Composition Of Volatile Components Research Articles

Effect of Lacticaseibacillus rhamnosus L08 fermentation on xanthine oxidase inhibitory activity and flavour profile of honeysuckle (Lonicera japonica Thunb.)

Xanthine oxidase (XOD) catalyses the oxidation of hypoxanthine and xanthine to uric acid, and inhibition of its activity has become the main strategy to reduce uric acid production. Honeysuckle (HON) which is rich in polyphenols potentially has the capacity to inhibit XOD activity. However, it carries the bitter and astringent flavor as well as many traditional Chinese medicines, along with that most of the polyphenols in HON exist in bound form, the exploitation and application of HON in food is limited. In this study, we investigated the effects of Lacticaseibacillus rhamnosus L08 fermentation on the bioactive components, XOD inhibitory activity and flavour characteristics of HON. The results showed that the XOD inhibitory activity was increased by 2.08 times after 96 h of fermentation. It was demonstrated that the increase in the total flavonoid content and total phenol content was the main reason for the enhancement of the fermentation solution's XOD inhibitory activity and antioxidant activity. Moreover, the fermentation also enriched the composition of volatile components of HON and reduced levels of undesirable flavour substances, which made the usage of fermented HON as functional food or in pharmaceutical use feasible and applicable.

Chemical profiling and biological activity assessment of volatile and non-volatile compounds in Rosmarinus officinalis residues

Rosmarinus officinalis L. is a Mediterranean medicinal and aromatic plant, widely used in several industries. The present study aimed to characterize the chemical composition of volatile compounds, encompassing essential oils (EO): hydrosol extract (HE): and water residue extract (WRE1). Additionally, the investigation focused on non-volatile components, including powder phenolic extract (PPE): water residue extract (WRE2): and solid residue extract (SRE): while also assessing their antioxidant and antibacterial activities. The chemical compositions of volatile components were determined by using a Gas Chromatograph equipped with a Mass Spectrometer (GC/MS): while polyphenol extracts were analyzed using Ultra-High-Performance Liquid Chromatograph equipped with a photodiode array detection Mass Spectrometer (UHPLC-DAD-ESI/MS). The antioxidant activity was determined by 1,1-diphenyl-2-picrylhydrazyl free radical scavenging (DPPH) and ferric reducing antioxidant power (FRAP): while the antibacterial effect was evaluated against four pathogenic bacterial strains using disc diffusion and broth microdilution methods. The GC/MS analysis showed that R. officinalis EO was dominated by 1,8-cineole (47.70%) and α-pinene (15.50%). 1,8-cineole (56.67%) and camphor (26.27%) were found as the predominant constituents of HE, while volatile components of WRE1 were mainly dominated by camphor (10.11%). The UHPLC-DAD-ESI/MS analysis revealed the existence of a plethora of polyphenolic components. In PPE and SRE, the predominating compounds were carnosic acid and carnosol, respectively. Rosmarinic acid was the main constituent in WRE2. The results of DPPH free radical scavenging and FRAP activities showed that PPE exhibited strong antioxidant activity, followed by SRE and WRE2. EO and HE showed moderate antioxidant activity, while volatile components of WRE1 exhibited the lowest antioxidant effect. Regarding the antibacterial activity, PPE and SRE indicated the highest effect against the pathogenic bacteria, while WRE1 volatile components had the weakest antibacterial activity. The conducted study showed that material plant left after hydrodistillation of R. officinalis may be used as a new source of bioactive volatile and polyphenolic components with valuable pharmacological activities.

Composition of Volatile Components and Antibacterial Activity of Dysoxylum densiflorum Sawdust Essential Oil

Composition of Volatile Components and Antibacterial Activity of Dysoxylum densiflorum Sawdust Essential Oil

Determining the Relationship between Aroma and Quality of Bao-Chung Tea by Solid-Phase Microextraction (SPME) and Electronic Nose Analyses

Despite extensive studies, the relationship between the quality/quantity of tea odorants and oolong tea quality remains unclear. To investigate the key components affecting Bao-chung tea quality, we collected samples of different grades from a tea-tasting competition and determined the content and composition of volatile components and individual catechins using gas chromatography–mass spectrometry and high-performance liquid chromatography. We used an electronic nose (E-nose) to collect odor component signals and established a quality recognition model. The different tea grades did not significantly differ in catechin content, but their specific odor intensity and proportion of odor components varied significantly. Linear discriminant analysis showed that the intensity and proportion of volatile organic compounds could be used for distinguishing the different grades of Bao-chung tea. By combining different quantities of indole, linalool, and butanoic acid and proportions of p-cymene, cis-β-ocimene, nonanal, allo-ocimene, cis-jasmone, and α-farnesene, the ability to distinguish among Bao-chung tea grades was significantly improved. Our results revealed that the quality of Bao-chung tea should be evaluated based on the combined perception of odor component intensity and proportion rather than solely relying on the concentration or composition of specific compounds. Therefore, individuals can judge a Bao-chung tea grade based on the combined perception of odor component intensity and proportion. The E-nose can be used to identify Bao-chung tea grades based on its ability to determine the odorant composition.

Fluid Components in Cordierite from the Rocks of Epidote-Amphibole Facies of the Muzkol Metamorphic Complex, Tajikistan: Pyrolysis-Free GC-MS Data

The composition of volatile components of cordierite from the Muzkol metamorphic complex was studied using shock destruction with pyrolysis-free gas chromatography-mass spectrometry (GC-MS) with simultaneous IR and Raman spectroscopy. Applying the GC-MS procedure, the component relative concentrations (rel.%) and composition of different zones of cordierite crystals were determined. It was found that the substantially magnesian cordierite was formed with a predominantly aqueous-carbonic acid fluid (from 57.06 to 67.88 rel.% H2O, from 24.29 to 32.95 rel.% CO2). From the center towards the crystal periphery, the molar fraction of carbon dioxide (CO2/(H2O + CO2)) decreases from 0.36 to 0.26, whereas the alkane/alkene ratio increases from 0.80 to 0.88. At least 11 homologous series of organic compounds among the identified volatile components, in addition to water and carbon dioxide, were determined, including oxygen-free aliphatic and cyclic hydrocarbons (paraffins, olefins, cyclic alkanes and alkenes, arenes, polycyclic aromatic hydrocarbons (PAHs)), as well as oxygen-containing (alcohols, esters, aldehydes, ketones, carboxylic acids) and heterocyclic (furans, dioxanes) organic compounds.

An electric-field instrument for accelerated aging to improve flavor of Chinese Baijiu

Chinese Baijiu is a traditional distilled spirit that is consumed abundantly in China and around the world. Aging would dramatically increase the flavor of Baijiu, and famous Baijiu usually needs the long storage time for aging. Therefore, artificial aging that could accelerate the flavor improvement is in high demand. In this study, an electric-field treatment device was developed for the electric-field aging of the liquor. We used three types of strong-flavor crude Baijiu from different manufacturers in Sichuan as samples for electric-field aging. The total acids and esters, volatile flavor components, and sensory evaluation of the Baijiu samples before and after treatment were determined. It was found that the total acids and total esters of the Baijiu samples decreased and increased, respectively, with aging. The composition of volatile components changed after the aging treatment, and the volatile flavor components associated with the changes in the quality of Baijiu were analyzed. Combined with the sensory evaluation results, it was concluded that the quality of the treated Baijiu was significantly improved via electric-field aging. The result showed that electric-field aging can be an effective way to improve the flavor of Baijiu.

Влияние активной кислотности на качественные характеристики дистиллятов

The quality of distillates depends on the biochemical composition of the raw material, the operating parameters of the wort production and fermentation, and the methods and modes of distillation. The active acidity of the medium (pH) can affect wort fermentation and distillation processes. The research objective was to study the effect of the active acidity of bakery waste wort on fermentation and distillation processes. 
 The study featured fermented wort samples from wheat bread, a mix of wheat and rye-wheat bread, and distillate fractions obtained by a single fractionated distillation of fermented wort. The distillation occurred in laboratory conditions in a direct distillation unit (Kothe Destillationstechnik, Germany) with a 10 dm3 cube. The effect of the acidification degree of saccharified wort on the fermentation efficiency was determined by the strength of the fermented wort. The composition of volatile components in the distillates was defined by gas chromatography in a Thermo Trace GC Ultra chromatograph (Thermo, USA). 
 When the pH of saccharified wort fell from 5.5 to 4.5–3.5, the synthesis of higher alcohols and ethers of higher fatty acids decreased during fermentation, while the acetone mass concentration increased. The acidification of fermented wort to pH = 3.5–3.0 at the distillation stage had a positive effect on the distillates from recyclable baking waste. This technique increased the yield of the middle fraction (distillate) by reducing the loss of absolute alcohol with the head and tail fractions. The concentration of acetaldehyde and ethyl acetate in the middle fraction decreased by 1.5 times while the content of enanthic ether components increased by more than 75%. As a result, the sensory profile increased by 0.4–0.5 points. The distillates from the mix of wheat and rye-wheat bread were superior to distillates from wheat bread. The statistical analysis provided the following criteria for a qualitative assessment of the distillates from recyclable baking waste: the mass concentration of acetaldehyde and the ratio of alcohols C5 to the sum of alcohols C3 and C4.
 Pre-fermentation oxidation of saccharified wort proved impractical for bakery waste recycling, whereas acidification of fermented wort before distillation increased the distillate yield and improved its sensory profile.

Chemical composition of volatile components in the honey of some species of stingless bees

Using the technique of headspace solid-phase microextraction in combination with gas chromatography and mass spectrometric detection (HS-SPME/GC-MS), the composition of the volatile organic compounds (VOCs) of the honey of four species of stingless bees was studied in comparison with the honey of Apis mellifera bees. Peaks for 284 volatile components were registered on the chromatograms. Only eight components were present in all six studied samples. A high level of specificity in the composition of VOCs is a prerequisite for differentiating honey produced by different types of stingless bees and honey bees. Several specific features have been identified that are characteristic of the composition of VOCs in the honey of each species of stingless bees. These characteristics can be used to distinguish it from the honey of A. mellifera. The data obtained indicate the applicability of the HS-SPME/GC-MS technique for establishing the origin and for quality control of stingless bee honey.

Effects of Five Different Lactic Acid Bacteria on Bioactive Components and Volatile Compounds of Oat

In this research, oats were fermented with Lactobacillus plantarum, Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus bulgaricus and Streptococcus thermophilus for 48 h at 37 °C. The purpose of this work was to compare the growth capacities of the five lactic acid bacteria (LAB) in the oat matrix and the effects of fermentation on the contents of the bioactive components of oat, such as β-glucan, polyphenols, flavonoids and volatile compounds at different time (0, 4, 8, 12, 24, 36 and 48 h). After 48 h of fermentation, the number of living L. acidophilus in oat reached 7.05 × 109 cfu/mL, much higher than that of other strains. S. thermophilus retained the greatest β-glucan content, and L. casei had increased total polyphenol and total flavonoid contents. The proportion of free and bound polyphenols and flavonoids in all samples was changed by microbial action, indicating that forms of polyphenols and flavonoids can be transformed during the fermentation process, and the changes varied with different strains. The samples with L. plantarum, L. acidophilus, and L. casei fermentation contained more alcohols, whereas those with S. thermophilus and L. bulgaricus fermentation had more aldehydes, which revealed that the composition of volatile components was related to strains. The results indicate that oat substrate is a good medium for LAB growth. This study provides a reference for the use of different strains to achieve different fermentation purposes and a theoretical basis for the further processing of oat and fermented oat beverages.

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 role of the alkaline promoter on the formation of strength and burning of coal briquettes

Coal fines formed in the process of coal mining are of no commercial value and accumulate in dumps, harming the environment. At the same time, they can be used as a source of low-smoke fuel used by the population for domestic needs. To create such a product, it is necessary to solve many technical problems related to selecting binders for coal, providing mechanical strength, and initiating the combustion process of coal briquettes. This study presents the results of obtaining briquette fuel from fine particles of brown coal. Low-temperature pyrolysis determined the qualitative and quantitative composition of volatile components and proposed a mechanism for forming a porous structure of coal after thermal exposure. A composition of a mixture of caustic soda and grain processing waste was used as a binder for the production of briquettes. The mechanism of the formation of adhesive properties of the binder material is explained, and the optimal concentration of sodium hydroxide in it is determined. The positive role of caustic soda as a catalyst for the burning of briquettes is shown, and the activation energy of the burning process is calculated.

ЛЕТУЧИЕ СОЕДИНЕНИЯ СВЕЖЕГО PTERIDIUM AQUILINUM (L.) KUHN, ПРОИЗРАСТАЮЩЕГО В КРАСНОЯРСКОМ КРАЕ

The results of a comparative analysis of the individual composition of volatile compounds of vegetative parts of fresh bracken growing in different regions of the Krasnoyarsk Territory are presented for the first time. The collection of samples was carried out in May 2021, using an unopened plant with a size of 30 cm. Using chromatography-mass spectrometric analysis, 43 volatile components were identified, of which 30 were identified. It was revealed that in the composition of volatile components, the largest number of 12 compounds belong to the class of aldehydes, slightly less than 11 substances are represented by alcohols, the remaining 7 components belong to different classes of compounds. It was found that the predominant components in the composition of the bracken in terms of content are benzaldehyde, which accumulates up to 44% and hexanal - up to 23% of the total amount of substances. It was determined that the vayi plants differ in a large number of volatile compounds and their content, compared with the stems. Among the studied samples, in terms of the content of volatile components 98% in the wars and 94% in the stems, the fern collected in the southern part of the western Sayans (Shushenskoye settlement) prevails. Phenanthrene was identified in volatile components in samples No. 1 and No. 2 in an amount from 0.2% to 0.9%. The technique used did not allow the identification of ptaquiloside in fresh bracken.

РОЛЬ ЛЕТКИХ КОМПОНЕНТІВ У ПРОЦЕСІ ТЕРМАЛЬНОЇ ДЕCТРУКЦІЇ ТА ЗАПАЛЮВАННЯ БІОМАСИ ЛУШПИННЯ СОНЯШНИКА

The final composition of volatile components in the process of oxidative pyrolysis depends on the temperature level of the process. The gas output increases with the growth of hydrogen, methane and heavy hydrocarbons concentration in the process of pyrolysis in the range of 200-500°C. In this case, there is a noticeable decrease in undesirable impurities in the output of carbon dioxide and nitrogen in the fuel gas. The obtained data on the dynamics of thermal decomposition of biomass under heating conditions reflect the complex dependence of the yield of total gas individual components both on time and on the temperature of the process. The more volatiles contained in the source fuel, (the other things being equal) the faster the gas mixture ignites, and the more intensely it burns out. The composition and temperature of the gas mixture affects the pressure drop and auto-ignition temperature in the pyrolysis chamber. It was found that the lowest self-ignition temperature of a gas mixture is 490°C. A series of experiments to determine the critical condition for self-ignition at a constant temperature of 490°C and various initial pressures of the mixture (100-300 kPa) was carried out. It was found that the transition from a smooth increase in pressure of 90 kPa to an explosive one (up to 300-400 kPa) depends on the composition and temperature of the gas mixture. Therefore, the composition of the gas and its ignition temperature can be controlled by adjusting the mode of pressure increase in the reactor.

ТЕРМИЧЕСКИЙ АНАЛИЗ ПРОДУКТОВ ОКИСЛЕНИЯ АКТИВИРОВАННОГО СПЛАВА АЛЮМИНИЯ RAU-85 В РАЗЛИЧНЫХ ОКИСЛИТЕЛЬНЫХ СРЕДАХ

By methods of differential thermal and thermogravimetric analysis, the composition of the thermally active part of the studied multicomponent samples of the products of the interaction of the activated aluminum alloy with various oxidizers was determined, and their thermal behavior was revealed under conditions of dynamic temperature rise. Thermal analysis was carried out in air environment, in the temperature range from 20 to 1000°C. The heating mode of the furnace was linear (dT/dt = 10 grad/min), the reference substance was calcined Al2 O3 . Water, 3% aqueous solution of hydrogen peroxide, 5% aqueous solution of sulfuric acid were used as oxidizing agents. Establishment of the material composition of the active part of powder samples was carried out according to the morphologies of thermal curves and numerical values of the intensities of endo- and exothermic effects using the thermogravimetric readings of TG-lines associated with them. A series of endo- and exothermic effects revealed during the decomposition of the test samples made it possible to follow the order of the stage of their thermal destruction and quantitatively determine the composition of volatile components. A number of features of sample decomposition were established depending on their composition and weight ratios of thermally active sample components. The obtained data on the thermal analysis of the oxidation products of the activated alloy RAU-85 in various oxidizing environments can be successfully applied to develop a technology for cleaning the bottomhole zone of the well from asphalt resin paraffin deposits, based on the thermal gas-chemical interaction of the activated aluminum alloy and formation water, which results in the formation of a large amount of heat and vapor-gas mixture.

Analysis on volatile components of co-fermented fruit wines by Lycium ruthenicum murray and wine grapes

The aim of this study was to detect the volatile components in co-fermented fruit wines made by Lycium ruthenicum Murray (LRM) and wine grapes using gas chromatography–mass spectrometry (GC-MS). A total of 52 kinds of volatile components were detected in the co-fermented fruit wines, more than those detected in commercially available Changyu dry red wine (30 kinds) and 0# wine (26 kinds) made by wine grapes in the laboratory. Esters (22 kinds) and alcohols (17 kinds) constituted a major proportion of co-fermented fruit wines, then followed by volatile acids, phenols, aldehydes and ketones. The relative intensity of aroma in the co-fermented fruit wines was greater than that of the Changyu wine and 0# wine, exhibiting a comprehensive fruit and floral aroma profile. Additionally, grape wines (containing Changyu wine and 0# wine) were distinguished from the co-fermented fruit wines (1#–9#), 1# wines distinguished from the other co-fermented fruit wines (2#–8#) in second layer of clustering, indicating that the composition of raw material and fermentation conditions were the main influencing factor in the attributes of volatile components. Overall, co-fermented fruit wines possess more advantages in composition of volatile components and aromas, which showed a richer volatile and aroma structures.

Preparation of Kushui Rose (Rosa setate x Rosa rugosa) essential oil fractions by double molecular distillation: Aroma and biological activities

Kushui Rose (Rosa setate x Rosa rugosa, KR) is a distinctive Chinese rose variety. Its extracts, especially essential oil (EO), showed various biological activities. In this study, double molecular distillation was used to separate different fractions from KREO. GC-MS was used to detect the composition of volatile components in different fractions. The aroma analysis of different fractions was carried out by a professional sensory evaluation team. D1 (the light phase in the first stage) and R2 (the heavy phase in the second stage) showed better biological activities, with a lower IC50 value on antioxidant ability and a higher capacity for antimicrobial. Furthermore, D1 and R2 also effectively prevented the oxidation of sunflower oil. The antimicrobial mechanism was explored by relative conductivity, the content of protein and reducing sugar, and scanning electron microscopy on Escherichia coli. In all, molecular distillation could be considered an effective way to improve the aroma and biological activity for KREO.

Influence of Volatile Components from ‘Qiyueju’ (Chrysanthemum morifolium Ramat.) Flowerheads on the Mycelial Growth of Pleurotus ostreatus

Chrysanthemum is a traditional edible and medicinal flower, has many medicinal properties, and is used in the food and pharmaceutical industries. This study aimed to investigate the chemical composition of volatile components from ‘Qiyueju’ (Chrysanthemum morifolium Ramat.) flowerheads and their effect on Pleurotus ostreatus mycelial growth. The flower has been collected from the Yunwu Mountain region (Guizhou Province, China), and volatile components of ‘Qiyueju’ flowerheads have been obtained using headspace solid-phase micro-extraction (SPME). Gas chromatography-mass spectrometry (GC-MS) analysis of the volatile components has been carried out to reveal its chemical composition. A total of 67 volatile components have been identified, accounting for 95.28 % of the total volatile components. These volatile components have been dominated by camphor (48.64 %), followed by bornyl acetate (3.94 %), cis-β-Farnesene (3.55 %), sabinene (3.00 %), α-terpineol (2.65 %), Z,E-α-farnesene (2.55 %), and 1,8-cineole (2.43 %). In particular, the value of camphor was significantly above the range from 0 to 44.6 % in previous studies, most probably due to species, geographical location, seasonal factors, climatic conditions, and harvest time. The influence of volatile components on the mycelial growth of P. ostreatus was investigated using the growth rate method. The four selected major components exhibited strong sensitivity to P. ostreatus after five days. Notably, the fungus possessed the strongest sensitivity (EC50=0.175 μg/ml) and the best mycelial growth rate values of 6.10±0.03 mm/d when the camphor concentration was 1.25 μg/ml (P<0.05). Camphor also produced the best percentage of induction (47.30±8.96 %) at the same concentration. The four selected major components, especially camphor, from ‘Qiyueju’ flowerheads have some potential development value in terms of P. ostreatus culture medium and may be useful in the search for newer annexing agents in the culture substrate of edible fungi.

Volatile Components in Cordierite and Coexisting Tourmaline and Quartz from Pegmatites of the Kuhilal Deposit (Pamir, Tajikistan)

Abstract —The compositions of volatile components in cordierite, tourmaline, and quartz from pegmatites of the Kuhilal deposit were studied by pyrolysis-free gas chromatography–mass spectrometry (GC–MS), IR and Raman spectroscopy, and microthermometry, and their comparative analysis was performed. Capillary GC–MS was applied to determine the component composition and relative contents (rel.%) of volatiles from different zones of crystals and fractions of cordierite. It has been established that water and carbon dioxide prevail among them. Among hydrocarbons, aliphatic, cyclic, and oxygenated ones are predominant. Heterocyclic, nitrogenated, and sulfonated compounds have also been found. In tourmaline and quartz, volatile components are present in gas–liquid inclusions; in cordierites, they are localized both in structural cavities and in nonstructural positions.

Returnable baking waste — a new type of raw materials for distillates production (Part III. Distillation stage)

The distillation stage is a key step in distillate-based alcoholic beverage technology. The use of a new non-traditional type of raw materials to obtain distillates requires comprehensive research. The purpose of this work was to study the processes at the distillation stage of the discharged wort from the recyclable baking waste, in identifying significant factors and determining the optimal technological values of these factors. The objects of the study served 9 samples of fermented wort from various types of recyclable baking waste, distillate fractions and samples of distillates. The distillation was performed on the installation of direct distillation “KOTHE DESTILLATIONSTECHNIK” (Germany). In the objects of the study, the volume, the volume fraction of ethyl alcohol and the mass concentration of the main volatile components were determined. The composition and concentration of basic volatile components were determined using gas chromatography on the device “Thermo Trace GC Ultra” (Thermo, United States). The wide range of variation of the mass concentration of the main volatile components, depending on the composition of the initial raw materials, is revealed. It has been established that the nature of the distribution of volatile components according to distillate fractions does not depend on the physicochemical composition of the fermented wort from different types of recyclable baking waste. It is shown that the nature of the distribution of volatile components according to fractions in obtaining a distillate from the recyclable baking waste has certain differences from their distribution in the preparation of cognac and fruit distillates. A comparative assessment of distillates obtained by single fractionated distillation and double distillation showed the advantage of the first alcohol output and the composition of volatile components. It has been established that the distillation rate with a direct fractionated has a significant effect on the dynamics of the distribution of the main volatile components and the output of the distillate for anhydrous alcohol. With an optimal distillation rate (5.9 cm3 / min), an anhydrous alcohol output increases, on average, by 4% and reduced the losses of valuable aroma-forming volatile components with head and tail fractions.

Characterization and identification of different Chinese fermented vinegars based on their volatile components.

In this study, volatile components of 40 Chinese fermented vinegar samples, made from different raw materials, starters, and processing technologies, were collected from different geographic origins in China (Shanxi, Jiangsu, Sichuan, and Fujian Province) and their volatile components were analyzed by headspace-solid-phase microextraction-gas chromatography-mass spectrometry. Sixty-two aroma compounds have been identified by NIST library combined with retention index, mainly including esters, heterocyclics, acids, aldehydes, and ketones. In addition, multivariate analysis including principal component analysis and partial least squares-discriminant analysis (PLS-DA) were carried out to discriminate vinegars based on their composition of volatile components. For PLS-DA models, analysis of variance (ANOVA) or variable importance in the projection (VIP) value were used to select variables with the highest discriminatory power, and the Kennard-Stone algorithm was used to select the training and testing samples. The PLS-DA models (ANOVA or VIP) all provided a classification accuracy of 100% for the training set, and subsequent application of these models allowed the grouping of unknown samples (testing set) according to their characteristics (raw materials and processing technology). PRACTICAL APPLICATIONS: Traditional Chinese vinegars have a long history but nowadays adulterations of them are becoming a problem in the market. In this study, Chinese fermented vinegars from different varieties were identified based on volatile composition. We found that starter cultures and fermentation process have the greatest influence on the volatile components of vinegars, while the influence of raw material and steaming of raw material are weaker volatile components. Then, partial least squares-discriminant analysis models, we carried out could successfully be applied to predict unknown vinegar samples based on a database of volatile components. This study provided a strategy to detect the identity of different vinegars, which can also be used to monitor the quality and safety of traditional Chinese vinegars.