Volatile Solid and Bury Period Influence on Odorous Material Production in Simulating Landfill Treatment

Odor pollution in landfill area has attracted more social attention in China. It is very important to control the generation of odor pollutants in situ. Analyzing odorous materials production form buried waste, simulated columns of different volatile solid (VS) content and different buried period waste were designed. Gas compounds produced from the columns were collected and analyzed by comprehensive two-dimensional gas chromatography (GC × GC) method. It has remarkable relationship between VS content and concentrations of odorous material. When VS content more than 40%, the total amount of odorous compounds increases remarkably. It can be inferred that reduced VS content of original waste may effective decreasing odorous materials production in landfill area. The old rubbish produced more odorous compounds than that of fresh one in simulated columns.

Release of volatile organic compounds during bio-drying of municipal solid waste

Three treatments were tested to investigate the release concentrations of volatile organic compounds （VOCs） during the bio-drying of municipal solid waste （MSW） by the aerobic and combined hydrolytic-aerobic processes.Results showed that VOCs were largely released in the first 4 days of bio-drying and the dominant components were：dimethyl disulfide,dimethyl sulfide,benzene,2-butanone,limonene and methylene chloride.Thus,the combined hydrolytic-aerobic process was suggested for MSW bio-drying due to fewer aeration quantities in this phase when compared with the aerobic process,and the treatment strategies should base on the key properties of these prominent components.Malodorous sulfur compounds and terpenes were mainly released in the early phase of bio-drying,whereas,two peaks of release concentrations appeared for aromatics and ketones during bio-drying.Notably,for the combined hydrolytic-aerobic processes there were also high concentrations of released aromatics in the shift from hydrolytic to aerobic stages.High concentrations of released chlorinateds were observed in the later phase.For the VOCs produced during MSW bio-drying,i.e.,malodorous sulfur compounds,terpenes and chlorinateds,their release concentrations were mainly determined by production rates;for the VOCs presented initially in MSW,such as aromatics,their transfer and transport in MSW mainly determined the release concentrations.

Comparison of Headspace Solid-Phase Microextraction with Simultaneous Steam Distillation Extraction for the Analysis of the Volatile Constituents in Chinese Apricot

Volatile constituents in fully mature fruits of apricot （Prunus armeniaca L.） cultivar Xinshiji were extracted using headspace solid-phase microextraction （HS-SPME） and simultaneous steam distillation extraction （SSDE） and then analyzed using capillary gas chromatography and gas chromatography-mass spectrometry. A total of 70 components were identified by HSSPME, including 20 esters, 19 hydrocarbons, 5 alcohols, 5 ketones, 4 acids, 4 lactones, 3 aldehydes, and 10 miscellaneous components, with the esters being the dominant constituent. On the basis of the odor unit values, it is believed that the following compounds probably contributed to the fresh apricot odor： hexyl acetate, β-ionone, butyl acetate, （E）-2-hexenal, linalool, limonene, γ-decalactone, and hexanal. A total of 49 components were also detected by SSDE, including 13 hydrocarbons, 9 alcohols, 7 aldehydes, 9 esters, 4 ketones, 4 lactones, 2 acids, and 1 miscellaneous component, of which the monoterpene alcohols were the dominant constituents. It could be judged from the odor unit values that the following compounds were the major contributors to boiled apricot aroma： β-ionone, linalool, hexyl acetate, γ-dodecalactone, γ- decalactone, （E）-2-hexenal, hexanal, γ-octalactone, phenylacetaldehyde, butyl acetate, limonene, α-terpineol, and δ-decalactone. The results show that HS-SPME is a simple, rapid, and solvent-free method, which is an alternative to the classical SSDE.

Integration of GC-MS Based Non-Targeted Metabolic Profiling with Headspace Solid Phase Microextraction Enhances the Understanding of Volatile Differentiation in Tobacco Leaves from North Carolina, India and Brazil

In this report, gas chromatography-mass spectrometry (GC-MS) based non-targeted metabolomics is used to develop appropriate headspace solid phase microextractions (HS-SPME) to enhance the understanding of volatile complexity of flue-cured tobacco leaves. Non-targeted metabolic profiling of GC-MS shows that the extraction condition of HS-SPME at 100?C for 30 min provides a better metabolite profile than other extraction conditions tested. GC-MS and principal component analyses (PCA) show that among five types of fibers tested, 100 μm polydimethylsiloxane (PMDS), 65 μm polydimethylsiloxane/divinylbenzene (PMDS/DVB) and 75 μm carboxen/polydimethylsiloxane (CAR/ PMS) provide a better reproducible metabolite profile. Based on an appropriate PDMS extraction condition optimized, we use GC-MS analysis and PCA to compare metabolite profiles in flue-cured leaves of tobacco plants grown in North Carolina, India and Brazil, respectively. The resulting data of PCA show that the global metabolic profiles in North Carolina samples are separated from those in Brazil and India samples, two groups of which are characterized by a partially overlapped pattern. Several peaks that were differentially accumulated in samples were annotated to known metabolites by deconvolution analysis, such as norsolanadione, solavetivone and rishtin. Norsolanadione is detected only in Brazil samples. Solavetivone is detected in samples of India and Brazil but not in those of North Carolina. Rishtin is detected in samples of North Carolina and India but not in Brazil samples. These data indicate that not only can a non-targeted metabolic profiling approach enhance the understanding of volatile complexity, but also can identify marker volatile metabolites in tobacco leaves produced in different growth regions.

SlMYB75,an MYB-type transcription factor,promotes anthocyanin accumulation and enhances volatile aroma production in tomato fruits

Genetic manipulation of genes to upregulate specific branches of metabolic pathways is a method that is commonly used to improve fruit quality.However,the use of a single gene to impact several metabolic pathways is difficult.Here,we show that overexpression of the single gene SlMYB75(SlMYB75-OE)is effective at improving multiple fruit quality traits.In these engineered fruits,the anthocyanin content reached 1.86mg g−1 fresh weight at the red-ripe stage,and these SlMYB75-OE tomatoes displayed a series of physiological changes,including delayed ripening and increased ethylene production.In addition to anthocyanin,the total contents of phenolics,flavonoids and soluble solids in SlMYB75-OE fruits were enhanced by 2.6,4,and 1.2 times,respectively,compared to those of wild-type(WT)fruits.Interestingly,a number of aroma volatiles,such as aldehyde,phenylpropanoid-derived and terpene volatiles,were significantly increased in SlMYB75-OE fruits,with some terpene volatiles showing more than 10 times higher levels than those in WT fruits.Consistent with the metabolic assessment,transcriptomic profiling indicated that the genes involved in the ethylene signaling,phenylpropanoid and isoprenoid pathways were greatly upregulated in SlMYB75-OE fruits.Yeast one-hybrid and transactivation assays revealed that SlMYB75 is able to directly bind to the MYBPLANT and MYBPZM cis-regulatory elements and to activate the promoters of the LOXC,AADC2 and TPS genes.The identification of SlMYB75 as a key regulator of fruit quality attributes through the transcriptional regulation of downstream genes involved in several metabolic pathways opens new avenues towards engineering fruits with a higher sensory and nutritional quality.

Differential volatile organic compounds in royal jelly associated with different nectar plants

The aim of this work was to distinguish volatile organic compound（VOC） profiles of royal jelly（RJ） from different nectar plants. Headspace solid-phase microextraction（HS-SPME） was used to extract VOCs from raw RJ harvested from 10 nectar plants in flowering seasons. Qualitative and semi-quantitative analysis of VOCs extracts were performed by gas chromatography-mass spectrometry（GC-MS）. Results showed that VOC profiles of RJ from the samples were rich in acid, ester and aldehyde compound classes, however, contents of them were differential, exemplified by the data from acetic acid, benzoic acid methyl ester, hexanoic acid and octanoic acid. As a conclusion, these four VOCs can be used for distinguishing RJ harvested in the seasons of different nectar plants.

Volatile components of Rhizoma Alpiniae Officinarum using three different extraction methods combined with gas chromatography-mass spectrometry

Volatile components from Rhizoma Alpiniae Officinarum were respectively extracted by three methods including hydrodistillation, headspace solid-phase microextraction （HS-SPME） and diethyl ether extraction. A total of 40 （hydrodistillation）, 32 （HS-SPME） and 37 （diethyl ether extraction） compounds were respectively identified by gas chromatography-mass spectrometry （GC/MS） and 22 compounds were overlapped, including β-farnesene, 7-muurolene, 2,6-dimethyl-6- （4-methyl-3-pentenyl）bicyclo[3.1.1]hept-2-ene, eucalyptol and cadina-1（10）, 4-diene and so forth, varying in relative contents. HS-SPME is fast, sample saving and solvent-free and it also can achieve similar profiles as those from hydrodistillation and solvent extraction. Therefore, it can be the priority for extracting volatile components from medicinal plants.

Volatile Flavor Composition in Mutton of Ningxia Tan Sheep

[Objective] To analyze the volatile flavor compounds in mutton of different parts of Ningxia Tan sheep. [Method] The volatile flavor compounds in mutton were identified and quantified using the solid phase micro-extraction （SPME） method combined with GC-MS analysis. [ Re- sult ] The proportion of aldehydes in volatile compounds was the highest in the mutton of most parts of Ningxia Tan sheep, but no 4-methyl acid and 4-methyl nonyl acid was detected in the mutton. [ Conclusion]Aldehydes may be important for the volatile flavor of mutton of Ningxia Tan sheep. The study provides a basis for better development and use of Ningxia Tan sheep.

Analysis on Volatile Components of Flowers and Leaves of Thymus mongolicus by SPME-GC/MS

[Objectives] To analyze volatile components of flowers and leaves of Thymus mongolicus. [Methods]Volatile components of collected T. mongolicus flower and leaves were separated by headspace solid-phase microextraction( SPME) and identified by gas chromatography/mass spectrometry( GC/MS) and normallized by peak area. [Results] A total of 24 and 14 compounds were identified from flowers and leaves of T. mongolicus in the total ion chromatogram,accounting for 99. 573% and 97. 187% of the total peak area,respectively. Main components of flowers and leaves of T. mongolicus include phenols and terpenes,and thymol accounts for 35. 38% and 49. 13% of flowers and leaves of T. mongolicus,respectively. [Conclusions] SPME-GC/MS can be applied in analyzing volatile components of flowers and leaves of T. mongolicus,to provide basis for further development and utilization of T. mongolicus.

Effects of Grafting on Volatile Compounds in Bitter Gourd Fruit

[Objectives]This study was conducted to explore the effects of grafting on volatile compounds in bitter gourd fruit.[Methods]The volatile compounds and relative contents of grafted and non-grafted fruit were analyzed by headspace solid phase micro-extraction with gas chromatography-mass spectrometry.[Results]There were 59 volatile compounds in Haiyan No.2S,including six unique compounds.There were 58 volatile compounds in Haiyan No.2J,including five unique compounds.[Conclusions]This study provides a scientific basis for further analysis of bitter gourd flavor regulation mediated by grafting.

Analysis of Volatile Components in Different Parts of Polygala japonica Houtt.

[Objectives] To analyze the volatile components in different parts of Polygala japonica Houtt. and compare the differences of these volatile components. [Methods] The volatile components in different parts of P. japonica Houtt. were analyzed by the headspace solid-phase microextraction( HS-SPME) combined with GC-MS,and the relative percentage of each component was determined by peak area normalization. [Results] Thirty kinds of volatile components were identified from the leaves and rhizomes of P. japonica Houtt.,mainly including olefins,aromatic hydrocarbons,alkanes and esters. [Conclusions] The volatile components in different parts of P. japonica Houtt. were different,and there may be difference in the medicinal value of volatile components in different parts,thus it is required to take an overall consideration of these differences in the development and utilization of P. japonica Houtt.

不同产地沃柑挥发性成分的差异分析

该研究旨在分析4个主产地(四川、重庆、云南和广西)的沃柑果皮中挥发性成分的差异性,并为沃柑的产地溯源和深加工提供数据支撑。利用顶空固相微萃取-气相色谱-质谱联用技术测定了沃柑果皮挥发性成分,共鉴定出50种挥发性成分,其中萜烯类18种、醇类11种、醛类10种、酯类8种、酮类1种、其他类2种。柠檬烯是主要的挥发性物质,月桂烯、α-蒎烯、芳樟醇、正辛醇、正辛醛、香茅醇、己醛、反式-2-己烯醛、桧烯、香芹酮和α-松油醇等次之。基于挥发性成分半定量结果,建立四川和重庆,云南和广西沃柑的正交偏最小二乘法判别分析模型,进而筛选出潜在生物标志物。结果表明,柠檬烯、芳樟醇和香茅醇可作为区分重庆和四川的潜在生物标志物,醋酸辛酯和α-松油醇可作为区分广西和云南的潜在生物标志物。

基于HS-SPME-GC-MS的不同成熟度‘青皮’无花果挥发性成分分析

为探讨不同成熟度威海‘青皮’无花果挥发性成分差异,本研究采用固相微萃取(SPME)和气相色谱-质谱联用技术(GC-MS)对鲜食无花果挥发性成分进行分析,并采用内标法对风味物质进行定量分析。结果显示,在威海‘青皮’无花果中共检测出73种挥发性成分,主要为酯类、醛类、醇类、烯类、烷烃类等,其中六成熟无花果检出33种、八成熟检出29种、十成熟检出36种。不同成熟度无花果的挥发性组分、特征风味物质种类和含量差异明显。

不同萃取方法下绿萼梅花蕾挥发性成分的差异研究

2023年3月13日,从浙江省长兴县东方梅园有限公司梅花基地采集绿萼梅花蕾,采用顶空-固相微萃取、水蒸气蒸馏、超临界二氧化碳3种萃取方法,结合气相色谱-质谱联用仪(GC-MS)分析绿萼梅Prunus mume f.viridicalyx花蕾中的挥发性成分,以明确其花蕾中挥发性成分组成、含量及不同萃取方式对挥发性成分萃取效果的影响。结果表明,三种萃取方法获得的绿萼梅花提取物中共鉴定出醛、醇、酮、烯等9类57种化合物,主要挥发性成分是苯甲醛、壬醛、金合欢醇、苯甲酸、α-香树脂醇、D-柠檬烯,其中苯甲醛含量最高。绿萼梅花顶空-固相微萃取物中共鉴定出21种化合物,以醛、醇和酯类化合物为主;水蒸气蒸馏物中共鉴定出30种化合物,以酯、烯、酮等水难溶化合物为主;而超临界二氧化碳提取物中共鉴定出30种化合物,以长链烷、酯类化合物为主。三种提取方法中超临界二氧化碳萃取物中蜡质含量较高,顶空-固相微萃取和水蒸气蒸馏法结合更适合作为植物芳香类挥发物的检测手段。

基于顶空固相微萃取-气相色谱-质谱法分析加速氧化过程中全脂牛羊乳粉挥发性化合物

为探究全脂牛羊乳粉在储存过程中风味物质的变化,本研究采用顶空固相微萃取-气相色谱-质谱技术对加速氧化过程中全脂牛羊乳粉挥发性化合物进行分析。研究表明,全脂牛乳粉和全脂羊乳粉中分别鉴定出56、63种挥发性物质,主要为酸类、醇类、羰基类、酯类、芳香族类、杂环类等挥发性化合物。通过主成分分析和聚类热图分析,在全脂牛羊乳粉中筛选出10种显著性差异挥发性化合物,全脂牛乳粉在储存过程中丁酸相对含量降低,2-壬酮、1-氯戊烷相对含量升高;全脂羊乳粉中壬醛、辛酸、丙酸、丁羟甲苯相对含量降低,苯甲醛、2-庚酮、烯丙基正丙酯相对含量升高。

固相微萃取-气相色谱-质谱法分析油莎豆中挥发性成分

以油莎豆为研究对象,采用固相微萃取-气相色谱-质谱联用法(SPME-GC-MS)测定其挥发物成分。通过优化前处理过程中萃取头类型、萃取温度、萃取时间,确定最佳萃取条件。利用质谱数据库对挥发物成分进行鉴定,并采用归一化法进行含量分析。结果表明:最佳萃取条件为采用DVB/CAR/PDMS萃取头、萃取温度110℃、萃取时间30 min,在此条件下,油莎豆中共检测出27种挥发物,其主要特征挥发物为醇类和醛类物质,其相对含量分别为32.30%和43.56%。

酶解对香蕉果酒发酵前后风味的影响

本研究针对香蕉浆粘度高不易取汁的特点,分别对香蕉浆进行酶解和直接加水处理,制备酶解香蕉汁和非酶解香蕉汁,比较不同处理的香蕉果酒发酵前后理化指标和挥发性成分的变化。结果表明,经果胶酶处理的香蕉汁(果酒)可溶性固形物(TSS)和总酸(TA)分别为24.91°Brix(8.40°Brix)和4.70 g/L(5.67 g/L)高于非酶解处理的香蕉汁(果酒),pH则低于非酶解的香蕉汁(果酒);酶解样品酒精度11.5%vol,高于非酶解样品。采用顶空固相微萃取-气相色谱-质谱联用技术(HS-SPME-GC-MS)分析样品中的挥发性成分,在四个样品中共检出87种挥发性物质,其中酯类43种,醇类13种,其他种类物质相对较少,结合香气活度值(OAV)和主成分分析(PCA),共发现OAV>1的香气物质15种,正己醇、乙酸乙酯、乙酸异丁酯、乙酸丁酯、丁酸异戊酯、反式-2-己烯醛、己醛等10种物质是果汁中主要的挥发性成分,这些物质主要与甜香、香蕉香、覆盆子香、梨香、桃香、青草味相关,经果胶酶处理后的果汁中与青草味相关的己醛含量更少;苯乙醇、异戊酸乙酯、辛酸乙酯、癸酸乙酯、乙酸异戊酯等7种物质对果酒香气有较大贡献值,这些物质主要为果酒提供苹果香、玫瑰香、香蕉香、杏香、奶油香,经果胶酶处理的样品香气浓度更大,整体香气更加平衡丰富。综上所述,将香蕉浆酶解后再进行酒精发酵,所得果酒的整体香气会更加丰富和谐,本研究结果可为香蕉果酒的生产提供科学依据。

基于主成分分析的牛油火锅底料挥发性风味物质评价模型的构建

采用薄膜固相微萃取与气质联用技术对市场占有率较高的4种牛油火锅底料品牌的B端和C端产品的挥发性风味物质进行了比较分析,并构建主成分评分模型对其风味进行了差异性评价。结果表明,B端产品共检测有154种风味物质,C端产品则有158种,而8个样品检测出25种相同的风味物质,相同品牌的风味物质中,C端产品的烃类物质占比明显较低。利用主成分分析对火锅底料中的风味物质组成进行分析,结果表明,7个主成分因子累积方差贡献率达到100%,能有效表征火锅底料的风味物质信息。最后构建主成分分析模型,计算综合评价指数,对其风味进行评价排序,Pearson相关性分析发现主成分综合得分与感官评价结果相关性为极显著(P<0.01),相关系数为0.908,说明所构建的模型能够有效地对火锅底料进行风味评价。

基于HS-SPME-GC-MS与电子鼻分析芹菜贮藏期间挥发性物质的变化

采用顶空固相微萃取技术结合气相色谱-质谱联用(headspace solid phase microextraction-gas chromatography-mass spectrometry,HS-SPME-GC-MS)和电子鼻技术分析了20.0℃贮藏期间芹菜叶片挥发性物质的组成和含量的变化。结果显示,采用HS-SPME-GC-MS技术从芹菜中共检测到108种挥发性物质,单萜类(43.2%~52.92%)和苯酞类(19.93%~28.97%)为主要组分,其中D-柠檬烯含量丰富(6600.64~48566.12μg/kg)。新鲜芹菜总挥发性物质含量为165682.48μg/kg,贮藏9 d后含量下降了40.92%,单萜类和苯酞类物质分别下降了9.72%和上升了8.98%。OAV分析结果表明芹菜叶片中共有31种OAV>1的特征挥发性物质,0~7 d特征挥发性物质有31种且组成相同,第9 d特征挥发性物质减少至29种,贮藏期间总OAV值呈下降趋势。聚类分析结果表明,0~3 d芹菜叶片以薄荷香和青草香为主,第7 d具有甜香、木香和樟脑香,第9 d后以辛辣和药草气味为主。基于电子鼻检测结果的主成分分析可以清晰区分不同贮藏时间芹菜叶片的香气,基于Pearson相关性分析,引起电子鼻响应值变化的物质主要是芹菜中萜类、醇类、芳香型挥发性物质(r≥0.80,P<0.05)。本研究的结果阐明了贮藏期间芹菜叶片挥发性物质组成和含量的变化规律,为贮藏期间芹菜新鲜度的判断提供了理论基础。