{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/92850"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/92850","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Characterization of aroma components of raw and roasted almonds and the effect of the oxidative state of the nut on roasted flavor formation","abstract":"Almond is the most produced tree nut in the US. Along with potential health related studies, popularity of almonds has been rising among consumers in the last few decades. Furthermore, consumer liking the flavor of both raw and roasted almonds plays a role in its increasing popularity. However, because of its high unsaturated fat content almond is prone to lipid oxidation during storage that leads to flavor and quality changes. Predominant aroma-active compounds in almonds were identified and the effect of oxidative state of raw almonds on roasted aroma was observed in this study. Volatile components of raw, dry roasted and oil roasted almonds were isolated by solvent extraction-solvent-assisted flavor evaporation and the predominant aroma-active compounds were identified by gas chromatography-olfactometry (GCO) and aroma extract dilutions analysis (AEDA), and by GC-mass spectrometry determination of odor-activity values (OAVs). Results demonstrated the importance of lipid-derived volatile compounds such as ketones and aldehydes in raw almond aroma. Meanwhile, volatile compounds derived via the Maillard reaction, lipid degradation/oxidation and sugar degradation were predominant aroma compounds in dry and oil roasted almonds. These compounds were mainly pyrazines, pyridines, pyrrolines, aldehydes and furanones. Aroma changes of stored raw (SR) and stored raw-then-roasted (SRTR) almonds were investigated by gas chromatography-olfactometry (GCO) and aroma extract dilutions analysis (AEDA) and GC-mass spectrometry (GC-MS). Raw almonds were stored at either room temperature (24±1°C), 37°C or 4°C for 18, 9 or 12 months, respectively. Based on their relatively high flavor dilution (FD) factors and OAVs, the predominant aroma compounds in stored raw almonds were identified as 1-octen-3-one, hexanal and acetic acid. Aldehydes and acids were found in highest abundance in raw almonds. Storage of raw almonds resulted in an increase in the total concentration of aroma compounds at all storage temperatures. In SRTR almonds, methional, Furaneol, 3-methylbutanal and 2-acetyl-3,4,5,6 (& 1,4,5,6)-tetrahydropyridine were the predominant aroma compounds, while aldehydes, nitrogen-containing compounds and acids were found in highest overall abundance. Total concentration of aroma compounds increased in SRTR almonds stored at RT and 37°C, whereas they decreased in almonds stored at 4°C. Concentrations of nitrogen-containing aroma compounds, responsible for roasted notes, increased in the SRTR almonds throughout the storage period. Results of this study indicate that storing raw almonds prior to roasting affects the levels of thermally generated aroma compounds formed during roasting.","abstract_html":"Almond is the most produced tree nut in the US. Along with potential health related studies, popularity of almonds has been rising among consumers in the last few decades. Furthermore, consumer liking the flavor of both raw and roasted almonds plays a role in its increasing popularity. However, because of its high unsaturated fat content almond is prone to lipid oxidation during storage that leads to flavor and quality changes. Predominant aroma-active compounds in almonds were identified and the effect of oxidative state of raw almonds on roasted aroma was observed in this study. Volatile components of raw, dry roasted and oil roasted almonds were isolated by solvent extraction-solvent-assisted flavor evaporation and the predominant aroma-active compounds were identified by gas chromatography-olfactometry (GCO) and aroma extract dilutions analysis (AEDA), and by GC-mass spectrometry determination of odor-activity values (OAVs). Results demonstrated the importance of lipid-derived volatile compounds such as ketones and aldehydes in raw almond aroma. Meanwhile, volatile compounds derived via the Maillard reaction, lipid degradation/oxidation and sugar degradation were predominant aroma compounds in dry and oil roasted almonds. These compounds were mainly pyrazines, pyridines, pyrrolines, aldehydes and furanones. Aroma changes of stored raw (SR) and stored raw-then-roasted (SRTR) almonds were investigated by gas chromatography-olfactometry (GCO) and aroma extract dilutions analysis (AEDA) and GC-mass spectrometry (GC-MS). Raw almonds were stored at either room temperature (24±1°C), 37°C or 4°C for 18, 9 or 12 months, respectively. Based on their relatively high flavor dilution (FD) factors and OAVs, the predominant aroma compounds in stored raw almonds were identified as 1-octen-3-one, hexanal and acetic acid. Aldehydes and acids were found in highest abundance in raw almonds. Storage of raw almonds resulted in an increase in the total concentration of aroma compounds at all storage temperatures. In SRTR almonds, methional, Furaneol, 3-methylbutanal and 2-acetyl-3,4,5,6 (& 1,4,5,6)-tetrahydropyridine were the predominant aroma compounds, while aldehydes, nitrogen-containing compounds and acids were found in highest overall abundance. Total concentration of aroma compounds increased in SRTR almonds stored at RT and 37°C, whereas they decreased in almonds stored at 4°C. Concentrations of nitrogen-containing aroma compounds, responsible for roasted notes, increased in the SRTR almonds throughout the storage period. Results of this study indicate that storing raw almonds prior to roasting affects the levels of thermally generated aroma compounds formed during roasting.","abstract_has_math":false,"creators":["Erten, Edibe Seda"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Food Science & Human Nutrition","degree_department":null,"school":null,"contributors":["Cadwallader, Keith R.","Engeseth, Nicki J.","Lee, Soo-Yeun","Lee, Youngsoo"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2016,"date_issued":"2016-11-10T17:55:14Z","date_published":"2016-11-10T17:55:14Z","updated_at":"2026-07-22T22:26:35Z","subjects":["raw almonds","roasted almonds","aroma-active compounds","storage","lipid oxidation","solvent-assisted flavor evaporation (SAFE)","gas chromatography-olfactometry (GCO)","aroma extract dilution analysis (AEDA)"],"languages":["en"],"rights":["Copyright 2016 Edibe Erten"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/92850","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Cadwallader, Keith R.","Engeseth, Nicki J.","Lee, Soo-Yeun","Lee, Youngsoo"]},{"key":"dc:creator","label":"Author","values":["Erten, Edibe Seda"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2016-11-10T17:55:14Z","2016-07-15","2016-08"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Food Science & Human Nutrition"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["raw almonds","roasted almonds","aroma-active compounds","storage","lipid oxidation","solvent-assisted flavor evaporation (SAFE)","gas chromatography-olfactometry (GCO)","aroma extract dilution analysis (AEDA)"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2016 Edibe Erten"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/92850"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Almond is the most produced tree nut in the US. Along with potential health related studies, popularity of almonds has been rising among consumers in the last few decades. Furthermore, consumer liking the flavor of both raw and roasted almonds plays a role in its increasing popularity. However, because of its high unsaturated fat content almond is prone to lipid oxidation during storage that leads to flavor and quality changes. Predominant aroma-active compounds in almonds were identified and the effect of oxidative state of raw almonds on roasted aroma was observed in this study. Volatile components of raw, dry roasted and oil roasted almonds were isolated by solvent extraction-solvent-assisted flavor evaporation and the predominant aroma-active compounds were identified by gas chromatography-olfactometry (GCO) and aroma extract dilutions analysis (AEDA), and by GC-mass spectrometry determination of odor-activity values (OAVs). Results demonstrated the importance of lipid-derived volatile compounds such as ketones and aldehydes in raw almond aroma. Meanwhile, volatile compounds derived via the Maillard reaction, lipid degradation/oxidation and sugar degradation were predominant aroma compounds in dry and oil roasted almonds. These compounds were mainly pyrazines, pyridines, pyrrolines, aldehydes and furanones. Aroma changes of stored raw (SR) and stored raw-then-roasted (SRTR) almonds were investigated by gas chromatography-olfactometry (GCO) and aroma extract dilutions analysis (AEDA) and GC-mass spectrometry (GC-MS). Raw almonds were stored at either room temperature (24±1°C), 37°C or 4°C for 18, 9 or 12 months, respectively. Based on their relatively high flavor dilution (FD) factors and OAVs, the predominant aroma compounds in stored raw almonds were identified as 1-octen-3-one, hexanal and acetic acid. Aldehydes and acids were found in highest abundance in raw almonds. Storage of raw almonds resulted in an increase in the total concentration of aroma compounds at all storage temperatures. In SRTR almonds, methional, Furaneol, 3-methylbutanal and 2-acetyl-3,4,5,6 (& 1,4,5,6)-tetrahydropyridine were the predominant aroma compounds, while aldehydes, nitrogen-containing compounds and acids were found in highest overall abundance. Total concentration of aroma compounds increased in SRTR almonds stored at RT and 37°C, whereas they decreased in almonds stored at 4°C. Concentrations of nitrogen-containing aroma compounds, responsible for roasted notes, increased in the SRTR almonds throughout the storage period. Results of this study indicate that storing raw almonds prior to roasting affects the levels of thermally generated aroma compounds formed during roasting.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2016-11-09 without embargo terms","The student, Edibe Erten, accepted the attached license on 2016-07-15 at 10:21.","The student, Edibe Erten, submitted this Dissertation for approval on 2016-07-15 at 10:51.","This Dissertation was approved for publication on 2016-07-15 at 14:28.","DSpace SAF Submission Ingestion Package generated from Vireo submission #9959 on 2016-11-09 at 10:25:13","Made available in DSpace on 2016-11-10T17:55:14Z (GMT). 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Furthermore, consumer liking the flavor of both raw and roasted almonds plays a role in its increasing popularity. However, because of its high unsaturated fat content almond is prone to lipid oxidation during storage that leads to flavor and quality changes. Predominant aroma-active compounds in almonds were identified and the effect of oxidative state of raw almonds on roasted aroma was observed in this study. Volatile components of raw, dry roasted and oil roasted almonds were isolated by solvent extraction-solvent-assisted flavor evaporation and the predominant aroma-active compounds were identified by gas chromatography-olfactometry (GCO) and aroma extract dilutions analysis (AEDA), and by GC-mass spectrometry determination of odor-activity values (OAVs). Results demonstrated the importance of lipid-derived volatile compounds such as ketones and aldehydes in raw almond aroma. Meanwhile, volatile compounds derived via the Maillard reaction, lipid degradation/oxidation and sugar degradation were predominant aroma compounds in dry and oil roasted almonds. These compounds were mainly pyrazines, pyridines, pyrrolines, aldehydes and furanones. Aroma changes of stored raw (SR) and stored raw-then-roasted (SRTR) almonds were investigated by gas chromatography-olfactometry (GCO) and aroma extract dilutions analysis (AEDA) and GC-mass spectrometry (GC-MS). Raw almonds were stored at either room temperature (24±1°C), 37°C or 4°C for 18, 9 or 12 months, respectively. Based on their relatively high flavor dilution (FD) factors and OAVs, the predominant aroma compounds in stored raw almonds were identified as 1-octen-3-one, hexanal and acetic acid. Aldehydes and acids were found in highest abundance in raw almonds. Storage of raw almonds resulted in an increase in the total concentration of aroma compounds at all storage temperatures. In SRTR almonds, methional, Furaneol, 3-methylbutanal and 2-acetyl-3,4,5,6 (& 1,4,5,6)-tetrahydropyridine were the predominant aroma compounds, while aldehydes, nitrogen-containing compounds and acids were found in highest overall abundance. Total concentration of aroma compounds increased in SRTR almonds stored at RT and 37°C, whereas they decreased in almonds stored at 4°C. Concentrations of nitrogen-containing aroma compounds, responsible for roasted notes, increased in the SRTR almonds throughout the storage period. Results of this study indicate that storing raw almonds prior to roasting affects the levels of thermally generated aroma compounds formed during roasting.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2016-11-09 without embargo terms","The student, Edibe Erten, accepted the attached license on 2016-07-15 at 10:21.","The student, Edibe Erten, submitted this Dissertation for approval on 2016-07-15 at 10:51.","This Dissertation was approved for publication on 2016-07-15 at 14:28.","DSpace SAF Submission Ingestion Package generated from Vireo submission #9959 on 2016-11-09 at 10:25:13","Made available in DSpace on 2016-11-10T17:55:14Z (GMT). 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