Progress 10/01/99 to 09/30/05
Outputs
Key aroma-active components of American-style country hams were identified including neutral/basic compounds arising from lipid oxidation (such as(Z)-4-heptenal,(E)-nonenal,(E,E)-2,4-decadienal), and via Maillard/Strecker and associated reactions (3-methylbutanal, 2-acetyl-1-pyrroline, methional, phenylacetaldehyde, p-cresol) as well as numerous esters (e.g. ethyl 2-methylbutanoate). The acidic fraction contained mainly short-chain volatile acids (e.g. butanoic and hexanoic acids) and Maillard reaction products (e.g. 4-hydroxy-2,5-dimethyl-3(2H)-furanone). Predominant semi-volatile aroma compounds in chipotle peppers were identified as 2-isobutyl-3-methoxyphenol, linalool, guaiacol, syringol, 4-hydroxy-2,5-dimethyl-3(2H)-furanone and 3-hydroxy-4,5-dimethyl-3(5H)-furanone. Highly volatile aroma components of chipotle were methylpropanal, 2,3-butanedione, and 2- and 3-methylbutanal. 1,8-Cineol (eucalyptol; eucalyptus oil-like) was found to have the greatest impact on the
overall aroma of dried California bay leaves. Other aroma-active compounds included 4-methyl-1-(1-methylethyl)-bicyclo[3.1.0]hex-3-en-2-one (spearmint-like), alpha-pinene (pine needle-like), linalool (floral, honeysuckle-like), and eugenol (4-allyl-2-methoxyphenol, clove-like). Among the aroma-active compounds 1,8-Cineol (7515 to 9440 mg/g dry weight basis), alpha-pinene (2250 to 1640 mg/g) and eugenol (1185 to 1975 mg/g ) were present in high abundance, while linalool (918 to 1474 mg/g ) and 4-methyl-1-(1-methylethyl)-bicycle[3.1.0]hex-3-en-2-one (380 to 629 mg/g) were found at lower concentrations. Aroma impact compounds in liquid smoke from hickory and mesquite were identified. Remarkable similarity was found in the flavor profile of hickory and mesquite liquid smoke. Over 50 aroma compounds were identified. Some of the major aroma compounds were: Guaiacol, acetic acid, diacetyl, 2,3-pentanedione, maltol, 2-acetyl-1-pyrroline, 2/4-methyl phenol, furfural, cyclotene and syringol.
AEDA analysis showed mesquite samples had a particularly high flavor dilution factor (FD) for Guaiacol and diacetyl, however FD for diacetyl, maltol and 2,3-pentanedione were higher in hickory liquid smoke. Predominant aroma components of Mate tea were identified as geraniol, beta-damascenone, 2-methoxyphenol, linalool, beta-ionone, eugenol, 2-acetyl-1-pyrroline, (E,Z)-2,6-nonadienal and geranial. Aroma impact compounds in corn gluten meal were identified as o-aminoacetophenone (corn tortilla, stale); p-vinyl guaiacol (smoky, cloves); 2-3-methylbutanoic acid (cheesy, dried fruit); 3-hydroxy-4,5-dimethyl-2(5H)-furanone (curry, spice); phenylacetaldehyde (rosy, styrene, green); 3-methylindole (fecal, moth balls); phenylacetic acid (rosy, styrene); 2-phenylethanol (rosy); butyric acid (fecal, cheesy); p-cresol (dung, animal stable), vanillin (vanilla), beta-damascenone (apple sauce, cooked apple), 3-(methylthio)propanal (potato), and acetic acid (vinegar).
Impacts
Use of sensory-directed flavor analyses, such as combined use of gas chromatography-olfactometry and sensory descriptive evaluation, allows for the identification of aroma-impact components of foods. Such components can be monitored to evaluate the effects of processing and storage on product quality. This in turn allows for design of better manufacturing, packaging and storage practices.
Publications
- Rotsachakul, P., Cadwallader, K.R. and Chaiseri, S. 2005. Comparison of DHS and solvent extraction-SAFE for GCO-dilution analysis of key aroma components of Thai fried chili paste. ACS Symposium: Aroma-Active Compounds in Foods and Reaction Flavors: Formation, Measurement and Stability. (Ho, C.-T., Weerasinghe, D.K. and Cadwallader, K.R., organizers). 330th ACS National Meeting, Washington, D.C., August 28-September 1, AGFD paper 9.
- Cadwallader, K.R., Bordignon, J.R., Wang, P. and Sugiharto, R. 2005. Identification of odorants responsible for off-flavor of corn gluten meal. ACS Symposium: Grain-Based Products: Health and Flavor, and Safety Aspects (Cadwallader, K.R., Schieberle, P. and Morello, M.J., organizers). 330th ACS National Meeting, Washington, D.C., August 28-September 1, AGFD paper 167.
- Gnadt, T.A., Jasso, L. and Cadwallader, K.R. 2005. Characteristic aroma components of chipotle peppers. ACS Symposium: Chemistry and Flavor of Hispanic Foods (de Mejia, E. and Tunick, M.H., organizers). 229th ACS National Meeting, San Diego, CA, March 13-17.
- Lozano, P.R., Nicolalde, C.L. and Cadwallader, K.R. 2005. Identification of characteristic aroma components of mate (Ilex paraguariensis) tea. ACS Symposium: Chemistry and Flavor of Hispanic Foods (de Mejia, E. and Tunick, M.H., organizers). 229th ACS National Meeting, San Diego, CA, March 13-17.
- Lecona-Uribe, S., Loarca-Pina, G., Arcila-Lozano, C.C. and Cadwallader, K.R. 2005. Chemical composition of essential oil from Mexican oregano. ACS Symposium: Chemistry and Flavor of Hispanic Foods (de Mejia, E. and Tunick, M.H., organizers). 229th ACS National Meeting, San Diego, CA, March 13-17.
- Song, H. and Cadwallader, K.R. 2005. Aroma components of American country-style ham. Annual Meeting of the Institute of Food Technologists, New Orleans, LA, July 16-20, #17D-35.
- Yu, X., Song, Y.S. and Cadwallader, K.R. 2005. Identification of the characteristic aroma components of commercial dried California bay leaves (Laurus nobilis L.). Annual Meeting of the Institute of Food Technologists, New Orleans, LA, July 16-20, #17D-19.
- Cadwallader, K.R. 2005. Flavor and volatile metabolism in produce. Chapter 6. In: Produce Degradation: Pathways and Prevention, Lamikanra, O., Imam, S.H. and Ukuku, D.O. (Eds.), CRC Press LLC, Boca Raton, FL, pp 155-189.
- Jarunrattanasri, A., Cadwallader, K.R. and Theerakulkait, C. 2005. Aroma and amino acid composition of hydrolyzed vegetable protein from rice bran. In: Process and Reaction Flavors, Weerasinghe, D.K. (Ed.), ACS Symposium Series 905, American Chemical Society, Washington, DC, pp. 83-97.
- Cadwallader, K.R., Benitez, D., Pojjanapimol, S., Syriyaphan, O. and Singh, T. 2005. Characteristic aroma components of the cilantro mimics. In: "Natural Flavors and Fragrances, Frey, C. and Rouseff, R. (Eds.), ACS Symposium Series 908, American Chemical Society, Washington, D.C., pp. 117-128.
- Bohn, D.M., Cadwallader, K.R. and Schmidt, S.J. 2005. Development and validation of a dynamic vapor sorption-fast gas chromatography-flame ionization detection method for rapid analysis of volatile release from glassy matrices. J. Agric. Food Chem. 53: 3149-3155.
- Bohn, D.M., Cadwallader, K.R. and Schmidt, S.J. 2005. Use of DSC, DVS-DSC, and DVS-fast GC-FID to evaluate the physicochemical changes that occur in artificial cherry DuraromeTM upon humidification. J. Food Sci. 70(2): E109-16.
- Carunchia-Whetstine, M.E., Cadwallader, K.R. and Drake, M.A. 2005. Characterization of aroma compounds responsible for rosey/floral flavor in Cheddar cheese. J. Agric. Food Chem. 53: 3126-3132.
- Singh, T.K., Young, N.D., Drake, K.R. and Cadwallader, K.R. 2005. Production and sensory characterization of a bitter peptide from beta-casein. J. Agric. Food Chem. 53: 1185-1189.
- Gnadt, T.A., Jasso, L. and Cadwallader, K.R. 2005. Comparison of direct solvent extraction and dynamic headspace sampling for the analysis of characteristic aroma components of chipotle pepper. Annual Meeting of the Institute of Food Technologists, New Orleans, LA, July 16-20, #17D-34.
- Klein, B.P., Khanna, P., Cadwallader, K.R. and Endres, J.M. 2005. Reducing fat in school lunches by using soy-enhanced entrees. Annual Meeting of the Institute of Food Technologists, New Orleans, LA, July 16-20, #70E-27.
- Nowak, M.C., Singh, T.K. and Cadwallader, K.R. 2005. Identification of potent odorants in commercial hickory and mesquite liquid smoke. Annual Meeting of the Institute of Food Technologists, New Orleans, LA, July 16-20, #17D-36.
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Progress 01/01/04 to 12/31/04
Outputs
A system for measurement of permeability of aroma compounds through laminated polymer films was constructed by combining dynamic vapor sorption with purge-and-trap/fast gas chromatography. The general applicability of this system, as well as its potential for simultaneous measurement of permeability of multiple aroma compounds, was demonstrated by measuring the permeability of limonene and ethyl butyrate as single permeants or as copermeants under different environmental conditions (at 25, 30 or 35 C and 0 or 75% RH) through three different multilayer polymer films (film A, HDPE/EVOH/HDPE/HDPE; film B, HDPE/nylon/HDPE/HDPE; film C, HDPE/HDPE). The results showed that the aroma barrier performance of plastic films was determined by the polymer composition and was affected by various factors, such as temperature and the presence of other co-permeants. An inverse gas chromatographic (IGC) method was developed to study the binding interactions between selected volatile
flavor compounds and soy protein isolate (SPI) under controlled relative humidity (RH). Three volatile probes (hexane, 1-hexanol, and hexanal) at very low levels were used to evaluate and validate system performance. On the basis of the thermodynamic data and the isotherms measured at 0% RH, 1-hexanol and hexanal had higher binding affinities than hexane, which could be attributed to hydrogen-bonding interactions with SPI. At 30% RH, 1-hexanol and hexanal were retained less than at 0% RH, indicating possible competition for binding sites on the SPI surface between water and volatile probe molecules. Results showed that the thermodynamic data determined were comparable to the available literature values. Use of IGC allowed for the rapid and precise generation of sorption isotherms. Repeatability between replicate injections and reproducibility across columns were very good. IGC is a potentially high-throughput method for the sensitive, precise, and accurate measurement of
flavor-ingredient interactions in low-moisture foods. Strecker aldehydes were show to contribute to nutty flavor in aged Cheddar cheese. Cheddar cheeses with and without nutty flavors were selected by descriptive sensory analysis. More than 50 aroma-active compounds were detected in both types of Cheddar cheeses. Strecker aldehydes were detected in higher amounts in Cheddar cheeses with nutty flavors compared with Cheddar cheeses without nutty flavors. Strecker aldehydes, dimethyl sulfide, and propionic acid were evaluated in young and aged Cheddar cheese models for nutty flavor by descriptive sensory analysis. When Strecker aldehydes were incorporated into aged (>9 months old) Cheddar cheese models, nutty flavor perception increased.
Impacts
Use of sensory-directed flavor analyses, such as combined use of gas chromatography-olfactometry and sensory descriptive evaluation, allows for the identification of aroma-impact components of foods. Such components can be monitored to evaluate the effects of processing and storage on product quality. This in turn allows for design of better manufacturing, packaging and storage practices.
Publications
- Alasalvar, C., Odabasi, A.Z., Demir, N., Balaban, M.O., Shahidi, F. and Cadwallader, K.R. 2004. Volatiles and flavor of five Turkish hazelnut varieties as evaluated by descriptive sensory analysis, electronic nose, and dynamic headspace analysis/gas chromatography-mass spectrometry. J. Food Sci. 69:99-106.
- Avsar, Y.K., Karagul-Yuceer, Y., Drake, M.A., Singh, T.K., Yoon, Y. and Cadwallader, K.R. 2004. Characterization of nutty flavor in Cheddar cheese. J. Dairy Sci. 87:1999-2010.
- Brisske, L.K., Lee, S.-Y., Klein, B.P. and Cadwallader, K.R. 2004. Development of a prototype high-energy, nutrient dense food product for emergency relief. J. Food Sci. 69(9): S361-S367.
- Singh, T.K. and Cadwallader, K.R. 2004. Ways of measuring shelf-life and spoilage. Ch. 9. In: Understanding and Measuring the Shelf-life of Food, Steele, R. (Ed.). CRC Press LLC, Boca Raton, FL, pp. 165-183.
- Zhou, Q. and Cadwallader, K.R. 2004. Inverse gas chromatographic method for measurement of interactions between soy protein isolate and selected flavor compounds under controlled relative humidity. J. Agric. Food Chem. 52: 6271-6277.
- Zhou, Q., Guthrie, B. and Cadwallader, K.R. 2004. Development of a system for measurement of permeability of aroma compounds through multilayer polymer films by coupling dynamic vapor sorption with purge-and-trap/fast gas chromatography. Packaging Technol. Sci. 17:175-185.
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Progress 01/01/03 to 12/31/03
Outputs
Characteristic aroma components of rennet casein were determined by gas chromatography-olfactometry (GCO), aroma extract dilution analysis (AEDA) and sensory descriptive studies. Results of AEDA showed o-aminoacetophenone to be the most potent odorant among numerous short-chain volatile acids, phenolic compounds, lactones, and furanones. However, sensory descriptive analysis of model aroma systems revealed that the typical odor of rennet casein was principally due to hexanoic acid, indole, guaiacol and p-cresol. In a similar study, aroma-active components of liquid cheddar whey were determined by GCO, AEDA, and sensory methods. Key aroma components of whey were identified as 2,3-butanedione, hexanal, 2-acetyl-1-pyrroline, methional, (E,E)-2,4-decadienal and (E,E)-2,4-nonadienal, as well as various short chain fatty acids. A standardized descriptive language with 21 descriptors was developed for skim milk powder and dried dairy ingredients, with some flavors common to
all ingredients while some other flavors were specific to specific products. Natural (raw) and roasted Turkish hazelnuts (Corylus avellana L.) were discriminated (differentiated) based on volatile constituents and sensory attributes. Major metabolic pathways and agents responsible for the typical flavor of cheddar cheese were reviewed with special emphasis on the analytical and sensory procedures used for the study of cheddar cheese flavor. We investigated the potential of Refractance WindowT (RW) technology for dehydration of strawberry slices in terms of some important chemical and physical properties as compared to its freeze-dried (FD) counterpart. In particular, we evaluated the retention of flavor, color and ascorbic acid, rehydration capacity, moisture sorption behavior and glass transition temperature. Moisture-sorption isotherms and other physical data (e.g. glass transition and rehydration capacity data) indicated that RW produced a dehydrated sliced strawberry product
having nearly identical moisture sorption behavior as its FD counterpart. However, RW product showed greater quality deterioration in terms of flavor and ascorbic acid losses as well as color degradation (browning).
Impacts
Use of sensory-directed flavor analysis, such as gas chromatography-olfactometry, for identification of key aroma components will lead to an increased understanding of pathways involved in the formation and degradation of flavor (aroma) components of foods during manufacture and storage, which in turn will lead to production of higher quality products. Knowledge of compounds involved in environmental off-odors (e.g. odors emitted from intensive animal production operations) will lead to development improved odor-control strategies and better methods for odor analysis (monitoring).
Publications
- Pojjanapimol, S., Chaiseri, S. and Cadwallader, K. 2004. Heat-induced changes in aroma components of holy basil (Ocimum sanctum L.). Ch. 15. In: Handbook of Flavor Characterization: Sensory analysis, chemistry, and physiology, Diebler, K.D. and Delwiche, J. (Eds.), Marcel Dekker, Inc., New York, pp. 217-230.
- Cadwallader, K.R., Lopez, J.R., Menke, S.D. and Surakarnkul, R. 2003. Aroma components of wines from Chardonel - A French-American hybrid grape. In: Nutraceutical Beverages. Chemistry, Nutrition, and Health Effects, Shahidi, F. and Weerasinghe, D.K. (Eds.), ACS Symposium Series 871. American Chemical Society, Washington, DC, Chapter 27.
- Singh, T.K., Drake, M.A. and Cadwallader, K.R. 2003. Flavor of cheddar cheese: A chemical and sensory perspective. Comprehensive Reviews in Food Science and Food Safety 2: 139-162.
- Karagul-Yuceer, Y., Vlahovich, K.N., Drake, M.A. and Cadwallader, K.R. 2003. Characteristic aroma components of rennet casein. J. Agric. Food Chem. 51: 6797-6801.
- Kiatsrichart, S., Brewer, M.S., Cadwallader, K.R. and Artz, W.E. 2003. Pan frying stability of NuSun oil, a mid-oleic sunflower oil. J. Am. Oil. Chem. Soc. 80(5): 479-483.
- Alasalvar, C., Shahidi, F. and Cadwallader, K.R. 2003. Comparision of natural and roasted Turkish Tombul hazelnut (Corylus avellana L.) volatiles and flavor by DHA/GC/MS and descriptive sensory analysis. J. Agric. Food Chem. 51(17): 5067-5072.
- Drake, M.A., Karagul-Yuceer, Y., Cadwallader, K.R., Civille, G.V. and Tong, P.S. 2003. Determination of the sensory attributes of dried milk powders and dairy ingredients. J. Sensory Studies 18(3): 199-216.
- Karagul-Yuceer, Y., Drake, M.A. and Cadwallader, K.R. 2003. Aroma-active components of liquid Cheddar whey. J. Food Science 68(4): 1215-1219.
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Progress 01/01/02 to 12/31/02
Outputs
Flavor quality of nonfat dry milk (NDM) is an important parameter because it can directly impact final product quality. Six 'stored' NDM samples were selected for aroma analysis based on results of sensory descriptive analysis and storage time. Aroma components were extracted by direct solvent extraction (ether)/high vacuum distillation and characterized by gas chromatography-olfactometry (GCO), aroma extract dilution analysis (AEDA) and GC-MS analysis. A variety of aldehydes, ketones and volatile fatty acids were responsible for generation of flavors of stored NDM. Based on results of AEDA compounds exhibiting high aroma impact included 3-(methythio)propanal (potato-like), o-aminoacetophenone (corn tortilla-like), 2,5-dimethyl-4-hydroxy-3(2H)-furanone (Furaneol, burnt sugar-like), 2-methyl-3-hydroxy-4H-pyran-4-one (burnt sugar-like), butanoic acid (cheesy), pentanoic acid (sweaty), acetic acid (vinegar-like), hexanoic acid (sour, vinegar-like), octanoic acid (waxy),
decanoic acid (waxy), dodecanoic acid (waxy), p-cresol (cowy, barny), 3-methylindole (fecal, mothball), dimethyltrisulfide (cabbage-like), (E,E)-2,4-decadienal (fried/fatty), furfuryl alcohol (rubber, vitamin-like), phenylacetic acid (rose-like), and 1-octen-3-one (mushroom-like). Some descriptive terms were correlated with specific aroma compounds. However, the combined effects of several aroma compounds may generate other attributes. Characteristic aroma components of buckwheat honey were studied by combined sensory and instrumental techniques. Relative aroma intensity of individual volatile components was evaluated by AEDA of solvent extracts and GCO of decreasing headspace volumes (GCO-H). Results indicated that 3-methylbutanal, 3-hydroxy-4,5-dimethyl-2(5H)-furanone (sotolon) and (E)-beta-damascenone were the most potent odorants in buckwheat honey, with 3-methylbutanal being primarily responsible for the distinct malty aroma. Other important odorants included methypropanal,
2,3-butanedione, phenylacetaldehyde, 3-methylbutyric acid, maltol, vanillin, methional, coumarin and p-cresol. Defatted soybean meal was converted into enzyme-hydrolyzed vegetable protein (E-HVP) using the proteolytic enzyme Flavourzyme. Total free amino acids increased by 40-fold after enzyme hydrolysis, with leucine being the most abundant, followed by phenylalanine, lysine, glutamine/glutamic acid, and alanine. Volatile components from a meat-like process flavoring made from E-HVP were isolated by direct solvent extraction (DSE)-high vacuum transfer (HVT), dynamic headspace sampling (DHS) and static headspace sampling (H) and analyzed by gas chromatography-mass spectrometry (GC-MS) and GC-olfactometry (GCO). Aroma extract dilution analysis was used to establish a flavor dilution chromatogram of the DSE-HVT extract. Results of these complementary techniques indicated the importance of odorants of high (hydrogen sulfide and methanethiol), intermediate (2-methyl-3-furanthiol,
3-mercapto-2-pentanone, 2-furanmethanethiol and 3-(methylthiol)propanal) and low volatility (maltol and Furaneol) in the overall aroma of the meat-like process flavoring.
Impacts
Identification of compounds reponsible for food aroma/flavor (character-impact components) will lead to a greater understanding of pathways involved in flavor formation, which in turn will lead to foods and food products with improved flavor profiles. Similarly, identification of environmental off-odors (e.g. odors emitted from intensive animal production operations)can lead to development of better odor control strategies and methods of analysis (monitoring).
Publications
- Singh, T.K. and Cadwallader, K.R. 2002. The Shelf Life of Foods: An Overview. In: Freshness and Shelf Life of Foods. Cadwallader, K.R. and Weenen, H. (Eds.), ACS Symposium Series 836. American Chemical Society, Washington, DC, pp. 2-21.
- Wu, Y.-F.G. and Cadwallader, K.R. 2002. Characterization of the aroma of a meat-like process flavoring from soybean-based enzyme-hydrolyzed vegetable protein. J. Agric. Food Chem. 50(10): 2900-2907.
- Zhou, Q., Wintersteen, C.L. and Cadwallader, K.R. 2002. Identification and quantification of aroma-active components that contribute to the distinct malty flavor of buckwheat honey. J. Agric. Food Chem. 50(7): 2016-2021.
- Cadwallader, K.R. and Weenen, H. (Eds.). 2002. Freshness and Shelf Life of Foods. ACS Symposium Series 836, American Chemical Society, Washington, DC.
- Karagul-Yuceer, Y., Drake, M.A. and Cadwallader, K.R. 2002. Aroma characterization of fresh and stored nonfat dry milk. In: Freshness and Shelf Life of Foods. Cadwallader, K.R. and Weenen, H. (Eds.), ACS Symposium Series 836, American Chemical Society, Washington, DC, pp. 108-123.
- Karagul-Yuceer, Y., Cadwallader, K.R. and Drake, M.A. 2002. Volatile flavor components of stored nonfat dry milk. J. Agric. Food Chem. 50(2): 305-312.
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Progress 01/01/01 to 12/31/01
Outputs
Gas chromatography-olfactometry (GCO), aroma extract dilution analysis (AEDA) and GC-MS were applied for the determination of character-impact aroma components of low-, medium-, and high-heat-treated nonfat dry milk (NDM). Key compounds were identified as 2,5-dimethyl-4-hydroxy-3(2H)-furanone (Furaneol), butanoic acid, 3-(methylthio)propanal, o-aminoacetophenone, delta-decalactone, (E)-4,5-epoxy-(E)-2-decenal, pentanoic acid, 4,5-dimethyl-3-hydroxy-2(5H)-furanone (sotolon), 3-methoxy-4-hydroxybenzaldehyde (vanillin), 2-acetyl-1-pyrolline, 2-acetyl-2-thiazoline, hexanoic acid, phenylacetic acid, octanoic acid, nonanal, and 1-octen-3-one. Odor intensities of Furaneol, butanoic acid, methional, o-aminoacetophenone, sotolon, vanillin, (E)-4,5-epoxy-(E)-2-decenal and phenylacetaldehyde were higher in high-heat-treated NFD than others. Sensory evaluation results revealed that heat generated flavors have a major impact on NFM flavor. Aroma components responsible for typical
aroma of British farmhouse Cheddar cheese were identified by use of GCO, AEDA, and GC-MS. p-Cresol was responsible for a "cowy/barny" aroma note, whereas an intense "soil-like" note was due to 2-isopropyl-3-methoxypyrazine. At much lower intensity, 2-isobutyl-3-methoxypyrazine contributed a "bell pepper-like" note. Within the same wedge of cheese the concentration of p-cresol and 2-isopropyl-3-methoxypyrazine were lower at the narrow end (center) than at the rind side. Direct addition of p-cresol (>=)100 ppb) or 2-isopropyl-3-methoxypyrazine (>= 3 ppb) in a mild domestic Cheddar cheese resulted in increases in intensities of cowy/barny and earthy/bell pepper aroma notes. Key aroma components of cooked tail meat of American lobster (Hamarus americanus) were identified by GCO, AEDA, GC-MS, GCO of decreasing static headspace (GCO-H) and decreasing dynamic headspace (GCO-DHS) volumes. 3-Methylbutanal, 2,3-butanedione, 3-(methylthio)propanal, 1-octen-3-one, 2-acetyl-1-pyrroline, and
(E,Z)-2,6-nonadienal were identified as predominant odorants by all techniques. Highly volatile methanethiol and dimethyl sulfide were detected by headspace methods only. The above eight compounds along with three unidentified compounds (with crabby, amine, fishy odors) were found to predominate in the overall aroma of cooked lobster tail meat. Soy, rice and hydrogenated soy lecithins were added to milk with lactic acid fermentation to characterize and elucidate formation of volatile off-flavors. Sensory panelists detected off-aromas in fermented milk containing unmodified soy or rice lecithin. Instrumental analysis by GCO revealed that off-flavor compounds included (E,E)-2,4-nonadienal and (E,Z)- and (E,E)-2,4-decadienal. Formation of 2,4-decadienals occurred with the first 4 hours of lactic acid fermentation and reached maximum levels within 14 hours of incubation. Enzymatic assays confirmed that washed cells of Lactococcus produced hydrogen peroxide. Hydrogenated soy lecithin was
found suitable for use in cultured dairy products, but use of other soy or rice lecithin resulted in off-flavor formation due to oxidation of polyunsaturated fatty acids.
Impacts
Identification of compounds responsible for food flavor (character-impact compounds) will lead to a greater understanding of chemical pathways involved in flavor formation, which will in turn lead to food products having flavor profiles. Similarly, identification of environmental off-odors (e.g. odors emitted from animal production facilities) can lead to development of better methods for analyzing and monitoring these compounds. These methods can then be used to measure the efficacy of improved production strategies in reducing the odor problem.
Publications
- KARAGUL-YUCEER, Y., DRAKE, M.A. and CADWALLADER, K.R. 2001. Aroma-active components of nonfat dry milk. J. Agric. Food Chem. 49: 2948-2953.
- LEE, G.-H., SURIYAPHAN, O. and CADWALLADER, K.R. 2001. Aroma components of cooked tail meat of American lobster (Homarus americanus). J. Agric. Food Chem. 49: 4324-4332.
- SURIYAPHAN, O., CADWALLADER, K.R. and DRAKE, M.A. 2001. Lecithin associated off-aromas in fermented milk. J. Food Sci. 66: 517-523.
- SURIYAPHAN, O., DRAKE, M.A., CHEN, X.Q. and CADWALLADER, K.R. 2001. Characteristic aroma components of British farmhouse Cheddar cheese. J. Agrci. Food Chem. 49: 1382-1387.
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