Content Of Volatile Components Research Articles

Hydrolysis of Beef Sarcoplasmic Protein by Dry-Aged Beef-Isolated Penicillium oxalicum and Its Associated Metabolic Pathways.

Yanbian cattle have a unique meat flavor, and high-grade meat is in short supply. Therefore, in this study, we aimed to improve the added value of Yanbian cattle low-fat meat and provide a theoretical reference for the subsequent development of an excellent starter. Rump meat from Yanbian cattle was dry-aged and then screened for protease-producing fungi. Three protease-producing fungi (Yarrowia hollandica (D4 and D11), Penicillium oxalicum (D5), and Meesziomyces ophidis (D20)) were isolated from 40 d dry-aged beef samples, and their ability to hydrolyze proteins was determined using bovine sarcoplasmic protein extract. SDS-PAGE showed that the ability of Penicillium oxalicum (D5) to degrade proteins was stronger than the other two fungi. In addition, the volatile component content of sarcoplasmic proteins in the D5 group was the highest (45.47%) and comprised the most species (26 types). Metabolic pathway analysis of the fermentation broth showed that phenylalanine, tyrosine, and tryptophan biosynthesis was the most closely related metabolic pathway in sarcoplasmic protein fermentation by Penicillium oxalicum (D5). Dry-aged beef-isolated Penicillium oxalicum serves as a potential starter culture for the fermentation of meat products.

Conjugation of gum Arabic and lentil protein hydrolysates through Maillard reaction: Antioxidant activity, volatile compounds, functional and sensory properties.

Lentil protein hydrolysates (LPH) and lentil protein hydrolysates cross-linked (LPHC) were grafted with gum Arabic (GA) through a wet Maillard reaction at 100°C for 2 h and called MLPH and MLPHC. The samples were assessed for absorption, degree of grafting (DG), surface hydrophobicity, antioxidant activity, molecular weight (MW) profile, chemical alteration, volatile compounds, functional and sensory properties. Results showed that Maillard grafting led to increase in absorption and DG (maximum value: MLPHC), and led to the reduction of the surface hydrophobicity and antioxidant activity (minimum value: MLPHC). MW profiles indicated that MLPH and MLPHC formed new bands at MW >250 kDa. Regarding the Fourier transform infrared spectroscopy (FTIR), Maillard conjugation led to the occurrence of peaks at 1759 and 1765 cm-1, while the intensities of amide I bands at 1637 and 1659 cm-1 and amide II bands at 1498 and 1495 cm-1 were decreased. Hydrolysis, cross-linking, and especially Maillard grafting provided well-balanced content of volatile components. Indeed, the proportions of alcohols, ketones, aldehydes, and acids were changed, thereby, the inherent grassy and planty tastes were diminished while new umami taste was developed. Maillard grafting led to significant improvement of functional properties, while MLPH and MLPHC indicated the highest emulsifying activity at pH 10.0 (73.76 and 70.12 m2/g, respectively) and stability (369.64 and 288.22 min), foaming capacity (88.57% and 142.86%) and stability (60.57% and 72%). Sensory analysis has demonstrated that umami taste was highly developed in MLPH and MLPHC, which can be well considered as meat proteins and flavor enhancers such as monosodium glutamate (MSG).

Preparation of tobacco pyrolysis liquids in subcritical/supercritical ethanol and their application in the aroma enhancement of heated cigarettes.

For the aroma enhancement research of heated cigarettes, it is worth exploring whether tobacco can be pyrolyzed into pyrolysis liquids containing a large number of volatile aroma components. In this study, tobacco pyrolysis liquids were prepared in subcritical/supercritical ethanol, and their applications in the aroma enhancement of heated cigarettes were investigated. The optimal conditions of supercritical liquefaction reactions were determined by optimizing the reaction time, liquid/solid mass ratio and temperature conditions. Moreover, the effect of supercritical liquefaction conditions on volatile aroma components in tobacco pyrolysis liquids was investigated by GC-MS. The results indicated that the reaction temperature had the most significant impact on the tobacco pyrolysis reaction, and higher reaction temperature promoted the pyrolysis conversion of tobacco, resulting in enhanced tobacco conversion and a high content of volatile components in the tobacco pyrolysis liquid. The optimal reaction conditions for the preparation of tobacco pyrolysis liquid were found to be a temperature of 220°C, a liquid/solid mass ratio = 15, and a 2-h reaction time. Meanwhile, the content of ester compounds and nicotine in the tobacco pyrolysis liquid increased significantly with the increase of reaction temperature. Sub/supercritical ethanol treatment significantly destroyed the surface structure of tobacco, and the degree of tobacco depolymerization increased when temperature rised. The analysis of aroma compounds in the smoke of heated cigarettes indicated that the tobacco pyrolysis liquid could significantly increase the release of aromatic substances and has a significant aroma-enhancing effect. This article proposed and prepared tobacco pyrolysis liquid in subcritical/supercritical ethanol and explored its potential application in the aroma enhancement of heated cigarettes, offering a new route for flavor enhancement technology for this type of product.

Şarap Üretim Atıklarından Elde Edilen Farklı Üzüm Posalarının İzmir Tulum Peynirinin Olgunlaşmasına Etkisi: Yağ Asidi Bileşimi, Serbest Yağ Asitleri ve Uçucu Bileşikler Üzerine Bir Araştırma

This research aimed to examine the fatty acids, free fatty acids, and volatile compounds of İzmir Tulum cheeses ripened in brines prepared using different grape pomaces from wine production waste. For this purpose, four groups of Izmir Tulum cheese were produced: white wine waste: sultaniye grape pomace (W), red wine waste: petit-verdot grape pomace (R), red and white wine mixture waste: 1:1 mixture of sultaniye and petit-verdot (RW) and control: pomace-free group (C). Among the short chain fatty acids, butyric (C4), caproic (C6), caprylic (C8) and capric (C10) acids were determined in all cheese samples. Long chain fatty acids such as myristic (C14), palmitic (C16) and oleic (C18:1) acids were found in high amounts. The most abundant free fatty acids in all cheese samples were oleic acid (C18:1) followed by stearic acid. Butyric (C4) and caproic (C6) acid contents increased during storage and were highest in RW and R samples at the end of storage. A total of 32 volatile components (12 acids, 3 alcohols, 9 esters, 3 terpenes, 2 hydrocarbons, 3 other compounds) were detected in İzmir Tulum cheese samples during the ripening period. It was observed that the volatile components content varied according to the grape pomace type (p

Behavioral responses of Rhyzopertha dominica (F.) to volatiles of different stored grains

The aim of this study was to explore the behavioral responses of the lesser grain borer, Rhyzopertha dominica (F.) to volatiles of different stored grains. The olfactory responses of R. dominica to the volatiles of five grains, i.e. wheat, rice, maize, sorghum, and soybean, were studied in Y-tube and six-arm olfactometer experiments. The volatile components of these grain were analyzed by gas chromatography-mass spectrometry (GC-MS). Y-tube olfactometer bioassays showed that both adults and larvae of R. dominica showed significant preferences for volatiles from the five grains, compared with clean air. In six-arm olfactometer bioassays, adults of R. dominica showed the strongest olfactory preference for wheat, followed by rice, maize, sorghum, and soybean, and larve showed similar preferences for the volatiles of these stored grains. The GC-MS analysis identified 31, 24, 17, 11, and 10 components in the volatile profiles of wheat, soybean, rice, maize, and sorghum, respectively. 1-hexanol was the most abundant component of the volatiles of wheat (27.43%) and soybean (48.28%), whereas nonanal was the most abundant component of the volatiles of rice (21.75%), maize (31.22%), and sorghum (40.78%). Therefore, the different olfactory responses of R. dominica are reasonably related to the differences in the types and contents of volatile components among these five grains. Noteworthy, the volatile components identified in grains may be useful as attractants in traps combined with insect phermones for monitoring or even control R. dominica.

Effects of soybean endogenous enzyme hydrolysis on the quality of soymilk after blanching

This study examined the relationship between the endogenous enzymatic hydrolysis conditions and the quality and flavor of soymilk derived from blanched soybeans. Results represented that following blanching, the lipoxygenase activity of soybeans decreased by 88.50% and the endogenous protease activity greatly improved compared to unblanched. During the subsequent endogenous enzymatic hydrolysis, the stability factor and sensory score dropped as the amount of okara rose, although the content of peptides and amino acids nitrogen increased. At an enzymolysis temperature of 50 °C, the soymilk had the highest sensory score. After 60 min of enzymolysis, the beany odor was weakened maximumly; the levels of polypeptide and amino acid nitrogen increased by 45.00% and 43.33%, respectively. Enzymatic hydrolysis at 50 °C for 60 min without okara generated the finest soymilk. Blanching diminished the primary components of the beany odor of raw soymilk. Enzymolysis of blanched pretreatment soymilk further dropped the content of beany odor components and exhibited a richer variety and concentration of volatile components. Following the hydrolysis of endogenous enzymes generated after blanching, the overall quality of soymilk was enhanced.

Genesis of Carbonatite at Oldoinyo Lengai (Tanzania) from Olivine Nephelinite: Protracted Melt Evolution and Reactive Porous Flow in Deep Crustal Mushes

Abstract Carbonatites, carbon-rich magmatic rocks, are thought to form by low-degree partial melting of a relatively carbon-poor mantle followed by protracted differentiation and immiscibility. However, the nature of parental magmas and the characteristics of the early stages of differentiation that shape the subsequent crystal and liquid lines of descent remain poorly constrained. To provide new constraints, deep crustal cumulative xenoliths from Oldoinyo Lengai (East African Rift), the only active volcano erupting carbonatite magmas, were studied. We use major and volatile elements in primitive olivine-hosted melt inclusions, as well as major and trace elements in crystals, to reconstruct the conditions of formation and evolution of cumulates (pressure, temperature, composition). Xenoliths are composed of olivine, diopside, phlogopite, amphibole and accessory minerals. One remarkable feature is the presence of diopside and phlogopite oikocrysts enclosing roundish olivine chadacrysts. Melt inclusions do not have vapor bubble and have major element compositions resembling olivine nephelinite (7–10 wt % MgO after corrections for post-entrapment crystallization). The absence of vapor bubbles implies that the concentrations of volatile components (i.e. CO2, H2O, S) were not compromised by well-known post-entrapment volatile loss into the vapor bubble. Based on the melt inclusion study by SIMS, the volatile concentrations in olivine nephelinite magmas (early stage of differentiation) at Oldoinyo Lengai were 20–130 ppm S, 390–4500 ppm F, 50–540 ppm Cl, up to 6074 ppm CO2 and up to 1.5 wt % H2O. According to the calculated CO2-H2O saturation pressures and geophysical data, xenoliths from Embalulu Oltatwa document a mushy reservoir in the lower crust. Primitive olivine nephelinite melt inclusions have higher H2O contents than olivine nephelinite lavas from other further South volcanoes from the North Tanzanian Divergence (0.2–0.5 wt % H2O), suggesting that the lithospheric mantle source beneath the Oldoinyo Lengai is more hydrated than the mantle beneath the rest of North Tanzanian Divergence. We present a model in which resorption features observed in olivine chadacrysts, together with the LREE enrichments in olivine grains, are the consequences of reactive porous flows in a deep crustal mushy reservoir. We provide constraints on the major, trace and volatile element composition of the parental magmas of carbonatite series and demonstrate with Rhyolite-MELTS models that phonolites and related natrocarbonatites from Oldoinyo Lengai can be produced by protracted differentiation of olivine nephelinite melts.

Influence of electrohydrodynamics on the drying characteristics and volatile components of iron stick yam

The drying characteristics, rehydration capacity, color, infrared spectra and volatile components of iron stick yam slices were investigated under different alternating current (AC) voltages (13, 17, 21 kV), hot air drying (HAD) (60 °C) and natural drying (AD) by electrohydrodynamic (EHD) drying and HAD experimental devices. The results showed that slices of iron stick yam dried the quickest with HAD, which also had the fastest drying rate; while drying the slices of iron stick yam with EHD led to a better rehydration capacity, higher brightness L* and whiteness, a more stable protein secondary structure, and a greater variety and content of volatile components compared with AD and HAD. These finding indicated that EHD is a more promising method for drying iron stick yam.

Experimental and numerical study on suppressing coal dust deflagration flame with NaHCO3 and MPP

In this paper, the flame propagation behavior and free radical reaction mechanism of two powder explosive suppressants, sodium bicarbonate (NaHCO3) and polyphosphate melamine (MPP), at different additions were investigated using Hartmann experimental system and CHEMKIN-PRO numerical simulation. The results showed that NaHCO3 and MPP showed different inhibitory advantages. MPP mainly suppressed the propagation of flame during the development and rapid rise stages, while NaHCO3 had a better suppression effect at the preliminary stage of explosion. The gas phase kinetic analysis also proved that the NaHCO3 reaction was rapid, and it could decompose and endothermy at the beginning of the explosion, and generate gaseous H2O and CO2 to dilute the concentration of volatile components. Meanwhile, NaOH, NaO, and NaO2 produced by decomposition consumed free radicals and reduced the initial reaction rate of the explosion. In the process of gas phase reaction, MPP continuously reduced the amount of flame free radicals through a inhibition cycle of HPO3 ⇔ PO2, and generated a large number of inert products for inerting fixed carbon, exhibiting better long-term effectiveness. This study can provide a reference for the selection and design of explosion suppressants.

Evaluation of Physicochemical Characteristics and Sensory Properties of Cold Brew Coffees Prepared Using Ultrahigh Pressure under Different Extraction Conditions.

Although cold brew coffee is becoming increasingly popular among consumers, the long coffee extraction time is not conducive to the further development of the market. This study explored the feasibility of ultrahigh pressure (UHP) to shorten the time required for preparing cold brew coffee. The effects of pressure and holding time on the physicochemical characteristics and sensory evaluation of UHP-assisted cold brew coffee were also determined. The extraction yield; total dissolved solid, total phenol, and melanoid content; antioxidant capacity; and trigonelline and chlorogenic acid contents of UHP-assisted cold brew coffee increased as the pressure increased. The extraction yield and the total dissolved solid, total phenol, total sugar, and chlorogenic acid and trigonelline contents were higher when the holding time was longer. The HS-SPME-GC/MS analysis demonstrated that the furan, aldehyde, and pyrazine contents in coffee increased as the pressure and holding time increased. The pressure did not significantly impact the concentrations of volatile components of esters and ketones in coffee samples. However, the increase in holding time significantly increased the ester and ketone contents. The sensory evaluation results revealed that as pressure rose, the intensities of nutty, fruity, floral, caramel, and sourness flavors increased, whereas bitterness and sweetness decreased. Longer holding time increased nutty, caramel, sour, bitter, sweet, and aftertaste flavors. Principal component analysis (PCA) results indicated that holding time is a more crucial factor affecting the physiochemical indices and flavor characteristics of coffee. UHP can shorten the preparation time of cold brew coffee. Pressure and holding time significantly affected the physiochemical indices and volatile components of UHP-assisted cold brew coffee. UHP-assisted cold brew coffee had lower bitterness, higher sweetness, and a softer taste than conventional cold brew coffee.

Discussion on the Differences in Aroma Components in Different Fragrant Rice Varieties during Storage.

Rice (Oryza sativa L.) is an important food crop in Taiwan, among which fragrant rice is highly regarded for its special aroma when cooked. During the storage of fragrant rice, the aroma components will change, which will affect the aroma quality of fragrant rice. Therefore, headspace solid-phase microextraction (HS-SPME) was used in this study, combined with gas chromatography and gas chromatography-mass spectrometry, to analyze the difference in the aroma components of Taikeng No. 4 (TK4), Tainung No. 71 (TN71), Kaohsiung No. 147 (KH147), and Taichung No. 194 (TC194) fragrant rice. A total of 28 aroma components were identified in the four varieties of fragrant rice, and the main components were all Nonanal. Among them, TK4 contains a very high content of hydrocarbons, including Tridecane and Dodecane; TN71, KH147, and TC194 contain mainly aldehydes such as Nonanal and Hexanal. During different storage times, the contents of alcohols, monoterpenes, aromatic aldehydes, and furans increased with storage time, while the content of aliphatic aldehydes decreased with storage time. After storage, the fragrant rice samples showed a tendency for the total volatile component content to decrease, with the most pronounced reduction observed in Nonanal content.

Comparison of chemical constituents in Artemisiae Argyi Folium from different Dao-di producing areas based on UPLC and HS-GC-MS

This study aims to compare the chemical constituents in 24 batches of Artemisiae Argyi Folium samples collected from three different Dao-di producing areas(Anguo in Hebei, Nanyang in Henan, and Qichun in Hubei). An ultra-performance liquid chromatography(UPLC) method was established to determine the content of 13 nonvolatile components, and headspace-gas chromatography-mass spectrometry(HS-GC-MS) was employed for qualitative analysis and comparison of the volatile components. The content of phenolic acids in Artemisiae Argyi Folium was higher than that of flavonoids, and the content of nonvolatile components showed no significant differences among the samples from the three Dao-di producing areas. A total of 40 volatile components were identified, and the relative content of volatile components in Artemisiae Argyi Folium was significantly different among the samples from different Dao-di producing areas. The principal component analysis and partial least squares discriminant analysis identified 8 volatile components as the potential markers for discrimination of Artemisiae Argyi Folium samples from different Dao-di producing areas. This study revealed the differences in the chemical composition of Artemisiae Argyi Folium samples from three different Dao-di producing areas, providing analytical methods and a scientific basis for the discrimination and quality evaluation of Artemisia Argyi Folium in different Dao-di producing areas.

Non-aldehyde resins based on resorcinol and natural alkylresorcinols modified with styrene

The use of natural alkylresorcinols produced in Estonia (5-methylresorcinol, HONEYOL80 fraction) instead of the expensive resorcinol reduces the cost of the synthesized resins while maintaining their high technological characteristics. Resins based on resorcinol (R), 5-methylresorcinol (5-MR), HONEYOL80, dicyclopentadiene (DCPD), and styrene (S) were synthesized in the presence of an acid catalyst. Their physical and chemical characteristics have also been studied. It was shown that depending on the mole ratio of the components of the formulation, resins with different softening temperatures (66 to 97 °C), ash content of 0.04 to 0.39 wt%, and a low content of volatile components at 105 °C, including moisture, were obtained. The best conditions for the synthesis of resins with a softening point of 94 °C–97 °C are molar ratio of R (5-MR): DCPD: S = 1: 0.5: 0.3 at temperature 135 °C–170 °C, synthesis time 5 h 30 min. The synthesized resins did not require additional processing under a vacuum. The presence of unreacted resorcinol and 5-methylresorcinol (quantitatively and qualitatively) in the final product, the homogeneity, and molecular weight characteristics of the resin composition (qualitatively) were determined by TLC and GPC.

Методология оптимизации режимов дистилляции на основе критериев оценки качества продукта

The range of high-quality alcoholic beverages could be expanded by unconventional raw materials, e.g., bakery waste. Any new technology requires optimization of operating parameters at each production stage. The sensory properties of an alcoholic drink depend on the distillation mode. However, food science knows no objective methods for optimizing distillation parameters based on the biochemical composition of the raw material. The research objective was to develop a new methodology for optimizing the distillation procedure for alcoholic drinks based on unconventional raw materials. 
 The research featured distillates obtained from industrial samples of bakery waste. The variable factors included the distillation rate, which ranged from 5 to 17 cm3/min, and the wort acidification degree, which was pH 6.0–2.0. The composition and mass concentration of the main volatile components were determined by gas chromatography using a Thermo Trace GC Ultra device (Thermo, USA) with a flame ionization detector. The sensory evaluation was performed by a panel of qualified experts. The single-factor experiment showed that the distillation rate and the wort acidification degree affected the concentration of each volatile component in the distillate. 
 Using the method of pairwise correlation coefficients, the authors identified the most significant parameters: mass concentration of 1-propanol, phenylethyl alcohol, ethyl lactate, total enanthic esters, total enanthic esters vs. total esters, concentration of ethyl lactate vs. total enanthic esters, isobutanol concentration vs.1-propanol concentration. The linear pair correlation coefficients were calculated for these selected indicators, and the effect of each parameter on the sensory profile was represented as a regression model. The optimal operating parameters were determined by extremization of a two-variable function: pH 4.4 ± 0.2, speed 9.5 ± 1.0 cm3/min. 
 The new methodology provided for the following sequence of operations: determining the significance of the variable factor; selecting the evaluation parameters based on a single-factor experiment; determining the interaction; developing a regression model. This method can be used to calculate the optimal technological distillation parameters for other raw materials.

Comparative study on physicochemical properties, microbial composition, and the volatile component of different light flavor Daqu.

Baijiu, a type of liquor, is known for its pure fragrance and softness. Its unique style is attributed to the complex microbial flora and flavor precursors found in Daqu. In order to elaborate the nature of light flavor Daqu to guide the baijiu production, four Daqu samples (DQ1, DQ2, DQ3, and DQ4) from Shanxi province were analyzed to determine their microbial structure, physicochemical properties, and volatile flavors using high-throughout put seqencing and headspace solid-phase microextraction/gas chromatography-mass spectrometry method in this study. The findings indicated that there were no noticeable variations in the water content and esterase activity of the four Daqu. However, the DQ2 sample had a higher acidity value and saccharifying enzyme activity, whereas DQ3 had the highest protease activity. The microbial community structure of the four Daqu was similar, with Lactobacillus and Streptophyta as the dominant bacteria, but the abundance of bacteria was different among the four Daqu. Issachenkia was a common dominant fungus genus in all samples. Rhizopus and Lichtemia were higher in DQ1 and DQ2, while Torulaspora, Aspergillus, and Candida were more prevalent in DQ4. A total of 27 volatile components were detected in the four Daqu, including esters, alcohols, ketones, aldehydes, and acids. DQ2 had the most volatile components and ethyl lactate and ethyl acetate were the most significant esters in the four samples. In conclusion, the physicochemical indicators of the four light flavor Daqu had distinct differences. There were significant variations in the abundance of bacteria and fungi, leading to differences in the volatile component content. These research findings can serve as a theoretical foundation for blending different light flavors Daqu and hold great significance in enhancing the quality of baijiu.

Improving the hot air drying of garlic slices by perforation synergistic alcohol pretreatment

Long processing time represents a serious challenge in hot air drying since it led to high energy consumption and quality deterioration. A synergistic pretreatment of artificial perforation and alcohol maceration (PAT) was proposed in this study to improve hot air drying of garlic. Samples without pretreated, perforated, and subjected to alcohol pretreatments were used as control. The results showed that PAT pretreatment significantly reduced the drying time and energy consumed by 36.67%. Analysis showed that the mechanisms underlying the highest drying rate of PAT pretreated sample included pre-dehydration, capillary flow promotion and cell permeability enhancement. Samples pretreated with PAT exhibited the highest whiteness value, minimum shrinkage, lowest brittleness, and especially the highest content of volatile components, which is essential for its application as a spice. The antioxidant activity, total phenolics and allicin content were low in the PAT samples compared with other samples. This study provides a simple and effective approach to improve the drying of garlic.

Influence of ethanol content on the detection of volatile components in Huangjiu

Huangjiu (Chinese rice wine) is a traditional Chinese fermented wine with a unique flavor. The components of this wine are complex, and the ethanol content of different Huangjiu preparations varies greatly. In this study, changes in the chromatographic peak areas of the volatile components of Huangjiu samples with different ethanol contents were measured using headspace-gas chromatography (HS-GC). The influence of ethanol on the quantitative detection of different volatile components of Huangjiu at gas-liquid equilibrium was also analyzed. When the ethanol content of Huangjiu was in the range of 10%-19% vol, the peak areas of 16 volatile components (i. e., sec-butanol, n-propanol, isobutanol, n-butanol, isoamyl alcohol, β-phenyl-ethanol, acetaldehyde, isovaleraldehyde, benzaldehyde, ethyl formate, ethyl acetate, isobutyl acetate, isoamyl acetate, ethyl hexanoate, ethyl lactate, and diethyl succinate) were negatively correlated with the ethanol content. Increases in the ethanol content of the liquor changed the gas-liquid equilibrium of most other trace volatile components. In addition, only the peak area of acetal was positively correlated with ethanol content. The content of acetal in Huangjiu was affected by the alcohol content, and its decomposition reaction occurred along with the dilution process. The influence coefficient of ethanol content on the peak area of the above compounds ranged from -12.4% to 4.9%. The vapor pressure of most volatile components decreased with increasing ethanol content, and different components were affected in different ways. Compared with those of other components, the peak areas of methanol, furfural, and acetic acid were less affected by the ethanol content. These components were also affected by other factors, such as ionization and chemical reactions occurring during the dilution process. When different wine samples were adjusted to the same ethanol content, the concentration of volatile components in these samples became proportional to the total chromatographic peak area and the influence of the matrix effect of ethanol on the quantitative analysis was effectively eliminated. Thus, when researchers use pretreatment methods based on the principle of gas-liquid balance to carry out the quantitative detection of flavor components, they should adjust different rice wine samples to the same alcohol content to effectively control the matrix effect caused by differences in ethanol content and achieve accurate quantitative analysis.

Determination of the quality of special coke as a result of heat treatment of coal from the Shubarkolskoye field

To date, there is a tendency to increase the pace of production in the field of ferrous metallurgy. The constant demand for steel products is accompanied by an increase in prices for raw materials, including carbon reducing agents. In the conditions of the domestic market of Kazakhstan, of great interest is the study and the possibility of using low-baking and non-baking coal as a raw material for the production of special coke used as a reducing agent in metallurgy, the relevance and expediency of which is also due to the resource conservation and energy efficiency program in the use of raw materials put forward by the Government of the Republic of Kazakhstan. In this article, as a result of the search for high-quality, alternative types of reducing agents used in the production of ferroalloys, experimental data of thermal oxidation treatment (coking) of long-flame, non-baking coals of the Shubarkol deposit (Kazakhstan) are presented. In laboratory conditions, during the experiments, the tested grade D coals with a fraction of 70-80 mm were subjected to temperature exposure at temperatures of 800, 850, 900, 950 °C with various preset heating speeds to determine the quality characteristics that meet the requirements for reducing agents for the metallurgical industry, in particular for the production of ferroalloys, in electro thermal, steelmaking, for agglomeration of iron and non-ferrous ores, etc. A technical analysis of long–flame coal was carried out, the volatile and moisture content of which are Vdaf – 44.5%, W – 14.8%, respectively. Also, the obtained special coke was evaluated by the content of volatile components as a result of heat treatment of coals from the Shubarkol deposit: the volatile content averaged 1.73-3.15%, the moisture was 0.73-1.65%.Based on the results of the studies, the possibility of obtaining a special coke from these types of coals with appropriate characteristics was shown.

Chemotaxonomic Variation in Volatile Component Contents in Ancient Platycladus orientalis Leaves with Different Tree Ages in Huangdi Mausoleum.

To gain insight into the differences in the composition and volatile components content in ancient Platycladus orientalis leaves with different tree ages in Huangdi Mausoleum, the volatile components were identified by headspace solid-phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME-GC-MS) method. The volatile components were statistically analyzed by orthogonal partial least squares discriminant analysis and hierarchical cluster analysis, and the characteristic volatile components were screened. The results exhibited that a total of 72 volatile components were isolated and identified in 19 ancient Platycladus orientalis leaves with different tree ages, and 14 common volatile components were screened. Among them, the contents of α-pinene (6.40-16.76%), sabinene (1.11-7.29%), 3-carene (1.14-15.12%), terpinolene (2.17-4.95%), caryophyllene (8.04-13.53%), α-caryophyllene (7.34-14.41%), germacrene D (5.27-12.13%), (+)-Cedrol (2.34-11.30%) and α-terpinyl acetate (1.29-25.68%) were relatively higher (>1%), accounting for 83.40-87.61% of the total volatile components. Nineteen ancient Platycladus orientalis trees were clustered into three groups through the HCA method based on the 14 common volatile components content. Combined with the results of OPLS-DA analysis, (+)-cedrol, germacrene D, α-caryophyllene, α-terpinyl acetate, caryophyllene, β-myrcene, β-elemene and epiglobulol were the differential volatile components to distinguish ancient Platycladus orientalis with different tree ages. The results revealed that the composition of the volatile components in ancient Platycladus orientalis leaves with different tree ages was different, showing different aroma characteristics, which provided a theoretical reference for the differential development and application of volatile components in ancient Platycladus orientalis leaves.

Analysis of volatile components in different broken rice by HS‐SPME/GC‐TOFMS

AbstractIn this study, headspace solid‐phase microextraction (HS‐SPME) combined with gas chromatography‐time‐of‐flight mass spectrometry (GC‐TOFMS) was used to detect and analyse the volatile components of five samples with different degrees of fragmentation, combined with cluster analysis, orthogonal partial least squares discrimination analysis (OPLS‐DA) and relative odour activity value (ROAV) analysis. The results showed that 70 volatile components were detected and identified in samples with different degrees of fragmentation. 40 were co‐containing components. Cluster analysis revealed a high degree of similarity between samples B (20 mesh sieve top) and C (40 mesh sieve top), which were grouped into one category. The order of variation in the relative content of volatile components was A (unbroken) > E (120 mesh sieve top) > D (80 mesh sieve top) > B. C; the OPLS‐DA analysis revealed significant differences in the volatile composition of rice samples with different degrees of fragmentation, This variation between samples is mainly due to the relative content of volatile components of 36 projections of variable importance (VIP > 1), such as ethyl butyrate, ethyl phenylacetate, and dimethyl trisulfide. A total of 12 volatile components with ROAV > 1, including ethyl hexanoate, 2‐acetyl‐1‐pyrroline, and E‐2‐nonenal, were found to be the key volatile components in five samples based on their ROAV, the different degrees of crushing had a greater impact on the overall aroma of the rice, and the results can be used as a reference for further rice processors.