Comparative evaluation of commercial Douchi by different molds:biogenic amines,non-volatile and volatile compounds

To provide new insights into the development and utilization of Douchi artificial starters,three common strains(Aspergillus oryzae,Mucor racemosus,and Rhizopus oligosporus)were used to study their influence on the fermentation of Douchi.The results showed that the biogenic amine contents of the three types of Douchi were all within the safe range and far lower than those of traditional fermented Douchi.Aspergillus-type Douchi produced more free amino acids than the other two types of Douchi,and its umami taste was more prominent in sensory evaluation(P<0.01),while Mucor-type and Rhizopus-type Douchi produced more esters and pyrazines,making the aroma,sauce,and Douchi flavor more abundant.According to the Pearson and PLS analyses results,sweetness was significantly negatively correlated with phenylalanine,cysteine,and acetic acid(P<0.05),bitterness was significantly negatively correlated with malic acid(P<0.05),the sour taste was significantly positively correlated with citric acid and most free amino acids(P<0.05),while astringency was significantly negatively correlated with glucose(P<0.001).Thirteen volatile compounds such as furfuryl alcohol,phenethyl alcohol,and benzaldehyde caused the flavor difference of three types of Douchi.This study provides theoretical basis for the selection of starting strains for commercial Douchi production.

Effect of different drying methods on the amino acids,α-dicarbonyls and volatile compounds of rape bee pollen

The significant demand for high quality food has motivated us to adopt appropriate processing methods to improve the food nutritional quality and flavors.In this study,the effects of five drying methods,namely,pulsed vacuum drying(PVD),freeze drying(FD),infrared drying(IRD),hot-air drying(HAD)and sun drying(SD)on free amino acids(FAAs),α-dicarbonyl compounds(α-DCs)and volatile compounds(VOCs)in rape bee pollen(RBP)were determined.The results showed that FD significantly released the essential amino acids(EAAs)compared with fresh samples while SD caused the highest loss.Glucosone was the dominantα-DCs in RBP and the highest loss was observed after PVD.Aldehydes were the dominant volatiles of RBP and SD samples contained more new volatile substances(especially aldehydes)than the other four drying methods.Comprehensively,FD and PVD would be potential methods to effectively reduce the quality deterioration of RBP in the drying process.

Exploring Nutritional Compositions,Volatile Compounds,Health Benefits,Emerging Processing Technologies,and Potential Food Products of Glutinous Rice:A Review

Glutinous rice(Oryza sativa var.glutinosa)stands out as one of the most popular rice varieties globally,amidst thousands of rice cultivars.Its increasing popularity is attributed to its rich nutritional compositions and health benefits.This review aims to summarize the nutritional compositions,volatile compounds,and health benefits of glutinous rice.Further,in-depth studies are necessary to explore the utilization of glutinous rice in enhancing processing technologies and developing new food products.Glutinous rice has been shown to possess numerous health benefits,including antioxidant activity,bioactive compounds,anti-cancer properties,anti-inflammatory effects,anti-diabetic potential,and cholesterol-lowering effects.Besides its nutritional compositions,the major volatile compounds identified in glutinous rice could serve as a functional food for human consumption.Emerging processing technologies related to glutinous rice are elaborated to improve the latest developments for incorporating them into various food products.

Identification of breath volatile organic compounds to distinguish pancreatic adenocarcinoma,pancreatic cystic neoplasm,and patients without pancreatic lesions

BACKGROUND Volatile organic compounds(VOCs)are a promising potential biomarker that may be able to identify the presence of cancers.AIM To identify exhaled breath VOCs that distinguish pancreatic ductal adenocar-cinoma(PDAC)from intraductal papillary mucinous neoplasm(IPMN)and healthy volunteers.METHODS We collected exhaled breath from histologically proven PDAC patients,radiological diagnosis IPMN,and healthy volunteers using the ReCIVA®device between 10/2021-11/2022.VOCs were identified by thermal desorption-gas chromatography/field-asymmetric ion mobility spectrometry and compared between groups.RESULTS A total of 156 participants(44%male,mean age 62.6±10.6)were enrolled(54 PDAC,42 IPMN,and 60 controls).Among the nine VOCs identified,two VOCs that showed differences between groups were dimethyl sulfide[0.73 vs 0.74 vs 0.94 arbitrary units(AU),respectively;P=0.008]and acetone dimers(3.95 vs 4.49 vs 5.19 AU,respectively;P<0.001).After adjusting for the imbalance parameters,PDAC showed higher dimethyl sulfide levels than the control and IPMN groups,with adjusted odds ratio(aOR)of 6.98(95%CI:1.15-42.17)and 4.56(1.03-20.20),respectively(P<0.05 both).Acetone dimer levels were also higher in PDAC compared to controls and IPMN(aOR:5.12(1.80-14.57)and aOR:3.35(1.47-7.63),respectively(P<0.05 both).Acetone dimer,but not dimethyl sulfide,performed better than CA19-9 in PDAC diagnosis(AUROC 0.910 vs 0.796).The AUROC of acetone dimer increased to 0.936 when combined with CA19-9,which was better than CA19-9 alone(P<0.05).CONCLUSION Dimethyl sulfide and acetone dimer are VOCs that potentially distinguish PDAC from IPMN and healthy participants.Additional prospective studies are required to validate these findings.

Advanced Technologies for Volatile Organic Compound (VOC) Emission Treatment: An Overview

This paper presents a comprehensive overview of various advanced technologies employed in the treatment of volatile organic compounds(VOCs),which are crucial pollutants in industrial emissions.The study explores different methods,including direct combustion,thermal combustion,catalytic combustion,low-temperature plasma purification,photocatalytic purification,membrane separation,and adsorption methods.Each technology is critically analyzed for its operational principles,efficiency,and applicability under different conditions.Special attention is given to adsorption concentration and catalytic combustion parallel method,highlighting its efficiency in treating low-concentration,high-volume VOC emissions.The paper also delves into the advantages and limitations of each method,providing insights into their effectiveness in various industrial scenarios.The study aims to offer a detailed guide for selecting appropriate VOC treatment technologies,contributing to enhanced environmental protection and sustainable industrial practices.

Remove volatile organic compounds(VOCs) with membrane separation techniques

Membrane separation, a new technology for removing VOCs including pervaporation, vapor permeation, membrane contactor, and membrane bioreactor was presented. Comparing with traditional techniques, these special techniques are an efficient and energy saving technology. Vapor permeation can be applied to recovery of organic solvents from exhaust streams. Membrane contactor could be used for removing or recovering VOCs from air or wastewater. Pervaporation and vapor permeation are viable methods for removing VOCs from wastewater to yield a VOC concentrate which could either be destroyed by conventional means, or be recycled for reuse.

Identification and Recovery of Volatiles Organic Compounds (VOCs) in the Coffee-Producing Wastewater

The objectives of the present study were to recover and identify volatiles organic compounds (VOCs) in the wastewater (WW) coming from a soluble coffee industrial plant. For VOCs recover, the WW was concentrated by pervaporation using a polydimethylsiloxane (PDMS) membrane. Furthermore, the solid phase micro extraction (SPME) and gas chromatography-mass spectrometry (GC-MS) were used for VOCs identification. The multivariate method of principal component analysis (PCA) was performed to evaluate differences amongst the feed and concentrate streams. Regarding the number of VOCs identified in the wastewater (33) and permeate (72), a significant statistical difference at p Clusters discriminating were clearly observed, as the feed and permeate streams are compared. Thus, we can conclude that pervaporation process using a PDMS membrane was effective to recover different class of VOCs present in the aqueous effluent and can be recommended for industrial wastewater treatment.

Exhaled volatile organic compounds for diagnosis and monitoring of asthma

The asthmatic inflammatory process results in the generation of volatile organic compounds(VOCs),which are subsequently secreted by the airways.The study of these elements through gas chromatography-mass spectrometry(GC-MS),which can identify individual molecules with a discriminatory capacity of over 85%,and electronic-Nose(e-NOSE),which is able to perform a quick onboard pattern-recognition analysis of VOCs,has allowed new prospects for non-invasive analysis of the disease in an"omics"approach.In this review,we aim to collect and compare the progress made in VOCs analysis using the two methods and their instrumental characteristics.Studies have described the potential of GC-MS and e-NOSE in a multitude of relevant aspects of the disease in both children and adults,as well as differential diagnosis between asthma and other conditions such as wheezing,cystic fibrosis,COPD,allergic rhinitis and last but not least,the accuracy of these methods compared to other diagnostic tools such as lung function,FeNO and eosinophil count.Due to significant limitations of both methods,it is still necessary to improve and standardize techniques.Currently,e-NOSE appears to be the most promising aid in clinical practice,whereas GC-MS,as the gold standard for the structural analysis of molecules,remains an essential tool in terms of research for further studies on the pathophysiologic pathways of the asthmatic inflammatory process.In conclusion,the study of VOCs through GC-MS and e-NOSE appears to hold promise for the noninvasive diagnosis,assessment,and monitoring of asthma,as well as for further research studies on the disease.

Research Progress on Environmental Ecology and Human Health Benefits of Biogenic Volatile Organic Compounds(BVOCs)

Biogenic volatile organic compounds(BVOCs)have positive impact on environmental ecology and human physical and mental health.In this paper,the collection methods and components analysis,dynamic release mechanism,ecological function and the impact on human health of BVOCs were summarized.The purpose of this paper is to provide reference and suggestions for further study on the infl uence mechanism of BVOCs on human health,and to provide a theoretical basis for its application in landscape environment.

Understanding changes in volatile compounds and fatty acids of Jincheng orange peel oil at different growth stages using GC-MS

Jincheng orange(Citrus sinensis Osbeck)is widely grown in Chongqing,China,and is commonly consumed because of its characteristic aroma contributed by the presence of diverse volatile compounds.The changes in aroma during the development and maturation of fruit are indicators for ripening and harvest time.However,the influence of growth stages on the volatile compounds in Jincheng orange remains unclear.In addition,volatiles originate from fatty acids,most of which are the precursors of volatile substances.On this basis,gas chromatography-mass spectrometry(GC-MS)was performed to elaborate the changes in volatile constituents and fatty acids as precursors.This study tested proximately 60 volatiles and 8 fatty acids at 9 growth and development stages(AF1-AF9).Of those compounds,more than 92.00%of total volatiles and 87.50%of fatty acids were terpenoid and saturated fatty acids,respectively.As shown in the PCA plot,the AF5,AF6,and AF9 stages were confirmed as completely segregated and appeared different.In addition,most of the volatiles and fatty acids first increased at the beginning of the development stage,then decreased from the AF6 development stage,and finally increased at the AF9 maturity stage.Moreover,the highest contents of terpenoid,alcohols,aldehydes,ketones,and saturated fatty acids in Jincheng orange peel oil were d-limonene,linalool,octanal,cyclohexanone,and stearic acid during development stages,respectively.Our results found that the growth stages significantly affected the volatile constituents and precursors in Jincheng orange peel oil.

Effective technology for processing industrial volatile organic compounds by the atmospheric pressure microwave plasma torch

In this study,we investigated the abatement of volatile organic compounds(VOCs)by the atmospheric pressure microwave plasma torch(AMPT).To study the treatment efficiency of AMPT,we used the toluene and water-based varnish to simulate VOCs,respectively.By measuring the compounds and contents of the mixture gas before/after the microwave plasma process,we have calculated the treatment efficiency of AMPT.The experimental results show that the treatment efficiency of AMPT for toluene with a concentration of 17.32×10^(4) ppm is up to 60 g/kWh with the removal rate of 86%.For the volatile compounds of water-based varnish,the removal efficiency is up to 97.99%.We have demonstrated the higher potential for VOCs removal of the AMPT process.

Comprehensive lipidomics and volatile compounds profiling reveals correlation of lipids and flavors in DHA-enriched egg yolk

DHA-enriched eggs have gained popularity due to their unique nutritional value,but their flavor can be challenging for some consumers to accept.The study analyzed the correlation of lipids and flavors in DHA-enriched egg yolks using comprehensive lipidomics and volatile compound analysis.The results showed that 411 lipids were detected in two egg yolk samples.Among them,148 lipid species,including 48 DHA-containing lipids,were significantly higher in DHA-enriched egg yolks than in Common ones(P<0.05).Furthermore,of the 24 volatile compounds detected,the contents of benzaldehyde,heptanal,hexanal,decanal and 2-nonanone in DHA-enriched egg yolks were significantly higher than in Common egg yolks(P<0.05).The“fishy”smell characteristic of DHAenriched egg yolks was mainly caused by volatile aldehydes,which may be produced through the hydrolysis of lipids in the egg yolk to free fatty acids and further oxidation.Analysis of the correlation network diagram revealed that phospholipids containing docosahexaenoic acid(DHA),linoleic acid,or oleic acid chains were the main contributors to the characteristic flavor of DHA-enriched egg yolks.Overall,this study explored the effect of different lipids on the flavor of DHA-enriched egg yolks and provided a theoretical basis for the production and improvement of DHA-enriched eggs.

苹果等6种经济林不同时期果实BVOCs成分分析

为探究常见经济林树种不同时期果实在自然状态下释放植物源挥发性有机物(BVOCs)组成成分差异,并分析其香气类型,选取苹果、桃、李、梨、山楂和枣6种经济林树种为研究对象,采用动态顶空采集法收集释放的BVOCs,结合自动热脱附-气相色谱/质谱联用技术进行BVOCs分析。结果表明,6种果实膨大期和成熟期均检测出12类BVOCs,组分总数量前者(305)大于后者(275),2个时期果实释放烷烃类、烯烃类、芳香烃类、酯类和醛类BVOCs占比最大;不同时期6种果实有10种共有BVOCs为2,2,4,6,6-五甲基庚烷、正十九烷、a-柏木烯、正戊醛、庚醛、辛醛、天然壬醛、癸醛、苯乙酮和庚胺醇;苹果、桃、李和梨随着果实生长发育BVOCs成分数量减少;不同时期6种果实香韵涵盖香型有差异,并随果实生长发育,青草香、果香、檀木香、醛香和柑橘香占比明显增加。表明不同时期6种经济林植物果实释放BVOCs组成成分和相对含量差异明显,在果实成熟期,主要香气BVOCs成分相对含量较高,是果实香精开发的最佳时期。

山楂和枣释放BVOCs组分生长季动态变化特征研究

【目的】探究北京地区经济林树种山楂和枣不同时期释放植物源挥发性有机物(BVOCs)组成成分的变化规律,以及两者释放有益BVOCs特征。【方法】采用动态顶空采集法收集释放的BVOCs,结合自动热脱附-气相色谱/质谱联用技术进行分析。【结果】在整个生长季从山楂叶中共检测出12类328种BVOCs,从枣叶中共检测出12类301种BVOCs,枣叶释放类别的数量与山楂叶相同,释放种类少于山楂叶,两树种均在9月释放类别最多;山楂叶和枣叶主要释放烷烃类、烯烃类和芳香烃类、酯类和醇类BVOCs;枣叶主要释放烷烃类、烯烃类、芳香烃类、酯类、醛类和醇类BVOCs,其中天然壬醛山楂叶和枣叶每月都有释放,但枣叶每月释放BVOCs的种类更加丰富;山楂是烯烃类夏季高释放量树种,枣是春季芳香烃高释放量树种;从山楂叶中共检测出烯烃类、芳香烃类、酯类、醛类、有机酸类、酮类、醇类和酰胺类8类43种有益成分,而枣叶不释放酮类,释放种类总数量比山楂叶多。【结论】两个树种释放烯烃类有益BVOCs在总有益BVOCs成分中占比最大,以释放对薄荷-1(7),3-二烯、α-蒎烯、罗汉柏烯、3-蒈烯、右旋萜二烯为主,夏季是山楂叶和枣叶释放有益BVOCs组分的主要季节,两者均在7月达到最大值。总之,树种释放BVOCs成分呈明显的季节性变化,尤其是山楂叶释放总有益BVOCs最大值超过60%。

添加剂对堆肥过程中挥发性有机物(VOCs)的减排效果

为明确添加剂对堆肥挥发性有机物(Volatile organic compounds,VOCs)排放的减排效果和影响因素,通过文献筛选出吸附类添加剂(活性炭和沸石)与有机酸类添加剂(柠檬酸和草酸)开展实验研究。在鸡粪-玉米秸秆堆肥实验中,设置5个处理,分别为对照(CK)、添加活性炭、添加沸石、添加柠檬酸和添加草酸处理。研究对象包括115种VOCs、三甲胺和6种含硫有机挥发气体(二甲硫醚、二甲基二硫醚、二甲基三硫醚、甲硫醇、乙硫醇、乙硫醚)。结果表明:在28 d的好氧发酵中,所有处理均达到50℃并维持7 d,满足无害化标准。检出110种VOCs、三甲胺和3种含硫有机挥发气体(二甲硫醚、二甲基二硫醚,二甲基三硫醚)。VOCs的排放集中在前9 d,在第3天时VOCs达到峰值。5个处理在堆肥第3天检测到的VOCs浓度范围为169.22~548.26 mg·m^(-3)。4种添加剂对各类VOCs均有减排效果。在第3天,活性炭、沸石、柠檬酸和草酸对烷烃类的减排效率分别为79%、26%、77%和46%,对卤烃类的减排效率分别为96%、38%、93%和97%,对芳香烃类的减排效率分别为28%、11%、24%和53%。从堆肥第6天开始只有沸石对各类VOCs有减排效果,最高减排效率为30%。针对含硫有机挥发气体减排,减排效果依次是草酸>柠檬酸>沸石>活性炭。4种添加剂对含硫有机挥发气体均有减排效果,但是对三甲胺没有减排效果。综合堆肥前9 d VOCs的减排情况,4种添加剂中沸石对各类VOCs减排效果最好。堆肥过程中添加沸石有利于VOCs和其他气体的协同减排,并且对土壤和农作物不存在风险,所以沸石在堆肥工程中有广阔的应用前景。

碱处理改性ZSM-5分子筛孔结构对VOCs吸附性能的影响

采用氢氧化钠和四丙基氢氧化铵混合碱溶液处理制备一系列改性ZSM-5分子筛,通过X射线衍射(XRD)、扫描电子显微镜(SEM)、N_(2)吸附、水接触角测定等手段对改性样品进行了分析表征,采用固定床吸附器对比评价5A、NaY和不同碱改性ZSM-5分子筛吸附剂对正己烷和乙酸乙酯的动态吸附性能。结果表明:氢氧化钠和四丙基氢氧化铵摩尔浓度均为0.2 mol/L的碱改性ZSM-5-G-3样品的比表面积及总孔体积分别为425 m^(2)/g和0.585 cm^(3)/g,比改性前高硅ZSM-5-G-1样品分别提高了17.7%和174.6%,介孔比表面积增加8.6倍,达到317 m^(2)/g,介孔体积增加12.3倍,达到0.531 cm^(3)/g;随着碱溶液浓度的增加,改性分子筛材料水接触角减小;25℃时,正己烷和乙酸乙酯在ZSM-5-G-3吸附剂床层上的穿透吸附量分别为76.99和101.08 mg/g,比改性前ZSM-5-G-1吸附剂床层分别提高了40.3%和17.4%。改性ZSM-5-G-3样品对挥发性有机化合物(VOCs)吸附性能的显著提高主要归因于碱改性提供了更多的吸附位和介孔结构。

加油站及周边空气中VOCs物种构成与示踪特征

选择典型城市区域加油站,在汽柴油加油口及周边开展VOCs样品采集与物种构成分析,探究加油站排放VOCs的标识性物种,根据加油站周边区域VOCs物种浓度与比值在空间梯度上的变化评估关键物种的示踪作用与转化规律.结果表明:加注汽油排放VOCs主要组分为烷烃(70%~72%)、烯烃(13%~14%)和含氧有机物(11%~12%),主要物种为异戊烷(20%~24%),其它C4~C6类烷烃也是高占比物种;加注柴油排放VOCs中烷烃是主要成分,占VOCs总量的70%~72%,其次是烯烃和含氧有机物,分别贡献13%~14%和11%~12%,芳香烃占比为2%~3%,异戊烷(17%~21%)和正丁烷(15%~17%)含量较高,低碳C2~C4类烷烯烃和较重高碳C7~C12烷烃的比例高于汽油.加油站下风向受体区域受加油站排放影响明显,与单一物理扩散模型的结果对比,发现烯烃类物种在实际传输过程中已发生明显光化学反应,特征物种比值在距离加油站大于70m的区域外开始接近机动车尾气的比值范围并趋于稳定,超出此范围加油站排放贡献影响可能较小.

城市商业建筑地下车库挥发性有机物(VOCs)污染特征及健康风险评价

为研究城市商业建筑地下车库中挥发性有机物(VOCs)的污染特征及潜在影响,在所选取盐城市3个典型商场的地下车库里进行了VOCs采样监测,获得了VOCs浓度水平、组成和日变化特征,评价了人体健康风险.观测期间,3个地下车库在9:00—13:00时间段内所有样品的总挥发性有机物(TVOCs)平均值分别为(2547.9±1595.2)μg·m^(−3)、(1376.7±122.7)μg·m^(−3)、(1689.1±93.1)μg·m^(−3);在所分析的75种VOCs中3个地下车库VOCs检出率分别为52.0%、36.0%和34.7%.各地下车库所测VOCs占前几位的组分分别为甲苯(30.5%—48.2%)、异丙醇(4.5%—27.2%)、2-丁酮(3.8%—12.4%)、甲基环戊烷(2.2%—2.8%)、苯(1.5%—2.6%)、1,2-二氯乙烷(1.7%—2.2%).VOCs日变化浓度主要与车流量有关,在11:00和21:00时刻出现浓度峰值,分别为3785.4μg·m^(−3)、8694.3μg·m^(−3).健康风险评价结果表明,3个地下车库内所监测的VOCs的非致癌风险危害指数(HI)分别为4.1、4.3和7.4,均超过了美国环境保护局推荐的最大可接受水平(HI=1);苯和乙苯的终生致癌风险因子值(Risk)分别在(1.2×10^(−4)—6.2×10^(−4))、(3.8×10^(−6)—2.5×10^(−5)),均超出了安全阈值范围(Risk≤1×10^(−6)),3个地下车库均存在一定健康风险.

2D和3D培养肺细胞释放VOCs的质谱检测比较研究

挥发性有机物(volatile organic compounds,VOCs)作为一种潜在的癌细胞标志物被广泛研究。目前,体外细胞多采用二维(two-dimensional,2D)贴壁培养方式,这与体内肿瘤细胞呈三维结构存在差别。本实验分别以肺癌细胞A549和肺上皮细胞BEAS-2B为例,构建三维(three-dimensional,3D)培养模型,并以2D模型和培养基作为对照,利用固相微萃取气相色谱-质谱(solid phase microextraction-gas chromatography-mass spectrometry,SPME-GC-MS)法检测细胞释放的VOCs。通过非靶向统计分析细胞在2D和3D培养中释放的差异性VOCs,其中A549细胞有4种(乙酸、1-吡咯啉、4-甲基庚烷、2,4-二甲基-1-庚烯),BEAS-2B细胞也有4种(乙醇、1-吡咯啉、4-甲基庚烷、2,4-二甲基-1-庚烯)。与2D模型相比,这些VOCs在3D模型中的释放量增加了2.11~12.81倍。此外,还讨论了差异性VOCs可能的生化来源以及在2D/3D模型中释放量差异的可能原因。本工作证明了3D培养在体外细胞VOCs检测方面具有广阔的应用前景,有望成为癌症标志物筛查有价值的研究平台。