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As part of our efforts to identify volatile decomposition products in used frying oils, a series of 4- and 5-oxoaldehydes were synthesized, purified, and characterized by gas chromatography, gas chromatography-mass spectrometry, gas chromatography-Fourier transform infrared spectrometry, and nuclear magnetic resonance spectrometry. Oxoaldehydes have been proposed as possible precursors of alkylfurans, which have potential anticancer effects. In a model reaction 4-oxononanal was refluxed in hexane for 40 days and only trace amounts of 2-pentylfwan were produced, suggesting that it is not a major precursor of the furan. The volatile constituents of used frying oils obtained from commercial food processors were studied, and 4-oxohexanal, 4-oxooctanal, 4-oxononanal, and 4-oxodecanal were identified

Infrared heating was recently used to develop a more efficient roasting technology than traditional hot air roasting. Therefore, in this study, we evaluated the shelf-life of almonds roasted with three different approaches, namely infrared (IR), sequential infrared and hot air (SIRHA) and regular hot air (HA). Nine medium roasted almond samples produced by the aforementioned heating methods were processed at three different temperatures (130, 140 and 150 C), packed in paper bags and then stored at 37 C for three, six or eight months. Shelf-life of the roasted almonds was determined by measuring the changes in colour, peroxide value, moisture content, water activity, volatile components and sensory quality. No significant difference was observed in moisture content and water activity among the almond samples processed with different roasting methods and stored under the same conditions. GC/MS analysis showed that aldehydes, alcohols, and pyrazines were the main volatile components of almonds. Aliphatic alde- hydes such as hexanal, (E)-2-octenal, and nonanal were produced as off-odours during storage. Although the overall quality of roasted almonds produced with SIRHA and HA heating was similar during the first three months of storage, their peroxide value and concentration of aliphatic aldehydes differed signifi- cantly for different roasting methods and increased significantly in all roasted samples during storage. We postulate that hexanal and nonanal might be better indicators of the shelf life of roasted almonds than the current standard, peroxide value.

Preface Overview and Analytical Methods 1. Progress in Authentication of Food and Wine Gary R. Takeoka and Susan E. Ebeler 2. NMR Studies in Food Authentication Roberto Consonni and Laura Ruth Cagliani 3. Establishing Natural Product Content with the Natural Radiocarbon Signature Bruce A. Buchholz, Miranda J. Sarachine, and Paula Zermeno 4. Using Chemometrics To Classify Samples and Detect Misrepresentation Karl J. Siebert Authentication of Wine and Alcholic Beverages 5. Authentication Approach of the Chemodiversity of Grape and Wine by FTICR-MS Regis D. Gougeon, Marianna Lucio, Lemia Boutegrabet, Dominique Peyron, Francois Feuillat, David Chassagne, Herve Alexandre, Andree Voilley, Philippe Cayot, Istvan Gebefugi, Norbert Hertkorn, and Philippe Schmitt-Kopplin 6. Authentication of Red Wine Vintage Using Bomb-Pulse 14C Robert E. Asenstorfer, Graham P. Jones, Gerald Laurence, and Ugo Zoppi 7. Overview of Chemical Markers for Varietal Authentication of Red Wines Carola Vergara, Dietrich von Baer, Claudia Mardones, and Luis Gutierrez 8. Flavonol Profiles for Grape and Wine Authentication Isidro Hermosin-Gutierrez, Noelia Castillo-Munoz, Sergio Gomez-Alonso, and Esteban Garcia-Romero 9. Authentication of Different Terroirs of German Riesling Applying Sensory and Flavor Analysis Andrea Bauer, Sascha Wolz, Anette Schormann, and Ulrich Fischer 10. Analytical and Multivariate Statistical Methods for Differentiation of Wines Produced with Oak Chips and Barriques Magdalena Muller, Norbert Christoph, Helmut Wachter, Hans-Juergen Koehler, and Peter Winterhalter 11. Correlation between the Concentrations of Two Oak Derived Key Odorants and the Intensity of a Woody- " Odor Note in Different Red Wines Stephanie Frank and Peter Schieberle Authentication of Foods and Beverages 12. Authentication of Foods Enriched with Plant Sterols/Stanols and Their Esters Karl-Heinz Engel and Andreas Barnsteiner 13. Authenticity Control of Oils and Fats via Large Capacity Sorptive Extraction Andreas Degenhardt, Stefan Brennecke, Birgit Kohlenberg, Margit Liebig, Lars Grohmann, Rudiger Wittlake, Berthold Weber, and Gerhard Krammer 14. Phenolic Compounds as Markers for the Authentication of Sherry Vinegars: A Foresight for High Quality Vinegars Characterization M. C. Garcia-Parrilla, A. B. Cerezo, W. Tesfaye, and A. M. Troncoso 15. Proteolytic Peptides as Molecular Markers of Species' Authenticity in Cheeses Stefano Sforza, Francesca Lambertini, Laura Manzini, Gianni Galaverna, Arnaldo Dossena, and Rosangela Marchelli 16. Authenticity of Caffeine Containing Beverages Ulrich H. Engelhardt 17. Evaluation of an FDA Method for the Determination of Melamine and Cyanuric Acid in Food by Liquid Chromatography-Tandem Mass Spectrometry Alexander J. Krynitsky, Michael S. Smoker, Jon W. Wong, Steven Barrientos, and John A. G. Roach Authentication of Fruit Juices and Fruit Products 18. Authentication of Fruit Juices Derived from Morinda citrifolia (Noni) S. Tolle, V. Lander, and P. Winterhalter 19. Authentication of Fruit Juice Aroma: Evaluating Re-Aromatization Carolin Wolter, Achim Gessler, and Peter Winterhalter 20. Rapid Authentication of Fruit Juices by Infrared Spectroscopic Techniques M. Monica Giusti, Allison Atnip, Christian Sweeney, and Luis E. Rodriguez-Saona 21. Quality and Authenticity Control of Fruit-Derived Products Andreas Schieber, Ralf Fugel, Christina Kurz, and Reinhold Carle Authentication of Spices, Herbs, and Botanicals 22. Authentication of Saffron Spice (Crocus sativus L.) Ana M. Sanchez, Luana Maggi, Manuel Carmona, and Gonzalo L. Alonso 23. Multiresidue Pesticide Analysis of Ginseng and Other Botanical Dietary Supplements Jon W. Wong, Kai Zhang, Feng Shi, Douglas G. Hayward, Carolyn M. Makovi, Alexander J. Krynitsky, Katherine Tech, Alex L. DiBenedetto, and Nathaniel S. Lee 24. Detecting the Components of Botanical Mixtures by Single-Strand Conformation Polymorphism Analysis Michelle R. Lum and Ann M. Hirsch Editors' Biographies Indexes Author Index Subject Index

Root oil of Ligusticum grayi (Apiaceae) contains numerous irregular sesquiterpenoids. In addition to the known acyclic sesquilavandulol and a sesquilavandulyl aldehyde, two thapsanes, one epithapsane, and 14 sesquiterpenoids representing eight hitherto unknown carbon skeletons were found. These skeletons are: prethapsane, i.e. 1,1,2,3a,7,7-hexamethyloctahydro-1H-indene; isothapsane, i.e. 1,2,3a,6,7,7a-hexamethyloctahydro-1H-indene; ligustigrane, i.e. 1,1,2,7,7,7a-hexamethyloctahydro-1H-indene; isoligustigrane, i.e. 1,1,2,6,7,7a-hexamethyloctahydro-1H-indene; preisothapsane, i.e. 1,1,2,3a,6,7-hexamethyloctahydro-1H-indene; isoprethapsane, i.e. 1,1,2,4,7,7-hexamethyloctahydro-1H-indene; allothapsane, i.e. 1,1,2,3a,7,7a-hexamethyloctahydro-1H-indene; and oshalagrane, i.e. 1,1,2,4,6,6-hexamethylspiro[4.4]nonane. The bicyclic sesquiterpenoids are presumably biosynthesized by head-to-head coupling of geranyl diphosphate and dimethylallyl diphosphate, followed by a cyclization sequence leading to a hydroindane skeleton with six one-carbon substituents. Subsequent rearrangements--primarily methyl migrations--account for the remarkable variety of structures represented in L. grayi root oil.

The volatiles of Asian pear (Seuri cultivar) were studied by high-resolution gas chromatography and combined gas chromatography/mass spectrometry (GUMS) using vacuum simultaneous distillationextraction of blended fruit and dynamic headspace sampling of intact and enzymatically inhibited blended fruit. Esters were the dominant constituents in all of the samples. A total of 72 components were identified in the headspace of intact fruit, including 39 constituents reported for the first time in pear. Odor unit values calculated from concentration and odor threshold data indicate that the following compounds are important contributors to pear aroma: ethyl 2-methylbutanoate, ethyl hexanoate, ethyl butanoate, ethyl 2-methylpropanoate, hexyl acetate, ethyl heptanoate, hexanal, ethyl pentanoate, and ethyl propanoate. Asian pears (Pyrus serotina) are a completely distinct species from the more common European-type pears (Pyrus communis L.) such as Bartlett and La France and are not a cross between apples and pears. Though the volatile constituents of Bartlett pears have been extensively investigated (Maarse and Visscher, 1984), there has been, to our knowledge, only one publication on the flavor compounds of Asian pears (Shiota et al., 1981). These researchers studied four Asian pear cultivars [Nijisseiki (20th Century), Kosui, Hosui, and Kikusuil and found distinct compositional differences between the peel and pulp. The peel contained major amounts of nonanal, cy-farnesene, phenylacetaldehyde, and straight-chain hydrocarbons with 19-23 carbon atoms, while the pulp had ethyl butanoate, hexanol, hexyl acetate, butylbenzene, and

Three triterpenoids, betulinic acid, oleanolic acid, and ursolic acid, were isolated as their methyl esters (treatment with diazomethane) from diethyl ether extracts of almond hulls (Nonpareil variety) using flash chromatography and preparative high-performance liquid chromatography. The triterpenoids, which comprised approximately 1% of the hulls, were characterized using chromatographic and spectroscopic methods. These studies demonstrate that almond hulls are a rich source of these triterpenoids, which have reported anti-inflammatory, anti-HIV, and anti-cancer activities.

T h e volatiles of pineapple essence were isolated by liquid-liquid extraction, fractionated on neutral alumina, and analyzed by high-resolution gas chromatography and coupled gas chromatography/mass spectrometry (GC/MS). Twenty-six constituents (1 tentative) were identified for the Wrst t ime in pineapple including the following sulfur compounds: methyl 3-(methylthi0)-(E)-2-propenoate, methyl 3-(methy1thio)-(2)-2-propenoate, ethyl 3-(methy1thio)-(E)-2-propenoste, ethyl 3-(methy1thio)-(2)-2propenoate, methyl 4-(methylthio)butanoate, ethyl 4-(methy1thio)butanoate (tentative), and dimethyl trisulfide. Their odor contribution t o pineapple aroma is assessed.

Analytical Methods in Flavor Research Comprehensive Two-Dimensional Gas Chromatography: Application to Aroma and Essential Oil Analysis Analytical and Sensory Characterization of Chiral Flavor Compounds via Capillary Gas Chromatography on Cyclodextrins Modified by Acetal-containing Side Chains Improved Application of Semiconducting Metal Oxides as a Detector for High-Resolution Gas Chromatography Measurement of Flavor-Soy Protein Interactions in Low Moisture Solid Food Systems by Inverse Gas Chromatography Flavor Chemistry of Foods Volatile Components and Characteristic Odorants in Headspace Aroma Obtained by Vacuum Extraction of Philippine Pineapple (Ananas comosus [L.] Merr.) C13-Norisoprenoid Concentrations in Grapes as Affected by Sunlight and Shading Effects of Characteristic Volatiles of Boiled Celery on Chicken Broth Flavor Identification of Aroma Components during Processing of the Famous Formosa Oolong Tea "Oriental Beauty" Volatile Constituents of Mesquite (Prosopis) Pods Flavor Formation Painting and Memory in the Discovery of Aroma Chemicals: The Case of Sulfur Containing Odorants and Odorant Precursors in Axillary Sweat Odour Effect of Irradiation and Other Processing Treatments on the Flavor Quality of Apple Cider Maillard Volatile Generation from Reaction of Glucose with Dipeptides, Gly-Ser and Ser-Gly The role of (5E)-2,6-Dimethyl-5,7-octadiene-2,3-diol as Aroma Precursor in Badea (Passiflora quadrangularis L.) Fruit Genes and Enzymes Involved in Strawberry Flavor Formation Volatiles from the Thermal Interaction of E-2-pentenal with Methionine or Cysteine under Non-aqueous Conditions Flavor Contribution and Formation of Epoxydecenal Isomers in Black Tea Sensory Evaluation of Foods and Flavors Mixture Suppression of Perceived Intensities in an Odor Mixture Why Naturally Healthy Berries May Be Seen as Unpleasant and Non-appetitive? Picking Aroma Character Compounds in Citrus limon Oils by Using Odor Thresholds in Aroma Mixtures Flavor Release and Perception of Custard Desserts: Influence of Food Composition and Oral Parameters Biological Activity of Essential Oils and Flavors Evaluation of the Antioxidant Potential of Various Plant Essential Oils Some Biological Effects of Raspberry Ketone and Its Precursor

Piperlongumine, a pyridone alkaloid isolated from Piper longum L., exhibited a potential inhibitory effect on washed rabbit platelet aggregation induced by collagen, arachidonic acid (AA) and platelet activating factor (PAF), without any inhibitory effect on that induced by thrombin. Piperlongumine was used as a lead compound for the synthesis of new antiplatelet agents. Seven synthetic compounds were newly synthesized from 3,4,5-trimethoxycinnamic acid (TMCA). They were 1-piperidin-1-yl-3-(3,4,5-trimethoxy-phenyl)prop-2-en-1-one (1'), 1-morpholin-4-yl-3-(3,4,5-trimethoxyphenyl)prop-2-en-1-one (2'), 1-(3,5-dimethylpiperidin-1-yl)-3-(3,4,5-trimethoxyphenyl)prop-2-en-1-one (3'), 1-(2-methylpiperidin-1-yl)-3-(3,4,5-tri-methoxyphenyl)prop-2-en-1-one (4'), 1-(3-hydroxypiperidin-1-yl)-3-(3,4,5-trimethoxyphenyl)- prop-2-en-1-one (5'), 1-[3-(3,4,5-tri-methoxyphenyl) acryloyl]-piperidin-2-one (6') and ethyl 1-[3-(3,4,5-trimethoxyphenyl)-acryloyl]piperidine-4-carboxylate (7'). Among those seven synthetic derivatives, 1-(3,5-dimethylpiperidin-1-yl)-3-(3,4,5-trimethoxyphenyl)prop-2-en-1-one (3') had the most inhibitory effect on platelet aggregation induced by collagen, AA and PAF.

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.

The study was begun to learn more about volatile-producing tomato glycosides. Hydrolysis of the glycoside fraction was carried out at pH 2.5, 3.0, 4.1 and 5.0 to give the volatile aglycons, which were isolated by steam distillation extraction. Volatile compounds were identified by GC-MS.

Des applications des colonnes capillaires contenant la β-cyclodextrine permethylee sont presentees telles que des separations d'enantiomeres de monoterpenes, de sesquiterpenes et des esters

Le defaut Rio provoque un arriere gout prononce de medicament. Le but de l'etude est d'identifier les composes responsables de ce defaut. Les composes volatils extraits sont analyses par CPG, CPG couplee a la spectrometrie de masse ou a une detection olfactive

Commercial grapefruit seed extracts (GSE) were extracted with chloroform. The solvent was evaporated, and the resulting solid was subsequently analyzed by high-performance liquid chromatography (HPLC), electrospray ionization mass spectrometry (ESI/MS), tandem mass spectrometry (ESI/MS/MS), and elemental analysis (by proton-induced X-ray emission analysis). Three major constituents were observed by HPLC and were identified as benzyldimethyldodecylammonium chloride, benzyldimethyltetradecylammonium chloride, and benzyldimethylhexadecylammonium chloride. This mixture of homologues is commonly known as benzalkonium chloride, a widely used synthetic antimicrobial ingredient used in cleaning and disinfection agents.

The antiplatelet and antiproliferative activities of extract of Tabebuia impetiginosa inner bark (taheebo) were investigated using washed rabbit platelets and cultured rat aortic vascular smooth muscle cells (VSMCs) in vitro. n-Hexane, chloroform and ethyl acetate fractions showed marked and selective inhibition of platelet aggregation induced by collagen and arachidonic acid (AA) in a dose-dependent manner. These fractions, especially the chloroform fraction, also significantly suppressed AA liberation induced by collagen in [(3)H]AA-labeled rabbit platelets. The fractions, especially the chloroform fraction, potently inhibited cell proliferation and DNA synthesis induced by platelet derived growth factor (PDGF)-BB, and inhibited the levels of phosphorylated extracellular signal regulated kinase (ERK1/2) mitogen activated protein kinase (MAPK) stimulated by PDGF-BB, in the same concentration range that inhibits VSMC proliferation and DNA synthesis.

The growth-inhibiting activity of anthraquinone-2-carboxylic acid and lapachol identified in the inner bark of taheebo, Tabebuia impetiginosa, toward 10 human intestinal bacteria was evaluated by using a paper disk diffusion bioassay and compared to those of seven lapachol congeners (1,4-naphthoquinone, naphthazarin, menadione, lawsone, plumbagin, juglone, and dichlone) as well as two commercially available antibiotics, chloramphenicol and tetracycline. Anthraquinone-2-carboxylic acid exhibited very strong growth inhibition of Clostridium paraputrificum at 1 microg/disk while 100 microg/disk of lapachol was needed for moderate growth inhibition of the same organism. These two isolates exhibited weak inhibition of Clostridium perfringens and Escherichia coli at 100 microg/disk while no adverse effects were observed on the growth of Bifidobacterium adolescentis, Bifidobacterium bifidum, Bifidobacterium infantis, Lactobacillus acidophilus, and Lactobacillus casei at 1000 microg/disk. Structure-activity relationships indicate that a methyl group in the C-2 position of 1,4-naphthoquinone derivatives might play an important role in antibacterial activity.

The identities and possible origins of three minor unusual volatile components of tomato are discussed. These are pentyl nitrate, the first identification of a volatile alkyl nitrate in a fresh vegetable or fruit; 5-ethyl-2(5H)-furanone, which, besides its presence in tomato, was found to be a major autoxidation product of pure (Z)-3-hexenal; and 5-ethylcyclopentene-1-carbaldehyde, a likely unusual linolenic acid oxidation product.

The effects of methanol extract from Hericium erinaceus cultivated with Artemisia iwayomogi (HEAI) on proliferation of vascular smooth muscle cells and CCl(4)-induced hepatic damage were evaluated. HEAI was shown to have a potent inhibitory effect on the proliferation of vascular smooth muscle cells (VSMCs). Interestingly, a methanol extract of Hericium erinaceus showed no inhibitory effect on the proliferation of VSMCs, while a methanol extract of Artemisia iwayomogi possessed strong inhibitory effects on the proliferation of VSMCs. Therefore, the inhibitory effects of HEAI may be caused by the changes of chemical components in the culture broth after the addition of Artemisia iwayomogi in the HEAI growth media. HEAI also had a strong protective effect on CCl(4)-induced hepatic damage in rats. The activity was evaluated using biochemical parameters such as glutamic oxalacetic transaminase (GOT), glutamic pyruvic transaminase (GPT) and alkaline phosphatase (ALP). HEAI treatment caused a significant reduction in the activity of GOT but not of GPT and ALP in comparison with CCl(4) treatment alone. Histopathological studies showed that liver samples treated with HEAI were significantly different when compared to non-treated animals after CCl(4) exposure.

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.

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.

Almond hulls (Nonpareil variety) were extracted with methanol and analyzed by reversed phase HPLC with diode array detection. The extract contained 5-O-caffeoylquinic acid (chlorogenic acid), 4-O-caffeoylquinic acid (cryptochlorogenic acid), and 3-O-caffeoylquinic acid (neochlorogenic acid) in the ratio 79.5:14.8:5.7. The chlorogenic acid concentration of almond hulls was 42.52 +/- 4.50 mg/100 g of fresh weight (n = 4; moisture content = 11.39%). Extracts were tested for their ability to inhibit the oxidation of methyl linoleate at 40 degrees C. At an equivalent concentration (10 microg/1 g of methyl linoleate) almond hull extracts had higher antioxidant activity than alpha-tocopherol. At higher concentrations (50 microg/1 g of methyl linoleate) almond hull extracts showed increased antioxidant activity that was similar to chlorogenic acid and morin [2-(2,4-dihydroxyphenyl)-3,5,7-trihydroxy-4H-1-benzopyran-4-one] standards (at the same concentrations). These data indicate that almond hulls are a potential source of these dietary antioxidants. The sterols (3beta,22E)-stigmasta-5,22-dien-3-ol (stigmasterol) and (3beta)-stigmast-5-en-3-ol (beta-sitosterol) (18.9 mg and 16.0 mg/100 g of almond hull, respectively) were identified by GC-MS of the silylated almond hull extract.

The water-soluble volatile components of fresh tomatoes were isolated by liquid-liquid continuous ether extraction of filtered blended tomato and separated from non-volatiles by high flow dynamic headspace sampling, after careful evaporation of the ether. Capillary GCMS analysis identified the important aroma compound 2,5-dimethyl-4-hydroxy-3(2H)-furanone (furaneol) and the related compound 5-methyl-4-hydroxy-3(2H)-furanone occurring in the fresh tomato at concentrations of the order of 2 mg and 10 mg/kg of tomato respectively. From the odor threshold and concentration evidence it seems probable that Furaneol contributes to fresh and processed tomato aroma.

Microcellular starch foams (MCFs) are made by a solvent-exchange process and consist of a porous matrix with pores generally ranging from approximately 2 microm to submicrometer size. MCF may potentially be useful as a slow-release agent for volatile compounds because of its ability to sorb chemicals from the atmosphere and to absorb liquids into its porous structure, and because it can be compressed to form a starch plastic. MCF made of high-amylose corn and wheat starches was prepared with or without 2% (w/w) silicone oil (SO) or palmitic acid (PA). The MCF was loaded with 1% of various volatile compounds with vapor pressures ranging from 0.02 to 28 mm. The MCF depressed the vapor pressure from 0.37 to 37% compared to a control containing no MCF. Incorporating SO or PA in the matrix of the MCF had little effect on sorption of volatiles. Compressing MCF at 1.4, 6.9, and 69 MPa made a starch plastic with varying porosity. The vapor transmission rate of various volatile compounds through MCF was positively correlated to the vapor pressure of the test compound but was inversely proportional to the compression force used to form the starch plastic. The results indicate that uncompressed and compressed MCFs could be effective slow-release agents for a variety of volatile compounds, especially if used together.

The tomato, a profitable vegetable crop in both the USA and Israel, has benefited significantly from intensive breeding efforts in both countries, and elsewhere (esp. Holland). : Modem hybrids are highly prolific and resistant to a variety of major pests. They produce attractive, firm fruit for both processing and fresh-marketing. In all cases, however, reduction in flavor and aroma have occurred concomitantly with the increase in yield. Sugars-acids ratio dominate fruit taste, whereas aroma volatiles (potent at minute ppb and ppt levels) contribute to the total characteristic tomato flavor. An increase in sugars (1-2%) contributes significantly to tomato fruit taste. However, because of energy reasons, an increase in fruit sugars is immediately compensated for by a decrease in yield. Our main objectives were to: (a) pinpoint and identify the major impact aroma components of fresh tomato; (b) study the genetic and environmental effects on fruit aroma; (c) determine precursors of appealing (flavors) and repelling (off-flavors) aroma compounds in tomato. Addition of saturated salts blocked all enzymatic activities prior to isolation of volatiles by dynamic and static headspace, using solvent assisted flavor evaporation (SAFE) and solid phase micro-extraction (SPME) from highly favored (FA-612 and FA-624) and less preferred (R 144 and R 175) tomato genotypes. Impact aroma components were determined by gas chromatography-olfactometry (GC-O), gas chromatography-mass spectrometry (GC- MS) and aroma extract dilution analysis (AEDA). The potent odorant (Z)-1,5-octadien-3-one, was identified for the first time in fresh tomato. From the ca. 400 volatile compounds in the headspace of fresh tomato, the following compounds are proposed to be impact aroma compounds: (Z)-3-hexenal, hexanal, 1-penten-3-one, 2-phenylethanol, (E)-2-hexenal, phenyl acetaldehyde, b-ionone, b-damascenone, 4-hydroxy-2,5-dimethyl-3-(2H)-furanone (FuraneolR), (Z)-l,5-octadien-3-one, methional, 1-octen-3-one, guaiacol, (E,E)- and (E,Z)- 2,4-decadienal and trans- and cis-4,5-EPOXY -(E)-2-decenal. This confirms the initial hypothesis that only a small number of volatiles actually contribute to the sensation of fruit aroma. Tomato matrix significantly affected the volatility of certain impact aroma components and thus led to the conclusion that direct analysis of molecules in the headspace . may best represent access of tomato volatiles to the olfactory receptors. Significant differences in certain odorants were found between preferred and less-preferred cultivars. Higher consumer preference was correlated with higher concentrations of the following odorants: l-penten-3-one, (Z)-3-hexenal, (E,E)- and (E,Z)-2,4-decadienal and especially Furaneol, whereas lower consumer preference was associated with higher concentrations of methional, 3-methylbutyric acid, phenylacetaldehyde, 2-phenylethanol, and 2-isobutylthiazole. Among environmental factors (salinity, N source, growth temperature), temperature had significant effects on the content of selected aroma compounds (e.g., 3-methylbutanal, 1- penten-3-one, hexanal, (Z)-3-hexenal, (E)-2-hexenal, 2-isobutylthiazole, 6-methyl-5-hepten- 2-one, 1-octen-3-one, methional, 2-phenylethanal, phenyl acetaldehyde, and eugenol) in fresh tomatoes. Salt stress (20 mM NaCl) increased the content of odorants such as (Z)-3-hexenal, 2-phenylethanol and 3-methylbutanal in the R-144 cultivar whereas salinity had minor effects on 1-pentene-3-one, 2-isobutylthiazole and b-ionone. This fundamental knowledge obtained by comprehensive investigation, using modem chemical, sensory and agrotechnical methodology will assist future attempts to genetically modify the concentrations of key odorants in fresh tomatoes, and thus keep the tomato production of Israel and the USA competitive on the world market.

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.

Consumption of tomato products has been associated with decreased risk of some cancer types, and the tomato antioxidant, lycopene, is thought to play an important role in the observed health effects. In this study, four carotenoids, trans-lycopene, phytofluene, phytoene, and zeta-carotene, were quantified in tomato products. Samples of raw tomatoes, tomato juice after hot break scalder, and final paste were obtained from two different processing plants over two years. Comparison of carotenoid levels throughout processing indicated that lycopene losses during processing of tomatoes into final paste (25-30 degrees Brix) ranged from 9 to 28%. The initial Brix level of the raw tomatoes appeared to influence the amount of lycopene loss that occurred, possibly due to the differences in processing time required to achieve the final desired Brix level of the paste. In general, no consistent changes in the other carotenoids were observed as a function of processing. The antioxidant activity of fresh tomatoes, tomato paste, and three fractions obtained from these products (i.e., aqueous, methanol, and hexane fractions) was also determined. In both a free radical quenching assay and a singlet oxygen quenching assay, significant antioxidant activity was found in both the hexane fraction (containing lycopene) and the methanol fraction, which contained the phenolic antioxidants caffeic and chlorogenic acid. The results suggest that in addition to lycopene, polyphenols in tomatoes may also be important in conferring protective antioxidative effects.

PREFACE 1. Chemical and Sensory Characterization of Food Volatiles: An Overview PART 1: INSTRUMENTAL ANALYSIS OF FOOD FLAVORS 2. Odor-Active Compounds of Dry-Cured Meat: Italian-Type Salami and Parma Ham 3. Aroma-Active Benzofuran Derivatives: Analysis, Sensory Properties, and Pathways of Formation 4. Volatile Constituents of Asafoetida 5. Gas Chromatographic Analysis of Chiral Aroma Compounds in Wine Using Modified Cyclodextrin Stationary Phases and Solid Phase Microextraction 6. Sensing Systems for Flavor Analysis and Evaluation 7. Novel Aspects of Tomatillo Flavour PART 2: CORRELATION BETWEEN SENSORY PROPERTIES AND CHEMICAL STRUCTURES OF FLAVOR COMPONENTS 8. Descriptors for Structure-Property Correlation Studies of Odorants 9. Influence of the Chain Length on the Aroma Properties of Homologous Epoxy-Aldehydes, Ketones, and Alcohols 10. Flavor Chemistry of Peppermint Oil (Mentha piperita L.) 11. Chemical and Sensory Properties of Thiolactones PART 3: SYNTHETIC, THERMAL REACTION, AND ENZYMATIC APPROACHES TO FLAVOR COMPONENTS 12. Synthetic Approaches to Chiral Flavor Components 13. Specifity of Glycosidases from Tea Leaves toward Glycosidic Tea Aroma Precursors 14. Biosynthesis of *g-Nonalactone in Yeast 15. The Formation of Strecker Aldehydes 16. Analysis of Low Molecular Weight Aldehydes Formed during the Maillard Reaction 17. Chiral 1,3-Octanediol Synthetic Studies Using Enzymatic Methods as Key Steps 18. Formation Pathways of 3-Hydroxy-4,5-dimethyl-2[5H]-furanone (Sotolone) in Citrus Soft Drinks PART 4: ADDITIONAL PROPERTIES OF FLAVOR COMPONENTS AND FLAVORS 19. Antimicrobial Activities of Isothiocyanates 20. Processing Modulation of Soymilk Flavor Chemistry INDEXES Author Index Subject Index

Volatiles were obtained from commercially prepared and laboratory-prepared rice cakes using high-flow dynamic headspace isolation with Tenax trapping. Analysis was carried out by capillary GC/MS. More than 60 compounds were identified. Major volatiles included 1-hydroxy-2-propanone, furfuryl alcohol, 2,5-dimethylpyrazine, 2-methylpyrazine, pyrazine, hexanal, furfural, pentanol, 3-hydroxy-2-butanone (acetoin), and ethyl-3,6-dimethylpyrazine. Although not ideally applicable to a dry product, concentration/threshold ratios indicated that the compounds with a high probability of contributing to the aroma and flavor included 3-methylbutanal, dimethyl trisulfide, 2-ethyl-3,5-dimethylpyrazine, 4-vinylguaiacol, hexanal, (E,E)-2,4-decadienal, 2-methylbutanal, 2-acetyl-1-pyrroline, 1-octen-3-ol, and 1-octen-3-one. Keywords: Rice cakes; volatiles; flavor; aroma; identification; concentrations; concentration/threshold ratios

Vegetables are edible plant products which can be modified stems, roots, leaves, flowers, or even fruits. They are usually classified on the basis of the part of the plant that is used for food. Stem vegetables include asparagus and kohlrabi while beets, carrots, radishes and turnips are root vegetables. Among the leaf and leafstalk vegetables are brussel sprouts, cabbage, celery, endive, kale, lettuce, rhubarb and spinach. The head or flower vegetables include artichokes, broccoli, and cauliflower. Garlic, leeks, and onions are classified as bulb vegetables. Botanically, the term “fruit” applies to the structure, usually containing seeds, which develops from the flower ovary after pollination and fertilization (Vaughan and Geissler, 1997). Therefore, beans, cucumbers, eggplant, okra, peppers, squash, sweet corn and tomatoes would be classified as fruits according to this definition. However, the important distinction between fruits and vegetables has come to be made on a usage basis; those plant products that are usually consumed with the main course of a meal are considered to be vegetables while those used mainly as desserts are considered fruits.

Foods and food ingredients produced via recombinant DNA techniques - an overview, Karl-Heinz Engel et al. Part 1 Regulatory oversight: US food and drug administration policy for foods developed by biotechnology, J.H. Marayanski regulatory oversight and safety assessment of genetically-modified foods in the European Union, Karl-Heinz Engel et al administrative oversight to ensure safety of biotechnologically-produced foods in Japan, Ryoji Takahara the role of the public and federal advisory committees in providing advice to the government on agricultural science policy, Alvin L. Young and Daniel D. Jones safety assessment of flavour ingredients produced by genetically-modified organisms, J.B. Hallagan and R.L. Hall. Part 2 Plants: determination of the safety of genetically-engineered crops, Keith Redenbaugh et al exotic germ plasm for allergenicity in transgenic foods, Oscar L. Frick use of plant virus genes to produce disease-resistant crops, Lynn E. Murry molecular cloning of cereal cystatins and evaluation of their antiviral and antipest effects, S. Arai et al safety assessment of the bacillus thuringiensis insecticidal crystal protein CRYIA(B) expressed in transgenic tomatos, H.P.J.M. Noteborn et al safety assessment of potatos resistant to Colorado potato beetle, P.B. Lavrik et al. Part 3 Microorganisms: improvement of beer brewing by using genetically-modified yeast, J. Vogel et al genetic modification of brewer's yeast to produce acetolactate decarboxylase and the safety aspects of the beer brewed by the transformed yeast, R. Takahashi et al safety aspects of genetically-modified lactic acid bacteria, W.P. Hammes et al. Part 4 Enzymes: enzymes from genetically-modified microorganisms, Sven Pedersen et al. Part 5 Animals: progress in genetic modifications of farm animals, V.G. Pursel.

We have previously determined the odor thresholds of various cyclic and branched esters and found them to be surprisingly low [1]. In this chapter we examine the effect of substitution of different heteroatoms in the ring system on odor thresholds. In addition, we determine the odor thresholds of various polycyclic esters.

Thermal and Enzymatic Conversions of Precursors to Flavor Compounds: An Overview Monoterpene Biosynthesis: The Cyclization of Geranyl Pyrophosphate to (+)-Sabinene Lipases: Useful Biocatalysts for Enantioselective Reactions of Chiral Flavor Compounds Carboxylester-Lipase Mediated Reactions: A Versatile Route to Target the Chiral Molecules Biosynthesis and Studies on the Biotechnological Production of Aliphatic *g- and *d-Lactones Precursor Atmospheric Technology: Efficient Aroma Enrichment in Fruit Cells Glycosidic Precursors of Varietal Grape and Wine Flavor Glucosides of Limonoids Oxytenated C[1[3-Norisoprenoids: Important Flavor Precursors Free and Bound Flavor Constituents of White-Fleshed Nectarine Thermally Degraded Thiamin: A Potent Source of Interesting Flavor Compounds Studies on the Formation of Furaneol in Heat-Processed Foods Flavor Compounds Formed from Lipids by Heat Treatment Formation of Meat-like Flavor Compounds Peptides as Flavor Precursors in Model Maillard Reactions Meat Flavor Generation from Cysteine and Sugars Analysis and Reactivity of Glucosones Formation of Smoke Flavor Compounds by Thermal Lignin Degradation Reaction Kinetics for the Formation of Heterocyclic Compounds in a Temperature and Pressure Controlled Experiment

The chemical composition of the volatiles from the Gaura drummondii (night-blooming) flowers was determined by GC/MS, NMR and IR. The major compounds found were: syn- and anti-2-methyl-butanal oximes. Ten other compounds were also identified.