Harris pathways could lead to an increase in the synthesis of important precursor substances during the synthesis of phenylethyl alcohol and isoamyl alcohol. However, the significant down-regulation of ARO10 , PDC , ADH1 and AHD2 genes was the main reason for the low production of phenylethyl alcohol and isoamyl alcohol. These results could provide a theoretical reference for the construction of genetic engineering strains of W. anomalus in the future so as to reasonably control the content of higher alcohols during the brewing process of alcoholic products.
研究领域:
微生物学
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生物化学
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发酵科学
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分子生物学
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DOI
高影响因子
Biotechnology for Biofuels
·
2021
·Vol. 14
·期 1
·1-13
·
IF 6.04
Zhao Yu,Liu Shiqi,Lu Zhihui,Zhao Baixiang,Wang Shuhui,Zhang Cuiying,Xiao Dongguang,Foo Jee Loon,Yu Aiqun
Background In biological cells, promoters drive gene expression by specific binding of RNA polymerase. They determine the starting position, timing and level of gene expression. Therefore, rational fine-tuning of promoters to regulate the expression levels of target genes for optimizing biosynthetic pathways in metabolic engineering has recently become an active area of research.Results In this study, we systematically detected and characterized the common promoter elements in the unconventional yeast Yarrowia lipolytica, and constructed an artificial hybrid promoter library that covers a wide range of promoter strength. The results indicate that the hybrid promoter strength can be fine-tuned by promoter elements, namely, upstream activation sequences (UAS), TATA box and core promoter. Notably, the UASs of Saccharomyces cerevisiae promoters were reported for the first time to be functionally transferred to Y. lipolytica. Subsequently, using the production of a versatile platform chemical isoamyl alcohol as a test study, the hybrid promoter library was applied to optimize the biosynthesis pathway expression in Y. lipolytica. By expressing the key pathway gene, ScARO10, with the promoter library, 1.1–30.3 folds increase in the isoamyl alcohol titer over that of the control strain Y. lipolytica Po1g KU70∆ was achieved. Interestingly, the highest titer increase was attained with a weak promoter PUAS1B4-EXPm to express ScARO10. These results suggest that our hybrid promoter library can be a powerful toolkit for identifying optimum promoters for expressing metabolic pathways in Y. lipolytica.Conclusion We envision that this promoter engineering strategy and the rationally engineered promoters constructed in this study could also be extended to other non-model fungi for strain improvement.
研究领域:
微生物学
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生物技术
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代谢工程
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合成生物学
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DOI
PubMed
高影响因子
Food Bioscience
·
2022
·
IF 5.318
Yaling Huang,Junwen Wan,Min Sun,Tao Feng,Qian Liu,Shiqing Song,Xiaoming Zhang,Chi-Tang Ho
The sensomics approach was applied to elucidate the flavor profile of Chinese steamed breads (CSBs) fermented by different fresh and dry yeast, respectively. The quantitative descriptive analysis (QDA) led to the establishment of seven sensory attributes. Results noted that fresh yeast CSBs were characterized by milk, bouquet, sweet, and sour attributes, while the corresponding dry yeast CSBs exhibited wheat and yeast attributes. According to OAVs ≥1, 34 aroma-active chemicals were shown to be significant odorants. Isoamyl alcohol, 2,3-butanediol, benzoic acid , acetoin, hexanal, and indole had a significant contribution to the different aroma profiles of dry and fresh yeast CSBs. The result of correlation analysis showed that 2,3-butanediol and benzoic acid were correlated with sweet, milk, and sour attributes, hexanal and indole were related to bouquet attribute, and acetoin was associated with flour. Further aroma recombination confirmed the contribution of these key components in flavor discrimination of CSBs. These results will provide guidance for the yeast-CSBs flavor evaluation, improvement, and quality control.
研究领域:
食品科学
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感官科学
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化学
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DOI
高影响因子
Scientific Reports
·
2024
·Vol. 14
·期 1
·1-11
·
IF 3.8
Chu Yajing,Ge Dianlong,Zhou Jijuan,Liu Yue,Zheng Xiangxue,Liu Wenting,Ke Li,Lu Yan,Chu Yannan
Characteristic volatile organic compounds (VOCs) are anticipated to be used for the identification of lung cancer cells. However, to date, consistent biomarkers of VOCs in lung cancer cells have not been obtained through direct comparison between cancer and healthy groups. In this study, we regulated the glycolysis, a common metabolic process in cancer cells, and employed solid phase microextraction gas chromatography mass spectrometry (SPME–GC–MS) combined with untargeted analysis to identify the characteristic VOCs shared by cancer cells. The VOCs released by three types of lung cancer cells (A549, PC-9, NCI-H460) and one normal lung epithelial cell (BEAS-2B) were detected using SPME–GC–MS, both in their resting state and after treatment with glycolysis inhibitors (2-Deoxy- d -glucose, 2-DG/3-Bromopyruvic acid, 3-BrPA). Untargeted analysis methods were employed to compare the VOC profiles between each type of cancer cell and normal cells before and after glycolysis regulation. Our findings revealed that compared to normal cells, the three types of lung cancer cells exhibited three common differential VOCs in their resting state: ethyl propionate, acetoin, and 3-decen-5-one. Furthermore, under glycolysis control, a single common differential VOC—acetoin was identified. Notably, acetoin levels increased by 2.60–3.29-fold in all three lung cancer cell lines upon the application of glycolysis inhibitors while remaining relatively stable in normal cells. To further elucidate the formation mechanism of acetoin, we investigated its production by blocking glutaminolysis. This interdisciplinary approach combining metabolic biochemistry with MS analysis through interventional synthetic VOCs holds great potential for revolutionizing the identification of lung cancer cells and paving the way for novel cytological examination techniques.
研究领域:
生物化学
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医学诊断
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代谢组学
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产品关联
DOI
PubMed
高影响因子
Food Bioscience
·
2024
·
IF 4.8
Baoqing Bai,Lanqi Zhang,Ying Zhang,Bin Feng,Tao Bo,Jinhua Zhang,Sanhong Fan,Yukun Yang
The fermentation rounds in the brewing process of Qingxiangxing Baijiu (QXB) significantly influence its quality and flavor. This study investigates the flavor characteristics of two rounds of QXB: Dacha-Baijiu and Ercha-Baijiu. Analysis via HS-SPME-GC × GC-TOFMS revealed a higher number of volatile organic compounds (VOCs) in Ercha-Baijiu, whereas Dacha-Baijiu exhibited elevated concentrations of alcohols and esters. Orthogonal partial least squares discrimination analyses indicated significant flavor differences between the two rounds. Based on odor activity value (OAV >1) assessment, 51 VOCs were identified as key aroma contributors, with β-damascenone, isovaleraldehyde, ethyl caprylate, and ethyl hexanoate being particularly prominent. Furthermore, 37 volatile compounds were accurately identified using GC-IMS, effectively constructing a fingerprint of the flavor differences between two rounds of QXB. Sensory analysis revealed significant distinctions in both aroma and taste. Dacha-Baijiu exhibited more intense aroma of sweet, floral, and grain, as well as taste of sour and fresh, while Ercha-Baijiu was marked by strong acid, alcoholic, and fruit aroma, as well as sweet, bitter and salty taste. This study elucidates the flavor characteristics of two rounds of QXB, which providing valuable insights for the processing technology and flavor quality control of QXB.
研究领域:
食品科学
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分析化学
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风味化学
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产品关联
DOI
高影响因子
MOLECULES
·
2025
·Vol. 30
·期 4
·933
·
IF 4.6
Jialing Lu,Jia Zheng,Dong Zhao,Yan Xu,Shuang Chen
Strong-aroma type Baijiu and its diluted samples were characterized through descriptive analysis. Significant changes were observed in four (ethanol, Jiao-aroma, fruity, and grain) of the nine aroma attributes, primarily attributed to variations in ethanol concentration rather than other compounds. The thresholds of 40 compounds in aqueous solutions with alcohol concentrations of 20%, 30%, 40%, 50%, and 60% were measured using three-alternative forced-choice tests. The thresholds of 30 compounds were significantly positively correlated with ethanol concentration. The thresholds of 40 compounds were affected by ethanol concentration to varying degrees, with changes ranging from 2 to 692 times. Due to the varying degrees of alcohol influence on the compound threshold, the aroma profile of diluted Baijiu sample is different from the original Baijiu sample.
研究领域:
食品科学
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感官分析
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产品关联
DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2024
·
IF 6.7
Jijuan Zhou,Dianlong Ge,Yue Liu,Yajing Chu,Xiangxue Zheng,Yan Lu,Yannan Chu
Cellular volatile organic compound (VOC) detection is crucial for studying lung cancer biomarkers. However, the reported VOC biomarkers from the same cell line seem to be inconsistent across different research groups. It is possibly related to the variation in culture media, and the result obtained by a conventional single medium approach (SMA) depends on what medium is used in the cell experiment. This study proposes a multiple media approach (MMA) to investigate reproducible characteristic VOCs of lung cancer cells. Using solid-phase microextraction–gas chromatography–mass spectrometry (SPME-GC-MS) in combination with untargeted analysis, we conducted two independently repetitive experiments to compare lung cancer cells (A549) and normal lung cells (BEAS-2B) under three culture media conditions (RPMI 1640, DMEM, and Ham’s F12). Both experiments indicated that, compared with 62–96 VOCs obtained by the SMA, only two VOCs (3-methyl-1-butanol and 2-methyl-1-butanol) were reproducibly achieved by the MMA. Moreover, their concentrations were significantly lower in lung cancer cells than in normal cells. Further targeted analysis confirmed the downregulation trend of both VOCs in subcutaneous and primary tumor tissues from the lung cancer model mouse. The present work demonstrated that the MMA cell experiment, just like the multicenter trials for cell lines, can facilitate the discovery of reproducible characteristic VOCs. This provides a cellular experimental basis and scientific evidence for lung cancer biomarker investigation and even breath biopsy technique development.
研究领域:
医学
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分析化学
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肿瘤学
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）