Volatile constituents of feijoa—headspace analysis of intact fruit

The volatile constituents emanating from intact feijoa fruit during storage were concentrated on to Tenax GC using a headspace trapping technique. Analysis by gas chromatography and gas chromatography-mass spectrometry led to the identification of 11 components of which myrcene, ethyl hexanoate, trans β-ocimene, 2-heptyl butanoate, cis hex-3-enyl butanoate and cis hex-3-enyl hexanoate are reported for the first time. Measurement of sequential changes in the aroma profile following natural abscission of the fruit suggests that ethyl benzoate may be an important compound in determining optimum ripeness of feijoa. Gas chromatographic sniffing trials on the headspace concentrate led to the conclusion that ethyl butanoate, methyl benzoate and ethyl benzoate are important in the aroma of intact feijoa fruit.     

The aroma volatile repertoire in strawberry fruit: a review

Aroma significantly contributes to flavor, which directly affects the commercial quality of strawberries. The strawberry aroma is complex as many kinds of volatile compounds are found in strawberries. In this review, we describe the current knowledge of the constituents and of the biosynthesis of strawberry volatile compounds, and the effect of postharvest treatments on aroma profiles. The characteristic strawberry volatile compounds consist of furanones, such as 2,5‐dimethyl‐4‐hydroxy‐3(2H)‐furanone and 4‐methoxy‐2,5‐dimethyl‐3(2H)‐furanone; esters, including ethyl butanoate, ethyl hexanoate, methyl butanoate, and methyl hexanoate; sulfur compounds such as methanethiol, and terpenoids including linalool and nerolidol. As for postharvest treatment, the present review discusses the overview of aroma volatiles in response to temperature, atmosphere, and exogenous hormones, as well as other treatments including ozone, edible coating, and ultraviolet radiation. The future prospects for strawberry volatile biosynthesis and metabolism are also presented. © 2018 Society of Chemical Industry     

Storage and ultraviolet‐induced tissue stress effects on fresh‐cut pineapple

The effect of UV‐induced stress on the volatile aroma compounds in cut pineapple was compared with that of storage at 4 °C for 24 h. Eighteen volatile compounds were identified by solid‐phase microextraction (SPME) in fresh‐cut pineapple. Methyl‐2‐methylbutanoate, methyl hexanoate, methyl 5‐hexenoate, ethyl hexanoate and ethyl 5‐hexenoate were the major aroma compounds. Storage at 4 °C for 24 h, and exposure of cut fruit to UV radiation for 15 min caused a considerable decrease in the concentration of esters and increase in the relative amount of copaene. This sesquiterpene, when added to crushed cantaloupe melon (0.1 mg g^?1), inhibited microbial growth in the fruit over a period of 24 h at 20 °C. Cis‐ and trans‐ocimene were present in the fruit but their production was not photo‐induced by UV irradiation. Ocimene, however, was a potent antimicrobial agent that killed microorganisms when added to the crushed fruit and stored at 20 °C for 24 h. The results indicate that sesquiterpene phytoalexins could contribute to the defense mechanism in wounded pineapple tissue. Published in 2004 for SCI by John Wiley & Sons, Ltd.     

Elevated carbon dioxide affects fruit flavor in field‐grown strawberries (Fragaria × ananassa Duch)

The effect of elevated carbon dioxide on fruit quality and aroma volatile composition in field‐grown strawberries (Fragaria × ananassa Duch) was studied. Elevating the ambient CO₂ concentration (ambient + 300, and ambient +600 µmol mol^?1 CO₂) resulted in high fruit dry matter, fructose, glucose and total sugar contents and low citric and malic acid contents. High CO₂ growing conditions significantly enhanced the fruit content of ethyl hexanoate, ethyl butanoate, methyl hexanoate, methyl butanonate, hexyl acetate, hexyl hexanoate, furaneol, linalool and methyl octanoate. Thus, the total amounts of these compounds were higher in berries grown in CO₂‐enriched conditions than those grown in ambient conditions. The highest CO₂ enrichment (600 µmol mol^?1) condition yielded fruit with the highest levels of these aroma compounds. Copyright © 2004 Society of Chemical Industry     

不同品种草莓的特征香气成分

以"宝交""大将军"和"红宝石"3个品种的草莓为试材,采用顶空固相微萃取-气相色谱质谱联用技术(GC-MS)和嗅闻技术(GC-O)、感官评价以及快速气相电子鼻对果实的香气成分进行分析。3个品种共检测到71种挥发性成分,"宝交""大将军"和"红宝石"分别有60,70和66种。酯类物质种类最多(21~26种),而醛类物质含量最多(51.37%~63.63%)。其中,丁酸甲酯、丁酸乙酯、乙醛、己酸甲酯、(E)-2-己烯醛、己酸乙酯、乙酸己酯、芳樟醇在3个样品中具有较高的含量及香气强度,为草莓的主要特征香气物质。经感官评价,"宝交"较强甜香气的来源可能是由于2-戊酮的存在;"大将军"青香和花香更强,青香可能由于它具有更高的己醛和反式-2-己烯醛含量,而花香可能来源于芳樟醇、橙花叔醇和β-紫罗兰酮。由快速气相电子鼻可以显示出3个品种草莓很好的区分度。     

Methyl jasmonate in conjunction with ethanol treatment increases antioxidant capacity,volatile compounds and postharvest life of strawberry fruit

The antioxidant capacity, total anthocyanins, total phenolics, volatile compounds, and postharvest quality of strawberry fruit were evaluated after treatment with natural antimicrobial compounds and during storage at 7.5 °C. Strawberries treated with methyl jasmonate (MJ) in conjunction with ethanol (MJ-ETOH) showed higher antioxidant capacity, total phenolics, and anthocyanins than those treated with ethanol or control (non-treated). MJ-ETOH and ethanol treatments also increased volatile compounds during storage period. However, individual volatile compounds were affected differently. Methyl acetate, isoamyl acetate, ethyl hexanoate, butyl acetate, and hexyl acetate increased, while ethyl butanoate, 3-hexenyl acetate, and methyl hexanoate decreased during storage. The postharvest life was longer for those berries treated with MJ-ETOH and MJ than for those treated with ethanol or control fruit. In conclusion, strawberries treated with MJ-ETOH maintained an acceptable overall quality for the longest storage duration and retained higher levels of volatile compounds; also, berries treated with MJ showed the highest antioxidant capacity compared with other treatments during the postharvest period.     

Changes in the composition of aromatic compounds and other quality parameters of strawberries during freezing and thawing

Six strawberry cultivars were analysed, as fresh and as frozen and thawed fruit, for their content of anthocyanins, ascorbic acid, titratable acid, soluble solids and aromatic compounds. During freezing and thawing the content of titratable acid and soluble solids remained constant, whereas the content of anthocyanins and ascorbic acid decreased. The composition of aromatic compounds was also changed during freezing and thawing and greatest decreases were found fortrans-2-hexenal and hexanol. The content of volatile acids, linalool and methyl hexanoate was doubled after freezing and thawing, and, for all cultivars except from Pandora and Dania, ethyl butanoate and ethyl hexanoate increased strongly. This cultivar-dependent ethyl ester formation occurred during thawing rather than during freezing.     

Aroma profile and volatiles odor activity along gold cultivar pineapple flesh

Physicochemical attributes, aroma profile, and odor contribution of pineapple flesh were studied for the top, middle, and bottom cross-sections cut along the central axis of Gold cultivar pineapple. Relationships between volatile and nonvolatile compounds were also studied. Aroma profile constituents were determined by headspace solid-phase microextraction at 30 °C, followed by gas chromatography/mass spectrometry analysis. A total of 20 volatile compounds were identified and quantified. Among them, esters were the major components which accounted for 90% of total extracted aroma. Methyl butanoate, methyl 2-methyl butanoate, and methyl hexanoate were the 3 most abundant components representing 74% of total volatiles in pineapple samples. Most odor active contributors were methyl and ethyl 2-methyl butanoate and 2,5-dimethyl 4-methoxy 3(2H)-furanone (mesifuran). Aroma profile components did not vary along the fruit, but volatile compounds content significantly varied (P < 0.05) along the fruit, from 7560 to 10910 μg/kg, from the top to the bottom cross-sections of the fruit, respectively. In addition, most odor-active volatiles concentration increased from the top to the bottom 3rd of the fruit, concurrently with soluble solids content (SSC) and titratable acidity (TA) differences attributed to fruitlets distinct degree of ripening. Large changes in SSC/TA ratio and volatiles content throughout the fruit found through this study are likely to provoke important differences among individual fresh-cut pineapple trays, compromising consumer perception and acceptance of the product. Such finding highlighted the need to include volatiles content and SSC/TA ratio and their variability along the fruit as selection criteria for pineapples to be processed and quality assessment of the fresh-cut fruit.     

Odour‐active compounds in mango (Mangifera indica L. cv. Corazón)

Simultaneous distillation–extraction combined with GC‐FID and GC‐MS were used to analyse volatile compounds from mango (Mangifera indica L. cv. Corazón) and to estimate the most odour‐active compounds in the fruit. The analyses led to the identification of 167 components, from which 128 were positively identified. The aroma‐active areas in the gas chromatogram were screened by the application of the aroma extract dilution analysis and by odour activity values. Eighteen odorants were considered as the most odour‐active compounds: (E)‐β‐damascenone, ethyl butanoate, (E,Z)‐nonadienal, ethyl 2‐methylpropanoate, (E)‐2‐nonenal, (E)‐β‐ionone, terpinolene, δ‐3‐carene, β‐caryophyllene, ethyl 2‐methylbutanoate, limonene, myrcene, linalool, γ‐octalactone, nonanal, methyl benzoate, 2,5‐dimethyl‐4‐methoxy‐3(2H)‐furanone and hexanal.     

Evaluation of volatile flavour compounds from cashew apple (Anacardium occidentale L) juice by the Osme gas chromatography/olfactometry technique

The headspace volatile components of the juice of cashew apples from a commercial Brazilian dwarf genotype were separated by high‐resolution gas chromatography and identified by GC/MS. Five judges evaluated the GC effluents using the Osme technique in order to determine the importance of each compound to the characteristic cashew aroma. Esters methyl 3‐methyl butanoate, ethyl 3‐methyl butanoate, methyl butanoate, ethyl butanoate, ethyl trans‐2‐butenoate and methyl 3‐methyl pentanoate were important to the sweet, fruity and cashew‐like aroma. Cis‐3‐hexenol, hexanal and 2‐methyl‐2‐pentenal presented different green notes. In spite of the flame ionisation detector being unable to detect sulphur compounds, the olfactometric analysis revealed chromatographic regions where sulphur‐like odours were perceived by the Osme sensory panel. The most intense unpleasant odour was due to 2‐methyl butanoic acid, which was described as very stinky. The sensory panel showed good olfactory sensitivity and reproducibility. Sensory and instrumental data correlation allowed a greater understanding of the role of several volatile compounds in the sensory quality of the juice. Copyright © 2003 Society of Chemical Industry     

Characterisation of odour‐active compounds in papaya (Carica papaya L.) wine

The volatile compounds of papaya wine were isolated by continuous solvent extraction and analysed by gas chromatography‐flame ionization detector and gas chromatography‐mass spectrometry. A total of 118 volatile constituents were detected, and ninety‐seven were positively identified. The composition of papaya wine included fifty‐three esters, twenty‐two alcohols, nine acids, seven phenols and derivatives, seven sulphur compounds, five lactones, five terpenes, three ketones, two aldehydes and five miscellaneous compounds. The aroma‐active areas in the gas chromatogram were screened by application of the aroma extract dilution analysis and by odour activity values. Six odorants were considered as odour‐active volatiles: ethyl octanoate, (E)‐β‐damascenone, 3‐methylbutyl acetate, benzyl isohtiocyanate; ethyl hexanoate and ethyl butanoate.     

Influence of yeast on the yield of fermentation and volatile profile of ‘Węgierka Zwykła’ plum distillates

The character of plum brandies depends on a unique aroma profile of the plum and the microbiota present on the surface of the fruits, as well as yeast used for fermentation. In this study, an evaluation of the effect of microorganisms applied for the fermentation of W?gierka Zwyk?a var. plum mashes and processing temperature (18 °C, 30 °C) on its efficiency and volatile profile, as well as taste and flavour of distillates obtained was performed. An estimation of the odour activity values (OAVs) of the volatile compounds was also conducted. Regardless of whether the fermentation was carried out using Saccharomyces bayanus wine yeast or by native microflora present on plums as well as raisins, the efficiency of this process was high and ranged between 91.7 and 96.7% of the theoretical efficiency. Especially rich in esters (among others ethyl acetate and isoamyl acetate) was the distillate derived after fermentation with the microflora of plums and raisins, at 18 °C. An evaluation of the individual aromatic effect of chemical compounds present in tested distillates, in terms of their OAVs, revealed that the highest OAVs were reached with isovaleraldehyde. Other compounds that showed aroma values >1 and possibly had an effect on the overall aroma of tested plum distillates were the following: hexanal, benzaldehyde, ethyl acetate, isoamyl acetate, ethyl benzoate, ethyl hexanoate, 1‐propanol, 2‐methyl‐1‐butanol, 3‐methyl‐1‐butanol and 1‐hexanol. The performed sensory ranking showed that the best rated distillate was the one obtained after fermentation with the indigenous microflora of plums and raisins, at 18 °C. Copyright © 2016 The Institute of Brewing & Distilling     

应用HS-SPME技术测定固态发酵浓香型酒醅微量成分

HS-SPME的方法是检测酒醅中微量风味物质的一种好的方法。该法简单、方便、快速。样品不需要进行预处理。检测成分完全可以用于浓香型固态发酵酒醅的发酵过程分析。从浓香型固态发酵酒醅中共检测出106种挥发性化合物,其中醇类9种,醛类6种,酮类2种,酸类10种,酯类47种,芳香族化合物12种,硫化物3种,呋喃类化合物4种,酚类化合物8种,以及其它化合物5种。重要的挥发性化合物是己酸乙酯、己酸、辛酸乙酯、丁酸、乙酸乙酯、乳酸乙酯和丁酸乙酯。     

Key aroma volatile compounds of gulupa (Passiflora edulis Sims fo edulis) fruit

By application of the aroma extract dilution analysis of gulupa (Passiflora edulis Sims fo edulis), fruit pulp extract obtained by solvent-assisted flavour extraction, and also comparison of chromatographic, spectroscopic (mass spectrum), and odour properties with standards, β-ionone, γ-nonalactone, ethyl butanoate, and ethyl cinnamate were identified as volatiles exhibiting the highest flavour dilution (FD) factor. Among the nineteen odour-active compounds of gulupa, only those showing the highest FD factors were quantified by stable isotope dilution assay. After calculation of odour activity values (OAVs; ratio of concentration to odour threshold in water), ethyl butanoate, ethyl hexanoate, and β-ionone were identified as key aroma compounds in gulupa, responsible for the fruity and floral odour notes.     

Effect of (−)- and (+)-methyl jasmonate on the bioformation of aroma-active esters in strawberry fruits

The effect of (−)- and (+)-methyl jasmonate on the bioformation of selected volatile esters in strawberry was evaluated. To that end, post-harvest treatments of strawberry fruits with (−)- and (+)-methyl jasmonate vapors were accomplished. The selected esters were ethyl 2-methyl butanoate, isoamyl acetate, ethyl hexanoate and hexyl acetate. The results obtained were compared with those provided by the treatment of strawberries with the commercial racemic mixture, i.e., (−/+)-methyl jasmonate. In addition, untreated samples were analyzed to be used as a control. Although the target esters were differently affected by the three treatments depending on the ester considered, a general trend could be observed. The levels of ethyl 2-methyl butanoate and isoamyl acetate decreased significantly with respect to the control sample with both (−)-methyl jasmonate and (+)-methyl jasmonate treatments. However, the variation in the concentrations of ethyl hexanoate and hexyl acetate depended on whether the (−)- or the (+)-enantiomer of methyl jasmonate was used in the treatment. These results reflect different activity of both methyl jasmonate enantiomers on the enzymes regulating strawberry ester biosynthesis. The application of methyl jasmonate enantiomers is here proposed as a possible mean to minimize strawberry aroma alterations and/or losses during post-harvest and storage.     

Changes in volatile aroma compounds of pineapple (Ananas comosus) during freezing and thawing

Changes in the volatile aroma compounds of pineapple (Ananas comosus) during freezing and thawing were compared against fresh samples to determine the effect of freezing on pineapple flavour. An HS‐SPME–GC–MS analysis showed that the Smooth Cayenne pineapple variety had nineteen volatile compounds, in four classes of compounds including fourteen esters, two hydrocarbons, two sulphur‐containing compounds and one lactone. The main characteristic volatile compounds of the fresh pineapple were methyl hexanoate, ethyl hexanoate, ethyl 3‐methylthiopropanoate and 1‐(E,Z)‐3,5‐undecatriene. Freeze–thaw cycles were associated with the loss of some volatile aroma compounds, particularly the esters which were found to be the main characteristic of fresh pineapples. The freezing and thawing process was found to cause damage to the pineapple tissues due to ice recrystallisation and dehydration which lead to the reduction of volatile aroma compounds.     

Impact of postharvest methyl jasmonate treatment on the volatile composition and flavonol content of strawberries

BACKGROUND: Although strawberry aroma is very complex, certain compounds have been described as main contributors, i.e. furanones, aldehydes, alcohols, sulfur compounds and particularly methyl and ethyl esters. In addition, strawberries possess potent antioxidant activity because of their high content of phenolic compounds. Among them, flavonols are highlighted as important antioxidant compounds in strawberry. The objective of this study was to assess the effect of methyl jasmonate (MJ) on the composition of the major contributors to aroma and on the content of certain flavonols in strawberry fruits. RESULTS: The levels of all studied volatile compounds were significantly affected by MJ treatment, though the individual effect differed according to the specific compound considered. Most of them increased significantly (P < 0.05), except methyl butanoate, which always showed higher levels in untreated strawberries. In contrast to aroma compounds, the change in the concentration of flavonols (i.e. myricetin, quercetin and kaempferol) was not significant in MJ‐treated strawberries. Considering the health‐promoting activity of these compounds, further investigations on the experimental conditions related to the treatment are required to control flavonol bioformation by means of MJ. CONCLUSION: The exogenous application of MJ vapour to strawberry enhances, in general, the production of the most relevant aroma‐active compounds. On the contrary, MJ treatment does not appear to influence the levels of myricetin, quercetin and kaempferol. Thus postharvest MJ treatment is proposed as an approach to obtain improved strawberry fruits in terms of sensory quality and health‐promoting properties. Copyright © 2010 Society of Chemical Industry     

GC-O-MS法对比3种红枣白兰地的挥发性成分

采用固相微萃取的方法提取3种红枣白兰地中的挥发性成分,以气相色谱-嗅闻-质谱联用对红枣白兰地中的挥发性成分进行分离鉴定。结果测得76种气味活性成分,主要包括酯类、醇类、萜类和芳香化合物。从挥发性成分的数量和总峰面积上看,A#行唐白兰地明显高于B#金相府和C#董家红枣白兰地。气相色谱-嗅闻(GC-O)结果表明,红枣白兰地的主要香气成分是:乙酸乙酯、丁酸乙酯、3-甲基-丁酸乙酯、己酸乙酯、1,1-二乙氧基-2-丙酮、壬酸乙酯、月桂酸甲酯、月桂酸乙酯、苯丙酸乙酯。其中,月桂酸乙酯、苯丙酸乙酯能赋予白兰地红枣的香味,形成此酒的特色。综上所述,从酒的组成和气味评分考虑,A#行唐酒业的香气成分比较全面。     

Establishment of Monstera deliciosa fruit volatile metabolomic profile at different ripening stages using solid-phase microextraction combined with gas chromatography–mass spectrometry

The volatile metabolomic profile of Monstera deliciosa fruits (M. deliciosa, ceriman) at three ripening stages, ripe, half-ripe and unripe, was established using headspace solid-phase microextraction (HS-SPME) combined with gas chromatography–quadrupole mass spectrometry detection (GC–qMS). To obtain the optimal HS-SPME conditions, the main experimental parameters that influence the extraction efficiency and experimental response were analyzed. The highest extraction efficiency was achieved with 1 g of ceriman sample, using a polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber for 60 min at 40 °C with 15% NaCl (w/w). After optimization, all ceriman samples were analyzed with the best extraction conditions that allowed to identify 80 volatile metabolites (VOMs), belonging to different chemical groups namely ethyl esters (88.61–77.94%), terpenoids (18.08–9.83%), carbonyl compounds (3.41–1.05%), higher alcohols (1.41–0.51%) and lactones (0.14–0.03%). Thirty-eight of the identified volatile metabolites (47.50%) have not been reported in M. deliciosa, so far, providing a more complete characterization of its volatile composition. The predominant VOMs identified in M. deliciosa fruits were ethyl butanoate, linalool, ethyl hexanoate, ethyl 2-methyl butanoate, butanoic acid, ethyl benzoate and propyl butanoate. Remarkable differences were found in both the quantitative and qualitative composition of M. deliciosa fruits at different ripening stages.Principal component analysis (PCA) provided a suitable tool to differentiate the volatile profile of target fruits among three ripening stages.