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Studies on the Aroma of Five Fresh Tomato Cultivars and the Precursors of cis- and trans-4,5-Epoxy-(E)-2-Decenals and Methional
Abstract
Three tasty (BR-139, FA-624, and FA-612) and two less tasty (R-144 and R-175) fresh greenhouse tomato cultivars, which significantly differ in their flavor profiles, were screened for potent odorants using aroma extract dilution analysis (AEDA). On the basis of AEDA results, 19 volatiles were selected for quantification in those 5 cultivars using gas chromatography-mass spectrometry (GC-MS). Compounds such as 1-penten-3-one, ( E, E)- and ( E, Z)-2,4-decadienal, and 4-hydroxy-2,5-dimethyl-3(2 H)-furanone (Furaneol) had higher odor units in the more preferred cultivars, whereas methional, phenylacetaldehyde, 2-phenylethanol, or 2-isobutylthiazole had higher odor units in the less preferred cultivars. Simulation of the odor of the selected tomato cultivars by preparation of aroma models and comparison with the corresponding real samples confirmed that all important fresh tomato odorants were identified, that their concentrations were determined correctly in all five cultivars, and that differences in concentration, especially of the compounds mentioned above, make it possible to distinguish between them and are responsible for the differential preference. To help elucidate formation pathways of key odorants, labeled precursors were added to tomatoes. Biogenesis of cis- and trans-4,5-epoxy-( E)-2-decenals from linoleic acid and methional from methionine was confirmed.
... Each aliphatic aldehyde gives off an odor expressed as "green" (Table 1). Hexanal and Z-3-hexenal are also released from fruit other than tomato (e.g., apple and guava) and are likely to endow these fruits, including tomato, with a pleasant "freshness" (Fuhrmann and Grosch 2002;Mayer et al. 2008;Steinhaus et al. 2009). Furthermore, volatile compounds, such as hexyl acetate and E-2-hexenal, are derived from hexanal and Z-3-hexenal, respectively, via enzymatic reactions and contribute to the aroma of the fruit of the Rosaceae family (e.g., apples, apricots, and peaches) (Fuhrmann and Grosch 2002;Aubert et al. 2003;Mehinagic et al. 2006;Aubert and Chanforan 2007) (Table 1). ...
... No enzymes involved in E,E-2,4-decadienal biosynthesis have indeed been identified. Nonetheless, this aldehyde is often found in foods without heat treatment and serve as key odorants -postharvest tomato fruit, parsley leaves, and freshly prepared handsqueezed orange juice (Masanetz and Grosch 1998;Buettner and Schieberle 2001;Mayer et al. 2008). Certain amounts of the odorant inevitably occur, probably due to autoxidation and/or photo-oxidation during harvest, storage, shipping, and others (Frankel et al. 1981;Derail et al. 1999;Pan et al. 2004). ...
... The volatile products from these n-3 LC-PUFA species are essentially the same as those from ALA (Hammer and Schieberle 2013). Indeed, foods rich in EPA and DHA such as fish release volatiles, including Z-3-hexenal and E,Z-2,6-nonadienal, that were described above to occur from ALA (Table 1) (Schieberle et al. 1990;Milo and Grosch 1996;Mayer et al. 2008). Although one finds their odors pleasant in cases of specific fruits (Schieberle et al. 1990;Fuhrmann and Grosch 2002;Mayer et al. 2008), such volatiles become "off odor" components in foods rich in EPA and DHA (e.g., fish) (Hartvigsen et al. 2000;Lee et al. 2003). ...
Fat (triglycerides) consumption is critical for the survival of animals, including humans. Being able to smell fat can be advantageous in judging food value. However, fat has poor volatility; thus, olfaction of fat seems impossible. What about fatty acids that comprise fat? Humans smell and discriminate medium-chain fatty acids. However, no conclusive evidence has been provided for the olfactory sense of long-chain fatty acids, including essential acids such as linoleic acid (LA). Instead, humans likely perceive the presence of essential fatty acids through the olfaction of volatile compounds generated by their oxidative breakdown (e.g., hexanal and γ-decalactone). For some people, such scents are pleasing, especially when they come from fruit. Nonetheless, it remains unclear whether the olfaction of these volatiles leads to the recognition of fat per se. Nowadays, people often smell LA-borne aldehydes such as E,E-2,4-decadienal that occur appreciably, for example, from edible oils during deep frying, and are pronely captivated by their characteristic “fatty” note, which can be considered a “pseudo-perception” of fat. However, our preference for such LA-borne aldehyde odors may be a potential cause behind the modern overdose of n-6 fatty acids. This review aims to provide a view of whether and, if any, how we olfactorily perceive dietary fats and raises future purposes related to human fat olfaction, such as investigating sub-olfactory systems for detecting long-chain fatty acids.
... In tomato more than 400 volatile compounds have been described (Petro-Turza, 1987), though mainly 20 compounds, and especially hexanal, (E)-2-hexenal, (Z)-3-hexenal, 1-hexanol, (Z)-3-hexen-1-ol, 2-isobutylthiazole, 6-methyl-5-hepten-2-one, geranyl-acetone and -ionone, have been classically considered as important in the determination of the characteristic tomato flavor (Buttery, 1993). Although recent literature has emphasized the role of other compounds such as 1-penten-3-one, (E,E) and (E,Z)-2,4decadienal, 4-hydroxy-2,5-dimethyl-3(2H)-furanone (furaneol), methional, phenylacetaldehyde or 2-phenylethanol (Mayer et al., 2008), and it has questioned the role of some compounds previously found as important (reviewed by Rambla et al., 2014). Apart from these main aroma volatiles, minor volatiles with negative logodor units may still be important to determine specific tomato flavor as background notes . ...
... Additionally, low levels of this compound have been recommended to improve tomato flavor (Vogel et al., 2010). Nevertheless, it should be noted that both cultivars accumulated (E,E)-2,4-decadienal, and this compound has been recently related with a positive influence on tomato acceptance (Mayer et al., 2008) and its role in flavor intensity has also been acknowledged (Tieman et al., 2012). This considerably superior effect of genotype over environment, including cultivation year and irrigation dose, has also been described for different growing conditions: open-air or in protected cultivation (Cebolla-Cornejo et al., 2011). ...
... In our opinion, the differences in the exact moment of analysis and differences in growing conditions should also be accounted for. In any case, the concentrations obtained for hexanal (i.e.) were on the range described by other authors for fresh tomato varieties (Mayer et al., 2008;Birtic et al., 2009). ...
The influence of irrigation doses on standard and high lycopene tomato varieties has been analyzed during two years in one of the main processing tomato growing areas of Spain. Deficit irrigation (75% ETc) implied a mean reduction in water use of 28.2%, while it caused a significant reduction in the marketable production of 16.4% and increase in soluble solids (8.4%) and Hunter a/b ratio (2.4%). The effect on lycopene content was not significant. Increasing irrigation dose over the recommended 100% ETc had no significant effect on the agronomical performance, while it provoked a dilution effect reducing total soluble solids and lycopene content. The effects on 33 tomato volatiles were also analyzed, 11 of them related to main aroma notes and 22 to the background volatile profile. The effect of deficit irrigation on aroma was dependant on climatic conditions and it may either not have a significant effect on the aroma profile or may lead to higher logodor units in main aroma volatiles. High lycopene cultivars showed higher contents in most volatiles, including some volatiles originated in pathways that have not been related with carotenoid degradation processes. In both the fresh and processing tomato market the improvement of organoleptic and functional quality and the reduction of the impact of agriculture on environment represent main goals. The use of high lycopene cultivars and restricted irrigation would enhance the aroma of materials targeted to quality markets, contributing to increase the efficiency of water use in agriculture.
... These compounds contribute to the musty character of quinoa and are known for their extremely low odor-recognition thresholds. [40][41][42][43] The sensory evaluations revealed their perceived intensity in the ground samples decreased upon malting. Further, the boiled potato note, commonly associated with 3-(methylsulfanyl)propanal, was less frequently recorded in quinoa malt. ...
... The impact of malt modification and the effect of storage on the odor-active volatiles were examined by cAEDA. A similar number (43)(44)(45)(46)(47) of volatile compounds was perceived in all fresh quinoa malts but their intensity and composition varied. The presence of the esters as well as selected malty compounds (e.g., 3-methylbutanal) was exclusive of Qui-M. ...
Background
Quinoa (Chenopodium quinoa Willd.) is a gluten‐free pseudocereal, rich in starch and high‐quality proteins. It can be used as a cereal. Recently, a variety of nontraditional food products were developed; however, the sharp bitterness and the earthy aroma of unprocessed quinoa interfered with the acceptance of these products. Malting of cereals is known to improve their processing properties and enhance their sensory quality. To evaluate the acceptance and potential of quinoa malt as a raw material for beverage production, malt quality indicators (e.g., soluble protein) and the aroma profiles of different quinoa malts were compared.
Results
Initial sensory assessment of quinoa in its native and malted state identified differences in their aroma profiles and revealed that pleasant nutty and caramel aromas were formed by malting. Subsequently, three complementary isolation techniques and gas chromatography‐olfactometry/mass spectrometry (GC‐O/MS) were used for volatile analysis. Instrumental analysis detected 34 and 62 odor‐active regions in native quinoa and quinoa malt, respectively. In the second part, storage and the impact of three malting parameters on volatile formation were examined. By varying the malting parameters, seven additional odor‐active malting byproducts were revealed.
Conclusion
Three naturally occurring methoxypyrazines were identified as important contributors to the characteristic quinoa aroma. In all fresh quinoa malts a similar number of volatile compounds was perceived but their intensity and composition varied. Higher germination temperature promoted the formation of lipid oxidation products. Fatty smelling compounds and carboxylic acids, formed during storage, were classified as aging indicators of quinoa malt. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
... The cultivars RC, BC and BB had the highest levels of C5 volatile compounds and the highest typical tomato aroma scores. Mayer et al. (2008) have reported that 1-penten-3-one, 2,4decadiene and furanol compounds were more abundant volatiles in tasty tomato cultivars. In tomatoes, colour and aroma compounds are frequently associated, and this relationship is probably a result of the degradation of carotenoids into aroma volatiles. ...
... The cultivar YC had the highest amount of 2-isobutylthiazole. The less preferred cultivars had higher odour units such as methional, phenylacetaldehyde, 2-phenylethanol or 2-isobutylthiazole (Mayer et al., 2008). At lower levels, 2-isobutylthiazole increased fresh tomato aroma, but at higher levels, the aroma became objectionable, rancid and medicinal, and metallic off-odours were more dominant (Yilmaz, 2001). ...
Antioxidant capacity, total phenolic content, colour, sugar, volatiles, ascorbic acid and carotenoid (β-carotene and lycopene) contents of differently coloured and shaped tomato cultivars (cvs) grown in the Eastern Mediterranean region, Turkey were determined, along with a sensory evaluation. Tomato cultivars of two different types (cherry and beefsteak) and four different colours (red, yellow, orange and brown) were analysed. All plants were simultaneously grown in the same field and subjected to identical horticultural practices to minimise the effects of environmental conditions and to maximise those related to genotype. The red cherry cultivar had the highest lycopene content, while the orange beefsteak cultivar had the highest β-carotene content. The highest antioxidant capacity, total phenolic content and hardness scores were found in cherry-type tomatoes, except the yellow one. The red cherry cultivar had the highest sugar content. Red and brown cherry cultivars were also significant in terms of their high carotenoid and sugar contents, along with a high antioxidant activity. The brown cherry cultivar had the highest total phenol content. The highest quantities of 2-hexenal, 3-hexen-1-ol, and 6-methyl-5-hepten-2-one were detected in red cultivars. The brown cherry cultivar had the highest sweetness, typical aroma and hardness scores, while the yellow beefsteak cultivars the lowest sweetness typical aroma scores. In terms of sensory parameters, red and brown cultivars scored higher than yellow and orange ones. ********* In press - Online First. Article has been peer reviewed, accepted for publication and published online without pagination. It will receive pagination when the issue will be ready for publishing as a complete number (Volume 47, Issue 3, 2019). The article is searchable and citable by Digital Object Identifier (DOI). DOI link will become active after the article will be included in the complete issue. *********
... By the use of gas chromatography-olfactometry (GC-O), odouractive compounds can be detected in a complex mixture of hundreds of volatile compounds. The odour-active compounds in fresh tomato have been investigated using GC-O in many studies (Krumbein & Auerswald, 1998;Langlois, Etievant, Pierron, & Jorrot, 1996;Mayer et al., 2008;Selli, Kelebek, Ayseli, & Tokbas, 2014). However, few studies have been performed to assess the odour-active compounds of cooked tomatoes (Landy et al., 2002). ...
... Both compounds have been reported as odour-active volatiles in tomato using AEDA (Krumbein & Auerswald, 1998;Tandon, Jordan, Goodner, & Baldwin, 2001). 1-Octen-3-one is a fatty acid degradation product, while methional is coming from methionine through an enzyme-catalysed process (Koutidou et al., 2016;Mayer et al., 2008;Vervoort et al., 2012). 4,5-Dimethylthiazole is a Maillard reaction product; sotolone and 2-phenylacetaldehyde are amino acid-derived flavour compounds. ...
... The C 6 aldehydes and alcohols (hexanal, cis-3-hexenal, trans-2-hexenal, hexanol, cis-3-hexenol, and trans-2-hexenol) are the most important volatile compounds in fresh tomato fruit according to quantitative and qualitative analyses. [4][5][6][7] These compounds are produced by the breakdown of fatty acids via lipoxygenase and hydroperoxide lyase during homogenizing. [8][9][10] In a 2016 study, trans-2-hexenal was revealed to be produced from cis-3-hexenal by isomerases. ...
... In previous studies, C 6 -compounds such as hexanal and cis-3-hexenal were detected as the most common aroma compounds expressing "green note" in fresh tomato fruit based on aroma extract dilution analyses. 4,6,7,36) Even in the fruits of cv. Momotaro, cis-3-hexenal was reported as the most odor-active compound. ...
Various commercial tomato juices with different flavors are available at markets worldwide. To clarify the marker compounds related to the flavor characteristics of tomato juice, we analyzed 15 pure commercial tomato juices by a combination of volatile profiling and sensory evaluation. The correlations among volatiles and the relationship between volatiles and sensory descriptors were elucidated by multivariate analyses. Consequently, the tomato juices made from fresh market tomatoes (including the popular Japanese tomato variety "Momotaro") were clearly separated from other juices made from processing tomatoes, by both the volatile composition and sensory profiles. cis-3-Hexenol, hexanal, and apocarotenoids negatively contributed to the juices from fresh market tomatoes, whereas Strecker aldehydes and furfural showed positive contributions to the juices. Accordingly, the sensory characteristics of juices from fresh market tomatoes were related to cooked and fruity flavors but not to green or fresh notes.
... The volatile compounds were preliminarily identified by a computer-matching of their mass spectral data supplemented with a Wiley7n.1 and Nist 02.L. GC-MS libraries, and then the identifies of most were confirmed by GC retention time (RT) and MS ion spectra of authentic standards (Sigma-Aldrich, Milwaukee, WI, USA). The retention indices were also determined for all constituents by using homologous series of n-alkanes C 5 -C 25 . Results from the volatile analyses were expressed as the percentage of each compounds integrated area relative to the total integration of compounds identified. ...
... Of lipid-derived aldehydes, (Z)-3-hexenal was previously reported in tomatoes, whereas it was not detected in tomatoes at any stage of ripening. (Z)-3-hexenal is an instable compound and then it is converted to (E)-2-hexenal by cis/trans-isomerase [25]. Compounds (Z)-3-hexen-1-ol and n-hexenol decreased and increased in red tomato, respectively, compared to green tomato. ...
... A total of 23 aroma-active compounds were determined in this study by the authors. Mayer et al. (2008) screened the potent odorants of fresh tomatoes using AEDA and concluded that 1-penten-3-one, (E,E)-2,4-decadienal, (E,Z)-2,4-decadienal, and 4-hydroxy-2,5-dimethyl-3(2H)-furanone (furaneol) had higher odour units in the more preferred cultivars, whereas methional, phenylacetaldehyde, 2-phenylethanol, or 2-isobutylthiazole had higher odour units in the less preferred cultivars. ...
... The present study suggested that this compound is the strongest aroma-active compound of fresh cherry tomato due to its relatively low threshold value. Our present study supports earlier results on tomatoes (Mayer et al., 2008;Ruiz et al., 2005) that (Z)-3-hexenal is probably the most important contributor to fresh tomato aroma profile. It is worth noting that the key difference in flavour of fresh and processed tomato is the almost complete loss of (Z)-3-hexenal and the presence of furfural in processed tomatoes (Markovic, Vahcic, Ganic, & Banovic, 2007). ...
... A total of 23 aroma-active compounds were determined in this study by the authors. Mayer et al. (2008) screened the potent odorants of fresh tomatoes using AEDA and concluded that 1-penten-3-one, (E,E)-2,4-decadienal, (E,Z)-2,4-decadienal, and 4-hydroxy-2,5-dimethyl-3(2H)-furanone (furaneol) had higher odour units in the more preferred cultivars, whereas methional, phenylacetaldehyde, 2-phenylethanol, or 2-isobutylthiazole had higher odour units in the less preferred cultivars. ...
... The present study suggested that this compound is the strongest aroma-active compound of fresh cherry tomato due to its relatively low threshold value. Our present study supports earlier results on tomatoes (Mayer et al., 2008;Ruiz et al., 2005) that (Z)-3-hexenal is probably the most important contributor to fresh tomato aroma profile. It is worth noting that the key difference in flavour of fresh and processed tomato is the almost complete loss of (Z)-3-hexenal and the presence of furfural in processed tomatoes (Markovic, Vahcic, Ganic, & Banovic, 2007). ...
Aroma and aroma-active compounds of cherry tomato (Lycopersicum esculentum) was analyzed by gas chromatography–mass spectrometry–olfactometry (GC–MS–O). According to sensory analysis, the aromatic extract obtained by liquid–liquid extraction was representative of tomato odour. A total of 49 aroma compounds were identified and quantified in fresh cherry tomato. Aldehydes were qualitatively and quantitatively the most dominant volatiles in cherry tomato, followed by alcohols. Aroma extract dilution analysis (AEDA) was used for the determination of aroma-active compounds of tomato sample. A total of 21 aroma-active compounds were detected in aromatic extract of fresh tomato, of which 18 were identified. On the basis of the flavour dilution (FD) factor, the most powerful aroma-active compounds identified in the extract were (Z)-3-hexenal (FD = 1024) and (E)-2-hexenal (FD = 256), which were described as the strong green-grassy and green-leafy odour, respectively. The major organic acid and sugar found were citric acid and fructose, respectively.
... Researchers have reported more than 400 VOCs in the ripening of the tomato fruit including limonene, phenethyl alcohol, phenyl-acetaldehyde and methyl salicylate, four of the components used in the Insect Science (Pty) Ltd. T.V. PheroLure® (Pyne and Wick 1965;Dalal et al. 1967;Viani et al. 1969;Buttery et al. 1971;Petro-Turza 1986;Buttery et al. 1987;Baldwin et al. 2000;Tikunov et al. 2005;Beltran et al. 2006;Mayer et al. 2008;Baldwin 2010;Wang et al. 2016;Wang et al. 2018). Literature pertaining to the presence of methyl 2-methoxybenzoate, the fifth component, as a VOC in tomatoes is lacking. ...
Pheromone-based or semiochemical lures for insect detection and monitoring in agriculture is common
practice. Many countries exempt these devices from regulatory requirements, but not South Africa. The
question arises whether the pheromone/semiochemical lures influence the naturally occurring compounds
significantly, to justify concern for human toxicity and ecotoxicity. T.V. PheroLure® is a novel five-component
lure developed by Insect Science (Pty) Ltd. used for monitoring African bollworm, Helicoverpa armigera (an
important insect pest on tomatoes). T.V. PheroLure® is a volatile organic compound (VOC) blend impregnated in
a polyethylene bulb. The influence of T.V. PheroLure® on the volatile profile of a tomato field was evaluated in a
commercial growing area of South Africa. Tomato VOCs were collected before, during and after the application
of six T.V. PheroLures® in yellow bucket funnel traps randomly distributed over 1 ha. VOCs were collected from
planting until harvest (22 weeks) at five randomly selected sites. Collection also took place in adjacent tomato
fields where no T.V. PheroLure® was applied. The constituents of T.V. PheroLure® had no significant influence on
the naturally occurring VOCs observed in the tomato field. The results suggest that the concern for toxicity and
ecotoxicity is unjustified when using semiochemical devices for monitoring purposes. The natural physiology
of the plant, rather than T.V. PheroLure®, influenced the VOCs observed in a tomato field.
... Five and three aldehyde compounds were found in relative amounts higher than their threshold concentrations (relative OAVs > 1) for pulp and peel, respectively. Methional, perceived as potato skin and tomato, [44], had the highest relative OAV in all of the analyzed samples. The relative OAV of methional in pulp was significantly higher than that in peel by approximately 7.5 times. ...
Tamarillo is a nutrient-dense fruit with a unique aroma from its volatile compounds (VCs). In this study, we aimed to compare the volatile profiles: (i) of fresh and freeze-dried tamarillo; (ii) detected using Thermal Desorption–Gas Chromatography–Mass Spectrometry (TD–GC–MS) and Solid-Phase MicroExtraction–Gas Chromatography-Mass Spectrometry (SPME–GC–MS); (iii) of freeze-dried pulp and peel of New Zealand grown tamarillo. The possible antibacterial activity of freeze-dried tamarillo extracts was also investigated. We show that freeze-drying maintained most of the VCs, with some being more concentrated with the loss of water. The most abundant VC in both fresh and freeze-dried tamarillo was hexanoic acid methyl ester for pulp (30% and 37%, respectively), and (E)-3-Hexen-1-ol for peel (36% and 29%, respectively). With the use of TD–GC–MS, 82 VCs were detected for the first time, when compared to SPME–GC–MS. Methional was the main contributor to the overall aroma in both peel (15.4 ± 4.2 μg/g DW) and pulp (118 ± 8.1 μg/g DW). Compared to water as the control, tamarillo extracts prepared by water and methanol extraction showed significant antibacterial activity against E. coli, P. aeruginosa, and S. aureus with zone of inhibition of at least 13.5 mm. These results suggest that freeze-dried tamarillo has a potential for use as a natural preservative to enhance aroma and shelf life of food products.
... It can also be used in type II hyperlipidemia, atherosclerosis and chronic tracheitis, as well as in early cervical cancer and skin ulcers [22].In aldehydes, the highest content of trans -2decenal is 2.75%. Trans -2-decene aldehyde can be used as spice, mainly for poultry and citrus flavors [23]. The highest content of styrene in hydrocarbon compounds is 2.4%, styrene is mainly used to produce styrene series resin and styrene butadiene rubber, and also produces ion exchange resins and pharmaceuticals. ...
Olive oil is a kind of high-quality edible oil obtained by quick extraction from the fresh olive fruit. It has rich biological activity and positive effect on human health which leads to the increase of the demand for olive oil. Olive pomace is a by-product of olive oil during processing which is also rich in biologically active ingredients. But it is often treated as waste, not only causes environmental pollution but also a great waste of resources. In order to explore the high value utilization of olive oil by-products, the extract components of olive oil pomace by benzene, ethanol and acetone were analyzed by gas chromatography-mass spectrometry. The results showed that there were 109, 70, and 71 components which identified in benzene, ethanol and acetone extracts of olive oil pomade respectively. Many of these components can be resourced in industries of biomedicine, bioenergy, spices, and food additives.
... However, different chemicals with distinct aroma characteristics showed different temporal trends ( Table S3). The second group of phenolic VOCs associated with floral and sweet aroma (Tandon et al., 2000;Baldwin et al., 2008;Mayer, 2008;Selli et al., 2014;Du et al., 2015) increased dramatically in the fruits of more modern varieties when compared to earlier varieties (Figures 4B and S5). The third group of phenylpropanoid VOCs, which express a "smoky" (Tikunov, 2013) or "medical" aroma (Causse, 2002), and the fourth group of VOCs produced from branched-chain and sulfurous amino acids, associated with earthy/musty/pungent/medicinal types of aroma (Baldwin et al., 2004;Baldwin et al., 2008), showed a very significant reduction in fruits of the more recent varieties (Figures 4C, D, Figure S5 and Table S3). ...
It is generally believed that domestication and breeding of plants has led to genetic erosion, including loss of nutritional value and resistances to diseases, especially in tomato. We studied the diversity dynamics of greenhouse tomato varieties in NW Europe, especially The Netherlands, over the last seven decades. According to the used SNP array, the genetic diversity was indeed very low during the 1960s, but is now eight times higher when compared to that dip. The pressure since the 1970s to apply less pesticides led to the introgression of many disease resistances from wild relatives, representing the first boost of genetic diversity. In Europe a second boost ensued, largely driven by German popular media who named poor tasting tomatoes Wasserbomben (water bombs). The subsequent collapse of Dutch tomato exports to Germany fueled breeding for fruit flavor, further increasing diversity since the 1990s. The increased diversity in composition of aroma volatiles observed starting from 1990s may reflect the efforts of breeders to improve fruit quality. Specific groups of aroma compounds showed different quantitative trend over the decades studied. Our study provides compelling evidence that breeding has increased the diversity of tomato varieties considerably since the 1970s.
... In addition to the use of methional as a food additive, various foods naturally contain methional via degradation of methionine 25 . Foods that are used globally as seasonings, such as tomatoes 8,9 , cheese 10,11 , and soy sauce 12 , commonly contain methional as one of their main flavor components. Among the structural analogs that we used, 2-methylthioacetaldehyde (5) and 3-(methylthio)butanal (8) are also reported in natural products, such as tomatoes and krill 25 . ...
Taste is a vital sensation for vertebrates, enabling the detection of nutritionally important substances or potential toxins. A heteromeric complex of two class C GPCRs, T1R1 and T1R3, was identified as the umami (savory) taste receptor. Amino acids and 5'-ribonucleotides are well known to be natural ligands for human T1R1/T1R3. In this study, we reveal that methional, which is a familiar flavor component in foods, is an allosteric modulator of T1R1/T1R3. Receptor expression experiments showed that methional served as a positive allosteric modulator (PAM) of human T1R1/T1R3 and functioned as a negative allosteric modulator (NAM) of mouse T1R1/T1R3. Although amino acids and 5'-ribonucleotides bound to the extracellular domain of T1R1, the use of interspecies chimeric receptors demonstrated that methional interacted with the transmembrane domain of T1R1. Site-directed mutagenesis and molecular modeling showed that methional could potentially bind at two distinct sites in the transmembrane domain of T1R1 and that the amino acid residues in the bottom of the allosteric pocket engendered the switch between the PAM and NAM modes, which could contribute to switching the binding position of methional. These results may be applicable for elucidating the molecular mechanisms underlying ligand recognition by other class C GPCRs.
... For example, 3-(methylthio)-propanal (methional) is found in 54% of the KFOs studied in the literature and listed as a generalist in natural products. Methional can be formed through the thermal or enzymatic breakdown of L-methionine and is commonly perceived by gas chromatography-olfactometry (GC-O) [3]. The next class of VSCs in foods is called intermediaries, like furfurylthiol, which are found in 15% of KFOs. ...
Global production and demand for tropical fruits continues to grow each year as consumers are enticed by the exotic flavors and potential health benefits that these fruits possess. Volatile sulfur compounds (VSCs) are often responsible for the juicy, fresh aroma of tropical fruits. This poses a challenge for analytical chemists to identify these compounds as most often VSCs are found at low concentrations in most tropical fruits. The aim of this review is to discuss the extraction methods, enrichment techniques, and instrumentation utilized to identify and quantify VSCs in natural products. This will be followed by a discussion of the VSCs reported in tropical and subtropical fruits, with particular attention to the odor and taste attributes of each compound. Finally, the biogenesis and enzymatic formation of specific VSCs in tropical fruits will be highlighted along with the contribution each possesses to the aroma of their respective fruit.
... Forty-two compounds were determined: three as possible markers of fermentative processes (acetaldehyde, ethyl acetate, and ethanol) [24], and the other 39 as compounds identified as tomato fruit key odorants by gas chromatography-olfactometry or present in the fruit at levels close to odour threshold and, hence, potentially giving contribution to global aroma [1,25,26]. ...
Tomato fruits of cv. Caramba harvested at the pink ripening stage were cold stored for 4 and 7 days at 6 °C, then allowed to fully ripen at ambient temperature, and finally evaluated for eating quality, and compared with fruit fully ripened on the vine. In addition, fruits harvested at full ripeness were subjected to cold storage at 6 °C by a conventional or the innovative passive refrigeration PRS™ system for 2, 4, and 7 days, and then evaluated. Tomato quality evaluation included sensory, chemical (volatile compounds, sugars, and organic acids), and physical (flesh texture and skin colour) attributes. Fruit harvested at the pink stage, and then subjected to cold storage, when attained full external red colour showed less intense tomato odour, red ripe tomato odour, and flavour when compared to fruit fully ripened on the vine, and, at the same time, developed a perceptible mould off-odour. These differences were consistent with those observed in the levels of aroma compounds and fermentation metabolites. Main effects associated with cold storage of red ripe fruits by both conventional and passive refrigeration were increased skin toughness and decreased sourness. Passive refrigeration caused a more pronounced toughening of the skin, but no development off-odours were detected. Analysis of alteration of volatile synthesis confirmed recent findings on the molecular mechanism underlying chilling-induced loss of flavour in tomatoes.
... Moreover, methional has been reported that to show higher odor units in the less preferred tomato cultivars when compared to five fresh tomato cultivars. Also, the biogenesis of methional has been confirmed from methionine [16]. Methional was identified in a previous lychee study using sulfur selective detector, pulsed flame photometric detector (PFPD) [3]. ...
Volatile compounds in 'Sweetheart' lychee were examined using gas chromatography-olfactometry/mass spectrometry (GC-O/MS). Solvent assisted flavor evaporation (SAFE) technique was used to identify the aroma-active compounds in lychee. Further characterization of the most important odorants in 'Sweetheart' lychee was achieved using aroma extract dilution analysis (AEDA). Thirty-one key aroma-active odorants were identified in the flavor dilution (FD) factor range of 2-1024. Methional (cooked potato) and geraniol (sweet, floral) exhibited the highest FD factors of 1024 and 512, respectively, these were followed by furaneol (sweet, caramel), nerol (floral, sweet), dimethyl trisulfide (DMTS) (preserved vegetable, sulfury), linalool (floral), (E,Z)-2,6 nonadienal (cucumber) and nerolidol (metalic, sesame oil). Furthermore, the flavor profile of 'Sweetheart' lychee was described by sensory analysis. Floral, tropical fruit, peach/apricot and honey were scored with relatively high scores for each aroma attribute. The sweetness rating was the highest score among all the attributes.
... Whether GLVs would be preferable as flavor constituents depends on the nature of the food in which they are found. They are preferred constituents in most fresh fruits, such as tomatoes, apples and pears (Mayer et al. 2008, Song and Forney 2008, Souleyre et al. 2014, and in olive oil (Kalua et al. 2007). For foods made from soybeans, they can provide either a good or off flavor. ...
Green leaf volatiles (GLVs) are six-carbon volatile compounds. They are formed from fatty acids by a dioxygenation reaction catalyzed by lipoxygenase and a subsequent cleavage reaction catalyzed by hydroperoxide lyase. GLVs are involved in direct and indirect plant defense against herbivores and pathogens. In intact plant tissues, GLVs are usually present at low concentrations, but upon wounding, GLVs are synthesized rapidly: within seconds to minutes. It has been hypothesized that this ‘GLV burst’ is supported by activation of pre-existing enzymes on endogenous substrates; however, the detailed mechanism of the GLV burst has not been elucidated. Recently, we found that a certain portion of GLVs is formed without liberation of free fatty acids from lipids. Accordingly, we hypothesized that lipoxygenase plays an essential role in the GLV burst. In particular, direct oxygenation by lipoxygenase on membrane lipids seems to be responsible. Lipoxygenase is also a target for controlling GLV levels in food derived from plants.
... In general, components concentration and odour threshold are important variables in determining the contribution of various volatiles to fruit fl avour (Baldwin et al., 2000). Most fruits and vegetables produce aromatic volatiles, as has been revealed by studies on mango (MacLeod and Snyder, 1985;MacLeod et al., 1988;Andrade et al., 2000), guava (Wilson et al., 1982;Porat et al., 2011), watermelon (Lewinsohn et al., 2005), apple (Dixon and Hewett, 2000), strawberry (Song et al., 1998) and tomato (Buttery et al., 1988;Buttery and Ling, 1993;Maul et al., 1997;Krumbein and Auerswald, 1998;Markovic´ et al., 2007;Mayer et al., 2008;Christiansen et al., 2011). Over 400 aroma volatiles have been detected in tomato, but fewer than 30 have been proposed to impact on organoleptic properties (Baldwin et al., 2000;Tieman et al., 2006a). ...
This book, divided into four parts, aims to gather comprehensive and concise information on the advances in fruit research. Part one focuses on physiology and metabolism. Part two deals with fruit nutritional quality and part three with signalling and hormonal control of fruit ripening. Part four covers genetic and epigenetic control of fruit ripening. This book also aims to fill a long-felt need for a comprehensive treatise contributed to by world experts in each subdiscipline, covering various aspects of fruit development and ripening. Each chapter concisely describes the recent advances in our understanding of individual ripening pathways including those of cell walls, aroma volatiles and cuticle/waxes; micro-nutrients such as carotenoids, vitamins, other antioxidants and bioactive compounds; features of chromoplast development; and primary and secondary metabolism. Developments on the hormonal control of fruit ripening with a special focus on ethylene biosynthesis and responses are described. The potential role(s) of other phytohormones such as abscisic acid, auxin, gibberellins, brassinosteroids and the jasmonate family and their interaction with ethylene responses is featured. Similarly, biogenic amines are shown to impact on fruit ripening. The involvement of key transcription factors and their interactions with the promoters of ripening-related genes provide a deeper insight into the molecular basis of fruit ripening. Chapters on ripening mutants, genomics/metagenomics and epigenetic control of ripening, emphasizing novel strategies, together with the subjects mentioned above and those on fruit biodiversity, the genetics of sensory quality and biotechnology, provide overall a present day meaning to diverse and complex processes that regulate the life of a fruit.
... Based on this technique, identified compounds are subjected to threshold measurements in water and from these analyses, ratios between the compound concentration in the fruit and its threshold in water are computed; if the calculated odor threshold of a specific compound is determined to be lower than the concentration in that particular food, then the OAV is less than 1, thereby suggesting that the volatile does not contribute substantially, or not at all, to the flavor of the particular food tested. For example, of the approximately 400 volatiles present in tomatoes, only 30 have concentrations above 1 nL/L and of these 30, only 19 have OAVs surpassing 1 (Buttery et al. 1987;Goff and Klee 2006;Mayer et al. 2008). Because the other volatile constituents are assumed to exist in quantities below the threshold (i.e., and have an OAV <1), their influence is considered to be significantly less important (Yilmaz 2001). ...
Throughout the field of food chemistry, attempts to reconstruct the characteristic flavor of the tomato have remained a persistent challenge. Although the established method for analyzing tomato volatiles has focused on calculating odor thresholds for a single compound against a basic water background, the current study sought to demonstrate the influence of volatile interactions on perceptual threshold by comparing thresholds for a volatile alone and in the presence of another volatile. Thresholds were compared for methyl salicylate and guaiacol alone and in a 50/50 binary mixture. While the traditional method does not regard guaiacol as contributing significantly to the overall flavor of the tomato, results demonstrated an interaction effect, such that threshold concentrations for mixtures were consistently lower than thresholds reported separately for either methyl salicylate or guaiacol alone, with subjects displaying increased sensitivity (additivity) to a solution comprised of both chemicals. Further research will be needed to thoroughly investigate the underlying mechanisms responsible for such effects, but the results demonstrate that perithreshold and subthreshold volatiles can potentially have a measurable impact on odor perception.
PRACTICAL APPLICATIONS
Given the persistent complaints surrounding the flavor of contemporary tomatoes, researchers within the field of food science have continued to make rigorous attempts to improve the overall taste and percept of the standard supermarket tomato. While emphasis has previously focused predominantly on storage, handling and esthetic appeal, priorities are beginning to shift, with consumers more readily requesting the sought after flavor of fresh, heirloom tomatoes. As a consequence, many scientists are undertaking the challenge of studying and manipulating the proportion of plant volatiles thought to be responsible for promoting the characteristic flavor of the tomato fruit, but to fully understand the impact of such volatiles, the issue of retronasal olfaction must be considered. The current research discusses how two such volatiles are capable of interacting at the level of the nose, thereby potentially altering the taste. Hopefully, future researchers will be able to incorporate such olfactory psychophysics techniques into testing panels, thereby providing a more thorough examination of consumer perception.
... The identification of isolated volatile compounds was performed by comparing their mass spectra, retention times and linear retention indices (Kovats retention indices; KI) against those obtained from authentic standards when they were available: acetic acid, 1-hexanol , 3-hexen-1-ol, 2-methyl 1-butanol, 2-methyl-1-propanol, 1-pentanol, 1-penten-3-ol, benzaldehyde, 2-hexenal, 2-octenal, 6-methyl-5-hepten-2-one, 3-pentanona, 1-penten-3one, 1-butanol, 2-methyl-2-butenal, furfural, 3-hydroxy-2-butanone and acetonitrile (Sigma-Aldrich, San Louis, Missouri; Acros Organics, Geel, Belgium and Fluka Buchs,Schwiez, Switzerland). Otherwise they were tentatively identified by comparing their mass spectra (m/z values of the most important ions) with spectral data from the National Institute of Standards and Technology 2002 library, as well as retention indices published in the literature (Alves & Franco, 2003;Barrios, Sinuco, & Morales, 2010;Kondjoyan & Berdague, 1996;Mayer et al., 2008;Tatsuka, Suekane, Sakai, & Sumitanis, 1990). Kovats retention indices were determined by injection into the Tenax of a solution containing the homogeneous series of normal alkanes (C 8 -C 20; by Fluka Buchs, Schwiez, Switzerland) in the same temperature-programmed run, as described above. ...
Vegetable flavour is a quality characteristic for consumer acceptability. Sun and air are traditionally used for drying tomatoes; however, the optimal combination of techniques such as osmotic dehydration or microwave-assisted air-drying could lead to high quality self-stable products. The aim of this paper was to study the influence of different process variables on the volatile profile of dehydrated cherry tomato halves. The analysed variables were: air-drying temperature (40 and 55 °C), microwave power (0 and 1 W/g) and previous osmotic dehydration with a 55 Brix binary sucrose solution at 30 °C for 120 min (OD1) or ternary solution of 27.5% sucrose + 10% NaCl (w/w) at 40 °C for 60 min (OD2). Twenty major volatile compounds were identified in fresh tomatoes. Among them, 2-isobutylthiazole and 6-methyl-5-hepten-2-one stand out as impact volatile compounds. Dehydration modified the volatile profile, mainly due to the changes induced in some typical fresh-like tomato compounds, but also due to the generation of five new compounds: 1-butanol, 2-methyl-2-butenal, 3-hydroxy-2-butanone, furfural, acetonitrile, related to Maillard reactions, and the catabolism of carotenoids and polyunsaturated fatty acids. Principal component analysis showed the possibility of obtaining dried cherry tomatoes with different volatile profiles, depending on drying conditions.
... By application of aroma extract dilution analysis and calculation of odor activity values, HDMF was defined as one of the key odorants in pineapples [39,40]. HDMF was also among the volatiles that showed higher odor units in more preferred tomato cultivars [41]. Highest HDMF concentrations were found in the summer crop of home-grown tomatoes while the lowest levels were detected in the common ethylene-ripened, field-grown, supermarket tomatoes [35]. ...
4-Hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF, furaneol®) and its methyl ether 2,5-dimethyl-4-methoxy-3(2H)-furanone (DMMF) are import aroma chemicals and are considered key flavor compounds in many fruit. Due to their attractive sensory properties they are highly appreciated by the food industry. In fruits 2,5-dimethyl-3(2H)-furanones are synthesized by a series of enzymatic steps whereas HDMF is also a product of the Maillard reaction. Numerous methods for the synthetic preparation of these compounds have been published and are applied by industry, but for the development of a biotechnological process the knowledge and availability of biosynthetic enzymes are required. During the last years substantial progress has been made in the elucidation of the biological pathway leading to HDMF and DMMF. This review summarizes the latest advances in this field.
... The simple act of transportation may cause the machine to go out of tune. Therefore, we designed an experiment to compare the retention index of limonene as a representative of the compounds that can be found in volatile blends of tomato plants (Baldwin et al. 2008; Mayer et al. 2008; Mathieu et al. 2009) both in the lab and in a commercial tomato greenhouse. As explained before, the retention indices are related to a n-alkane series and they are relatively unique for most compounds unlike retention times that change with chromatographic methods. ...
Qualitative performance of a portable gas chromatograph (zNose™) was assessed by comparing retention indices of major constituents
of an essential oil-based insect repellent, and by comparing retention index of limonene, a major chemical in volatile blends
of tomato plants, in the laboratory, a research greenhouse and a commercial greenhouse. Effects of temperature and relative
humidity on the performance of the device were also assessed. In all experiments, the zNose™ produced consistent results comparable
to that of a conventional GC–MS. Our results concur with previous studies confirming the zNose™ as a suitable device for analyzing
plant volatiles in the field and for monitoring their rapid changes.
KeywordsGas Chromatograph-Retention Index-zNose™-Volatile organic chemicals
The effect of the QTL involved in climacteric ripening ETHQB3.5 on the fruit VOC composition was studied using a set of Near-Isogenic Lines (NILs) containing overlapping introgressions from the Korean accession PI 16375 on the chromosome 3 in the climacteric ‘Piel de Sapo’ (PS) genetic background. ETHQB3.5 was mapped in an interval of 1.24 Mb that contained a NAC transcription factor. NIL fruits also showed differences in VOC composition belonging to acetate esters, non-acetate esters, and sulfur-derived families. Cosegregation of VOC composition (23 out of 48 total QTLs were mapped) and climacteric ripening was observed, suggesting a pleiotropic effect of ETHQB3.5. On the other hand, other VOCs (mainly alkanes, aldehydes, and ketones) showed a pattern of variation independent of ETHQB3.5 effects, indicating the presence of other genes controlling non-climacteric ripening VOCs. Network correlation analysis and hierarchical clustering found groups of highly correlated compounds and confirmed the involvement of the climacteric differences in compound classes and VOC differences. The modification of melon VOCs may be achieved with or without interfering with its physiological behavior, but it is likely that high relative concentrations of some type of ethylene-dependent esters could be achieved in climacteric cultivars.
Fruits have different aromatic profiles according to their stage of ripeness, therefore, volatile compounds profile is an important quality attribute, which also determines flavor and aroma characteristics, making this profile a perfect option to guide the optimization of postharvest treatment of fruits. In this context, the objective was to discuss the effects of postharvest treatments, associating them with the biosynthesis of volatile compounds in fruits. There are three major groups of fruit flavor precursors: carbohydrates, amino acids, and fatty acids. The biosynthesis of volatile compounds is directly related to metabolic changes that occur according to the fruit ripening stage. This process occurs under the regulation of hormones, which have ethylene as one of the main agents. Several hormones are also part of this complex mechanism and interact by regulating ethylene levels positively or negatively to form a fine adjustment. Therefore, hormonal treatments have an impact on the biosynthesis of volatile compounds in different ways. Other postharvest treatments such as cold storage, controlled atmosphere, and UV radiation can also impact the volatile compounds biosynthesis, but are generally used synergistically, which circumvents the negative effects on the aromatic profile of the fruits.
The proposed work compares a combination of ohmic and vacuum heating (OH-VC) with conventional heating. Tomato paste was freshly extracted from tomatoes and subjected to 0-220 V alternating current (AC) with 50 Hz frequency under a pressure of 0.3-0.7 bar until the temperature reached 87 °C and compared with tomato paste heated in a double jacket vat. Tomato paste was further analyzed using Fourier transform infrared spectroscopic analysis (FTIR), volatile analysis using gas chromatography-mass spectrometry (GC-MS), minerals analysis using scanning electron microscope – energy dispersive spectrometer (FEG-SEM), scanning electron microscopy, and colour measurements. Based on FTIR analysis, tomato paste processed with OH-VC heating was found to have higher deformations of sugars than conventionally heated paste. Similarly, OH-VC heated product contained caramel-like odours associated with furfural and 5-methyl furfural generation due to electric treatment of food. Electrodes used in ohmic heating did not cause any changes in the minerals content due to heavy metal ion migration. Structurally, OH-VC treated cells were found to have a more regular and preserved structure than conventional heating. No effect on the colour of the tomato paste was observed. These results demonstrate the advantageous effect of OH-VC heating compared to conventional heating, primarily attributed to the lower treatment time and higher heating homogeneity. Yet, the generation of caramel-like odours suggests the need to optimize OH-VC treatment for each particular product.
Tomato is one of the most widespread horticultural species in the world. Used in a wide and diverse range of forms, from being suitable for consumption fresh to use as a manufactured derivative, e.g. sauce, peeled, juices, ketchup, etc., it is hard to imagine tomato-free cuisine. With many national traditions and dishes based on this culinary vegetable, it is said to be one of the symbols of Mediterranean cuisine.
This book looks at the many changes that are taking place in the tomato market and industry; tomato producers are combining tomato origin, tradition, territory, quality, service and supply chain to adapt to the needs of the new consumers. It deals with the topics that are pertinent to the current industry: rheology and mechanical properties; origin determination; innovation and new product development; market research; sensory and consumer preference; quality control and new methods; volatile compounds and aroma; non-conventional processing technologies; functional and healthy compounds; waste and by-product valorization; and sustainability and traditional products.
Providing a comprehensive overview of the actual tomato industry; how it ensures product authenticity; new product development, particularly focused on consumer demands; the presence of bio-active substances able to prevent chronic diseases (carotenoids, phenolic and flavonoids); and how to convert industrial waste into added value by-products; this book will appeal to professionals and food product developers.
Free and glycosidically bound volatiles from two major tomato cultivars (Lycopersicon esculantum L. cv. Alida and Merve) of Turkey were determined. Free volatile compounds were extracted using liquid–liquid microextraction, while bound volatiles were extracted using solid phase extraction. The compounds were analyzed using GC-FID and GC–MS. Alida showed presence of, 39 free and 32 bound aroma compounds again 38 free and 31 bound aroma compounds is Merve. The odor activity values of the volatile compounds suggested that hexanal, (Z)-3-hexenal, (E,Z)-2,4-decadienal, (E,E)-2,4-decadienal and 2-phenylethanol were most significant odorants in both cultivars. Guaiacol and eugenol were flavor contributors for Merve. The norisoprenoids 5,6-epoxy-β-ionone and 3-hydroxy-β-ionone were observed in free form in tomato. Norisoprenoids, terpenoids, volatile phenols and higher alcohols were present in the glycosidic extract. Among the glycosidically bound compounds, 2-phenylethanol, guaiacol and eugenol were found to be potential contributors to overall tomato flavor upon hydrolysis.
The volatile profile of crushed rocket leaves (Eruca sativa and Diplotaxis tenuifolia) was investigated by applying headspace solid-phase microextraction (HS-SPME), combined with GC-MS, to an aqueous extract obtained by homogenization of rocket leaves, and stabilized by addition of CaCl2. A detailed picture of volatile products of the lipoxygenase pathway (mainly C6-aldehydes) and of glucosinolate hydrolysis (mainly isothiocyanates), and their dynamics of formation after tissue disruption was given. Odor-active compounds of leaves were characterized by GC-olfactometry and aroma extract dilution analysis: volatile isolates obtained by HS-SPME from an aqueous extract and by stir-bar sorptive extraction from an ethanolic extract were analyzed. The most potent odor-active compounds fully or tentatively identified were (Z)- and (E)-3-hexenal, (Z)-1,5-octadien-3-one, responsible for green olfactory notes, along with 4-mercaptobutyl and 4-(methylthio)butyl isothiocyanate, associated with typical rocket and radish aroma. Relatively high odor potency was observed for 1-octen-3-one, (E)-2-octenal and 1-penten-3-one.
An aroma distillate was prepared by solvent extraction and subsequent SAFE distillation from Italian vine-ripe tomatoes eliciting an intense overall aroma. Application of gc/olfactometry and the aroma extract dilution analysis revealed 44 odor-active compounds, 42 of which could be identified. The highest odor activity value of 2048 was established for the green, grassy (Z)-3-hexenal, the metallic smelling trans-4,5-epoxy-(E)-2-decenal, the potato-like smelling 3-(methylthio)propanal and the caramel-like smelling 4-hydroxy-2,5-dimethyl-3(2H)-furanone. Of the further odorants, thirteen compounds have previously not been reported as tomato odorants. Although most of these showed lower FD-factors, in particular, the coconut/dill-like smelling wine lactone ((3S,3aS,7aR)-3a,4,5,7a-tetrahydro-3,6-dimethyl-benzofuran-2(3H)-one) appeared with a quite high FD factor. In addition, a fruity, almond-like odorant with an FD factor of 1024 (6) was detected. By application of high resolution mass spectrometry and polarity considerations the structure of a methyl-2-ethoxytetrahydropyran isomer was suggested for 6. Four of the five possible isomers, the 3-methyl-, 4-methyl-, 5-methyl-, and 6-methyl-2-ethoxytetrahydropyran were synthesized and showed similar mass spectrometric patterns. However, these were excluded by their different retention indices. Although the synthesis of the remaining 2-methyl-2-ethoxytetrahydropyran resulted in only small yields, which were not sufficient for NMR measurements, this structure is very likely for 6. This compound was never reported as a food constituent before. Finally, quantitation of twenty-three odorants by stable isotope dilution assays allowed the preparation of an aroma recombinate resembling the overall aroma of the tomatoes.
Strecker aldehydes have been negatively associated to flavor of heat sterilized plant-based foods. The present study demonstrated the importance of processing conditions (temperature, pressure and time) as a strong means for the control of Strecker aldehyde formation in vegetables purees. A kinetic study was set up (at isothermal and isothermal-isobaric conditions) to quantify the effects of single process parameters on the changes of 3-methylbutanal (3-MB) in carrot puree as a case study. The increase in 3-MB concentrations was best described by an empirical, logistic model. During the isothermal treatment at atmospheric pressure, the maximum reaction rate constant of 3-MB formation was increased as a function of processing temperature. However, the formation rate was clearly slower at high pressure (600 MPa) compared to the process at 0.1 MPa. Hence, the reduced formation of Strecker aldehydes under high pressure could open a new possibility for process control and optimization of the formation of these compounds.
Ten sulphur volatiles were observed in two Florida tomato cultivars (‘Tasti-Lee’ and ‘FL 47’) harvested at three maturity stages (breaker, turning, and pink) using gas chromatography with a pulsed flame photometric detector (GC-PFPD). Eight PFPD peaks were identified using retention values from authentic sulphur standards and GC–MS characteristic masses. Seven were quantified using an internal standard combined with external calibration curves. Dimethyl sulphide, dimethyl disulphide, dimethyl trisulphide 2-propylthiazole and 2-s-butylthiazole were newly identified in fresh tomatoes. Principal component analysis of sulphur volatiles indicated that there were appreciable maturity stage differences clustered in separate quadrants. GC-olfactometry (GC-O) identified 50 aroma-active compounds in ‘Tasti-Lee’, with 10 reported as odorants in fresh tomatoes for the first time. Four sulphur volatiles exhibited aroma activity, including two of the newly-reported fresh tomato sulphur volatiles, 2-s-butylthiazole and dimethyl sulphide. GC-O aroma profiling indicated that the most intense aroma category was earthy-musty, followed by fruity-floral, green-grassy, sweet-candy and sweaty-stale-sulphurous.
Yuzu (Citrus junos Sieb. ex Tanaka) is a variety of sour citrus fruit that is popular in Japan. In this study, we investigated its aroma, which many people, especially in Japan, find appealing. Aroma extract dilution analysis was used to screen the odour-active compounds in the yuzu volatile oil. An unknown odorant with an albedo-like odour and a high flavour-dilution factor was detected. To identify this odorant, it was separated via flash column chromatography on silica gel and then fractionated by preparative high-performance liquid chromatography on a reverse-phase column. The volatile fraction, which contained a significant amount of the target unknown compound, was analysed by gas chromatography–mass spectrometry and gas chromatography–olfactometry to determine its mass spectrum, retention index, and odour quality. By comparing the resultant data with that of a synthesised authentic reference compound, it was evident that the unknown odorant was trans-4,5-epoxy-(E,Z)-2,7-decadienal (3); this is the first time that it has been identified as an odour-active unsaturated aldehyde in yuzu volatile oil. From the results of a model formation experiment, we propose that trans-4,5-epoxy-(E,Z)-2,7-decadienal originates from α-linolenic acid via 13(S)-hydroperoxy-(Z,E,Z)-9,11,15-octadecatrienoic acid (13(S)-HPOT), which is a lipoxygenase-induced oxidation product of α-linolenic acid.
Metabolomics is one of the most recent additions to the functional genomics approaches. It involves the use of analytical chemistry techniques to provide high-density data of metabolic profiles. Data is then analyzed using advanced statistics and databases to extract biological information, thus providing the metabolic phenotype of an organism. Large variety of metabolites produced by plants through the complex metabolic networks and their dynamic changes in response to various perturbations can be studied using metabolomics. Here, we describe the basic features of plant metabolic diversity and analytical methods to describe this diversity, which includes experimental workflows starting from experimental design, sample preparation, hardware and software choices, combined with knowledge extraction methods. Finally, we describe a scenario for using these workflows to identify differential metabolites and their pathways from complex biological samples.
Expression of dissatisfaction with tomato aroma prompted us to lead this study on the impact of domestic storage conditions on volatile compounds. Two storage modalities (20 and 4°C) and two cultivars (Levovil and LCx) were used. Volatile compounds were analysed by gas chromatography-mass spectrometry detection after accelerated solvent extraction. Physical characteristics, lipoxygenase activity, hydroperoxide lyase activity; linoleic acid and linolenic acid were monitored. Storing tomatoes at 4°C induced a drastic loss in volatiles, whatever their biosynthetic origin. After 30days at 4°C, the concentration of volatiles had decreased by 66%. Reconditioning for 24h at 20°C was able to recover some aroma production after up to 6days storage at 4°C. Volatile degradation products arising from carotenoids and amino acids increased when tomatoes were kept at 20°C, while lipid degradation products did not vary. Storing tomatoes at fridge temperature, even for short durations, was detrimental for their aroma. This should be taken into account to formulate practical advice for consumers.
Tomato (Solanum lycopersicum) fruits of three cultivars picked at different ripening stages were subjected to conditions in the laboratory simulating both short and long distribution chains as occurring in commercial practice and to recommended storage conditions. At the end of the postharvest experiments, a flavor quality profile of fruits was obtained by chemical determination of volatile compounds, sugars, and organic acids, and physical measurement of texture properties. In two of the three cultivars, the overall profile and many of the individual quality attributes was significantly affected by the distribution chain conditions, the effect being more pronounced in tomatoes marketed at full ripeness than in those marketed at an intermediate ripening stage. In these cultivars, tomatoes harvested at the Breaker stage, subjected to long chain conditions and then allowed to achieve full ripeness at room temperature, did not develop the same overall profile observed on fruits fully ripened on the vine and exposed to a simulated short chain. Fruits subjected to recommended commercial storage conditions, cold stored above the chilling range (10 or 13 °C) and at high relative humidity (95%), developed a different profile when compared to fruit exposed to the simulated long distribution chain (6 °C and 55-80% RH), suggesting that these changes in temperature and relative humidity may remarkably affect flavor formation in tomato fruits. Major drivers of profile differentiation between tomatoes subjected to different postharvest scenarios were the levels of some aroma compounds derived from aminoacids (1-nitro-2-phenylethane, 2-isobutylthiazole, phenylacetaldehyde, 2-phenylethanol, and 2- and 3-methylbutanal) and lipids ((E,E)- and (E,Z)-2,4-decadienal), and, among nonvolatile flavor compounds, of organic acids (citric and malic).
Background:
The present work was carried out because there is only a small amount of literature on how the volatile composition of tomatoes can be modified by the effect of exogenous substances in contact with tomato plants. This work studies how eugenol and guaiacol, either by foliar application and/or in the surrounding atmosphere, can affect the volatile composition of this fruit. An important work of this study was also conduced to validate the analytical method [headspace stir bar sorptive extraction-gas chromatography-mass spectrometry (HS-SBSE-GC-MS)] to determine the composition of the volatiles in tomato.
Results:
Analytical method validation parameters such as linearity, limit of detection, limit of quantification, and recovery proved that this method is suitable for the analysis of tomato volatiles. Their eugenol and guaiacol content changed, with an increase of 200 and 35 times, respectively, when foliar treatment was used, and an increase of 10, in both cases, when plants were in contact with the contaminated atmosphere. As consequence of the treatments other volatile compounds changed considerably.
Conclusion:
For first time, a HS-SBSE-GC-MS method was successfully validated for the study of volatiles in tomatos. Results suggests that exogenous compounds in contact with the plants, such as eugenol and guaiacol, can be absorbed changing the global volatile composition of fruits, which could produce a negative or positive effect in their aroma.
Systematic investigations of the volatiles of field-grown plants and shoot cultures of Gynura bicolor have been conducted to obtain indispensable plant physiological information for propagating plants of consistent quality. Volatiles obtained by solvent-assisted flavour evaporation (SAFE) of solvent extracts from leaves of commercial cultivars, shoot cultures and their regenerates were analysed using gas chromatography (GC), GC–mass spectrometry (GC–MS) and GC–olfactometry (GC–O). It was revealed for the first time that this plant had the following chemical characteristics: field-grown plants, i.e. those plants commercially cultivated in three different regions of Japan and 7 month-old regenerates of shoot cultures had almost the same GC profiles; their major components were (E)-caryophyllene, α-humulene and bicyclogermacrene; in contrast, the major components of the shoot cultures were (Z,E)-α-farnesene, (E)-caryophyllene and α-copaene. The biosynthetic pathways for the sesquiterpenes found in these materials were presumed from the analytical results. Aroma evaluations using GC–O revealed that 1-octen-3-one, (Z)-1,5-octadien-3-one and trans-4,5-epoxy-(E)-2-decenal were aroma-impact compounds contributing to the characteristic metallic, green aroma, especially in the shoot cultures. In addition to these results, it was found that 2-isopropyl- and 2-isobutyl-3-methoxypyrazines were additional compounds related to the green, earthy aroma in the regenerates. These aroma-impact compounds were detected only because of the GC–O analysis. Copyright © 2009 John Wiley & Sons, Ltd.
Two unsupervised pattern recognition techniques such as stepwise linear discriminant analysis (SLDA) and Soft Independent Modeling of Class Analogy (SIMCA) were used to classify tomato samples in categories corresponding to the cultivation areas. The same approach was used for triple concentrated pastes for discrimination between two different Italian production areas. Accordingly, HS-SPME-GC-MS with 85 μm carboxen/polydimethylsiloxane fiber was used for the determination of the volatile fraction in tomatoes and triple concentrate tomato pastes samples. Ethyl isobututanoate was used as internal standard for semiquantitative analysis and the concentration data (μg/kg) of 38 compounds for tomatoes and of 32 compounds for triple concentrates were used in following chemometric analysis. Sixteen and three variables were selected by forward stepwise LDA for tomatoes and pastes, respectively. SLDA and SIMCA models showed respectively 96% and 94% in term of prediction ability for tomatoes. The two supervised techniques provided 100% and 97% in prediction of the production areas of tomato pastes, respectively.
Ten different varieties of tomatoes were separated into peel and flesh and each portion was measured separately. Headspace volatiles were measured in real time using selected ion flow tube mass spectrometry. Lipoxygenase activity was measured using the adsorption of conjugated dienes formed by lipoxygenase. Lipid was extracted and fatty acids were quantified using a gas chromatograph. Volatiles were significantly greater in the peel than flesh when there was a significant difference. The lipoxygenase activity of flesh and peel correlated with the volatiles produced by the lipoxygenase pathway. There was no correlation with other volatiles, which are not dependent on lipid oxidation by lipoxygenase. The lipoxygenase activity, total fatty acid content, and linolenic acid of the peel were greater than the flesh, which is directly related to an increase in fresh, green volatiles. Addition of exogenous lipoxygenase had no effect on lipoxygenase-derived volatiles formed. The addition of linoleic acid caused an increase in hexanal, 1-hexanol, and (E)-2-heptenal in the flesh and (E)-2-heptenal in the peel. Stored unrefrigerated peel had higher volatile concentrations, whereas refrigerated peel had significantly lower concentration than day 0. Storage decreased lipoxygenase activity in the unrefrigerated and refrigerated peel, but had no effect on the fatty acid content. Overall, linolenic acid was the most important to the formation of headspace volatiles, but lipoxygenase activity and unknown factors are also important.
Practical Application: The peel of a tomato is most beneficial to the production of volatiles associated with the fresh aroma of tomatoes; therefore, it should be used in the processing of tomato products to produce a fresh, green aroma rather than being removed. Knowledge of the effects of lipoxygenase activity, total fatty acid content, and fatty acid profile on flavor volatiles will allow for better selection of a variety for raw consumption.
Currently, sensory quality is the primary objective for almost all tomato breeding programs. In this study, postharvest behaviour
of a breeding line with genetic resistance to important viruses (ToMV, TSWV, and TYLCV) has been compared with the original
traditional landrace (Muchamiel) from an aromatic point of view. The breeding line has been obtained by backcrossing, introgressing three resistance genes
but trying to keep the aromatic characteristics of the traditional variety. The main aim was to obtain qualitative (solid
phase microextraction, SPME) and semi-quantitative (simultaneous steam-distillation extraction, SDE, and hydrodistillation,
HD) volatile compositions of Muchamiel tomatoes. Fruits were randomly picked at a green-immature stage and stored at 10°C during 13days. Volatile compositions
of tomatoes in two stages of ripening (green-immature and red-mature) were obtained by three different extraction methods:
SDE, HD, and SPME. Besides, sensory evaluation with a trained panel was carried out on both types of tomatoes at two ripening
stages. Main fresh tomato aroma compounds (cis-3-hexenal, hexanal, cis-3-hexanol, 6-methyl-5-hepten-2-one, 2-isobutylthiazole and β-ionone) were found at similar concentrations in both types of
samples, confirming the success of the breeding program. Finally, SPME could be considered as a useful tool to get realistic
values on fresh tomato odour, while HD and SDE results correlated better with fresh tomato aroma. Although a long time has
been required to develop the breeding line, results indicate that sensory quality has been recovered through backcrossing,
confirming the success of the breeding program.
KeywordsAroma-HD-Genetic improvement-SDE-
Solanum lycopersicum
-SPME
As part of their indirect defense, plants under herbivore attack release volatile chemicals that attract natural enemies of the herbivore. This is a very well-documented phenomenon. However, relatively few studies have investigated the response of plants to different population levels of herbivores and their feeding duration.
Working with larvae of the cabbage looper, Trichoplusia ni (Hübner), and tomato plants, Lycopersicon esculentum Mill cv. clarence, and using an ultrafast gas chromatograph (the zNose™) for volatile analyses, the authors studied the effect of larval density and feeding duration on levels of plant volatile emissions. Intense herbivory caused higher emission levels of the herbivore-induced plant volatiles (HIPVs) (Z)-3-hexenyl acetate, (E)-β-ocimene and β-caryophyllene than those caused by moderate herbivory. When herbivory had ceased following 12-24 h of larval feeding, plants kept releasing HIPVs at a high level for a longer period of time than they did following only 6 h of larval feeding. The plants' slow adjustment in their volatile emissions following prolonged larval feeding might be strategic, as such feeding is more likely to have ceased just temporarily.
This information may help in the development of a pest monitoring system that is based on herbivore-induced plant volatiles.
An investigation by aroma extract dilution analysis (AEDA) of the aroma concentrate of soy milk made from a major Japanese soybean cultivar, Fukuyutaka (FK), revealed 20 key aroma compounds having flavor dilution (FD) factors of not less than 64. Among them, 2-isopropyl-3-methoxypyrazine, cis-4,5-epoxy-(E)-2-decenal, trans-4,5-epoxy-(E)-2-decenal, 3-hydroxy-4,5-dimethyl-2(5H)-furanone, and 2'-aminoacetophenone were identified as the key aroma compounds in soy milk for the first time. (E,E)-2,4-Decadienal exhibiting a fatty note and trans-4,5-epoxy-(E)-2-decenal exhibiting a metallic/sweet note were detected as having the highest FD factors of 4096, followed by hexanal (green), (E)-2-nonenal (fatty), and (E,E)-2,4-nonadienal (fatty) having FD factors of 1024. Although all of these compounds might be generated from lipids, various aroma components, which were thought to be generated from amino acids, sugars, and ferulic acid, were detected having FD factors of 64-256. Investigation by comparative AEDA experiments of the soy milk aroma concentrates of two cultivars for soybean curd and soy milk, FK and Vinton81 (VT), and one cultivar for boiled beans, Miyagishirome (MY), revealed that most of the key aroma compounds were common to all of them, but 2-isopropyl-3-methoxypyrazine, exhibiting a pea-like/earthy note, was detected only in FK and VT. In addition, a sensory experiment revealed that the pea-like/earthy notes in FK and VT were significantly stronger than that in MY. These results demonstrated that a pea-like/earthy note contributed by 2-isopropyl-3-methoxypyrazine might be one of the essential characteristics to describe soy milk aromas.
MS has evolved as a critical component in metabolomics, which seeks to answer biological questions through large-scale qualitative and quantitative analyses of the metabolome. MS-based metabolomics techniques offer an excellent combination of sensitivity and selectivity, and they have become an indispensable platform in biology and metabolomics. In this minireview, various MS technologies used in metabolomics are briefly discussed, and future needs are suggested. © 2011 by The American Society for Biochemistry and Molecular Biology, Inc.
Monitoring of insect populations is an important component of integrated pest management and typically is based on the presence and number of insects in various development stages. Yet plants respond to insect herbivory and release herbivore-induced plant volatiles (HIPVs), which could be exploited in monitoring systems. The present objective was to investigate whether the information associated with HIPVs has potential to become part of advanced technologies for monitoring pest insect populations.
In a laboratory experiment, it was determined that tomato plants, Lycopersicon esculentum Mill cv. clarence, each infested with 20 caterpillars of the cabbage looper, Trichoplusia ni (Hübner), emit HIPVs, of which (Z)-3-hexenyl acetate, (E)-beta-ocimene and beta-caryophyllene were selected as chemicals indicative of herbivory. Using an ultrafast portable gas chromatograph (zNose()) in a research greenhouse and in a commercial greenhouse, it was possible (i) to reveal differential emissions of these three indicator chemicals from plants with or without herbivory, (ii) to detect herbivory within 6 h of its onset, (iii) to track changes in indicator chemical emissions over time and (iv) to study the effect of environmental and crop-maintenance-related factors on the emission of indicator chemicals.
HIPVs appear to be promising as reliable indicators of plant health, but further studies are needed to fully understand the potential of this concept.
The relationship between fruit maturation and volatile contents was investigated in two contrasted Cervil (CER) and Levovil (LEV) tomato ( Solanum lycopersicum ) lines. As fruits ripened, their volatile contents mainly increased. Although some compounds displayed contrasting patterns, overall, volatiles were clearly more abundant and conferred stronger aromas to CER than to LEV fruits. This intervarietal difference in volatile contents yielding much lower volatile contents in LEV was further investigated to determine whether it is due to a higher capacity of volatile glycosylation within LEV as compared to CER. Again, glycosides mainly increased during fruit maturation and were more abundant within CER than within LEV. Overall glycoside findings were indicative of a superior capacity to biosynthesize rather than an inferior capacity to glycosylate volatiles of CER. Eugenol and 2-methoxyphenol volatiles were exceptional compounds as they remained at higher levels in maturing LEV than in CER. 2-Methylthioacetaldehyde was for the first time identified as putatively related to differences of aroma between lines, as it was abundant in Cervil but absent in Levovil. Considering the described odor value of these three products, they should contribute differently to the particular olfactive features of LEV and CER fruits.
Two epimers of methyl (12S,13S)-(E)-12,13-epoxy-9-hydroperoxy-10-octadecenoate were isolated after esterification of a mixture of fatty acids obtained from
decomposition of (13S)-(9Z,11E)-13-hydroperoxy-9,11-octadecadienoic acid by an Fe++-cysteine catalyst. These epimeric epoxyhydro-peroxyoctadecenoates were decomposed by heat (210 C) in the injection port of
a gas chromatograph, and the cleavage fragments were subsequently separated by gas chromatography (GC) and identified by mass
spectrometry (MS). Among the scission products obtained, the most prominent in the GC peak profile were methyl octanoate and
methyl 9-oxononanoate. Other peaks were identified as pentane, 1-pentanol, hexanal, 2-heptanone, 2-pentylfuran, methyl heptanoate,
2-octenal, 4,5-epoxy-2-decenal, methyl 8-(2-furyl)-octanoate, 11-oxo-9-undecenoate and methyl 13-oxo-9,11-tridecadienoate.
In addition, 3,4-epoxynonanal, methyl 8-oxooctanoate, 3-hydroxy-2-pentyl-2,3-dihydrofuran and methyl 10-oxodecanoate were
tentatively identified. Except for the furan compounds, the formation of the fragmentation products could be explained by
conventional free-radical scission mechanisms.
Odour‐active compounds in muscle of turbot ( Psetta maxima ) fed experimental diets containing fish oil (FO), soybean oil (SO) or linseed oil (LO) were investigated by a gas chromatography/olfactometry technique. Thirty‐one areas associated with odours were detected in muscle extracts. Among the compounds responsible for these odours, 23 were formed by oxidation of unsaturated fatty acids. Independently of diet, ( E )‐2‐penten‐1‐ol and ( E )‐3‐hexen‐1‐ol contribute strongly to the odour of turbot. ( E , Z )‐2,6‐Nonadienal, ( E )‐2‐pentenal and ( E , E )‐1,3‐( Z )‐5‐octatriene seem to contribute strongly to the odour of turbot fed diets containing high levels of n‐3 PUFA (FO and LO groups). Hexanal and decanal show a high detection frequency in turbot fed diets containing vegetable oils. Odorous compounds which are not formed by lipid oxidation (methional, 1‐acetyl pyrazine, 4‐ethyl benzaldehyde and 2‐acetyl‐2‐thiazoline) were not affected by dietary lipid sources.
© 2001 Society of Chemical Industry
Incubation of linoleic or linolenic acid with tissue slices as well as cell-free extracts of tomato fruits produced hexanal. Biogenesis of hexanal from these fatty acids was further substantiated by the use of uniformally labelled ¹⁴C substrates. Based on the fact that hydrogen peroxide inhibited oxygen uptake and also production of carbonyls, it is apparent that lipoxidase is involved in these reactions. The activity of the crude soluble extract was increased by dialysis and ammonium sulphate fractionation.
In general, ripe fruits contained greater enzymatic activities but smaller amounts of linoleic and linolenic acid than green fruits. The enzymatic activity was enhanced by metal ions and compounds containing free -SH groups.
Although the flavor of tomatoes has been extensively studied over decades (1, 2, 5) it is not yet clear whether all odorants that are important contributors to fresh tomato aroma have been identified or whether the contribution of others has been overestimated. For the identification of the character impact odorants of fresh field tomatoes the method of aroma extract dilution analysis (AEDA, 4) was applied to several different tomato cultivars. This resulted in finding 20 odorants with flavor dilution (FD)-factors larger than 1, which seem to contribute to the flavor of fresh tomato. Among these were (Z)-3-hexenal, hexanal, 1-penten-3-one, 2-phenylethanol, (E)-2-hexenal, phenylacetaldehyde and β-ionone, but also β-damascenone, 4-hydroxy-2,5-dmethyi-3-(2H)-furanone (Furaneol®), methional, l-octen-3-one, guaiacol, (E,E)- and(E,Z)-2,4-decadienal and trans- and cis-4,5-epoxy-(E)-2-decenal, some of which have been underestimated so far. One previously unknown flavor compound in fresh tomato aroma was identified as (Z)-l,5-octadien-3-one. Different methods of sample preparation were employed. Solvent assisted flavor evaporation (SAFE, 5) was found to be the most suitable method for the quantification of tomato odorants. The concentrations of all important odorants were determined in two different tomato cultivars and the odor units (ratio of the concentration of a flavor compound and its odor threshold) were calculated. The biggest differences between the two cultivars were found in the concentrations and odor units of methional, phenylacetaldehyde, 1-penten-3-one and 4-hydroxy-2,5-dimethyl-3-(2H)-furanone.
The conversion of a tomato fruit from the mature green to fully ripe state involves dramatic changes in colour, composition, aroma, flavour and texture. Ripening used to be thought of simply as the result of a series of degradative processes, probably because some of the more obvious changes require the action of hydrolytic enzymes. However, it is now clear that ripening is dependent on a wide range of separate synthetic as well as degradative reactions. These include alterations in metabolism and gene expression which have a dramatic effect on fruit quality. The changes are highly coordinated; they occur in the majority of the cells of the fruit and involve every subcellular compartment. The various facets of ripening appear to be coordinated and regulated by plant hormones but may be modified by genetic and environmental factors. In this chapter the general features of tomato ripening are outlined first, together with a discussion of the cellular mechanisms regulating the process. This is followed by a consideration of the ways in which genotype, growing conditions, disease, and post-harvest history can influence specific quality attributes.
A simple new synthesis of primary and secondary nitro compounds which involves treating alkyl halides with sodium nitrite in dimethylformamide is described; 55-62% yields of pure nitro compounds are obtained.
The determination of the odor thresholds of Furaneol and norfuraneol in water and in buffered solutions showed that their thresholds varied depending on the pH of the solution, being lower the more acid the solution. Calculations of concentration/threshold ratios showed that Furaneol occurs at a concentration well above its threshold and is among the 10 compounds with the highest probability of contributing to both fresh and processed tomato aroma and flavor. Norfuraneol, however, occurs below its threshold concentration in fresh tomato and only slightly above in the paste and has only a low probability of contributing.
Thermal degradation of several possible precursors of the intense flavor compoundtrans-4,5-epoxy-(E)-2-decenal in model experiments revealed that the odorant is formed in significant yields from 13-hydroperoxy-9,11-octadecadienoic
acid (13-HPOD) and 9-hydroperoxy-10,12-octadecadienoic acid (9-HPOD). Of these hydroperoxides, arising in equal amounts during
autoxidation of linoleic acid, the 9-HPOD was established as the more effective precursor. The key intermediates in the generation
of the epoxyaldehyde were found to be 2,4-decadienal, arising from 9-HPOD, and 12,13-epoxy-9-hydroperoxy-10-octadecenoic acid,
a degradation product of 13-HPOD. Isolation and characterization of the precursors from a baking margarine confirmed glycerine-bound
9- and 13-HPOD as the intermediates in the formation of the epoxyaldehyde during heating of fats that contain linoleic acid.
Oct-1-en-3-one and the more potent octa-1,cis-5-dien-3-one have been identified as being responsible for the metallic odour which developed when a model system containing butterfat, α-tocopherol and cupric palmitate was allowed to oxidise at 35°C for 35 h. These vinyl ketones were synthesised, their mass and n.m.r. spectra determined, and odour descriptions and odour thresholds assessed. Octa-1, cis-5-dien-3-one in aqueous solution could be detected at a dilution of 1 in 1012. Its metallic odour was also described as like geranium leaves. Oct-1-en-3-one (detectable at 1 in 1010 dilution) was described as mushroom like at low concentrations and only exhibited a metallic odour at higher concentrations. Both compounds had an odour threshold concentration about five hundred times greater in groundnut oil than in water. The significance of these compounds is discussed with reference to the published literature and their formation from (n-3) and (n - 6) polyenoic fatty acids.
A few odor-active epoxyaldehydes, formed during lipid peroxidation, have recently been reported as intense aroma compounds in foods. However, very little is known about their flavor properties in general. Syntheses of homologous trans-2,3-epoxyalkanals (C(6)-C(12)) and trans-4,5-epoxy-(E)-2-alkenals (C(7)-C(12)) followed by structural characterization using mass spectrometry (MS/EI; MS/CI) and (1)H NMR measurements were performed. An evaluation of their odor qualities and odor thresholds by gas chromatography-olfactometry revealed the following: within the trans-2,3-epoxyalkanals, the odor quality changed from grassy for the compounds with six and seven carbon atoms to citrus-like or soapy for aldehydes with eight and more carbon atoms. The odor thresholds lay in the range of 3-15 ng/L (in air) and were nearly identical within the series; however, a slight minimum was measured for trans-2,3-epoxyoctanal to trans-2,3-epoxydecanal. In the series of the trans-4,5-epoxyalk-(E)-2-enals the C(10) compound was characterized by the lowest odor threshold of 0.6-2.5 pg/L of air. However, all trans-4,5-epoxy-alk-(E)-2-enals smelled intensely metallic.
Dilution techniques, like aroma extract dilution analysis (AEDA) and static headspace analysis and olfactometry (SHA-O), were applied to analyse food flavors. AEDA of soybean oil led to the identification of butane-2,3-dione and 3-methylnonane-2,4-dione as the most important odorants, which mainly caused the "butter-like" and "beany" off-flavors which were formed during storage of the oil in the presence of light. AEDA and SHA-O were also applied to fresh tomatoes and tomato paste. Due to the high flavor dilution (FD-factors, (E)-ß-damascenone, acetic acid, methional, 4-hydroxy-2,5-dimethyl-3(2H)-furanone, 3-hydroxy-4,5-dimethyl-2(5H)-furanone (Sotolon) and eugenol were the most important odorants in both samples. Differences in the FD-factors were found for (Z)-3-hexenal, which was the most important odorant compound in fresh tomatoes, but without significance for tomato paste. After quantification by isotope dilution assays 15 compounds in concentration levels equal to those in tomato pste were dissolved in water. As the aroma of this mixture was vey close to that of the original, the conclusion was drawn, that all of the odorants contibuting to the aroma paste hadbeen detected by the application of AEDA and SHA-O.
The concentrations of 44 of the major aroma components of tomato paste were determined. Comparison with studies for fresh tomatoes showed marked decreases in concentration for some compounds, particularly aliphatic aldehydes ((Z)-3-hexenal and hexanal >400 times lower) in the paste. Other compounds, however, such as the potent odorant β-damascenone (also 6-methyl-5-hepten-2-one, other ketones, linalool, and α-terpeneol) show severalfold increases in concentration in the paste. The observation by other workers of the formation of relatively large (0.5-10 ppm) concentrations of dimethyl sulfide in processed tomato was confirmed. Considerations of the odor thresholds of components and their determined concentrations indicated that the compounds most important to tomato paste aroma include dimethyl sulfide, β-damascenone, β-ionone, 3-methylbutanal, 1-nitro-2-phenylethane, eugenol, methional, 3-methylbutyric acid, 6-methyl-5-hepten-2-one, phenylacetaldehyde, and linalool.
A method for the quantitative analysis of major C5-C9 fresh tomato volatiles was developed using Tenax trapping and CaCl2 enzyme deactivation. Information was obtained on the concentrations of (Z)-3-hexenal, hexanal, 1-penten-3-one, 2-isobutyl cyanide, 2- and 3-methylbutanols, (E)-2-hexenal, (E)-2-heptenal, 6-methyl-5-hepten-2-one, (Z)-3-hexenol, 2-isobutylthiazole, and 6-methyl-5-hepten-2-ol in fresh ripe tomatoes. The identities of components were confirmed by GC-MS methods. Refrigerator storage (2°C) of fresh ripe tomatoes was found to lead to a lowering of the concentration of (Z)-3-hexenal and other volatiles in the macerated tomato. This provides a scientific basis for the informal subjective observation that such cold storage is deleterious to fresh tomato flavor. It is also of interest in regard to the generally expressed belief that there is a lack of flavor in fresh market tomatoes.
Application of an aroma extract dilution analysis to freshly prepared popcorn revealed 23 odorants among which 2-acetyl-1-pyrroline (roasty, popcorn-like), (E,E)-2,4-decadienal (fatty), 2-furfurylthiol (coffee-like), and 4-vinyl-2-methoxyphenol (spicy) predominated with the highest FD factors (odor activities). Further potent flavor compounds showing roasty odors were 2-acetyltetrahydropyridine and 2-propionyl-1-pyrroline. The latter compound showed a very low odor threshold of 0.02 ng/L (air), which was in the same magnitude as that reported for the 2-acetyl-1-pyrroline homologue. Sensory analysis of homologues 2-butanoyl- and 2-hexanoyl-1-pyrroline revealed that a longer alkyl side chain canceled the roasty flavor note and increased the odor thresholds by a factor of 10(5).
The volatile compound produced in greatest yield from the aerobic incubation at 35°C for 35 h of a mixture of butterfat, cupric palmitate and α-tocopherol was characterised by chromatography and spectroscopy. The same compound was also isolated from a similar reaction mixture containing cod-liver oil instead of butterfat. The compound was identified as trans-4,5-epoxyhept-trans-2-enal and was found to have the same properties as that synthesised by the epoxidation of hepta-trans-2,trans-4-dienal. Volatile epoxyalkenals of this type have not been previously identified as products from lipid oxidation.
ABSTRACTA systematic study was performed to determine the odorants contributing to the warmed-over flavor (WOF) of cooked beef patties. The most potent odorants of the freshly cooked patties and of the cooked, refrigerated and reheated patties showing WOF were screened by dilution experiments. Eleven odorants were selected for quantification by stable isotope dilution assays. Three aroma models were prepared on the basis of the results. A sensory comparison of the models indicated that WOF was the result of a combination of a loss of desirable odorants, e.g. 4-hy-droxy-2,5-dimethyl-3(2H)-furanone and 3-hydroxy-4,5-dimethyl-2(5H)-furanone, along with an increase in lipid peroxidation products, in particular n-hexanal and trans-4,5-epoxy-(E)-2-decenal.
SUMMARY38 compounds were identified in tomato volatiles. Some of these had not been reported previously. Many factors, namely, fruit maturity, the physical condition of the fruit, the type of fruit crushing, the holding time of the juice or pulp after crushing, heat and oxygen were important for the development of certain tomato volatiles. Linolenic acid was indicated to be the precursor of cis-3-hexenal which developed during tissue maceration. fn turn, cis-3-ehexenal appeared to be the source of tram-2-hexenal. Some of the compounds were found to be important to tomato flavor. 2-lsobutylthiazole and cis-3-hexenal appeared to intensify the fresh tomato flavor notes. 2-lsobutylthiazole was also responsible for the characteristic flavor of certain tomato varieties. The quality of tomato volatiles appeared to depend on the interrelationships of both enzymic and chemical reactions that occurred during the preparative treatments used to isolate the volatiles.
A compact and versatile distillation unit was developed for the fast and careful isolation of volatiles from complex food
matrices. In connection with a high vacuum pump (5×10–3 Pa), the new technique, designated solvent assisted flavour evaporation (SAFE), allows the isolation of volatiles from either
solvent extracts, aqueous foods, such as milk or beer, aqueous food suspensions, such as fruit pulps, or even matrices with
a high oil content. Application of SAFE to model solutions of selected aroma compounds resulted in higher yields from both
solvent extracts or fatty matrices (50% fat) compared to previously used techniques, such as high vacuum transfer. Direct
distillation of aqueous fruit pulps in combination with a stable isotope dilution analysis enabled the fast quantification
(60 min including MS analysis) of compounds such as the very polar and unstable 4-hydroxy-2,5-dimethyl-3(2H)-furanone in strawberries (3.2 mg/kg) and tomatoes (340 μg/kg). Furthermore, the direct distillation of aqueous foods, such
as beer or orange juice, gave flavourful aqueous distillates free from non-volatile matrix compounds.
The volatile compounds formed during autoxidation of linoleic acid and methyl linoleate at 22–24 °C were analysed by high resolution gas chromatography and eluate sniffing. The application of this technique to stepwise diluted extracts of the volatile compounds allowed the determination of a new parameter, theD-value, which reveals the most intense flavour compounds of an extract.
Hexanal, 2(Z)-octenal and 2(E)-nonenal exhibited the highestD-values in both lipids. 1-Octen-3-ol followed in the case of linoleic acid and 1-octen-3-one in that of methyl linoleate. The grading of the flavour compounds was dependent on the autoxidation time. 2(E)-Nonenal was the most potent aroma compound up to 24 h of linoleic acid autoxidation. After 48 h aldehyde and hexanal and after 72 h hexanal and 2(Z)-octenal possessed the highestD-values. TheD-value can also be used for the approximation of odour threshold values as demonstrated for 2(Z)-octenal, 2(E)-nonenal and 1-octen-3-ol.
The flavour compounds showing higher odour units resulting from peroxidation of unsaturated fatty acids were analysed comparatively in freshly boiled beef and in a stored (48 h, 4 C) sample exhibiting warmed-over flavour. The results obtained by aroma extract dilution analysis revealed that this flavour was mainly caused by hexanal, 1-octen-3-one, (E)- and (Z)-2-octenal, (Z)-2-nonenal, (E, E)-2,4-nonadienal andtrans-4,5-epoiiy-(E)-2-decenal.Die Aromastoffe mit hohen Aromawerten, die aus der Peroxidation ungesttigter Fettsuren hervorgehen, wurden in frisch gekochtem Rindfleisch und in einer gelagerten (48 h, 4 C) Probe mit WOF analysiert. Ein Vergleich der Ergebnisse von Aromaextraktverdnnungsanalysen ergab, da der WOF hauptschlich durch Hexanal, 1-Octen-3-on, (E)- und (Z)2-Octenal, (Z)-2-Nonenal, (E, E)-2,4-Nonadienal sowietrans-4,5-Epoxy-(E)-2-decenal verursacht wird.
Characterization of the crumb flavour of wheat bread by means of an aroma extract dilution analysis indicated diacetyl, methional, 1-octen-3-one, (Z)-and (E)-2-nonenal, (E,E)-2,4-decadienal andtrans-4,5-epoxy-(E)-2-decenal as the most potent odorants. The epoxydecenal had the lowest odour threshold (1.5 pg/L, air) among the homologous series oftrans-4,5-epoxy-(E)-2-alkenals C7-C11. Prolongation of the dough fermentation resulted in a change of the crumb flavour which was mainly due to an increase in the concentrations of 3-methylbutanol and 2-phenylethanol. Stable isotope dilution assays indicated that the concentrations of the roasty smelling flavour compounds 2-acetyl-1-pyrroline and 2-acetyltetrahydropyridine were 30-fold lower in the crumb than in the crust. (E)-2-Nonenal, which is present in the flour, increased strongly during the baking process.Durch eine Aromaextraktverdnnungsanalyse wurden Diacetyl, Methional, 1-Octen-3-on, (Z)- und (E)-2-Nonenal, (E,E)-2,4-Decadienal undtrans-4,5-Epoxy-(E)-2-decenal als intensivste Geruchsstoffe der Weibrotkrume ermittelt. In der homologen Reihe dertrans-4,5-Epoxy-(E)-2-alkenale C7-C11 hatte das Epoxydecenal die niedrigste Geruchsschwelle (1,5 pg/L, Luft). Bei einer Verlngerung der Fermentation des Teigs vernderte sich das Aroma der Krume durch einen Anstieg der Konzentrationen von 3-Methylbutanol und 2-Phenylethanol. Isotopenverdnnungsanalysen ergaben fr die rstig riechenden Aromastoffe 2-Acetyl-1-pyrrolin und 2-Acetyltetrahydropyridin 30mal niedrigere Konzentrationen in der Krume als in der Kruste. (E)-2-Nonenal, das schon im Mehl vorkam, nahm beim Backen stark zu.
Homogenates of tomato fruits catalysed the enzymic conversion of linoleic and linolenic acids (but not oleic acid) to C6 aldehydes in low (3–5%) molar yield. Hexanal was formed from linoleic acid; cis-3-hexenal and smaller amounts of trans-2-hexenal were formed from linolenic acid. With the fatty acids as substrates, the major products were fatty acid hydroperoxides (50–80% yield) and the ratio of 9- to 13-hydroperoxides as isolated from an incubation with linoleic acid was at least 95:5 in favour of the 9-hydroperoxide isomer. When the 9- and 13-hydroperoxides of linoleic acid were used as substrates with tomato homogenates, the 13-hydroperoxide was readily cleaved to hexanal in high molar yield (60%) but the 9-hydroperoxide isomer was not converted to cleavage products. Properties of the hydroperoxide cleavage system are described. The results indicate that the C6 aldehydes are formed from C18 polyunsaturated fatty acids in a sequential enzyme system involving lipoxygenase (which preferentially oxygenates at the 9-position) followed by a hydroperoxide cleavage system which is, however, specific for the 13-hydroperoxy isomers.
By application of the aroma extract dilution analysis on an extract prepared from fresh grapefruit juice, 37 odor-active compounds were detected in the flavor dilution (FD) factor range of 4-256 and subsequently identified. Among them the highest odor activities (FD factors) were determined for ethyl butanoate, p-1-menthene-8-thiol, (Z)-3-hexenal, 4,5-epoxy-(E)-2-decenal, 4-mercapto-4-methylpentane-2-one, 1-heptene-3-one, and wine lactone. Besides the 5 last mentioned compounds, a total of 13 further odorants were identified for the first time as flavor constituents of grapefruit. The data confirmed results of the literature on the significant contribution of 1-p-menthene-8-thiol in grapefruit aroma but clearly showed that a certain number of further odorants are necessary to elicit the typical grapefruit flavor.
It is proposed to describe briefly the rise in popularity of the tomato during the 20th century to become the world's fourth most significant fruit, making an important contribution to human nutrition. The grading standards for fruit used in various major tomato-producing countries will be outlined. A major part of the review will be devoted to describing changes in composition during the maturation, ripening, preservation, and storage of good quality tomatoes especially as regards carbohydrates, organic and amino acids, proteins, steroids, pigments, minerals, and the lipids, volatiles, and other minor constituents. A range within which composition should normally fall will be given. Additionally, the effects on composition of environment, cultivar, nutrition, and physiological disorders inter alia will be described. How new growing methods and genetic manipulation could influence the tomato of the future will also be considered.
Using gas chromatography-olfactometry and aroma extract dilution analysis 34 aroma compounds were found with flavour dilution factors > or = 4. (Z)-3-hexenal, hexanal, 1-octen-3-one, methional, 1-penten-3-one and 3-methylbutanal belonged to the most odour-active aroma volatiles in fresh tomatoes. Smell, taste and aftertaste of different tomato cultivars were evaluated by quantitative descriptive analysis. By applying principal component analysis to both sensory attributes and chemical compounds (odour-active aroma volatiles, titratable acid and reducing sugars) the first three components explained 70% of the total variance. The data set was reduced to the sensory attributes intensive, tomato, sour, fruity, sweet and bitter as well as to important chemical compounds. Relations between chemical compounds and sensory attributes were found.
This work describe products of reactions between four alpha-dicarbonyl compounds (diacetyl, pentan-2,3-dione, glyoxal, and methylglyoxal) or two alpha-hydroxy ketones, (acetoine and acetol) and amino acids present in wines. The results shows the formation of odorous products or strong-smelling additives resulting from the Maillard and Strecker reaction in a primarily aqueous medium, at low temperature and low pH ( approximately pH 3.5) of the wine. GC/FID, GC/FPD, GC/NPD and GC/MS techniques were used. The olfactive characteristics of the products are described. In the presence of sulfur amino acids and in particular cysteine, many products were formed with a heterocycle production such as pyrazines and methylpyrazines, methylthiazoles, acetylthiazoles, acetylthiazolines, acetylthiazolidines, trimethyloxazole, and dimethylethyloxazoles. These various compounds present odors of sulfur, cornlike, pungent, nut, popcorn, roasted hazelnut, toasted, roasted, and ripe fruits. The chemical conditions of the model reactions are specified. The influence of temperature and pH on the reactions in the presence of cysteine were also studied.
A few odor-active epoxyaldehydes, formed during lipid peroxidation, have recently been reported as intense aroma compounds in foods. However, very little is known about their flavor properties in general. Syntheses of homologous trans-2,3-epoxyalkanals (C(6)-C(12)) and trans-4,5-epoxy-(E)-2-alkenals (C(7)-C(12)) followed by structural characterization using mass spectrometry (MS/EI; MS/CI) and (1)H NMR measurements were performed. An evaluation of their odor qualities and odor thresholds by gas chromatography-olfactometry revealed the following: within the trans-2,3-epoxyalkanals, the odor quality changed from grassy for the compounds with six and seven carbon atoms to citrus-like or soapy for aldehydes with eight and more carbon atoms. The odor thresholds lay in the range of 3-15 ng/L (in air) and were nearly identical within the series; however, a slight minimum was measured for trans-2,3-epoxyoctanal to trans-2,3-epoxydecanal. In the series of the trans-4,5-epoxyalk-(E)-2-enals the C(10) compound was characterized by the lowest odor threshold of 0.6-2.5 pg/L of air. However, all trans-4,5-epoxy-alk-(E)-2-enals smelled intensely metallic.
High-flow dynamic headspace sampling with excess anhydrous sodium sulfate was found to be an effective method of isolating Furaneol from fresh tomatoes. Quantitative analysis was carried out by gas chromatography using maltol as internal standard. Furaneol was found in the highest concentrations (660-1100 ppb) in the summer crop of home-grown tomatoes and in some of the greenhouse hydroponically grown tomatoes, which are ripened on the plant before being transported to the supermarkets. Furaneol was found in the lowest concentrations (38-180 ppb) in the common ethylene-ripened, field-grown, supermarket tomatoes.
Lactic acid bacteria were screened for methional production from 4-methylthio-2-ketobutanoate. Only Lactococcus lactis IFPL730 produced high amounts of methional. It was demonstrated that production of this compound was an exclusively enzymatic reaction. The present work describes for the first time that L. lactis can convert enzymatically methionine to methional in a process mediated by aminotransferase and α-ketoacid decarboxylase activities. The activity seems to be strain dependent. © 2001 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.
Significant tomato matrix effects on the volatility of certain fresh tomato odorants were found. The concentrations of odorants such as (E,E)-2,4-decadienal, beta-damascenone, and beta-ionone, in crushed fresh tomato fruit obtained by solid-phase microextraction (SPME), resulting from a tomato matrix calibration curve were 5.5-, 2-, and 12-fold higher, respectively, than those calculated by calibration based on buffer solutions. Static headspace analyses indicated that, in most cases, the tomato matrix significantly retains the odorants relative to the buffer solution. Thus, the concentration of odorants in the headspace of tomato is lower than expected compared to a simple matrix such as buffer. CaCl(2), although needed in crushed fruit tissue to block enzymatic activity, was found to interact specifically with 2-isobutylthiazole, reducing its content in the headspace by at least 6-fold. If a matrix effect is found, analysis of the odorant molecule contents in the headspace rather than in the food is recommended in order to better evaluate their access to the olfactory receptors.
In a black tea (Dimbula) infusion, the potent "sweet and/or juicy" odorants were identified as the cis- and trans-4,5-epoxy-(E)-2-decenals by comparison of their gas chromatography retention indices, mass spectra, and odor quality to those of the actual synthetic compounds. Of the two odorants, cis-4,5-epoxy-(E)-2-decenal has been identified for the first time in the black tea. On the basis of the aroma extract dilution analysis on the flavor distillate obtained using the solvent-assisted flavor evaporation technique from the black tea infusion, these isomers showed higher flavor dilution (FD) factors. The FD factors and concentrations of these odorants in the black tea infusion were observed to be much higher than those from Japanese green tea. In addition, the model studies showed that these odorants were generated from linoleic acid and its hydroperoxides by heating, but the generated amounts of these odorants from linoleic acid were much less than those of its hydroperoxides. It can be assumed from these results that the withering and fermentation, which are characteristic processes during the manufacturing of the black tea, which includes the enzymatic reaction such as lipoxygenase, is one of the most important factors for the formation of the epoxydecenal isomers.
Differences in the aroma of selected fresh tomato cultivars
- F Mayer
- G Takeoka
- R Buttery
- L Whitehand
- Y Bezman
- M Naim
- H D Rabinowitch
Mayer, F.; Takeoka, G.; Buttery, R.; Whitehand, L.; Bezman, Y.;
Naim, M.; Rabinowitch, H. D. Differences in the aroma of selected
fresh tomato cultivars. In Handbook of FlaVor Characterization:
Sensory Analysis, Chemistry, and Physiology; Food Science and
Technology 131; Deibler, K. D., Delwiche, J., Eds.; Dekker: New
York, 2004; pp 189-205.
Fresh tomato aroma volatiles: a quantitative study Analysis of furaneol in tomato using dynamic headspace sampling with sodium sulfate
- R G Buttery
- R Teranishi
- L C Ling
- R G Buttery
- G R Takeoka
- M Naim
Buttery, R. G.; Teranishi, R.; Ling, L. C. Fresh tomato aroma volatiles: a quantitative study. J. Agric. Food Chem. 1987, 35, 540–544. (22) Buttery, R. G.; Takeoka, G. R.; Naim, M.; Rabinowitch, H. D.; Nam, Y. Analysis of furaneol in tomato using dynamic headspace sampling with sodium sulfate. J. Agric. Food Chem. 2001, 49, 4349–4351.
Fresh tomato volatiles In FlaVor Chemistry, Trends and DeVelopments
- R G Buttery
- R Teranishi
- R A Flath
- L Ling
- R Teranishi
- R G Buttery
- F Shahidi
Buttery, R. G.; Teranishi, R.; Flath, R. A.; Ling, L. C. Fresh tomato volatiles. In FlaVor Chemistry, Trends and DeVelopments; Teranishi, R., Buttery, R. G., Shahidi, F., Eds.; ACS Symposium Series 388; American Chemical Society: Washington, DC, 1989; Chapter 17, pp 213–222.
Conversion of methionine to methional by Lactococcus lactis Received for review November 9 Revised manuscript received March 3 This research was supported by Research Grant Award IS-2980-98 from BARD, the United States-Israel Binational Agricultural Research and Development Fund
- F Amárita
- Fernández
- D Esplá
- T Requena
- C Pelaez
Amárita, F.; Fernández-Esplá, D.; Requena, T.; Pelaez, C. Conversion of methionine to methional by Lactococcus lactis. FEBS Microbiol. Lett. 2001, 204, 189–195. Received for review November 9, 2007. Revised manuscript received March 3, 2008. Accepted March 8, 2008. This research was supported by Research Grant Award IS-2980-98 from BARD, the United States-Israel Binational Agricultural Research and Development Fund. JF0732915 Fresh Tomato Aromas J. Agric. Food Chem., Vol. 56, No. 10, 2008 3757
Volatile Compounds in Food, QualitatiVe and QuantitatiVe Data
- Ed Nijssen
- L M Visscher
- C A Maarse
- H Willemsens
- L C Boelens
(1) Volatile Compounds in Food, QualitatiVe and QuantitatiVe Data, 7th ed.; Nijssen, L. M., Visscher, C. A., Maarse, H., Willemsens, L. C., Boelens, M. H., Eds.; TNO Nutrition and Food Research Institute: Zeist, The Netherlands, 1996; Vegetables 29.1–29.12
Differences in the aroma of selected fresh tomato cultivars. In Handbook of FlaVor Characterization: Sensory Analysis
- M Naim
- H D Rabinowitch
Naim, M.; Rabinowitch, H. D. Differences in the aroma of selected fresh tomato cultivars. In Handbook of FlaVor Characterization: Sensory Analysis, Chemistry, and Physiology; Food Science and Technology 131; Deibler, K. D., Delwiche, J., Eds.; Dekker: New York, 2004; pp 189–205.
Enzymatic production of volatiles in tomatoes
- R G Buttery
- L Ling
Buttery, R. G.; Ling, L. Enzymatic production of volatiles in
tomatoes. In Progress in FlaVour Precursor Studies; Schreier, P.,
Winterhalter, P., Eds.; Allured Publishing: Carol Stream, IL, 1993;
pp 137-146.
Studies on the flavour of roasted white sesame seeds In Progress in FlaVour Precusor Studies
- P Schieberle
(14) Schieberle, P. Studies on the flavour of roasted white sesame seeds.
In Progress in FlaVour Precusor Studies; Schreier, P., Winterhalter, P., Eds.; Allured Publishing: Carol Stream, IL, 1993; pp
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Aroma of fresh field tomatoes. In Freshness and Shelf Life of Foods
- F Mayer
- G Takeoka
- R Buttery
- Y Nam
- M Naim
- Y Bezman
- H D Rabinowitch
Mayer, F.; Takeoka, G.; Buttery, R.; Nam, Y.; Naim, M.; Bezman, Y.; Rabinowitch, H. D. Aroma of fresh field tomatoes. In Freshness and Shelf Life of Foods; Cadwallader, K. R., Weenen, H., Eds.; ACS Symposium Series 836; American Chemical Society: Washington, DC, 2002; pp 144–161.
Odorants contributing to warmed-over flavor (WOF) of refrigerated cooked beef) Schieberle, P.; Grosch, W. Potent odorants of the wheat bread crumbsdifferences to the crust and effect of a longer dough fermentation
- J Kerler
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(11) Kerler, J.; Grosch, W. Odorants contributing to warmed-over flavor
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(12) Schieberle, P.; Grosch, W. Potent odorants of the wheat bread
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fermentation. Z. Lebensm. Unters. Forsch. 1991, 192, 130-135.
Formation of flavor components by the reaction of amino acid and carbonyl compounds in mild conditions
- L Pripis-Nicolau
- G De Revel
- A Bertrand
- A Mauean
Pripis-Nicolau, L.; de Revel, G.; Bertrand, A.; Mauean, A.
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