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To Dr. Mitchel.
No full textThe letter written to certain Dr. Mitchel follows on a report which the author composed at the request of Governor Clinton and also dated August 17, 1751. As Cadwallader finds that the report was too long to include specific examples of frauds committed against the Indians, he provides for examples and requests that Dr. Mitchel convey to the authorities
Identification and quantitation of predominant odorants in roasted chicory
No full textVolatile components of roasted chicory brews were isolated by direct solvent extraction followed by solvent-assisted flavor evaporation (SAFE). Identification of potent odorants was achieved by gas chromatography-olfactometry (GC-O) combined with aroma extract dilution analysis (AEDA) and gas chromatography-mass spectrometry (GC-MS). Forty-six compounds were quantitated by stable isotope dilution analysis (SIDA) and odor-activity values (OAVs). Based on the combined results of AEDA and OAVs rotundone was the most potent odorant in roasted chicory. Additional potent odorants in roasted chicory were identified as 3-hydroxy-4,5-dimethylfuran-2(5H)-one (sotolon), 3-methlbutanal, 2,3-dihydro-5-hydroxy-6-methyl-4H-pyran-4-one (dihydromaltol), 1-octen-3-one and 2-ethyl-3,5-dimethylpyrazine, 4-hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF), 3-hydroxy-2-methyl-4-pyrone (maltol) , (E,E)-2,4-decadienal, and trans-4,5-epoxy-(E)-2-decenal. Rotundone, with its distinctive aromatic woody, peppery and “chicory-like” note was also detected in five different commercial ground roasted chicory products. It is believed to an important, distinguishing and characterizing odorant in roasted chicory aroma. Collectively a group of caramel and sweet smelling odorant are also believed to be important aroma contributors to roasted chicory aroma, dihydromaltol, 3-methyl-1,2-cyclopentanedione (cyclotene), maltol, HDMF and sotolon. Overall, the predominant aroma compounds were formed via Maillard reaction, lipid oxidation and other thermal reactions during roasting of chicory. This study is the first to report a comprehensive listing of the predominant odorants in roasted chicory brew, and is the first to indicate rotundone contribution to the distinctive “aromatic woody, peppery and chicory-like” aroma of roasted chicory.Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2019-08-01The student, Tiandan Wu, accepted the attached license on 2017-07-12 at 20:48.The student, Tiandan Wu, submitted this Thesis for approval on 2017-07-12 at 21:03.This Thesis was approved for publication on 2017-07-17 at 16:08.DSpace SAF Submission Ingestion Package generated from Vireo submission #11439 on 2017-09-29 at 11:19:18Made available in DSpace on 2017-09-29T17:52:20Z (GMT). No. of bitstreams: 5
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Rightslink? by Copyright Clearance Center janpannese one.pdf: 98718 bytes, checksum: 549206fd159228a9297f4950ab918386 (MD5)
permission (studies on flavor compoenents of roasted chicory root).pdf: 98677 bytes, checksum: 93373b6acd153e8125ec5feeb94f3de2 (MD5)
permission cadwallader License.pdf: 167912 bytes, checksum: 20045111b5ccb1ced04a562fb8a5952d (MD5)
Previous issue date: 2017-07-17Embargo set by: Colleen Fallaw for item 103497
Lift date: 2019-09-29T17:52:45Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemLimited Restriction Lifted for Item 103497 on 2019-09-30T09:15:20Z
Identification and characterization of mint lactones: trace-level odor-important aroma compounds in peppermint oil
No full textMade available in DSpace on 2016-11-10T18:27:49Z (GMT). No. of bitstreams: 2
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Previous issue date: 2016-07-13Embargo set by: Seth Robbins for item 95369
Lift date: 2018-11-10T18:28:02Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemLimited Restriction Lifted for Item 95369 on 2018-11-11T10:15:12Z."Mentha piperita L., commonly known as peppermint, is an essential oil bearing plant that was introduced to the United States in the early-19th century. By 1900 peppermint cultivation and oil production had reached the Pacific Northwest where the majority of peppermint oil in the United States is produced today. In 2015 the United States produced 5.9 million pounds of peppermint oil which is used in a wide variety of food and flavor applications including chewing gum, oral hygiene products, pharmaceuticals, confectionary, and liquor among others. Trace odorants are crucial to the flavor profile of well-balanced peppermint oil. Certain lactones have been identified in peppermint oils in trace levels that contribute important sweet, coconut, coumarin-like aroma characteristics to the oils. Among these lactones, collectively known as ""mint lactones"", (−)-mintlactone and (+)-isomintlactone are the most well characterized, although numerous others remain unidentified.
Four peppermint oils were analyzed by gas chromatography-olfactometry (GCO) and gas chromatography-mass spectrometry (GC-MS) to identify the odor-active lactones. Since lactones are present at trace levels, a silica gel fractionation method was developed to isolate and concentrate the lactones from peppermint oil prior to GC analysis. A total of five odor-active ""mint"" lactones were detected, including (−)-mintlactone and two menthofurolactone (MFL) diastereomers (""MFL A"" and ""MFL B""). The lactones were quantitated using stable isotope dilution analysis (SIDA) with a 2H-labeled saturated mint lactone as the internal standard. The two diastereomers of menthofurolactone were resolved using chiral gas chromatography and their independent in-air odor thresholds and odor qualities were approximated using GCO. The enantiomeric ratio of the MFL diastereomers was also examined in relation to the menthofuran content of the oils and the concentrations of the MFL isomers.
A model peppermint oil (MPO) system was also developed and used to study the degradation of menthofuran to form mint lactones. The concentrations of four lactone compounds, MFL A, MFL B, (−)-mintlactone, and (+)-isomintlactone, were tracked over a period of six months. After an initial increase in the concentrations of all four lactones, the levels at six months approached those found in actual peppermint oils. The MPO sample stored at ambient conditions maintained a constant enantiomeric ratio of the MFL diastereomers over time. A proposed scheme for the formation of lactones from menthofuran is presented."Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2018-08-01The student, Samantha McKenna, accepted the attached license on 2016-07-12 at 19:16.The student, Samantha McKenna, submitted this Thesis for approval on 2016-07-12 at 19:26.This Thesis was approved for publication on 2016-07-13 at 11:04.DSpace SAF Submission Ingestion Package generated from Vireo submission #9911 on 2016-11-10 at 12:20:3
Feasibility of spray chilling encapsulation for protection and stabilization of flavor compound-zinc ion complexes
No full textThe aim of this study was to investigate the feasibility of utilizing spray chilling encapsulation technology to protect the flavor compound-zinc ion complex, 2-acetylpyridine-ZnCl2 (2-APri-ZnCl2). 2-APri-ZnCl2 was loaded at 5% (w/w) in molten Hydro-KoteC®, a commercial vegetable stearin. Spray chilling of this suspension was performed using a laboratory scale Mini Spray-dryer B-290 equipped with a spray chilling accessory, a dehumidifier and a two-fluid nozzle (nozzle cap, ∅= 2.2 mm; nozzle tip, ∅ =1.4mm; 046376). The heating temperature (94C) was set at 40% above the melting point of the lipid (60-63C). Two independent trials were performed.
Microencapsules were stored in 20mL sealed amber vials and stored at ambient temperature (25°C). The percent change in 2-APri-ZnCl2 , was determined using gas chromatography-flame ionization detection (GC-FID) analysis at 0, 14, 21, 30, and 70 days. Scanning (SEM) and transmission electron microscopy (TEM) were used for micro-level observation of the physical structure of the microencapsules. SEM images of samples from the lower chamber and sample vessel compartments of the spray chiller showed that the materials had physical differences related to flowability (e.g., rough vs. smooth walls) as well as an inhomogeneity with respect to particle size. Samples from the lower chamber exhibited the preferred morphological characteristics in that they had smooth walls and were of relatively homogenous size. Stability studies showed that the microencapsulated 2APri-ZnCl2 complex with 2.5% initial loading in trials 1 and 2 maintained approximately 80 and 59% retention of 2APri, respectively, after 70 days of storage at ambient temperature. The difference in stability between the two trials is thought to be due to a variance in the operational parameters of the spray chiller.
Results indicate that spray-chilling encapsulation is a viable technique for the protection of the flavor compound-zinc ion complex 2-APri-ZnCl2, and may be applicable for the protection of the much less stable complexes, 2-acetyl-1-pyrroline-ZnI2 and 2-acetyl-1-pyrroline-ZnCl2. Spray-chilling encapsulated flavor compound-zinc ion complexes may be useful as flavoring materials in industrial food applications (e.g., bakery, ice cream, and soups).Item withdrawn by Mark Zulauf ([email protected]) on 2013-12-13T20:12:57Z
Item was in collections:
University of Illinois Theses & Dissertations (ID: 1)
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license.txt: 4059 bytes, checksum: dfb46f4c9eb1d3b52de1cc06900ef49e (MD5)Item marked as restricted to the 'Administrator' Group (id=1) by Seth Robbins ([email protected]) on 2014-01-16T18:27:38Z
Item is restricted until 2016-01-16T18:27:27ZRestriction data tranferred 2014-07-01T11:36:50-05:00
Original Data
Group with Access Administrator
Release Date: 2016-01-16 12:27:27 UTC
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemLimited Restriction Lifted for Item 46943 on 2016-01-16T11:01:53Z
Analysis of potent odorants in spearmint oils
No full textSpearmint has been grown in gardens since the 9th century as an herb thought to possess a wide range of health benefits. Spearmint was introduced to the Massachusetts Bay Colony in 1628. Commercial cultivation of spearmint in the United States began in the 1790’s. The production of spearmint spread west and now is primarily grown in Washington and Oregon. The majority of the world’s spearmint is grown in the United States, with production totaling 2.93 million pounds in 2013. The popularity of spearmint is attributed mainly to its use in chewing gum and breath mints, as well as other confectionery products and oral healthcare products. While the major volatile constituents of spearmint are well known, there has been little research on the potent odorants in spearmint. The identification and quantitation of these compounds was performed in this study to give a better understanding the flavor chemistry of spearmint oils.
Potent odorants in Native spearmint, Scotch spearmint, and Macho mint oils were identified by application of gas chromatography-olfactometry (GC-O) and gas chromatography-mass spectrometry (GC-MS). Aroma extract dilution analysis was performed to determine the potency of the odorants. Of the 85 odorants detected, R-(-)-carvone was the most potent odorant in all three spearmint oils. Eugenol, ethyl-2-methyl butyrate, β-damacenone, and (3E,5Z)-1,3,5-undecatriene were also identified to be predominant odorants in the spearmint oils. New potent odorants not previously identified in spearmint include 1-hexen-3-one, 3-methyl-2-butene-1-thiol, and 2-methylisoborneol.
Forty-six compounds in Native spearmint, Scotch spearmint, and Macho mint oils were quantified using various methods. Nineteen high abundance compounds were quantified using a gas chromatography-flame ionization detector (GC-FID), 20 were quantified by stable isotope dilution analysis (SIDA), and 14 were quantified by gas chromatography-olfactometry (GC-O) dilution analysis. Seven of the compounds quantified by GC-O dilution analysis were also quantified by SIDA. The concentration results were used to calculate the odor activity value (OAV) of each compound by dividing the concentration by the odor detection threshold of the compound in water. Among the compounds quantified, those with the highest OAVs were R-(-)-carvone, 1,8-cineole, (E,Z)-2,6-nonadienal, β-damascenone, and (3E,5Z)-1,3,5-undecatriene.Item withdrawn by Laura Spradlin ([email protected]) on 2014-07-23T18:56:15Z
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University of Illinois Theses & Dissertations (ID: 1)
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license.txt: 4063 bytes, checksum: b15d14666d9b22e743dc4411a7e961da (MD5)Embargo set by: Seth Robbins for item 50526
Lift date: 2016-09-16T17:13:01Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemLimited Restriction Lifted for Item 50526 on 2016-09-22T20:59:31Z
Characterization of a Value-Added Salmon Product: Infant/toddler Food
No full textSalmon are rich sources of omega-3 fatty acids. These are important in the human diet and especially for young children in the first two years of life. Wild Alaskan salmon was utilized in a novel way by development and investigation of basic baby food product formulations from sockeye and pink salmon. Thus, physical and sensory properties of baby food, formulated to comply with FDA definition of a toddler 'high meat dinner' were evaluated based on effects of retort processing and bone inclusion. A pureed base was compared with a chunked formulation, and consumer acceptability studies were conducted. The effects of inclusion of salmon roe in the formulations on sensory (odor, flavor, texture, visual color) and physical properties (pH, water activity, instrumental color) were determined. Changes in product quality during storage were examined by sensory and chemical testing. A preliminary investigation of the fate of astaxanthin during isothermal heating of salmon puree was also considered. The color of these products was significantly impacted by processing and inclusion of roe. Products maintained good sensory characteristics during evaluated storage period. Use of salmon with bone intensified sensory flavor attributes that may be undesirable. Nonetheless, consumers indicated willingness to feed these products to their young children since they recognize the healthfulness of fish consumption and welcome opportunities to include such foods in their children's diet.Made available in DSpace on 2015-09-25T21:10:10Z (GMT). No. of bitstreams: 2
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Previous issue date: 2009Embargo set by: Seth Robbins for item 84997
Lift date: Forever
Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDsRestricted to the U of I community idenfinitely during batch ingest of legacy ETDsU of I Only149 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2009
The characterization of rum as an odor object
No full textEmbargo set by: Seth Robbins for item 109940
Lift date: 2021-02-08T18:40:00Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 109940
Lift date: 2021-02-08T18:42:23Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 109940
Lift date: 2021-02-08T18:43:54Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemEmbargo set by: Seth Robbins for item 109940
Lift date: 2021-02-08T18:44:50Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemLimited Restriction Lifted for Item 109940 on 2021-02-09T10:15:12Z.Humans have a difficult time distinguishing individual odorants when presented in mixtures, especially when the number of odorants exceeds six. Due to this limitation, researchers have evaluated the mode in which brains process complex odorant mixtures, elemental or configural perceptions, in which mixtures maintain the odor quality of the parts or the sum of the parts create a new odor. Odor images are created by the brain as means to process configural mixtures. Rum is a distilled spirit that possesses an aroma distinction that is easily distinguished from other distilled spirits, thus creating the rummy odor object. In an attempt to explore if people can distinguish rum from other spirits based on the basis of aroma, a preliminary sensory evaluation study was conducted using a new variation of the Napping technique, called Partial Napping, in which panelists evaluate the perceived similarity of a set of samples limited to a specific sensory modality, i.e. aroma. In one session, 17 untrained panelists completed the Partial Napping of 22 alcoholic spirits belonging to 5 different spirit categories. This was paired with the Ultra-Flash Profiling technique for the development of aroma descriptive terms to assist in the understanding of what perceived aroma characteristics differentiate the various spirit types. The X and Y coordinates and descriptive terms of the samples were collected and analyzed using Multiple Factor Analysis, producing factor maps and hierarchical clusters to visualize the degree of similarity of each of the samples. Rum and brown whiskey aromas were regarded as most similar among all panelists, thus forming one cluster. The vodkas formed another cluster and were considered most different from the other spirit types. Meanwhile, tequilas, cachaças, and a white whiskey existed in a separate cluster. The supplementary descriptive terms collected from Ultra-Flash Profiling provided some insight into the perceived aroma similarities of the samples within each cluster and spirit type. With the data from PN and the further rum sample evaluation by a trained focus group, three rums were selected as the rummiest rums and thus used for further instrumental evaluation: Appleton Estate White, Appleton Estate 12 Year, and Diplomatico Reserva Blanco. Through decreasing headspace gas chromatography, seven impact compounds were identified, with five of them being detected in all three rum samples. Next, headspace solid phase microextraction was utilized as a more sensitive verification step, identifying fourteen key odorants in the headspace fraction, with twelve of them being detected across the three rums. Stable isotope dilution analysis paired with gas chromatography mass spectrometry was used for identification confirmation and quantitation of the compounds. Odor activity values (OAVs) were calculated for all of the quantitated compounds, leading to the identification of nine key odorants for the rummy odor object: 2-methylbutanal, 3-methylbutanal, acetal, acetaldehyde, ethyl 2-methylbutanoate, ethyl 2-methylpropanoate, ethyl 3-methylbutanoate, ethyl butanoate, and ethyl hexanoate. This study is the first to utilize Partial Napping for various alcoholic beverage types, as well as the first to identify rum aroma as an odor object.Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2020-12-01The student, Courtney Beckett, accepted the attached license on 2018-11-19 at 08:34.The student, Courtney Beckett, submitted this Thesis for approval on 2018-11-19 at 08:43.This Thesis was approved for publication on 2018-12-04 at 10:43.DSpace SAF Submission Ingestion Package generated from Vireo submission #13097 on 2019-02-08 at 11:39:05Made available in DSpace on 2019-02-08T18:39:47Z (GMT). No. of bitstreams: 2
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Previous issue date: 2018-12-0
Characterization of a Value-Added Salmon Product: Infant/toddler Food
No full text149 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2009.Salmon are rich sources of omega-3 fatty acids. These are important in the human diet and especially for young children in the first two years of life. Wild Alaskan salmon was utilized in a novel way by development and investigation of basic baby food product formulations from sockeye and pink salmon. Thus, physical and sensory properties of baby food, formulated to comply with FDA definition of a toddler 'high meat dinner' were evaluated based on effects of retort processing and bone inclusion. A pureed base was compared with a chunked formulation, and consumer acceptability studies were conducted. The effects of inclusion of salmon roe in the formulations on sensory (odor, flavor, texture, visual color) and physical properties (pH, water activity, instrumental color) were determined. Changes in product quality during storage were examined by sensory and chemical testing. A preliminary investigation of the fate of astaxanthin during isothermal heating of salmon puree was also considered. The color of these products was significantly impacted by processing and inclusion of roe. Products maintained good sensory characteristics during evaluated storage period. Use of salmon with bone intensified sensory flavor attributes that may be undesirable. Nonetheless, consumers indicated willingness to feed these products to their young children since they recognize the healthfulness of fish consumption and welcome opportunities to include such foods in their children's diet.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD
Identification and characterization of potent odorants in selected beet root (Beta vulgaris) products
No full textThe beet, in its various forms, has been an important agricultural commodity for millennia; it was first mentioned in writing in 8th century BC Mesopotamia. Although the sugar beet contributes to a quarter of sugar production worldwide, the red beet root is an equally, if not more, important product. Not only is the beet root consumed in a culinary setting, it is highly valued for its betalain pigments, which provide a natural source of colorant for food and pharmaceutical use. Despite the beet’s impact on our food supply, the majority of the flavor research on beets concentrates on contaminating aromas in beet sugar. A small number of studies have been performed on beet roots themselves; however, the focus is solely placed on the volatile compounds, which may or may not be aroma-active or impactful to the overall product. In order to fill these gaps in our understanding, a complete aroma analysis of the beet root was performed in the present study.
Potent odorants were characterized by the use of aroma extract dilution analysis (AEDA) coupled with gas chromatography-olfactometry (GCO), as well as supported analytically by the use of gas chromatography-mass spectrometry (GC-MS). Initial analyses were performed on four different types of beets: boiled, oven-roasted, canned, and colorant. Extraction of the aroma-active components was accomplished by direct solvent extraction (DSE) with ether as solvent, paired with solvent-assisted flavor evaporation (SAFE). Extracts were fractionated into acidic and neutral-basic components to improve accuracy of identification. During screening analyses using the four different beet preparations, twenty-one different compounds were detected, one of which was unidentified. Canned beets served as the primary focus in each subsequent analysis because they provided the most odor-active and consistent samples. Forty-one aroma compounds were identified and characterized by the use of AEDA, with some of the most important being 2-acetyl-1-pyrroline, geosmin, methional, furaneol, p-vinylguaiacol, and vanillin due to their very high odor potency. Three 3-alkyl-2-methoxypyrazines (isopropyl, sec-butyl, and isobutyl), as well as 1-octen-3-one, phenylacetic acid, and eugenol, were also identified at moderate odor potencies.
To detect compounds that might have otherwise been lost during extraction or co-eluted with ether during GCO, a static headspace technique for odor analysis was used. Decreasing volumes of headspace from gently heated canned beet mixtures were analyzed using GCO. Some compounds detected, such as geosmin and methional, were found in previous odor analyses. However, two potent compounds that were previously undetected, including methanethiol and dimethyl sulfide, which was a particularly potent odorant. This technique enabled the discovery of previously undetected compounds, which may be important for subsequent creation of a beet odor model system.
However, knowledge of the specific compounds in the beets does not provide complete information for the understanding of the beet’s odor profile. Therefore, it was necessary to perform quantification of compounds both in the solvent extract and headspace of the canned beets, using the technique stable isotope dilution analysis (SIDA). In the headspace, methanethiol and dimethyl sulfide were targeted for quantification using headspace solid-phase microextraction (HS-SPME). Twenty-four individual aroma-active compounds were selected for analysis by DSE-SAFE. After using SIDA to determine the concentration for each individual compound, odor activity values (OAVs) were determined. OAVs were calculated by dividing the concentration of a compound by its odor threshold. An OAV provides an estimate of a compound’s odor potency and its potential importance to the overall aroma of the product. Of the 26 aroma compounds analyzed in the headspace and solvent extracts, dimethyl sulfide, geosmin, E-4,5-epoxy-[E]-2-decenal, methanethiol, p-vinylguaiacol, and β-damascenone possessed the highest OAVs and, therefore, contributed the most to the overall aroma profile of the canned beets. Meanwhile, octanal, Z-1,5-octadien-3-one, nonanal, acetic acid, 2-isopropyl-3-methoxypyrazine, 2-isobutyl-3-methoxypyrazine, 2-sec-butyl-3-methoxypyrazine, E, Z-2,6-nonadienal, and vanillin were of moderate odor potency.Item withdrawn by Mark Zulauf ([email protected]) on 2013-07-16T12:46:59Z
Item was in collections:
University of Illinois Theses & Dissertations (ID: 1)
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Identification of key odorants in fresh-cut watermelon aroma and structure-odor relationships of cis,cis-3,6-nonadienal and ester analogs with cis,cis-3,6-nonadiene, cis-3-nonene and cis-6-nonene backbone structures
No full textThe scope of this study involved the identification of key odorants in fresh cut-watermelon, and the synthesis and evaluation of esters with potential watermelon-like aroma attributes. Aroma formation in fresh-cut watermelon is a dynamic enzymatic process, with the characteristic aroma components being formed immediately after cutting. The characteristic fresh-cut aroma is not long lasting due to further enzyme action that modifies the fresh-cut aroma components. The key to identifying the key components responsible for fresh-cut watermelon aroma was the application of a suitable volatile isolation strategy based on static headspace analysis (SHA). In this study, SHA was used to collect the headspace volatiles one minute after initial cutting of the fruit. This enabled a chemical “snap shot” of fresh-cut aroma to be taken. The most potent odorants in the headspace were determined by gas chromatography-olfactometry of decreasing headspace volumes (GCO-H) with confirmation achieved by application of a complimentary method based on GCO and aroma extract dilution analysis (AEDA) of fresh-cut watermelon aroma extracts prepared by solvent-assisted flavor evaporation (SAFE). Eight unsaturated nine-carbon aliphatic aldehydes and one six carbon unsaturated aldehyde were detected by GCO-H. These included cis-3-hexenal, cis,cis-3,6-nonadienal, cis-3-nonenal, cis-6-nonenal, trans-2-nonenal, cis-2-nonenal, trans,cis-2,6-nonadienal, trans,trans-2,4-nonadienal, and trans,trans,cis-2,4,6-nonatrienal. This finding is contrary to previous beliefs that alcohols are the main contributors to fresh-cut watermelon aroma. Most importantly, it was found that cis,cis-3,6-nonadienal was not only a potent odorant, but this compound alone possessed an aroma reminiscent of fresh-cut watermelon. Use of sensory evaluation, including ranking test, revealed that the aroma attributes of purified synthetic cis,cis-3,6-nonadienal closely matched those of fresh-cut watermelon. This “watermelon aldehyde” can be considered a potent odorants since its estimated odor detection threshold (in water) is very low (0.2 ppb). Unfortunately, cis,cis-3,6-nonadienal is a labile compound and is prone to both trans isomerization and oxidation of its aldehyde end group. For this reason, an attempt was made to create an ester with watermelon-like aroma attributes. Esters have been widely used in the food and beverage industries as flavoring agents because they are both stable and possess relatively low thresholds. To develop a watermelon-like ester, alcohol (formate, acetate, propionate, and butyrate) and carboxylic acid (methyl, ethyl, propyl, and butyl) esters with cis,cis-3,6-nonadiene backbones were synthesized. To achieve a more thorough understanding of the structure-odor relationship of these esters, the same types of alcohol and carboxylic acid esters were created with cis-3-nonene and cis-6-nonene backbones. The general structure/threshold trend was that threshold increased with increasing carbon number. In addition, threshold was also dependent on the number and position of the cis double bond. Descriptive sensory analysis was used to evaluate the effect of structure on the odor properties of the selected (low threshold) esters; however, no clear trend was found. Finally, further sensory analysis by ranking test was employed to determine, which, if any of these esters might be a suitable replacement for cis,cis-3,6-nonadienal for use as a watermelon flavoring. Although all esters had a “fruity” element to their aroma descriptions, none were significantly close in terms of their aroma attributes to cis,cis-3,6-nonadienal.Item withdrawn by Mark Zulauf ([email protected]) on 2010-07-22T18:05:39Z
Item was in collections:
University of Illinois Theses & Dissertations (ID: 1)
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2_Genthner_Elizabeth.pdf: 1203299 bytes, checksum: d32b5b5f9b483b43bbde6abc828e0fa4 (MD5)
license.txt: 4068 bytes, checksum: df52c88e088c990af24013bf8124422e (MD5
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