Differences In Volatile Components Research Articles

Analysis and Identification of Differences in Volatile Components of Various Alfalfa Seeds Based on GC-IMS

Volatile components are one key factor in sample identification, differential analysis, quality control and origin traceability. In order to identify and analyze the differences in volatile substances in different alfalfa seeds, this study used gas chromatography–ion mobility spectrometry (GC-IMS), combined with the Gallery Plot plug-in, and PCA, PLS-DA and other analysis methods. In this way, a comprehensive analysis of volatile components in 10 alfalfa seeds, including aerospace varieties, was conducted. A comparative analysis of the characteristics of different sample compounds using topographic maps and fingerprints led to isolation of 48 kinds of 54 volatile compounds. Among them, esters (9 types), olefins (8 types), ketones (8 types), alcohols (6 types) and aldehydes (6 types) were found to be the most abundant volatile compounds in alfalfa seeds. At the same time, PCA and PLS-DA analysis models showed that esters, ketones and alcohols were the main volatiles causing the differences among alfalfa seeds. Among them, the content of various substances in the ZT2 and ZT3 aerospace varieties were higher than that of other varieties, while the types and contents of volatiles in ZT1, ZM2 and GN3 were relatively low. Therefore, in combination with the differences in maturity of each sample, the 10 varieties of alfalfa were finally divided into three categories, and the varieties of the same series were basically classified into one category. This provides a basis and convenience for future seed screening, identification, traceability and forage breeding.

Analysis of Floral Scent Component of Three Iris Species at Different Stages

The research investigates the variations in floral scent composition among different species and developmental stages of Iris plants: Iris uniflora, Iris typhifolia, and Iris sanguinea. The study analyzes the fragrance components by utilizing electronic nose technology in tandem with headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). Principal component analysis (PCA), linear discriminant analysis (LDA), and loading analysis are applied to discern whether floral scents of the same Iris species at distinct stages could be differentiated. The results show that the electronic nose significantly distinguishes the aromas from different stages and that there are differences in aroma composition. Gas Chromatography-Mass Spectrometry confirms significant differences in volatile components regarding the three Iris species, with common compounds like alcohols, aromatics, and aldehydes present throughout stages. Notably, nonyl aldehyde, capric aldehyde, 2,4-di-tert-butylphenol, and n-heptadecane are consistently found. Cluster analysis reveals a grouping of decay stage samples of Iris typhifolia and Iris sanguinea due to terpene and ester abundance. Nonyl aldehyde significantly contributes to the aroma profiles of all species, owing to its high odor activity value. The significant content of volatile compounds in these Iris varieties suggests economic and medicinal potential beyond ornamental value, providing references for the development of Iris-scented products, aromatherapy, and the extraction of pharmacologically active substances from Iris.

Fingerprint analysis of volatile flavor compounds in twenty varieties of Lentinula edodes based on GC-IMS

The fingerprint database of volatile components in 20 varieties of Lentinula edodes were built using the gas chromatography-ion mobility spectroscopy (GC-IMS). Based on fingerprint and partial least squares discriminant analysis (PLS-DA), the differences in volatile components among varied L. edodes were further analyzed by cluster heat maps. A total of 57 volatile components were identified from all the mushroom samples, including 17 esters, 13 alcohols, 6 ketones, 6 aldehydes, 5 sulfur compounds, 3 acids, 1 alkane, and 6 other compounds. The varieties of ZP51, YS37, YS8, ZP46, XG172 showed the highest contents of esters (19 %∼41 %), alcohols (6 %∼17 %), ketones (4 %∼12 %), aldehydes (21 %∼48 %), sulfur compounds (7 %∼13 %), acids (2 %∼6 %), respectively. Twenty-eight key volatile flavor compounds were selected as the main characteristic aroma of L. edodes. GC-IMS could effectively distinguish different varieties of L. edodes, and the differences in the volatile components were visualized with fingerprint and cluster heat maps. These results provide a method to rapid evaluate the flavor profiles of L. edodes.

Dynamic Changes in Microbial Communities, Physicochemical Properties, and Flavor of Kombucha Made from Fu-Brick Tea.

In this study, Fu-brick tea (FBT) was used for kombucha preparation. The succession of microbial community structures, changes in physicochemical properties, and the volatiles were investigated during the kombucha fermentation. The sequencing analysis showed that Komagataeibacter was the most predominant bacterium. Aspergillus and Zygosaccharomyces were the dominant fungi before fermentation whereas Zygosaccharomyces and Derkella were the dominant fungi after 3 days of fermentation. The physicochemical analysis revealed that acetic acid, glucuronic acid, and polyphenols increased by 10.22 g/L, 0.08 g/L, and 177.40 mg/L, respectively, by the end of fermentation. The GC-MS analysis showed that a total of 49 volatile compounds were detected during the fermentation. Moreover, there were great differences in volatile components among the kombucha samples with different fermentation times. Furthermore, the relevance among microbial community and volatile compounds was evaluated through correlation network analysis. The results suggested that Komagataeibacter, Aspergillus, Zygosaccharomyces, and Dekkera were closely related to the main volatile compounds of FBT kombucha. The results in this study may provide deep understanding for constructing the microbiota and improving the quality of FBT kombucha.

Comparing the differences of physicochemical properties and volatiles in semi-dry Hakka rice wine and traditional sweet rice wine via HPLC, GC–MS and E-tongue analysis

This study aimed to explore effects of indica rice addition, rice soaking time and rice soup addition on total sugar and alcohol content of semi-dry Hakka rice wine (HRW) and compare its difference in physicochemical properties and volatiles with traditional sweet rice wine (TSRW) via HPLC, GC–MS and E-tongue. The optimal fermentation conditions of semi-dry HRW were 50 % indica rice addition, 12 h rice soaking time and 85 % rice soup addition. The total sugar (16.13 mg/mL) of semi-dry HRW was significantly lower than that of TSRW (135.79 mg/mL), especially the trehalose, glucose, sucrose and maltose. Its alcohol content was significantly higher than that of TSRW. There were significant differences in volatile components between semi-dry HRW and TSRW, especially esters, alcohols and ketones, but no significant differences in organic acids and amino acids. Results obtained could provide reference data for improving the fermentation process and quality of semi-dry HRW.

Identification on regional-markers based on the flavor molecular matrix analysis of sauce-aroma style Baijiu.

Baijiu is a very complex system and its flavor substances are endogenous influenced by raw materials, starter, production process, production region and other factors. The production region directly affects the composition of flavor substances and quality of Baijiu. However, identification of Baijiu region is challenging because the corresponding relationship between the production region and Baijiu quality is not clear, and the identification of regional-markers is indeterminate. In this study, the difference on volatile components of sauce-aroma style Baijiu from four representative regions were investigated. Consequently, a total of 94 volatile compounds were identified in samples tested. Additionally, it was verified that 35 potential flavor substances had important contributions to the aroma of sauce-aroma style Baijiu. Meanwhile, 9 potential regional-markers were screened through multivariate analysis. Further, based on distribution of volatile compounds and the results of sensory evaluation combined with multivariate analysis, molecular matrix and correlation network were established according to the result of addition experiments, which showed that 6 substances had a significant impact on the flavor of the tested samples. In this study, 6 key flavor substances (including ethyl octanoate, ethyl 2-methyl propanoate, propyl acetate, ethyl heptanoate, 2-nonanone and butyl hexanoate) were considered as important regional-markers to effectively identify the production region of sauce-aroma style Baijiu. This article is protected by copyright. All rights reserved.

Characterization of the Key Aroma Compounds of Shandong Matcha Using HS-SPME-GC/MS and SAFE-GC/MS.

Shandong matcha has the quality characteristics of bright green color, seaweed-like aroma and strong, fresh and brisk taste. In order to identify the characteristic aroma components and clarify the contribution of the grinding process to the aroma of Shandong matcha. Three grades of Shandong matcha and corresponding tencha material were firstly tested with sensory evaluation, and the volatile components were extracted with headspace solid-phase microextraction (HS-SPME) and solvent-assisted flavor evaporation (SAFE) and analyzed using GC–MS. The sensory evaluation results showed that high-grade matcha (M-GS) had prominent seaweed-like, fresh and roasted notes, whereas medium and low-grade matcha (M-G1, M-G2) were gradually coupled with grassy, fatty and high-fired aromas. GC–MS results showed that in the HS-SPME method, heterocyclic compounds (45.84–65.35%) were the highest in Shandong matcha, followed by terpenoids (7.44–16.92%) and esters (6.91–15.27%), while in the safe method, esters were the highest (12.96–24.99%), followed by terpenoids (10.76–25.09%) and heterocyclic compounds (12.12–17.07%). As a whole, the composition of volatile components between M-G1 and M-G2 is relatively close, and there are more differences in volatile components between them and M-GS. The volatile components unique to M-GS were screened using the odor activity value (OAV) evaluation method, with components such as 3-methyl-2-butene-1-thiol, 3-ethyl-Phenol, 2-thiophenemethanethiol, 2,4-undecadienal, (E,E)-2,6-nonadienal, (E,Z)- being evaluated. There were other differentially volatile components, that is, volatile components that coexist in the three grades of matcha, but with different concentrations and proportions. M-G1 and M-G2 contained more volatile substances with high-fired aroma, such as 2-ethyl-3-methyl-pyrazine, coumarin and 5,6,7,8-tetrahydroquinoxaline. The grinding process not only changes the appearance of tencha, but also increases the content of volatile components of matcha as a whole, enhancing the aroma and flavor characteristics of matcha. In this study, the contents of 24 volatile components in matcha were mainly increased, such as benzene, (2,2-dimethoxyethyl)-, cis-7-decen-1-al, safranal and fenchyl acetate. The dual factors of material tencha and matcha grinding technology are indispensable in forming the differences in aroma and flavor of Shandong matcha at different levels.

The influence of two yeast strains on fermentation and flavour composition of cider

AbstractTwo commercial dry strains of Saccharomyces cerevisiae and their different inoculum levels were used to carry out cider fermentation to assess their impact on the quality and volatile flavour composition of cider. Analyses indicated that the composition and production of flavour compounds of ciders are generally significantly affected by the strains and inoculation levels. Additionally, the Uvaferm CM strain produced the lowest amount of relative and total flavour compounds compared to Actiflore PM. According to the PCA, differences in volatile components were observed in ciders obtained from both yeasts. While the 1st and 2nd concentrations of Actiflore PM yeast fall to the same region and the others to the different region, the 1st, 2nd and 3rd concentrations of the Uvaferm CM yeast are located in the same region and the others in the different region. It could be said that the Actiflore PM strain synthesizes compounds (such as ethyl alcohol, relative and total esters) that are effective on the quality of cider, the higher amount that Uvaferm CM. The data obtained can be useful for cider producers.

Characterization of Volatile Component Changes in Peas under Different Treatments by GC-IMS and GC-MS

Volatile profiles of peas under 9 kinds of different treatments including native, washing, blanching, precooling, freezing, steaming, boiling, frying, and freeze-drying were characterized by GC-IMS and GC-MS. The differences of volatile compounds in different peas were observed from the characteristic fingerprints by GC-IMS. The Venn diagram found that the common flavor substances codetected by GC-IMS and GC-MS were n-hexanal, nonanal, 1-octene-3-ol, benzaldehyde, 6-methyl-5-hepten-2-one, trans-2-octenal, and 2-ethyl-3,5-dimethylpyrazine, which were speculated to be the key flavor substances of peas. The cluster analysis of the heat map conducted towards the differences of volatile components in peas under different treatments; the results indicated that peas could be mainly divided into four groups, which was consistent with the above conclusion of GC-IMS. Eight sensory descriptors were used to evaluate the aroma notes: sweet flowers, fat fragrance, waxy aldehydes, mushroom hay, roasted potato with nuts, vegetable-like bean, spicy dry tar, and bitter almond from the sensory analysis, and the sensory analysis also showed good agreement with the results of GC-IMS and GC-MS. The results indicated that the volatile compounds of peas under different treatments could be visualized and identified quickly via GC-IMS, and the samples could be clearly classified based on the difference of volatile compounds. Practical Application. In the study, fingerprints coupled with cluster analysis were a visualized method for the identification of volatile compounds. Meanwhile, a new method, the Venn diagram with OAV, was used to identify the key-aroma of products. Finally, a rapid method is established to classify products by GC-IMS. In future practical applications, GC-IMS can be used to classify products from different origins and different manufacturers. Similarly, it can identify fake and inferior products and whether the products have deteriorated. In addition, this research will provide a new strategy to find the relationship between flavor compounds and various processed technology towards different cereals.

Gas chromatography-mass spectrometry analysis reveals the differences in volatile components of royal jelly from different honeybee stocks

The aim of this study is to reveal differences of volatile components of royal jelly (RJ) produced by different honeybee stocks. Volatile components of three RJ samples from high and low RJ production honeybee stocks were extracted by headspace-solid phase micro-extraction and analyzed by gas chromatography-mass spectrometry. Principal component analysis, hierarchical clustering analysis of the volatile components are suggestive of the fact that honeybee stock selected for increasing RJ yields (royal jelly bees) has shaped distinct volatile component profile compared with the unselected Italian bees. In total, 37 components were identified that could distinguish three RJ samples, including 5 aldehydes, 5 esters, 5 alkanes, 14 alcohols and phenols, 4 ketones and 4 other components. Our study provides the first characterization of volatile components in RJs and uncovered the differences among royal jelly secreted by different bee stocks.

Comparative study of volatile components from male and female flower buds of Populus × tomentosa by HS-SPME-GC-MS

The differences of volatile components in male (MFB) and female flower buds (FFB) of Populus × tomentosa were analysed and compared by HS-SPME with GC-MS for the first time. A total of 34 compounds were identified. Two clusters were clearly divided into male and female by hierarchical clustering analysis. Both the male and female flower buds showed methyl salicylate (22.83 and 24.09%, respectively) and 2-hydroxy-benzaldehyde (10.05 and 12.41%, respectively) as the main volatile constituents. The content of 2-cyclohexen-1-one, benzyl benzoate, and methyl benzoate in FFB was remarkably higher than in MFB. In contrast, the content of ethyl benzoate in MFB was greater than that in FFB. The phenomena showed the characteristic differences between MFB and FFB of P. × tomentosa, which enriched the basic studies on dioecious plant.

Analysis on quality and differences of Mentha haplocalyx from different regions

A gas chromatography-mass spectrometry(GC-MS)method was established for the analysis of volatile components in Mentha haplocalyx, and seven principal components were quantified by gas chromatography(GC). Based on these analyses, the differences of volatile components in M. haplocalyx from Jiangsu, Anhui and other regions were compared. The results showed that the volatile oil of M. haplocalyx was divided into four chemical types：menthol-menthone type, pulegone-menthone type, piperitone-menthol type, piperitone epoxide type, and menthol-menthone type was the principal type. Menthol was the highest and pulegone was the lowest. The differences of M. haplocalyx from Anhui and other regions were obvious. The major volatile components and the differences of M. haplocalyx from different regions were confirmed and a quantitative method was established for the determination of volatile components, which provided the basis for improving the quality standard of M. haplocalyx.

Retention of color and volatile compounds of Spanish-style green table olives pasteurized and stored in plastic containers under conditions of constant temperature

Spanish-style green table olives pasteurized and stored in two types of pasteurizable plastic pouches and glass bottles were analyzed for color parameters and volatile components after 6.5 months of storage at 30 °C. Color parameters in pouches made of aluminium oxide coating on polyethylene terephthalate + medium-density polyethylene (AlOx-coated PET + MDPE) were acceptable and, in general, did not significantly differ from those in glass, but unacceptable values corresponding to dark visual colors of both olives and brine were found in pouches made of polyethylene terephthalate + medium-density polyethylene/ethylene vinyl alcohol (PET + MDPE/EVOH). Forty-three volatile compounds were identified and quantified in olive pulp by solid phase micro-extraction (SPME) and gas chromatography coupled to mass spectrometry (GC-MS), 36 of these compounds being significantly different between the plastic and glass treatments. The type of plastic container had an impact on the volatile composition of product. Oxidation and scalping were considered to be the most probable causes for the differences in volatile components between PET + MDPE/EVOH pouches and glass containers, but in AlOx-coated PET + MDPE pouches no oxidation process was apparent.

헤드스페이스 고체상미량추출(Solid-Phase Microextraction)을 이용한 시판 일본소주의 휘발성 향기성분 분석

일본 증류식 소주인 본격소주 9종을 수거하여 시료의 휘발성 향기성분을 헤드스페이스-고체상미량추출법에 의해 추출한 후, 가스크로마토그래피-질량분석기를 이용하여 분석하였다. 총 76개의 성분이 동정되었고, 화학적 특성에 따라 분류하면 에스터 48종, 알코올 13종, 기타 15종의 성분이 동정되었다. 에스터와 알코올이 주요한 성분으로 분석되었으며 아세트산아이소아밀, 폼산아이소아밀, 헥산산에틸, 옥탄산에틸, 데카노산에틸, 아이소아밀알코올, 2-페닐에탄올이 주요 성분으로 나타났다. 주성분 분석 결과 제조원료에 따라 주성분1 선상에서 대맥국 원료 본격소주의 향기패턴이 큰 차이를 보이는 것으로 나타났으며 쌀과 보리 원료에 따른 향기패턴의 차이는 크게 나타나지 않았다. 본 연구의 일본 본격소주 휘발성 향기성분 분석 결과와 국내산 증류식 소주의 주요 향기성분 분석 결과를 비교분석하면 향후 국내산 증류식 소주의 품질관리에 주요한 향기성분 파악이 가능하고 이를 통해 다양한 원재료와 제조방법에 따른 증류식 소주 제품 개발이 가능하리라 여겨진다. In this study, volatile compounds in nine commercial Japanese distilled liquors (Shochu) were isolated by headspace solid-phase microexrraction (SPME) and analyzed by gas chromatography (GC) and GC-mass spectrometry (MS). A total of 76 volatile components, including 48 esters, 13 alcohols, and 15 miscellaneous components, were identified. Esters and alcohols constituted the largest groups of quantified volatiles. Differences in volatile components among the distilled liquors and possible sample grouping were examined by applying principal component analyses to the GC-MS data sets. The first and second principal components explained 77.92% of the total variation across the samples. The samples using barley koji showed higher overall concentrations of total volatile components. Additionally, the principal component analysis did not reveal any sample grouping based on the raw material used.

Thermal analysis studies on combustion characteristics of seaweed

Abstract Combustion experiments of three typical seaweeds (Gracilaria cacalia, Enteromorpha clathrata and Laminaria japonica) have been studied using a DTA-60H Thermal Analyzer and the combustion processes and characteristics are studied. Thermogravimetric experiments are carried out on the samples with 0.18 mm particle size at the heating rate of 20°C min−1. The results indicate that the ignition mode of seaweed is homogeneous and the combustion process is composed of dehydration, the pyrolysis and combustion of volatile, transition stage, the combustion of char as well as the reaction at high temperature. And the combustion characteristic parameters are obtained such as ignition temperature, maximum rate of combustion, burnout temperature etc. The combustion models of these seaweeds are also analyzed. The combustion characteristics and model differences between the seaweed and woody biomass are caused by the differences of volatile components. The combustibility indexes of seaweeds calculated are bette...

Investigation of aromatic compounds in toasted almonds used for the manufacture of turrón

Turron is being elaborated in a traditional way using raw materials from Eastern Spain; however, the production of honey and especially almond does not meet current demands. Therefore, manufacturers are using almonds from other countries, especially USA. Three different almond cultivars (two from Spain and one from USA) were compared for their differences in volatile components and sensory responses. A total of 58 compounds were detected in toasted almonds; these included ketones, aldehydes, pyrazines, alcohols, aromatic hydrocarbons, furans, pyrroles, terpenes, and linear hydrocarbons. Pyrazines, together with furans and pyrroles, significantly contributed to the characteristic toasted aroma of almond. Further studies are needed, however, in order to optimize the roasting conditions for each one of the almond cultivars used in the manufacture of turron.

Difference in the Volatile Composition of Pine-Mushrooms (Tricholoma matsutake Sing.) According to Their Grades

The differences in volatile components of pine-mushrooms (Tricholoma matsutake Sing.) according to their grades were observed by applying multivariate statistical methods to GC-MS data sets. A total of 35 and 37 volatile components were identified in raw and cooked pine-mushrooms, respectively. The volatile components in pine-mushrooms were primarily composed of C8 species, such as 3-octanol, 1-octen-3-ol, 1-octanol, (E)-2-octen-1-ol, 3-octanone, 1-octen-3-one, (E)-2-octenal, and octanoic acid. The levels of ethyl octanoate, junipene, and 3-methyl-3-buten-2-one were much higher in raw pine-mushroom of higher grades, whereas the reverse was true for C8 components. On the other hand, furfuryl alcohol, benzyl alcohol, phenylethyl alcohol, dihydro-5-methyl-2(3H)-furanone, 2(5H)-furanone, (E)-2-methyl-2-butenal, furfural, phenylacetaldehyde, benzoic acid methyl ester, camphene, and beta-pinene were the major components of cooked mushrooms. These volatile components formed by various thermal reactions could be mainly responsible for the difference in volatile components of cooked pine-mushrooms according to their grades.

Effect of Heat Treatment on Antioxidant Capacity and Flavor Volatiles of Mead

ABSTRACT: The objective of this study was to evaluate the effects of heat processing on the antioxidant capacity of mead (honey wine). Soy and buckwheat honey musts were subjected to 2 heat treatments and fermented into wine. Total phenolic concentration was determined. High-performance liquid chromatography (HPLC) phenolic profiling was performed on the methanol fraction of Amberlite extraction. Antioxidant capacity was evaluated using the oxygen radical absorbance capacity (ORAC) assay. Changes in volatile components were evaluated by headspace-solid phase microextraction/gas chromatography-mass spectrometry (H-SPME/GC-MS). ORAC values of experimental meads (3.62 mMTrolox equivalent) were comparable to those of commercial white wine (3.66 mMTrolox equivalent). No significant difference in antioxidant capacity due to heat treatment or honey type was observed. There was no difference in total phenolics between heat treatments in buckwheat mead; however, soy mead made from high-heated must had significantly greater phenolic concentration than the gently heated mead (α= 0.05). Linear regression analysis indicated a strong positive correlation between total phenolic concentration and antioxidant capacity by ORAC (r= 0.9077; P < 0.0001). HPLC analysis of phenolic profiles in the methanol fractions of Amberlite extraction of the meads indicated significantly higher levels of certain phenolics as a result of the high-heat process in buckwheat mead, but not in soy mead. Differences in volatile components that potentially impact flavor were noted between high and low heat treatments. Results of this study suggest dramatic heat treatments that are often avoided because their flavor impact in mead production have the potential to alter the antioxidant capacity of mead by changing phenolic profiles.