Highest Odor Activity Values Research Articles

Characterization of volatile thiols in Chinese liquor (Baijiu) by ultraperformance liquid chromatography-mass spectrometry and ultraperformance liquid chromatography-quadrupole-time-of-flight mass spectrometry.

Volatile thiols give a unique flavor to foods and they have been extensively studied due to their effects on sensory properties. The analytical assay of volatile thiols in food is hindered by the complexity of the matrix, and by both their high reactivity and their typically low concentrations. A new ultraperformance liquid chromatography (UPLC) strategy has been developed for the identification and quantification of volatile thiols in Chinese liquor (Baijiu). 4,4’-Dithiodipyridine reacted rapidly with eight known thiols to form derivatives, which provided a diagnostic fragment ion (m/z 143.5) for tandem mass spectrometry (MS/MS). To screen for new thiols, Baijiu samples were analyzed by means of UPLC–MS/MS screening for compounds exhibiting the diagnostic fragment ion (m/z X→143.5). New peaks with precursor ions of m/z 244, 200 and 214 were detected. Using UPLC with quadrupole-time-of-flight mass spectrometry (UPLC–Q-TOF–MS) and authentic standards, ethyl 2-mercaptoacetate, 1-butanethiol, and 1-pentanethiol were identified in Baijiu for the first time. Commercial Baijiu samples were analyzed with the new method and the distribution of 11 thiols was revealed in different Baijiu aroma-types. The aroma contribution of these thiols was evaluated by their odoractivity values (OAVs), with the result that 7 of 11 volatile thiols had OAVs > 1. In particular, methanethiol, 2-furfurylthiol, and 2-methyl-3-furanthiol had relatively high OAVs, indicating that they contribute significantly to the aroma profile of Baijiu.

Enhanced aroma and flavour profile of fermented Tetragonula pagdeni Schwarz honey by a novel yeast T. delbrueckii GT-ROSE1 with superior fermentability

Beside a source of bioactive compounds, honey represents untapped-reservoir of beneficial microbes. Next generation sequencing technology was applied to aid the discovery of newly-isolated flavour yeast Torulaspora delbrueckii strain GT-ROSE1 from honey samples. Owing to the presence of natural duplicate regulatory sites in aromatic genes, it was used to create value-added fermented honey with unique aroma-flavour profile. This osmophilic strain could assimilate different carbons and tolerated to low pHs, high ethanol and sugars, exhibiting useful traits for food and alcoholic fermentation of sugar-based industries. Global analysis of aroma-flavour profile revealed higher total concentrations of key compounds after fermentation by GT-ROSE1, compared to commercial wine yeasts. Twenty-four volatile compounds were identified using a nontargeted HS-SPME-GC-MS method. High odour activity values and quantitative sensory analysis indicated fruity and rose flowery aroma of key compounds nonanol and 2-phenylethanol, respectively. Importantly, fermented Tetragonula pagdeni Schwarz honey with observed excellent antioxidant property displayed appealing characteristic of enhanced 2-phenylethanol of rose-like flavour with odour threshold of 16.08. Thus, flavour yeast could be used to improve chemical content and enhance sensory value of local food products.

Effect of thermal treatment on the flavor quality of Chinese spicy cabbage

The sensory properties and quality of Chinese spicy cabbage (CSC) are constantly changing, because of the ongoing fermentation in the process of packaging, storage, and marketing. Thermal treatment of CSC could inhibit microbial activities and prolong the shelf life. However, the research concerning the influence of different temperature treatments on CSC flavor quality is limited. In this study, the lactic acid bacteria (LAB) counts, physicochemical characteristics, odor profiles and sensory evaluations of CSCs treated with 80 °C (80P), 100 °C (100P) and 200 °C (200P) were determined. It was shown that thermal treatment could effectively reduce the LAB counts, and also showed significant influence on physicochemical properties and sensory of CSC. Principal component analysis, heatmap analysis, and calculation of odor activity values (OAVs) were used to distinguish CSC with different thermal treatments. A total of 54 volatile compounds (VCs) were detected in all samples, and 23 VCs were considered as key aroma compounds. Sulfides possessed high OAVs and were recognized as the most important key aroma compounds to CSC imparted cabbage, garlic, and onion odors. After thermal treatment, the sulfides content in 80P, 100P, and 200P groups decreased by 9.52%, 25.07%, and 81.10%, respectively. Thermal treatment at 80 °C does not increase or generate new key aroma compounds. When the temperature reached 100 °C, the contents of most aldehydes, ketones, acids, esters, terpenes, nitriles, and furans increased significantly, so increased the complexity of the overall aroma. The reduction of most VCs after thermal treatment at 200 °C resulted in the faint flavor of 200P. In addition, new compounds linalool and decanal were detected in the 100P and 200P groups, contributing to sweet, fruity, floral, fat and waxy odors. (E)-2-Decenal, (E)-2-octen-1-ol and 1-octen-3-ol were also identified as the potential aroma markers responsible for the aroma differences in CSCs thermally treated at different temperatures.

Decoding the Specific Roasty Aroma Wuyi Rock Tea (Camellia sinensis: Dahongpao) by the Sensomics Approach.

Aroma extract dilution analysis was performed on volatile fractions extracted from a freshly prepared Dahongpao (DHP) tea infusion using solvent-assisted flavor evaporation, yielding 65 odor-active domains with flavor dilution factors ranging between 32 and 32,768. In addition, six aromatic substances were captured by headspace analysis. Quantitation of 54 compounds by an internal standard method and stable isotope dilution assays revealed that the concentrations of 32 odorants exceeded their respective orthonasal odor threshold values in tea infusion. The results of odor activity values (OAVs) suggested that 2-metylbutanal (malty) and γ-hexalactone (coconut-like) had the highest OAVs (248 and 154). Eight odorants including γ-hexalactone (OAV 154), methyl 2-methylbutanoate (59), phenylacetic acid (7.2), acetylpyrazine (5.7), 2-methoxyphenol (3.4), p-cresol (2.7), 2,6-diethylpyrazine (2.7), and vanillin (1.8) were newly identified as key odorants in DHP tea infusion. An aroma recombination model in a non-volatile matrix extracted from tea infusion satisfactorily mimicked the overall aroma of DHP tea infusion, thereby confirming the identification and quantitative experiments. Omission experiments verified the obvious significance of 6-methyl-5-hepten-2-one (OAV 91), 2-ethyl-3,5-dimethylpyrazine (19), 4-hydroxy-2,5-dimethylfuran-3(2H)-one (13), and acetylpyrazine (5.7) as key odorants for the special roasty and caramel-like aroma of DHP tea.

Characterization of the key aroma compounds in four varieties of pomegranate juice by gas chromatography-mass spectrometry, gas chromatography-olfactometry, odor activity value, aroma recombination, and omission tests

Pomegranate (Punica granatum L.) has attracted considerable attention in world markets due to its valuable nutrients and highly appreciated sensory properties. The aroma profiles of 4 varieties of pomegranate juice, including Dahongtian (DP), Jingpitian (JP), Luyudan (LP), and Tianhonngdan (TP), were investigated via gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry (GC-O) analyses. A total of 43 volatile compounds were identified by using GC-MS. Among these compounds, 16 were considered as potential aroma-active compounds as detected by GC-O. These compounds belonged to the classes of terpinenes, alcohols, and aldehydes. Eleven volatile compounds were defined as the main contributors to the overall aroma of pomegranate juice due to their high odor activity values (OAVs ≥ 1). Aroma recombination and omission tests confirmed that β-myrcene, 1-hexanol, and (Z)-3-hexen-1-ol were the key aroma compounds, and limonene, 1-octen-3-ol, linalool, and hexanal were important aroma-active compounds in DP samples.

Investigation on key odorants in braised chicken thigh meat and their changes during storage

To identify the key odorants in braised chicken thigh meat (BCTM) and to investigate their changes during BCTM storage from 1 month to 23 months at room temperature, volatiles were isolated by both solid-phase microextraction and solvent extraction combined with solvent-assisted flavor evaporation; a total of 27 odor-active regions were detected in the isolates by gas chromatography–mass spectrometry–olfactometry. Twenty-four odor-active compounds were identified positively by comparison of their odor characteristics, mass spectral data and retention indices with those of authentic compounds; their flavor dilution (FD) factors ranging from 1 to 512 were measured by aroma extract dilution assay. Eugenol had the highest FD factor of 512. The odorants with FD factors ≥ 4 were quantitated by internal standard curve method, and their odor activity values (OAVs) were calculated. 2-Methyl-3-furanthiol and (E,E)-2,4-decadienal had the highest OAVs. Fourteen compounds with OAVs ≥ 1 were determined to be the key odorants of BCTM; recombination experiments confirmed that these odorants could simulate the overall aroma profile of BCTM. To further investigate the changes in odorants during storage, their concentrations and OAVs were determined. The results showed that the number of key odorants did not change, and no off-odor compound was detected.

Odorous gas emissions from sewage sludge composting windrows affected by the turning operation and associated health risks

The treatment and disposal of sewage sludge (SL) has long been a challenging task in China. Open windrow composting, coupled with mechanical turning, is preferred in small cities and rural areas, due to low costs and ease of operation. However, the emission of odorous volatile organic compounds (VOCs) from open composting windrows, as well as related health risks, has aroused strong protests from surrounding populations. This study investigated VOC emissions (including hydrogen sulphide) from five open SL composting windrows at a single site, before, during and after turning operations, and across different seasons. As expected, the highest VOC concentration (6676 μg m−3) was measured while turning the windrows, whilst an additional emission peak was observed at all windrows at different times after turning, which was determined by the raw material mixing ratio (SL: woodchips), as well as ambient and windrow temperatures. In general, higher VOCs emissions and odour concentrations were measured in summer, and odour pollution was mainly caused by sulphur and oxygenated compounds, due to their high odour activity values (OAVs). Methyl mercaptan, dimethyl disulphide, dimethyl sulphide, diethyl sulphide, acetaldehyde and ethyl acetate were identified as the odour pollution indicators for the composting facility. The results from a health risk assessment showed that acetaldehyde was the most hazardous compound, with both non-carcinogenic and carcinogenic risks exceeding acceptable levels. The carcinogenic risks of benzene and naphthalene were also above acceptable levels; however, their risks were insignificant at the studied site due to the low concentrations.

Effects of different thermal processing methods on nutrients and flavor of Toona sinensis

The nutrients, bioactives, and flavor compounds of Toona sinensis (TS) processed by blanching, steaming, roasting, and frying were analyzed. It was found that the loss of nutrients, bioactives, and flavor compounds was highest for fried TS and lowest for steamed TS. The thermal processing method had a significant impact on the quality characteristics of processed TS. Eleven new compounds were identified in raw and processed TS, while 2-mercapto-3,4-dimethyl-2,3-dihydrothiophene had the highest odor activity value (OAV) among the volatiles in all the samples. The principal component analysis (PCA) results indicated that the volatile compounds profiles in different processed TS were completely different. Eight compounds identified by the partial least square discriminant analysis (PLS-DA) method were the markers to distinguish the different processed TS. Steaming was the most suitable thermal processing method for TS. This study provides the theoretical basis for the selection of optimized processing methods for TS. Novelty Impact Statement The nutrients, bioactives, and flavor compounds of Toona sinensis processed by steaming, boiling, frying, and roasting were analyzed, and the thermal processing method had a significant impact on the quality characteristics of processed Toona sinensis. Eleven new compounds were identified in Toona sinensis; GC-IMS analysis offered their distinct advantages to the aroma analysis of Toona sinensis. Eight compounds identified by the PLS-DA method were the markers to distinguish the Toona sinensis. Steaming was the most suitable thermal processing method for Toona sinensis.

Characterization of the key compounds responsible for the fermented soybean-like cup aroma of raw Pu-erh tea using instrumental and sensory methods

Cup aroma refers to the volatiles emitted from an empty cup after tea infusion. In this study, gas chromatography–olfactometry (GC–O) and the odor activity value (OAV) approach were employed to investigate the composition of fermented soybean-like cup aroma from raw Pu-erh tea. Further, the aroma recombination and omission tests were performed, and the results demonstrated that 2-methylbutyric acid, acetic acid, 4-methyl-3-penten-2-one, ethyl isobutyrate, nonanoic acid, and phenylacetic acid exhibited relatively high aroma intensities (AI) and OAVs among the 12 odor-active compounds that were detected in the fermented soybean-like cup aroma. The aroma recombination, which was performed employing the 12 odorants with AI ≥1 successfully mimicked the overall aroma profile of the fermented soybean-like cup aroma. The omission test revealed that 2-methylbutyric acid contributed significantly to the fermented soybean-like cup aroma. And the enantiomeric ratio (ER) of the (S)- to (R)-forms of 2-methylbutyric acid was 67:33.

Effect of Salt (Sodium Chloride) Replacement With Potassium Chloride, High Pressure Processing, and Cold Storage at 4°C on Beef Sausage Volatile Compounds.

This study aimed to investigate the partial substitution of 0, 25 and 50% sodium chloride (NaCl) by potassium chloride (KCl) coupled with high-pressure processing (HPP) effects on volatile compounds and lipid oxidation of beef sausage at five (0, 3, 7, 14, and 21) different cold storage days (4°C). The odor activity values (OAV) of the various compounds were visualized by heat map analysis. Thiobarbituric acid reactive substances (TBARS) of the samples treated with 100% NaCl and HPP increased by an average of 0.52 ± 0.01 mg MDA/kg compared with the control (100% NaCl-no HPP) across the 21 storage days. In addition, 50% NaCl substitution with KCl in combinations with HPP treatments increased TBARS across the 21 storage days by an average of 0.40 ± 0.02 mg MDA/kg compared with no HPP treatment. However, on day 3, there was a sharp decrease in TBARS by an average of 0.10 ± 0.01 mg MDA/kg compared with days 0, 7, 14, and 21 in all treatments. At the end of 21 days of storage, a total of 227 volatile compounds were identified and quantified in the beef sausage, including 43 aldehydes, 46 phenols, 8 ketones, 30 alcohols, 14 acids, 12 esters, 27 terpenes, and 47 alkanes. However, no ketone compounds were detected on days 7, 14 and 21; esters on day 14 and acids on days 14 and 21 in the samples treated with or without HPP across the salts levels. However, high OAVs (OAV > 1) were obtained after partial substitution of NaCl with KCl at 25 and 50% with HPP treatment compared to the samples not treated with HPP. The aroma perceived in the beef sausage was due to compounds with the highest OAVs such as; pentadecanal, benzyl carbazate, anethole, myristicin, o-cresol, phenylacetaldehyde and (E)-methyl isoeugenol, pentadecanal, hexanoic acid, octanoic acid, eugenol, trans-2-nonenal, trans-2-octenal, trans-2-decenal, 2-butyl-1-octanol, 2,3-butanedione, ethyl hexanoate, ethyl octanoate, (-)-4-terpineol which had an OAV > 1 as compared to the other compounds with an OAV < 1. In conclusion, 25 and 50% NaCl partial replacement with KCl coupled with HPP technique can be considered in producing low-NaCl beef sausage in order to improve the flavor and decrease lipid oxidation during cold storage.

Characterization and Quantitative Comparison of Key Aroma Volatiles in Fresh and 1-Year-Stored Keemun Black Tea Infusions: Insights to Aroma Transformation during Storage.

The aroma of Keemun black tea (KBT) changes during storage. We investigated key aroma volatiles of fresh KBT (FKBT) and KBT stored for 1 year. Through gas chromatography–olfactometry–mass spectrometry/aroma extract dilution analysis (GC-O-MS/AEDA), 27 aroma volatiles with a flavor dilution (FD) value ≥16 were quantitated. In odor activity value (OAV) analysis, the two samples had nearly the same key aroma volatiles; (Z)-methyl epijasmonate was the exception. Dimethyl sulfide, 3-methylbutanal, 2-methylpropanal, and linalool had especially high OAVs. Except for β-damascenone, volatiles with OAVs > 1 had higher concentrations in FKBT, which revealed that most key aroma compounds were lost during storage. Sweet, malty, floral, and green/grassy aromas corresponded directly to certain compounds. Lastly, the addition test indicated that the addition of several key aroma volatiles decreasing during storage could enhance the freshness of KBT aroma, which may be a potential to control the aroma style of KBT or other teas in industry.

Effect of Partial Substitution of Sodium Chloride (NaCl) with Potassium Chloride (KCl) Coupled with High-Pressure Processing (HPP) on Physicochemical Properties and Volatile Compounds of Beef Sausage under Cold Storage at 4 °C

This study aimed to evaluate the effects of partial substitution of sodium chloride (NaCl) with potassium chloride (KCl) in combination with high-pressure processing (HPP) on the physicochemical properties and volatile compounds of beef sausage during cold storage at 4 °C. Significant differences were found in the volatile compounds of beef sausages with 0%, 25%, and 50% NaCl contents partially substituted with KCl subjected to 28 days of storage and were well-visualized by heat map analysis. A total of 75 volatile compounds were identified and quantified in the beef sausages at the end of 28 days of storage, including 12 aldehydes, 4 phenols, 2 ketones, 18 alcohols, 8 acids, 3 esters, 14 terpenes, and 14 alkanes. Thirteen compounds had low odor activity values (OAV) (OAV &lt; 1); however, high OAV (OAV &gt; 1) were obtained after partial substitution of NaCl by KCl at 25% and 50% with HPP treatment compared to the non-HPP treated samples. In addition, 50% NaCl substitution with KCl in conjunction with HPP treatments increased thiobarbituric acid reactive substances (TBARS) by (0.46 ± 0.03 mg/MDA) compared with no HPP treatments. Replacement of 25% and 50% NaCl with KCl decreased TBARS by an average of 10.8% and 11.10%, respectively, compared to 100% NaCl coupled with HPP beef sausages. In summary, HPP and partial substitution of NaCl with KCl at 25% and 50% can be used to compensate for the reduction of NaCl in beef sausage by keeping the physical and flavor fraction at required levels.

Flavor compounds with high odor activity values (OAV > 1) dominate the aroma of aged Chinese rice wine (Huangjiu) by molecular association

Aging is an essential operation to perfect the flavor quality of Hungjiu. In this study, formation mechanism of flavor compounds responsible for the characteristic flavor of aged Huangjiu was investigated. The contents of umami and bitter free amino acids (FAA) increased with the storage period prolonged, while that of sweet FAA showed downward trend. Gas chromatograph-mass spectrometry and principal component analysis indicated that the volatile flavor compounds with OAV exceed 1, especially middle-chain fatty-acid-ethyl-esters and aromatic compounds, dominated the characteristic flavor of aged Huangjiu. Low field-NMR was firstly applied to characterize the molecular association between water and dissolved flavor compounds in aged Huangjiu. The results showed that basic amino acids contributed greatly to the flavor formation of aged Huangjiu via molecular association. In addition, the molecular association significantly promoted the accumulation of flavor compounds with OAV > 1, especially ethyl esters.

Dynamic changes in the aroma profile of Qingzhuan tea during its manufacture

Changes in key odorants and aroma profiles of Qingzhuan tea (QZT) during its manufacture were determined using headspace solid-phase microextraction gas chromatography-mass spectrometry/olfactometry. An aroma profile was constructed to illustrate sensory changes during manufacture. The characteristic aroma of QZT was aged fragrance, which was mostly developed during pile fermentation and was enhanced during the aging and drying stages. Using volatile compounds found in the raw materials, sun-dried green tea and QZT finished product were compared by orthogonal partial least square-discriminant analysis. Among 108 detected volatiles, 19 were significantly upregulated and 15 were downregulated. (E)-β-Ionone, (E,Z)-2,6-nonadienal, 1-octen-3-one, (E,E)-2,4-heptadienal, (E,E)-2,4-nonadienal, safranal, (E)-2-nonenal, α-ionone, and 1,2,3-trimethoxybenzene were found to be significant contributors to the aged QZT fragrance, reflecting their high odor-activity values and aroma intensities. Finally, the metabolic transformation of key aroma-active compounds was systematically analyzed. This study provided a theoretical basis for improving the processing and quality of QZT.

Tracking volatile flavor changes during two years of aging of Chinese vinegar by HS-SPME-GC-MS and GC-O

Aging is an essential step for enriching the aroma profiles of Chinese vinegar. This study aimed to track the volatile flavor changes in the same batch of Chinese vinegar for the first time during two years of aging with the aid of HS-SPME-GC–MS. The aroma-active compounds were characterized at 0, 6, and 12 months of aging using GC-O coupled with a modified frequency method. A total of 67 volatile compounds and 30 aroma-active compounds were identified during the different stages of aging. Most alcohols, esters, ketones, acids, and phenols decreased during the aging from 628.4, 105.4, 132.1, 22.1, and 21.4 μg/L at 0 month to 228.7, 7.2, 9.69, 17.24, and 11.6 μg/L at 24 months separately, except aldehydes and pyrazines, which showed slight increases. Many aroma-active compounds were generated during the aging, such as methional, trimethylpyrazine, acetophenone, and 2-acetyl-3-ethylpyrazine, while pyrazines were formed during 24 months of aging. Three aroma-active compounds with high odor activity values (OAVs) showed significant contributions to the aroma profile of vinegar, which included isovaleric acid (2743, 340, and 3139), 4-ethylguaiacol (580, 429, and 516), and γ-nonalactone (324, 640, and 442) at 0, 6, and 12 months of aging, respectively.

Analysis of the Ability to Produce Pleasant Aromas on Sour Whey and Buttermilk By-Products by Mold Galactomyces geotrichum: Identification of Key Odorants.

Currently, there is a growing demand for flavorings, especially of natural origin. It is worth paying attention to the biotechnological processes of flavor production, characterized by simplicity, high efficiency and relatively low cost. In this study, we analyzed the ability of the Galac tomyces geotrichum mold to transform by-products of the dairy industry: sour whey and buttermilk to complex flavour mixtures with pleasant, honey-rose aroma. Furthermore, the aroma complexity of the fermentation product has been carefully identified applying a sensomic approach involving the use of gas chromatography-olfactometry (GC-O), gas chromatography-mass spectrometry (GC-MS) and stable isotope dilution assay (SIDA) to identify and quantify aroma compounds. Based on the calculation of odor activity value (OAV), 13 key aroma compounds were present in both tested variants. The highest OAVs were found for phenylacetaldehyde (honey-like) in the buttermilk variant (912) and 2-phenylethanol (rose-like) in the sour whey variant (524). High values of this indicator were also recorded for phenylacetaldehyde (319) and 3-methyl-1-butanol with a fruity aroma (149) in the sour whey culture. The other compounds identified are 3-methylbutanal (malty), 2,3-butanedione (cheesy), isovaleric acid (cheesy), 3-(methylthio)-propanal (boiled potato), butanoic acid (vinegar), (E)-2-nonenal (fatty), ethyl furaneol (burnt sugar), dimethyl trisulfide (cabbage), and acetic acid (vinegar).

Characterization of Volatile Compounds of Rosa roxburghii Tratt by Gas Chromatography-Olfactometry, Quantitative Measurements, Odor Activity Value, and Aroma Intensity.

Rosa roxburghii tratt (RRT), widely distributed in the southwest of China, is favored by consumers for its good taste and healthy functions. In this study, thirty-seven compounds of Rosa roxburghii Tratt (RRT) were identified and quantified by gas chromatography–olfactometry (G–O) and gas chromatography–mass spectrometry (GC–MS) analysis. Furthermore, ethyl 2-methylpropanoate, ethyl butanoate, ethyl 2-methylbutyrate, and ethyl hexanoate were present with much higher odor activity values (OAVs) than other compounds. The key notes were confirmed by omission tests. Possible interaction among key notes was investigated through odor intensity determination and sensory analysis. It showed fruity and woody notes had synergistic effects. Full factorial design was used to evaluate the notes contribution to the whole odor. One important finding is the major effect of order interactions, fruity note (X1) and woody note (X4) especially, emphasizing the existence of complex interactions occurring between odor notes. The interaction X1X4 was further investigated. The woody note has a positive effect when the fruity note is also in the mixture but tends to show a negative effect otherwise.

Evaluation of the effect of marination in different seasoning recipes on the flavor profile of roasted beef meat via chemical and sensory analysis.

Marinating is a Chinese meat-processing technique that involves treating meat products in an aged brine containing traditional Chinese spices and other condiments. In this study, beef meats were marinated in different seasoning recipes, including marinade solution of water as control (BS1), marinade solution consisting of water and 2% salt (BS2), marinade solution consisting of water, 2% salt, and 0.5% sugar (BS3), and marinade solution consisting of water, 2% salt, 0.5% sugar, 0.5% soy sauce, and spices (BS4). The effects of different marinade solutions through the tumbling on the flavor profile of roasted beef meat were comprehensively analyzed via chemical and sensory analysis. A total of 82 volatile flavor compounds were identified. Among them, 36 compounds were identified in BS1, 40 compounds in BS2, 46 compounds in BS3, and 64 compounds in BS4. Besides, 4 compounds showed high odor activity values (OAVs) in marinated samples, including decanal, trans-2-decenal, linalool, and nonanal. The metal oxide sensors of E-nose distinguished the differences among the different marinated samples. Marinated beef samples BS2 and BS3 showed a significant increase in the values of thiobarbituric acid reactive substances (TBARS). In contrast, marinated beef sample BS4 significantly reduced TBARS value to 4.11µg MDA/kg beef. It can be concluded that using this different seasoning processing enhances the aroma profile and provides a reference for the production of marinated meat products. PRACTICAL APPLICATIONS: Marinating is a Chinese meat-processing technique that involves treating meat products in an aged brine containing traditional Chinese spices and other condiments. Processing beef meat with different marinade solutions could enhance its aroma profile. Therefore, this study aimed to evaluate the effect of marination in different marinade solutions through the tumbling on the volatile flavor compounds of roasted beef meat using HS-SPME-GC-MS and E-nose. The obtained results from this study could enrich the theoretical knowledge of the flavor chemistry of marinated beef meat and provide a reference for the production of marinated meat products.

Key Odorants of Raw and Cooked Green Kohlrabi (Brassica oleracea var. gongylodes L.).

Volatile compounds of raw and cooked green kohlrabi were investigated using a sensomics approach. A total of 55 odor-active compounds were detected and identified in raw and cooked green kohlrabi using GC-O. Twenty-eight odor-active compounds with high flavor dilution (FD) factors ranging from 64 to 1024 were quantitated, and odor activity values (OAVs) were determined. Eight compounds showed high OAVs in raw and cooked kohlrabi: five sulfur compounds (dimethyl trisulfide, methyl 2-methyl-3-furyl disulfide, and three isothiocyanates (1-isothiocyanato-3-(methylsulfanyl)propane, benzyl isothiocyanate, and 1-isothiocyanato-4-(methylsulfanyl)butane)), two lipid oxidation products (1-octen-3-one and trans-4,5-epoxy-(2E)-dec-2-enal), and 2-isopropyl-3-methoxypyrazine. Among these, the sulfur compounds contributed most to the overall smell of the raw and cooked vegetables. The quantitation analysis indicates that the eight odorants are the backbone compounds for raw and cooked kohlrabi. The OAVs for the backbone compounds and also for minor odorants are clearly higher in raw kohlrabi than in the cooked one. Differences can be explained by the influence of the cooking process.

Characterization of Odorants in a 10-Year-Old Riesling Wine.

Riesling wines are mostly enjoyed as young wines, usually consumed within the first few years after bottling. Throughout several years of aging, Riesling wines begin to develop more robust flavor profiles, often displaying less fruity and floral notes and more pronounced maple, honey, and caramel notes. A body of scientific literature has been conducted on the aroma chemistry of young Riesling wines; however, comparatively less scientific reports have been published on the aroma chemistry of aged Riesling wines, and a comprehensive aroma analysis of a 10-year-old Riesling wine has not been previously completed. In this study, a total of 36 odorants were identified in a 10-year-old aged Riesling wine using solvent-assisted flavor evaporation and aroma extract dilution analysis. A total of 26 odorants were quantitated by employing stable isotope dilution assays. Odorants with high odor activity values (OAV) included wine lactone (coconut, OAV 460), ethyl octanoate (fruity, OAV 240), ethyl hexanoate (fruity, OAV 97), β-damascenone (cooked apple, OAV 60), 5-ethyl-3-hydroxy-4-methyl-(5H)-furan-2-one (maple, OAV 33), (S)-ethyl 2-methylbutanoate (fruity, OAV 22), 3-(methylsulfanyl) propanal (cooked potato, OAV 20), ethyl 2-methylpropanoate (fruity, OAV 9.5), ethyl butanoate (fruity, 7.1 OAV), and 1,1,6-trimethyl-1,2-dihydronapthalene (petrol, OAV 6.4). An odor simulation model prepared from all the odorants with an OAV greater than 1 closely matched the sensory profile of the authentic wine. The results of this study provide insight about odorants present in a 10-year-old bottle aged Riesling wine, and this knowledge may be useful for future studies aimed at probing the influence of aging on the aroma chemistry of Riesling wines and other white wines.