Flavor characteristics of Shanlan rice wines fermented for different time based on HS-SPME-GC-MS-O, HS-GC-IMS, and electronic sensory analyses

Flavor characteristics of Shanlan rice wines with different fermentation time were analyzed. Results suggested that 3-methyl-1-butanol, phenylethyl alcohol, ethyl acetate, and diethyl succinate were the characteristic volatiles of Shanlan rice wine by using headspace solid-phase microextraction-gas chromatography-mass spectrometry-olfactometry. The most varieties (38) of volatiles appeared at a 3-year-fermentation time, contributing a unique and harmonious aroma to the Shanlan rice wine fermented for 3 years, but only 19 types were observed at 45-days and 1-year fermentation times. A similar trend was intuitively visible in the headspace-gas chromatography-ion mobility spectrometry analysis. The Shanlan rice wine fermented for 3 years had a similar taste profile to that fermented for 45 days, but with distinguishing contents of free amino acids (1352.80 mg/L and 2261.50 mg/L, respectively) and organic acids (9.58 g/L and 49.88 g/L, respectively). The Shanlan rice wine fermented for 1 year had a strong taste with more intensity of most taste attributes.

The Effects of Ultrasonic and Gamma Irradiation on the Flavor of Potato Wines Investigated by Sensory Omics

Aroma is one of the most fascinating and least-known mysteries of Baijiu research. The volatile compounds (VOCs) of potato wine were evaluated by sensory omics techniques in order to comprehend their overall flavor characteristics and investigate the effects of ultrasonic treatment and gamma irradiation therapy on the aroma of the wine. The findings revealed that a total of 14 flavor compounds were identified by GC-MS. Isoamyl alcohol, ethyl octanoate, and 1,1-diethoxyethane were the key aroma components, according to GC-O analysis. A total of 50 volatile substances were identified by GC-IMS. After being subjected to irradiation and ultrasonic treatment, the alcohol level of the potato wine reduced while the esters content increased. By calculating the relative odor activity value, a total of 29 aroma components were classified as key aroma compounds (ROAV > 1). According to the results of the sensory evaluation-fruity, Fen-flavor, and sweet-and the acceptability of the irradiated and ultrasonicated potato wine were improved. Therefore, the use of ultrasonic and irradiation therapy in potato wine, as well as the overall aroma building of potato wine, can be supported theoretically by this study.

Identification and confirmation of key compounds causing cooked off-flavor in heat-treated tomato juice

Cooked off-flavor produced by heat treatment greatly limited the acceptability of commercial tomato juice. To screen and identify the cooked off-flavor compounds, gas chromatography-mass spectrometry-olfactometry (GC-MS-O), aroma extract dilution analysis (AEDA), gas chromatography-mass spectrometry (GC-MS), and odor activity value (OAV) calculation were applied simultaneously. The results showed that there were 17 aroma-active compounds in tomato juice samples. Among them, three newly formed sulfur-containing compounds (dimethyl sulfide, dimethyl trisulfide, and methional) and 1-octen-3-one, which exhibited cooked corn/potato, onion, and mushroom odor, were proved to be responsible for the cooked off-flavor in heat-treated tomato juice (HTJ) by omission experiments and electronic nose analysis. The three newly formed sulfur-containing compounds were further confirmed to be the key compounds responsible for the cooked off-flavor in four different tomato cultivars that were commonly consumed in the market. PRACTICAL APPLICATION: Tomato is one of the most popular vegetables in the world and tomato juice is an important part of the tomato industry. However, the cooked off-flavor of tomato juice after sterilization severely restricts its industrial development. This study analyzed and compared the changes of aroma compounds before and after sterilization, and identified and confirmed the major off-flavor components. This work could provide fundamental information for the prevention of cooked off-flavor.

Identifying aroma-active compounds in coffee-flavored dairy beverages

Coffee aroma is a complex mixture of volatile compounds. This study characterized the important aroma-active compounds associated with consumer liking in formulated coffee-flavored dairy beverages. Nine coffee-flavored dairy beverages were formulated: low fat-low coffee; medium fat-low coffee; high fat-low coffee; low fat-medium coffee; medium fat-medium coffee; high fat-medium coffee; low fat-high coffee; medium fat-high coffee; and high fat-high coffee. Regular coffee consumers, (n = 231) used a nine-point hedonic scale to rate acceptance of aroma. Volatile compounds were extracted by head space-solid phase micro-extraction (HS-SPME) and analyzed by gas chromatography-mass spectrometry-olfactometry (GC-MS-O) using a modified frequency (MF) approach. Fifty-two aroma-active compounds were detected. Thirty-one aroma-active compounds were considered important compounds with MF-value ≥ 50%. The total number of aroma-active compounds and their intensity were affected because of fat and coffee concentration. Partial least squares regression (PLSR) was performed to determine the relationship between aroma-active compounds and liking. PLSR analysis identified three groups of compounds regarding liking. Twenty-five compounds were associated with positive liking, for example, 2-(methylsulfanylmethyl) furan (coffee like). Sixteen compounds were negatively associated with liking, for example, 2-methoxyphenol (bacon, medicine like). Eleven detected compounds had no association with liking, for example, butane-2,3-dione (butter, fruit like). Practical Application: The result of this study may be applied to formulate coffee-flavored dairy beverages to maximize consumer acceptance and aroma-liking. This study suggested too low coffee concentration is not desirable. Too much fat affects aroma release and/or alters the characteristic coffee flavor which negatively affects consumer acceptance.

Flavour stability of sterilised chickpeas stored in pouches

The increasing need for sustainable food choices places a demand on developing palatable foods from lower impact production and with a suitable shelf-life. In this context, knowledge of the sensory properties of whole sterilised chickpeas is required to be able to make them more attractive to the consumers. The sensory quality of chickpeas is largely dependent on the aroma and flavour, which can be influenced by storage conditions. In this study, sterilised chickpeas in two different packaging materials with different oxygen permeabilities, stored up to 52 weeks at ambient temperature (20 °C) were investigated using both descriptive sensory profiling and gas chromatography – mass spectrometry – olfactometry analysis (GC-MS-O). During storage, intense, sulphury and meat-like aromas decreased in intensity, while with longer storage time hay-like, green-like and potato-like flavours and aromas became more apparent. A total of 40 odour-active volatiles were detected, of which some had properties reminiscent of the chickpea flavour profiles. However, no clear relationships could be established between these odorants and the sensory changes observed during storage by descriptive sensory analysis. It was concluded that, significant changes in the sensory attributes of sterilised chickpeas occurred during 52 weeks of storage, but that packaging material does not seem to largely influence the sensory attributes during storage.

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Significant sensory changes occur in sterilised chickpeas during 52 weeks storage.

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40 odour-active volatiles are detected in the sterilised chickpeas.

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Sulphur compounds formed during sterilisation change during storage.

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Hay and green attributes are perceived more intense with increased storage time.

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Oxygen permeability of packaging does not impact the sensory quality during storage.

Characterization of key aroma compounds in flat peach juice based on gas chromatography-mass spectrometry-olfactometry (GC-MS-O), odor activity value (OAV), aroma recombination, and omission experiments

The aroma profiles of fresh flat peach juice (FPJ) samples obtained from four different cultivars (RP1), (ZLP), (RP18), and (ZP) were characterized by gas chromatography-Mass spectrometry-olfactometry (GC-MS-O). Totally, 32 aroma-active compounds in FPJs were identified by GC-MS-O and further quantified. Of these, 14 aroma-active compounds presented odor activity values (OAVs) greater than 1, with several lactones and aldehydes contributing as key aroma-active components of FPJs. Partial least-squares regression (PLSR) revealed that RP18 was greatly related to "fruity", "sweet" and "peach-like" attributes, while ZLP was highly correlated with "floral" and "green and grassy" attributes, confirming the quantitative describe analysis (QDA) results. In addition, an aroma recombination experiment was conducted to mimic the aroma profile of flat peach juice based on the actual concentrations of RP18. Omission experiments indicated that lactones were very highly significant for the characteristic aroma of FPJ.

Characterization of the Aroma of an Instant White Tea Dried by Freeze Drying

The aroma of an instant white tea (IWT) was extracted through simultaneous distillation–extraction (SDE) and analyzed by sensory evaluation, gas chromatography-mass spectrometry-olfactometry (GC-MS-O), aroma reconstruction, omission test and synergistic interaction analysis. Sensory evaluation showed the IWT was dominated with floral and sweet notes. The SDE extract had the aroma similar to the IWT. The main volatile components in the SDE extract were benzyl alcohol, linalool, hotrienol, geraniol, α-terpineol, coumarin, camphene, benzeneacetaldehyde, 2-hexanone, cis-jasmin lactone and phenylethyl alcohol. GC-MS-O and aroma reconstruction experiments showed 16 aroma-active compounds. Linalool, trans-β-damascenone and camphene were the major contributors to floral, sweet and green notes based on flavor dilution analysis and omission test. Linalool and trans-β-damascenone had synergistic effect to promote floral and sweet notes. Camphene and trans-β-damascenone had synergistic effect to reduce green and sweet notes. The study helps to understand the aroma of IWT and antagonism interactions among aroma-active volatiles.

Reduction of green off-flavor compounds: Comparison of key odorants during fermentation of soy drink with Lycoperdon pyriforme

The consumption of soy drink in Western countries is limited due to its green off-flavor. Hence, fermentation of soy drink with Lycoperdon pyriforme to tailor the aroma has been investigated. After 28 h the green off-flavor was not perceived by 60% of the sensory panel (n = 23). Molecular sensory changes of soy drink during fermentation were decoded by means of direct immersion-stir bar sorptive extraction coupled with gas chromatography-mass spectrometry-olfactometry and aroma dilution analysis. The semi-quantification of key odorants revealed a significant decrease of the representative green odorants (i.e., hexanal, (E)-2-nonenal, (E,E)-2,4-decadienal) of soy drink, among of which hexanal even turned below its odor threshold. The quantitative reduction of these odorants correlated with the organoleptic difference. Besides that, nutritionally relevant parameters of soy drink including protein, fat, and polyphenol content kept consistent during the short fermentation process.

Characterization of Aroma-Active Compounds, Phenolics, and Antioxidant Properties in Fresh and Fermented Capers (Capparis spinosa) by GC-MS-Olfactometry and LC-DAD-ESI-MS/MS

Caper (Capparis spinosa) is an important food ingredient whose fresh parts, particularly the flower buds, are consumed as a starter with olives, cheese, and nuts, or are used as a component in other foods. It is one of the most popular species of aromatic plants grown in the Mediterranean zone. Fermentation makes the caper edible and affects the overall aroma as well as sensory and nutritional characteristics. This study aimed to evaluate the changes in aroma, aroma-active, and phenolic compounds of caper as affected by fermentation. Purge and trap method was used for the extraction of the aroma compounds, while gas chromatography-mass spectrometry olfactometry and Liquid chromatography coupled to diode array detection and electrospray ionization tandem mass spectrometry (LC-DAD-ESI-MS/MS) were employed for the detection of aroma-active compounds and phenolics, respectively. The results showed that the total amount of aroma compounds decreased drastically (62,616 to 21,471 µg/kg) in fermented sample. Twelve and 10 aroma-active compounds were detected in fresh and fermented caper buds, respectively, for the first time by the application of aroma extract dilution analysis. Among these compounds, methyl isothiocyanate (flavor dilution [FD] factor = 512) in fresh caper and acetic acid (FD factor = 128) in the fermented caper had the highest FD factor. With regard to the phenolic compounds, a total of 16 components were identified in fresh and fermented capers. As observed in aroma compounds, the total phenolic concentration decreased as a result of fermentation. Two phenolic compounds being kaempferol-3-O-glucosyl-rhamnosyl-glucoside and isorhamnetin hexoside were newly identified in caper. PRACTICAL APPLICATIONS: Capparis spinosa is one of the most popular sources of different secondary metabolites of interest to consumers. The results of the present study showed that the fermentation process of the capers is highly influential on the neutral composition of the sample. The total concentrations of aroma and phenolic compounds were reduced by 66% and 78%, respectively, in response to fermentation process.

Comprehensive sensory and chemical data on the flavor of 16 red wines from two varieties: Sensory descriptive analysis, HS-SPME-GC-MS volatile compounds quantitative analysis, and odor-active compounds identification by HS-SPME-GC-MS-O

This paper describes data collected on 2 sets of 8 French red wines from two grape varieties: Pinot Noir (PN) and Cabernet Franc (CF). It provides, for the 16 wines, (i) sensory descriptive data obtained with a trained panel, (ii) volatile organic compounds (VOC) quantification data obtained by Headspace Solid Phase Micro-Extraction - Gas Chromatography - Mass Spectrometry (HS-SPME-GC-MS) and (iii) odor-active compounds identification by Headspace Solid Phase Micro-Extraction - Gas Chromatography - Mass Spectrometry - Olfactometry (HS-SPME-GC-MS-O). The raw data are hosted on an open-access research data repository [1].

Elucidation of Infusion-Induced Changes in the Key Odorants and Aroma Profile of Iranian Endemic Borage ( Echium amoenum) Herbal Tea

Infusion-induced changes in the aroma and key odorants and their odor activity values of Iranian endemic herbal (Gol-Gavzaban) tea obtained from shade-dried violet-blue petals of borage ( Echium amoenum) were studied for the first time. Two hot teas and one cold tea were investigated and coded as 4MN (4 min/98 °C), 16MN (16 min/98 °C), and 24HR (24 h/ambient temperature), respectively. Aromatic extracts of the tea samples were isolated by the liquid-liquid extraction method and analyzed by gas chromatography-mass spectrometry-olfactometry (GC-MS-O) for the first time. According to the results of the aroma profiling, a total of 35 common aroma compounds comprising alcohols, acids, volatile phenols, lactones, aldehydes, ketone, pyrroles, and furans were identified and quantified in the tea samples. Indeed, it is worth noting that the aroma profiles of the borage teas were similar. However, the effects of the infusion techniques were clearly different as observed on the content of each individual and total compounds in the samples. The highest mean total concentration was detected in 24HR (266.0 mg/kg), followed by 16MN (247.1 mg/kg) and 4MN (216.1 mg/kg). 1-Penten-3-ol was the principal volatile component in all borage teas. On the basis of the result of the flavor dilution (FD) factors, a combined total of 22 different key odorants was detected. The potential key odorants with regard to FD factors in all samples were prevailingly alcohols, acids, and terpenes. The highest FD factors were observed in 2-hexanol (2048 in 4MN and 24HR; 1024 in 16MN) and 1-penten-3-ol (2048 in 24HR; 1024 in 4MN and 16MN) in samples providing herbal and green notes. Principal component analysis (PCA) showed that the tea samples could clearly be discriminated in terms of their aroma profiles and key odorants. The findings of the current study demonstrate that the tea preparation conditions have a significant impact on the organoleptic quality of borage tea.

Characterization of Odor-Active Volatiles in Hawthorn Puree Using Thermal Desorption System Coupled to Gas Chromatography-Mass Spectrometry-Olfactometry and GC-Flame Photometric Detector

The volatile compounds in hawthorn puree obtained from three cultivars (Y1, Crataegus pinnatifida Bunge cv. "Waibahong", Y2, Crataegus pinnatifida Bunge cv. "Damianqiu", and Y3, Crataegus pinnatifida Bunge cv. "Dajinxing") were analyzed by the thermal desorption system coupled to gas chromatography-mass spectrometry-olfactometry and GC-flame photometric detector. In the samples of Y1, Y2, and Y3, 40, 42, and 42 odor-active compounds were, respectively, identified by olfactometry. Methyl 2-methylbutanoate, methyl hexanoate, hexyl isobutanoate, methional, heptanal, and ( Z)-3-hexenyl acetate contributed largely to the characteristic aroma of the three samples. Additionally, the odor activity value (OAV) was used to determine the main compounds and 3-mercaptohexyl acetate (OAV: 10-18), 3-mercapto-2-methylpentanal (OAV: 4-7), methyl 2-methylbutanoate (OAV: 9-21), methyl hexanoate (OAV: 8-16), and 2-pentyl acetate (OAV: 5-12) were considered as the important contributors to the aroma of hawthorn samples.

GC-MS olfactometric and LC-DAD-ESI-MS/MS characterization of key odorants and phenolic compounds in black dry-salted olives

BACKGROUND

Olives are processed in different ways depending on consumption habits, which vary between countries. Different de-bittering methods affect the aroma and aroma-active compounds of table olives. This study focused on analyzing the aroma and aroma-active compounds of black dry-salted olives using gas chromatography-mass spectrometry-olfactometry (GC-MS-O) techniques.

RESULTS

Thirty-nine volatile compounds which they have a total concentration of 29 459 µg kg^-1 , were determined. Aroma extract dilution analysis (AEDA) was used to determine key aroma compounds of table olives. Based on the flavor dilution (FD) factor, the most powerful aroma-active compounds in the sample were methyl-2-methyl butyrate (tropical, sweet; FD: 512) and (Z)-3-hexenol (green, flowery; FD: 256). Phenolic compounds in table olives were also analyzed by LC-DAD-ESI-MS/MS. A total of 20 main phenolic compounds were identified and the highest content of phenolic compound was luteolin-7-glucoside (306 mg kg^-1 ), followed by verbascoside (271 mg kg^-1 ), oleuropein (231 mg kg^-1 ), and hydroxytyrosol (3,4-DHPEA) (221 mg kg^-1 ).

CONCLUSION

Alcohols, carboxylic acids, and lactones were qualitatively and quantitatively the dominant volatiles in black dry-salted olives. Results indicated that esters and alcohols were the major aroma-active compounds. © 2018 Society of Chemical Industry.

Uzun): Characterization of key odorants in a representative aromatic extract by GC-MS-olfactometry and phenolic profile by LC-ESI-MS/MS

Volatile, aroma-active, and phenolic compounds of pistachio oil obtained from cv. Uzun were investigated in the current study. To obtain a representative aromatic extract, three of the most widely used extraction methods were compared using a representative test; the solvent-assisted flavour extraction (SAFE) aromatic extract from pistachio oil was found to be the most representative. A total of 50 aroma compounds were determined in pistachio oil and it was found that terpenes, aldehydes, and alcohols were the most abundant volatile compounds. Applying GC-MS-olfactometry and aroma extract dilution analysis (AEDA) resulted in a total of 14 aroma-active areas being detected in the extract of pistachio oil. In the phenolic fraction obtained by the LC-ESI-MS/MS method, a total of 12 phenolic compounds was found in the pistachio oil, of which seven compounds were reported for the first time. Eriodictyol-7-O-glucoside and protocatechuic acid were the most dominant phenolic compounds.