2-hexenal--z-isomer and n-hexanal

'Gold Finger' is a grape cultivar with a finger-like shape and a milk flavor. The process by which its aroma profile evolves during ripening is unclear. Thus, changes in the free and bound volatile compounds present in 'Gold Finger' grapes during ripening were investigated using headspace sampling-solid-phase microextraction-gas chromatography-mass spectroscopy (HS-SPME-GC-MS).. A total of 83 volatile aroma components were identified in the grapes, with aldehydes, esters, acids, and alcohols being the main components. The total aroma compound content exhibited significant differences between the bound and free forms. The total content of bound volatile compounds did not change significantly during fruit development, although the free aroma compound content was significantly higher than the bound content. The total content of free aldehydes, free alcohols, bound norisoprenoids, and ketones gradually increased for up to 70 days after flowering (DAF), while the total free ester, terpene, and acid content decreased. The characteristic aroma compounds of 'Gold Finger' grapes were identified as hexanal, (E)-2-hexenal, and ethyl hexanoate.. These results give a foundation for the further development of 'Gold Finger' grapes and provide a theoretical basis for the selection and breeding of novel aromatic grape varieties. © 2021 Society of Chemical Industry.

Topics: Alcohols; Aldehydes; Flavoring Agents; Fruit; Gas Chromatography-Mass Spectrometry; Odorants; Solid Phase Microextraction; Vitis; Volatile Organic Compounds

The composition of volatile compounds in Korla fragrant pears was determined using headspace solid-phase microextraction followed by a gas chromatography-mass spectrometry analysis using fruits at 30, 90, and 150 days after bloom. Hexanal, (E)-2-hexenal, 1-hexanol, (E)-2-hexen-1-ol, (Z)-3-hexen-1-ol, and hexyl acetate were identified as the major compounds. The composition of volatile compounds was associated with fatty acid concentrations and key enzyme activity in the lipoxygenase pathway. In vitro linoleic and linolenic acid feeding experiments conducted using cubes of fruit flesh demonstrated that the concentrations of volatile esters, such as hexyl acetate, in the treated fruits increased significantly after incubation for 12 h compared with those in the control fruits, which was accompanied by a reduction in aldehyde and alcohol concentrations (p < 0.05 or p < 0.01). However, the treatments did not significantly influence the enzyme activity and expression of genes encoding the enzymes.

Topics: Aldehydes; alpha-Linolenic Acid; Esters; Fatty Acids; Food Analysis; Fruit; Gas Chromatography-Mass Spectrometry; Gene Expression Regulation, Plant; Hexanols; Linoleic Acid; Odorants; Pyrus; Solid Phase Microextraction; Volatile Organic Compounds

Virgin olive oil is inevitably subject to an oxidation process during storage that can affect its stability and quality due to off-flavors that develop before the oil surpasses its 'best before' date. Many parameters are involved in the oxidation process at moderate conditions. Therefore, a multiparametric study is necessary to establish a link between physico-chemical changes and sensory quality degradation in a real storage experiment. In this context, a storage experiment of 27 months was performed for four monovarietal virgin olive oils, bottled in transparent 500-mL PET bottles and subjected to conditions close to a supermarket scenario. Volatile composition, quality parameters and phenolic compounds were determined monthly. Simultaneously, an accredited sensory panel assessed their sensory characteristics. The stability of the fresh samples was also studied with the oxidative stability index (OSI) and mesh cell-FTIR. (

Topics: Aldehydes; Food Storage; Olive Oil; Oxidation-Reduction; Phenols; Taste; Volatile Organic Compounds

Small white apricot is well known as a famous fresh fruit and even a folk medicine in Xinjiang. To investigate nutritive value, antioxidant activity, and flavor of small white apricot, sugars, organic acids, total flavonoids, phenolic compounds, antioxidant activities, and volatile compounds in five apricot cultivars were examined by high-performance liquid chromatography (HPLC) and headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS). The results showed that sucrose (32.94% to 42.49%), malic acid (69.21% to 76.75%), and quercetin-3-rutinoside (72.84% to 74.05%) were the dominant sugar, organic acid, and phenolic compounds in small white apricot, respectively. The antioxidant activity reached up to 61.72 to 135.52 mg TEs 100 g

Topics: Aldehydes; Antioxidants; Carboxylic Acids; China; Flavonoids; Fruit; Gas Chromatography-Mass Spectrometry; Odorants; Phenols; Prunus armeniaca; Solid Phase Microextraction; Sugars; Taste; Volatile Organic Compounds

Brazil is an emerging virgin olive oil producer country whose oils have been scarcely studied till now and, in particular, no data are present in literature about their volatile profiles and organoleptic characteristics as well as the Pearson's correlations between chemical and sensory parameters. Hence, giving insights about these aspects was the aim of the current investigation. The volatile profiles showed the presence of the aldehydes responsible for the positive attribute of VOOs (i.e. trans-2-Hexenal and hexanal) although, in some cases, volatiles from anaerobic and aerobic fermentation were also detected. The panel test showed low values of fruity and pungent notes (mean values of 1.1 and 0.6, respectively) whereas the bitter taste was detected only in one sample, probably due to the low amount of total phenolic compounds (ranging from 40 to 280 mg kg

Topics: Aldehydes; Antioxidants; Brazil; Carotenoids; Fatty Acids; Food Analysis; Olea; Olive Oil; Phenols; Principal Component Analysis; Sensation; Taste; Tocopherols; Volatile Organic Compounds

Species of kalanchoe are rich in bioactive compounds and are widely used in folk medicine; however, these plants are not well known from the point of view of aroma. Two species, Kalanchoe pinnata and Kalanchoe daigremontiana, were examined after six months and two years of growth and their vitamin C content, succulence, and aroma composition were determined. The efficiency of juice extraction was highest (72%) for the leaves of K. daigremontiana after six months of growth. The concentration of vitamin C was highest in juices from two-year-old plants and much higher in the juice of K. pinnata (81 mg/100 g). SPME/GC/MS analysis identified 32 aroma components, considering those with the spectrum similarity over 75%. The main components were furan-2-ethyl, hexanal, 2-hexenal, 2,4-hexadienal, 1-octen-3-ol, nonanal. The quantitative relations of these compounds were somewhat different in the two species. The most dominant component, 2-hexenal, is responsible for the green-like aroma noted by the sensory panel.

Topics: Aldehydes; Alkadienes; Ascorbic Acid; Fruit and Vegetable Juices; Furans; Gas Chromatography-Mass Spectrometry; Kalanchoe; Octanols; Odorants; Plant Extracts; Plant Leaves; Principal Component Analysis

In the present study, the influence of production systems (net-house and open-field) on volatile profiles of three Texas A&M University (TAMU) and five commercial tomato varieties was investigated. Forty metabolites were determined using headspace solid phase microextraction (HS-SPME) equipped with gas chromatography and mass spectrometry (GC-MS). The data was evaluated by multivariate analyses to discriminate the effects of genotype and production system, and to identify potential biomarker(s). The levels of hexanal, p-cymene, and (E)-2-hexenal from TAMU varieties were distinct from those of commercial tomato varieties. Similarly, 16 metabolites were considerably affected by the production systems, and majority of these volatiles were significantly higher in the net-house-grown tomatoes. Multivariate analysis also allowed identifying geranylacetone and d-limonene as potential biomarkers to classify tomatoes according to production systems. These findings underline the importance of the selection of variety and production system to preserve or improve desirable aroma traits in tomatoes.

Topics: Aldehydes; Cymenes; Food Analysis; Gas Chromatography-Mass Spectrometry; Metabolomics; Monoterpenes; Multivariate Analysis; Odorants; Solanum lycopersicum; Solid Phase Microextraction; Terpenes; Volatile Organic Compounds

The changes of free and bound volatile compounds in Rubus corchorifolius fruit during ripening were determined with a headspace SPME-GC-MS method. The results suggest that the free aldehydes, alcohols, esters and phenols increases, while that of free terpenoids decreases, with the ripening of the fruit. The bound aldehydes, alcohols, terpenoids, esters and phenols gradually decreases during ripening because these bound compounds are hydrolyzed to their free form. The characteristic free aroma compounds of ripened red fruit were found to be hexanal, 2-heptanone, ethyl hexanoate, 4-terpineol, geranial and methyleugenol. The free aroma compounds in red and yellow fruits exhibit similar odor profiles, and both of them are much sweeter, more floral and greener than the green fruit. The overall aroma of the fruits all ripening stages are mainly attributed to the free aroma compounds including β-damascenone, hexanal, 2-hexenal and linalool. The formation mechanisms of some volatile compounds were proposed.

Topics: Acyclic Monoterpenes; Alcohols; Aldehydes; Esters; Fruit; Gas Chromatography-Mass Spectrometry; Monoterpenes; Norisoprenoids; Odorants; Phenols; Rubus; Volatile Organic Compounds

The objective of this study was to characterize the flavor of a premium Florida tomato variety that has significant potential for producing a high quality processed juice product. A high-quality Florida plum tomato variety (Garden Gem), and a typical grocery-store plum tomato variety (Roma) were thermally processed into tomato juices without any additives. The 2 pilot products and a popular commercially available tomato juice (low sodium with sugar and flavor added) were compared using sensory evaluation and instrumental analysis. Flavor compounds in these products were identified using dynamic headspace purge and trap-gas chromatography-mass spectrometry (PT-GC-MS) by MS library match and retention index and were semi-quantitated using internal standards. Color, uniformity, overall liking, tomato flavor, sweetness and texture were rated using a hedonic scale. Analysis of variance, correlation and principal component analysis were used to analyze both sensory and flavor data. Among the 3 products, Garden Gem juice was rated significantly (P < 0.05) higher for overall liking, tomato flavor, and sweetness by the 119 consumer panelists in both seasons. Garden Gem juice was found to contain higher levels of 3 sweet/fruity related aroma compounds: 6-methyl-5-hepten-2-one, linalool, and β-ionone. The commercial tomato juice contained a high level of the Maillard reaction-related notes furfural, dimethyl sulfide, and the least amount of green-related notes (hexanal, E-2-hexenal and Z-2-heptenal). The flavor profile of the Roma tomato juice was similar to Garden Gem juice except it contained substantially lower amounts of hexanal and 2-isobutylthiazole. The compound β-ionone (fruity note) was not detected in either the commercial or Roma juice.. This proof of concept study demonstrates that high flavor quality tomatoes can be used to create better tasting processed tomato products. The study also demonstrates how sensory preference can confer a potential market advantage over existing commercial products. The Garden Gem variety has potential to add desirable flavor attributes to processed tomato products. This research may also provide insights for product developers to which flavor volatiles best reflect sensory observations for different aspects of tomato flavor.

Topics: Adolescent; Adult; Aged; Aldehydes; Color; Consumer Behavior; Female; Florida; Fruit; Fruit and Vegetable Juices; Gas Chromatography-Mass Spectrometry; Humans; Ketones; Male; Middle Aged; Norisoprenoids; Pilot Projects; Principal Component Analysis; Solanum lycopersicum; Taste; Volatile Organic Compounds; Young Adult

The interactions of soy protein isolate (SPI) and flavor compounds (hexanal, trans-2-hexenal, 1-octen-3-ol, trans-2-octenal, nonanal, and trans-2-nonenal) were investigated. The influence of SPI structure modified by malondialdehyde (MDA) and flavor compound structure on the interactions were determined by using headspace solid-phase microextraction (SPME) and gas chromatography (GC) combined with mass spectrometry (MS). The binding of native SPI to the flavor compounds decreased in the order trans-2-nonenal>nonanal>trans-2-octenal>trans-2-hexenal>hexanal>1-octen-3-ol. It might be attributed to that aldehydes are more hydrophobic than alcohols. The former is more conducive to hydrophobic binding with the SPI. Furthermore, the aldehydes, in particular trans-s-undecenal, could also react covalently. The effect of MDA modification on protein-flavor interactions depended on the structure of the flavor compound. Upon low concentration of MDA (≤1mM), the binding of all six flavors to SPI increased. However, a further increase in the extent of MDA (≥2.5mM), more soluble and even insoluble aggregates formed, which reduced the binding of hexanal and nonanal to SPI. The other four flavors with double bond revealed little changes in binding (trans-2-octenal, and trans-2-nonenal) or even an increase in binding (trans-2-hexenal, and 1-octen-3-ol). The results suggested that hydrophobic interactions were weakened upon high extent of oxidation, whereas covalent interactions were enhanced.

Topics: Alcohols; Aldehydes; Chromatography, Gas; Flavoring Agents; Hydrophobic and Hydrophilic Interactions; Malondialdehyde; Mass Spectrometry; Octanols; Odorants; Oxidation-Reduction; Particle Size; Solid Phase Microextraction; Soybean Proteins

To analyze volatile components and special aroma in fresh roots of Codonopsis Radix.. Volatile components in fresh Codonopsis Radix origined from three plant sources were analyzed by HS-GC-MS, and n-hexanal, 2-hexenal and n-hexanol were quantified by HS-GC.. 64 constituents have been identified in Codonopsis Radix,which containing ten alcohol,20 aldehyde,14 terpene, three ketone, four ester, four furan, three acid, one olefin, one alkane, two sulfide and two other compounds. The total percentage of n-hexanal,2-hexenal and n-hexanol was large, which were the main volatile compounds in Codonopsis Radix. The content of n-hexanal in Lu Dangshen, Baitiao Dangshen, Wen Dangshen, Feng Dangshen and Banqiao Dangshen were 54. 89%,59. 01%,55. 07%,42. 42% and 56. 74%,which were the major volatile component contributing to special aroma in Codonopsis Radix. 61 compounds have been identified in Lu Dangshen including 8 specific compounds. An external calibration method was established for simultaneous determination of n-hexanal,2-hexenal and hexanol in Codonopsis Radix. The results showed that all calibration curve three volatile components exhibited good linearity at a range of concentrations( R2≥0. 9995). The recoveries of n-hexanal, 2-hexenal and hexanol were 100. 1%,94. 8% and 112. 6%,and the RSD were 4. 4%,8. 7% and 8. 1%,respectively. The analysis suggested that the content of n-hexanal in Lu Dangshen was 200. 41 μg / g and significantly higher than that in Banqiao Dangshen, Wen Dangshen and Feng Dangshen while similar to Baitiao Dangshen. The content of hexanol in three-year-old Lu Dangshen was significantly higher than that in twoyear-old Lu Dangshen.. The present research indicates that special aroma is an important feature of authentic Dangshen.

Topics: Aldehydes; Codonopsis; Drugs, Chinese Herbal; Gas Chromatography-Mass Spectrometry; Plant Roots; Volatile Organic Compounds

Mulberry (Morus atropurpurea Roxb.) is a popular and desirable fruit that is widely cultivated in China. Despite its popularity, the free volatile chemicals and glycosidically bound volatiles (GBVs) of mulberry have been minimally studied. To this end, we have investigated these compounds in 4 mulberry cultivars via solid phase extraction (SPE) and headspace solid phase microextraction with gas chromatography-mass spectrometry (HS-SPME-GC-MS). A total of 55 free volatile chemicals and 57 GBVs were identified and quantified. In 3 of the cultivars ("YFS," "T10," and "D10"), the GBVs were found in higher amounts than their free counterparts, corresponding to a ratio of 1.2 to 1.8. The characteristic aromas were determined by their odor activity values (OAVs) and by generating an aroma series (AS). A total of 20 volatile compounds had OAVs ≥ 1.0. In particular, ethyl butanoate, hexanal, (Z)-3-hexenal (E)-2-hexenal, (E)-2-nonenal, and eugenol had relatively high OAVs and were considered to be the key aromas contributing to the mulberry flavor. Consequently, mulberry was characterized by a variety of herbaceous scents having a background of sweet, spicy, fruity, and floral notes. The free volatiles exhibited strong herbaceous notes, whereas the GBVs were responsible for the sweet and spicy qualities of the fruit. Based on our results, 2 cultivars ("YFS" and "D10") are proposed to be good candidates suitable for the further development of mulberry-based food products due to their complex and desirable aromas.

Topics: Aldehydes; Butyric Acid; China; Fruit; Gas Chromatography-Mass Spectrometry; Humans; Morus; Odorants; Solid Phase Microextraction; Taste; Volatile Organic Compounds

The concentration of 31 volatiles were measured in the headspace of tomatillos using selected ion flow tube-mass spectrometry (SIFT-MS), and were compared with those in vine-ripened tomato, roma tomato, cherry tomato, and grape tomato. None of the volatiles were higher in the headspace of tomatillos than of tomatoes. Compounds (E)-2-octenal, (E)-2-pentenal, 2-isobutylthiazole, 6-methyl-5-hepten-2-one, and phenylacetaldehyde were significantly lower in tomatillo than in the tomato varieties in the headspace. After blending, volatiles in the headspace increased, and then decreased after reaching a maximum concentration, due to further degradation or depletion. Compounds (E)-2-pentenal and 1-penten-3-one reached a maximum concentration later than (E)-2-hexenal, (Z)-3-hexenal, and hexanal for tomatillo and tomatoes. The slope of the ratio of (E)-2-hexenal and (Z)-3-hexenal was not significantly different for any of the samples, implying that the activity of cis/trans isomerase was not different between tomatillos and tomatoes.

Topics: Aldehydes; Food Analysis; Food Handling; Fruit; Lipid Metabolism; Mass Spectrometry; Molecular Structure; Pentanones; Physalis; Solanum lycopersicum; Species Specificity; Stereoisomerism; Time Factors; Volatile Organic Compounds

In the present study, the aldehyde-induced pro-oxidative activity of xanthine oxidase was followed in an accelerated raw milk system using spin-trap electron spin resonance (ESR) spectroscopy. The aldehydes acetaldehyde, propanal, hexanal, trans-2-hexenal, trans-2-heptenal, trans-2-nonenal, and 3-methyl-2-butenal were all found to initiate radical reactions when added to milk. Formation of superoxide through aldehyde-induced xanthine oxidase activity is suggested as the initial reaction, as all tested aldehydes were shown to trigger superoxide formation in an ultrahigh temperature (UHT) milk model system with added xanthine oxidase. It was found that addition of aldehydes to milk initially increased the ascorbyl radical concentration with a subsequent decay due to ascorbate depletion, which renders the formation of superoxide in milk with added aldehyde. The present study shows for the first time potential acceleration of oxidative events in milk through aldehyde-induced xanthine oxidase activity.

Topics: Acetaldehyde; Aldehydes; Animals; Electron Spin Resonance Spectroscopy; Milk; Oxidants; Xanthine Oxidase

In this paper, the effects of hexanal and trans-2-hexenal, which are both natural molecules characterizing apple aroma, on the microbial population and on color retention of fresh sliced apples were evaluated. In particular, a central composite design (CCD) was developed to assess the individual and interactive effects of the chosen volatile molecules and storage temperatures on (i) the growth of the naturally occurring microflora, (ii) the evolution over time of an inoculated spoilage yeast (Pichia subpelliculosa), and (iii) the enzymatic browning reaction in minimally processed apples. The inclusion of hexanal and trans-2-hexenal in the storage atmosphere of apple slices determined a significant extension of shelf life also when P. subpelliculosa was inoculated at levels of 10(3) colony-forming units/g and abusive storage temperatures were used. In fact, the presence of these molecules in the packaging atmospheres considerably prolonged the lag phases of the inoculated yeast and reduced the growth potential of naturally occurring bacteria. Moreover, the addition to the modified atmosphere of low levels of the hexanal increased the color stability of the products up to 16 days.

Topics: Aldehydes; Food Handling; Fruit; Lipid Peroxidation; Odorants; Pichia; Temperature