{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,12]],"date-time":"2026-06-12T10:10:10Z","timestamp":1781259010134,"version":"3.54.1"},"reference-count":49,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2025,3,9]],"date-time":"2025-03-09T00:00:00Z","timestamp":1741478400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Slovenian Research and Innovation Agency","award":["P4-0234"],"award-info":[{"award-number":["P4-0234"]}]},{"name":"Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana","award":["P4-0234"],"award-info":[{"award-number":["P4-0234"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Foods"],"abstract":"<jats:p>The objectives of this study were to investigate the effects of extended and constant ethanol and hexanal exposure on \u2018Gala\u2019 apples\u2019 production of aroma compounds after long-term CA storage. \u2018Gala\u2019 apples were stored in a CA under 2 kPa O2 and 98 kPa N2 at 1.0 \u00b1 0.1 \u00b0C with a constant ethanol (CA-et) or hexanal (CA-he) concentration maintained at 50 \u00b5gL\u22121 throughout a six-month storage period. A total of 25 volatile compounds (VOCs) were identified. The odor activity value (OAV) results show that nine VOCs were key aroma compounds. Among them, hexyl acetate, 2-methylbutyl acetate, and 1-butanol were the highest. Hexanal increased the production of hexyl acetate, while ethanol increased the production of 2-methylbutyl acetate and ethyl 2-methylbutanoate. Both precursors promoted the production of 1-butanol after two months of storage and 1 day of shelf life. Overall, the impact of the precursors on aroma production was more pronounced after two months than after six months of storage. Different storage atmospheres significantly influenced VOC correlations, suggesting that ethanol and hexanal addition altered aroma biosynthesis pathways in the \u2018Gala\u2019 apples. For varieties like \u2018Gala\u2019 that rapidly lose their aroma during CA storage, CA-et and CA-he treatments may be beneficial for short-term storage, enhancing key aroma compounds and improving sensory quality.<\/jats:p>","DOI":"10.3390\/foods14060930","type":"journal-article","created":{"date-parts":[[2025,3,10]],"date-time":"2025-03-10T12:02:59Z","timestamp":1741608179000},"page":"930","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Comparative Analysis of Aroma Emissions in \u2018Gala\u2019 Apples Stored in Ethanol- and Hexanal-Enriched Controlled Atmosphere"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0009-0007-2024-9558","authenticated-orcid":false,"given":"Erika","family":"Jesenko","sequence":"first","affiliation":[{"name":"Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, SI-1000 Ljubljana, Slovenia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rajko","family":"Vidrih","sequence":"additional","affiliation":[{"name":"Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, SI-1000 Ljubljana, Slovenia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4689-7920","authenticated-orcid":false,"given":"Emil","family":"Zlati\u0107","sequence":"additional","affiliation":[{"name":"Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, Jamnikarjeva 101, SI-1000 Ljubljana, Slovenia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,3,9]]},"reference":[{"key":"ref_1","unstructured":"Food and Agriculture Organization of the United Nations (FAOSTAT) (2024, August 25). Crop Production Data. Available online: https:\/\/www.fao.org\/faostat\/en\/#data\/QCL."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"8200","DOI":"10.3390\/molecules18078200","article-title":"Advances in Fruit Aroma Volatile Research","volume":"18","author":"Zhang","year":"2013","journal-title":"Molecules"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Yang, S., Hao, N., Meng, Z., Li, Y., and Zhao, Z. (2021). Identification, Comparison and Classification of Volatile Compounds in Peels of 40 Apple Cultivars by Hs\u2013Spme with Gc\u2013Ms. Foods, 10.","DOI":"10.3390\/foods10051051"},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Espino-D\u00edaz, M., Sep\u00falveda, D.R., Gonz\u00e1lez-Aguilar, G., and Olivas, G.I. (2016). Biochemistry of Apple Aroma: A Review. Food Technol. Biotechnol., 54.","DOI":"10.17113\/ftb.54.04.16.4248"},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Yang, S., Li, D., Li, S., Yang, H., and Zhao, Z. (2022). GC-MS Metabolite and Transcriptome Analyses Reveal the Differences of Volatile Synthesis and Gene Expression Profiling between Two Apple Varieties. Int. J. Mol. Sci., 23.","DOI":"10.3390\/ijms23062939"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"903","DOI":"10.1111\/tpj.12518","article-title":"The AAT1 Locus Is Critical for the Biosynthesis of Esters Contributing to \u201cripe Apple\u201d Flavour in \u201cRoyal Gala\u201d and \u201cGranny Smith\u201d Apples","volume":"78","author":"Souleyre","year":"2014","journal-title":"Plant J."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"3132","DOI":"10.1111\/j.1742-4658.2005.04732.x","article-title":"An Alcohol Acyl Transferase from Apple (Cv. Royal Gala), MpAAT1, Produces Esters Involved in Apple Fruit Flavor","volume":"272","author":"Souleyre","year":"2005","journal-title":"FEBS J."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"156","DOI":"10.1016\/j.scienta.2016.06.028","article-title":"Effect of Low Oxygen Conditioning and Ultralow Oxygen Storage on the Volatile Profile, Ethylene Production and Respiration Rate of \u2018Royal Gala\u2019 Apples","volume":"209","author":"Both","year":"2016","journal-title":"Sci. Hortic."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Sriskantharajah, K., El Kayal, W., Ayyanath, M.M., Saxena, P.K., Sullivan, A.J., Paliyath, G., and Subramanian, J. (2021). Preharvest Spray Hexanal Formulation Enhances Postharvest Quality in \u2018Honeycrisp\u2019 Apples by Regulating Phospholipase d and Calcium Sensor Proteins Genes. Plants, 10.","DOI":"10.3390\/plants10112332"},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Thewes, F.R., Balkees, B.M., B\u00fcchele, F., W\u00fcnsche, J.N., Neuwald, D.A., and Brackmann, A. (2021). Ethanol Vapor Treatment Inhibits Apple Ripening at Room Temperature Even with the Presence of Ethylene. Postharvest Biol. Technol., 173.","DOI":"10.1016\/j.postharvbio.2020.111415"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1318","DOI":"10.1002\/jsfa.2740351208","article-title":"Changes in the Composition of Volatiles by Post-harvest Application of Alcohols to Red Delicious Apples","volume":"35","author":"Berger","year":"1984","journal-title":"J. Sci. Food Agric."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Thewes, F.R., Brackmann, A., Both, V., Ludwig, V., Wendt, L.M., Thewes, F.R., and Soldateli, F.J. (2023). Dynamics of Ethanol and Its Metabolites in Fruit: The Impact of the Temperature and Fruit Species. Postharvest Biol. Technol., 197.","DOI":"10.1016\/j.postharvbio.2022.112209"},{"key":"ref_13","first-page":"100114","article-title":"Transcriptome Analysis to Elucidate Hexanal\u2019s Mode of Action in Preserving the Post-Harvest Shelf Life and Quality of Banana Fruits (Musa Acuminata)","volume":"3","author":"Yumbya","year":"2021","journal-title":"J. Agric. Food Res."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1936","DOI":"10.1021\/acsfoodscitech.1c00205","article-title":"Encapsulation of a Volatile Biomolecule (Hexanal) in Cyclodextrin Metal-Organic Frameworks for Slow Release and Its Effect on Preservation of Mangoes","volume":"1","author":"Nagarajan","year":"2021","journal-title":"ACS Food Sci. Technol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"100447","DOI":"10.1016\/j.fpsl.2019.100447","article-title":"Effect of Hexanal Loaded Electrospun Fiber in Fruit Packaging to Enhance the Post Harvest Quality of Peach","volume":"23","author":"Ranjan","year":"2020","journal-title":"Food Packag. Shelf Life"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"2553","DOI":"10.1021\/jf9809028","article-title":"Biosynthesis of Straight-Chain Ester Volatiles in Red Delicious and Granny Smith Apples Using Deuterium-Labeled Precursors","volume":"47","author":"Rowan","year":"1999","journal-title":"J. Agric. Food Chem."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"M105","DOI":"10.1111\/j.1365-2621.2006.tb15632.x","article-title":"Effect of Hexanal Vapor on Spore Viability of Penicillin Expansum, Lesion Development on Whole Apples and Fruit Volatile Biosynthesis","volume":"71","author":"Fan","year":"2006","journal-title":"J. Food Sci."},{"key":"ref_18","first-page":"154","article-title":"Response of Controlled Atmosphere (CA) Stored \u201cGolden Delicious\u201d Apples to the Treatments with Alcohols and Aldehydes as Aroma Precursors","volume":"65","author":"Harb","year":"2000","journal-title":"Gartenbauwissenschaft"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"4399","DOI":"10.5194\/acp-15-4399-2015","article-title":"Compilation of Henry\u2019s law constants (version 4.0) for water as solvent","volume":"15","author":"Sander","year":"2015","journal-title":"Atmos. Chem. Phys."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"50","DOI":"10.1016\/j.foodchem.2014.01.094","article-title":"Effect of Storage under Extremely Low Oxygen on the Volatile Composition of \u201cRoyal Gala\u201d Apples","volume":"156","author":"Both","year":"2014","journal-title":"Food Chem."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"335","DOI":"10.1590\/1678-4499.189","article-title":"Respiration Rate and Ethylene Metabolism of \u2018Jonagold\u2019 Apple and \u2018Conference\u2019 Pear under Regular Air and Controlled Atmosphere","volume":"76","author":"Saquet","year":"2017","journal-title":"Bragantia"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"125346","DOI":"10.1016\/j.foodchem.2019.125346","article-title":"Influence of Respiratory Quotient Dynamic Controlled Atmosphere (DCA\u2014RQ) and Ethanol Application on Softening of Braeburn Apples","volume":"303","author":"Weber","year":"2020","journal-title":"Food Chem."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"109039","DOI":"10.1016\/j.scienta.2019.109039","article-title":"Volatile Compounds and Overall Quality of \u2018Braeburn\u2019 Apples after Long-Term Storage: Interaction of Innovative Storage Technologies and 1-MCP Treatment","volume":"262","author":"Schmidt","year":"2020","journal-title":"Sci. Hortic."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"403","DOI":"10.1590\/0001-3765201620140181","article-title":"Ethanol Reduces Ripening of \u2018Royal Gala\u2019 Apples Stored in Controlled Atmosphere","volume":"88","author":"Weber","year":"2016","journal-title":"An. Acad. Bras. Cienc."},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Thewes, F.R., Balkees, B.M., B\u00fcchele, F., Both, V., Brackmann, A., and Neuwald, D.A. (2022). The Isolated and Combined Impacts of Ethanol and Ethylene Application on Sugars and Organic Acids Dynamics in \u2018Elstar\u2019 and \u2018Nicoter\u2019 Apples. Postharvest Biol. Technol., 194.","DOI":"10.1016\/j.postharvbio.2022.112068"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"329","DOI":"10.1016\/j.plaphy.2011.01.007","article-title":"Microarray Analysis of Ripening-Regulated Gene Expression and Its Modulation by 1-MCP and Hexanal","volume":"49","author":"Tiwari","year":"2011","journal-title":"Plant Physiol. Biochem."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"315","DOI":"10.17660\/ActaHortic.2009.839.40","article-title":"Effect of Hexanal Treatment on Postharvest Quality of \u201cDarselect\u201d Strawberry (Fragaria \u00d7ananassa Duch.) Fruit","volume":"839","author":"Yuan","year":"2009","journal-title":"Acta Hortic."},{"key":"ref_28","first-page":"288","article-title":"Flavors of Apple Fruit\u2014A Review","volume":"2","author":"Sharma","year":"2016","journal-title":"J. Nutr. Ecol. Food Res."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Silu\u00e9, Y., Nindjin, C., Ciss\u00e9, M., Kouam\u00e9, K.A., Amani, N.G., Mb\u00e9gui\u00e9-A-Mb\u00e9gui\u00e9, D., Lopez-Lauri, F., and Tano, K. (2022). Hexanal Application Reduces Postharvest Losses of Mango (Mangifera indica L. Variety \u201cKent\u201d) over Cold Storage Whilst Maintaining Fruit Quality. Postharvest Biol. Technol., 189.","DOI":"10.1016\/j.postharvbio.2022.111930"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1016\/j.postharvbio.2014.03.012","article-title":"Improving Quality of Greenhouse Tomato (Solanum lycopersicum L.) by Pre- and Postharvest Applications of Hexanal-Containing Formulations","volume":"95","author":"Cheema","year":"2014","journal-title":"Postharvest Biol. Technol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"483","DOI":"10.1016\/j.foodchem.2016.08.009","article-title":"Effects of Dynamic Controlled Atmosphere by Respiratory Quotient on Some Quality Parameters and Volatile Profile of \u2018Royal Gala\u2019 Apple after Long-Term Storage","volume":"215","author":"Both","year":"2017","journal-title":"Food Chem."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"100443","DOI":"10.1016\/j.fpsl.2019.100443","article-title":"Impact of Dynamic Controlled Atmosphere Storage and 1-Methylcyclopropene Treatment on Quality and Volatile Organic Compounds Profile of \u2018Galaxy\u2019 Apple","volume":"23","author":"Anese","year":"2020","journal-title":"Food Packag. Shelf Life"},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Chen, J., Zhang, D., Mi, H., Pristijono, P., Ge, Y., Lv, J., Li, Y., and Liu, B. (2022). Tissue-Specific Recovery Capability of Aroma Biosynthesis in \u2018Golden Delicious\u2019 Apple Fruit after Low Oxygen Storage. Agronomy, 12.","DOI":"10.3390\/agronomy12112794"},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Schultz, E.E., Thewes, F.R., Wendt, L.M., Brackmann, A., Both, V., Ludwig, V., Thewes, F.R., Soldateli, F.J., and Wagner, R. (2023). Extremely Low Oxygen with Different Hysteresis and Dynamic Controlled Atmosphere Storage: Impact on Overall Quality and Volatile Profile of \u2018Maxi Gala\u2019 Apple. Postharvest Biol. Technol., 205.","DOI":"10.1016\/j.postharvbio.2023.112527"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1080\/14620316.2015.11513146","article-title":"The Trend toward Lower Oxygen Levels during Apple (Malus \u00d7 Domestica Borkh) Storage\u2014A Review","volume":"90","author":"Wright","year":"2015","journal-title":"J. Hortic. Sci. Biotechnol."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Wu, X., Bi, J., and Fauconnier, M.L. (2022). Characteristic Volatiles and Cultivar Classification in 35 Apple Varieties: A Case Study of Two Harvest Years. Foods, 11.","DOI":"10.3390\/foods11050690"},{"key":"ref_37","unstructured":"Sceentree (2024, October 17). Amyl Acetate. Available online: https:\/\/www.scentree.co\/en\/Amyl_acetate.html."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"135","DOI":"10.1016\/j.postharvbio.2008.05.002","article-title":"Physicochemical Measurements in \u201cMondial Gala\u00ae\u201d Apples Stored at Different Atmospheres: Influence on Consumer Acceptability","volume":"50","author":"Graell","year":"2008","journal-title":"Postharvest Biol. Technol."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"2727","DOI":"10.1021\/jf063018n","article-title":"Pathway Analysis of Branched-Chain Ester Biosynthesis in Apple Using Deuterium Labeling and Enantioselective Gas Chromatography-Mass Spectrometry","volume":"55","author":"Matich","year":"2007","journal-title":"J. Agric. Food Chem."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"7198","DOI":"10.1021\/jf050519k","article-title":"Developmental and Varietal Differences in Volatile Ester Formation and Acetyl-CoA: Alcohol Acetyl Transferase Activities in Apple (Malus Domestica Borkh.) Fruit","volume":"53","author":"Holland","year":"2005","journal-title":"J. Agric. Food Chem."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"uhae215","DOI":"10.1093\/hr\/uhae215","article-title":"ABIOTIC STRESS GENE 1 Mediates Aroma Volatiles Accumulation by Activating MdLOX1a in Apple","volume":"11","author":"Zhang","year":"2024","journal-title":"Hortic. Res."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"403","DOI":"10.1080\/14620316.2007.11512251","article-title":"Development of Aroma Compounds and Sensory Quality of \u201cRoyal Gala\u201d Apples during Storage","volume":"82","author":"Maria","year":"2007","journal-title":"J. Hortic. Sci. Biotechnol."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"297","DOI":"10.21273\/JASHS05064-21","article-title":"Emission Patterns of Esters and Their Precursors throughout Ripening and Senescence in \u2018Redchief Delicious\u2019 Apple Fruit and Implications Regarding Biosynthesis and Aroma Perception","volume":"146","author":"Ferenczi","year":"2021","journal-title":"J. Am. Soc. Hortic. Sci."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"714","DOI":"10.21273\/JASHS.125.6.714","article-title":"Characterization of Changes in \u201cGala\u201d Apple Aroma during Storage Using Osme Analysis, a Gas Chromatography-Olfactometry Technique","volume":"125","author":"Plotto","year":"2000","journal-title":"J. Am. Soc. Hortic. Sci."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"329","DOI":"10.1002\/(SICI)1097-0010(199607)71:3<329::AID-JSFA588>3.0.CO;2-8","article-title":"Causal Effects of Aroma Compounds on Royal Gala Apple Flavours","volume":"71","author":"Young","year":"1996","journal-title":"J. Sci. Food Agric."},{"key":"ref_46","unstructured":"Brattinga, C., de Kok, P.M.T., and Bult, J.H.F. (2018). Sugar reduction in flavoured beverages: The robustness of aroma-induced sweetness enhancement. Flavour Science: Proceedings of the XV Weurman Flavour Research Symposium, Verlag der Technischen Universit\u00e4t Graz."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"6087","DOI":"10.1021\/jf070464h","article-title":"Volatile Emission after Controlled Atmosphere Storage of Mondial Gala Apples (Malus Domestica): Relationship to Some Involved Enzyme Activities","volume":"55","author":"Lara","year":"2007","journal-title":"J. Agric. Food Chem."},{"key":"ref_48","unstructured":"Kreissl, J., Mall, V., Steinhaus, P., and Steinhaus, M. (2022). Leibniz-LSB@TUM Odorant Database, Version 1.2, Leibniz Institute for Food Systems Biology at the Technical University of Munich. Available online: https:\/\/www.leibniz-lsb.de\/en\/databases\/leibniz-lsbtum-odorant-database."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"1699","DOI":"10.1016\/S2095-3119(13)60620-6","article-title":"Replanting Affects the Tree Growth and Fruit Quality of Gala Apple","volume":"13","author":"Liu","year":"2014","journal-title":"J. Integr. Agric."}],"container-title":["Foods"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2304-8158\/14\/6\/930\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T16:49:37Z","timestamp":1760028577000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2304-8158\/14\/6\/930"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,3,9]]},"references-count":49,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2025,3]]}},"alternative-id":["foods14060930"],"URL":"https:\/\/doi.org\/10.3390\/foods14060930","relation":{},"ISSN":["2304-8158"],"issn-type":[{"value":"2304-8158","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,3,9]]}}}