Flavor components of olive oil—A review

Abstract The unique and delicate flavor of olive oil is attributed to a number of volatile components. Aldehydes, alcohols, esters, hydrocarbons, ketones, furans, and other compounds have been quantitated and identified by gas chromatography‐mass spectrometry in good‐quality olive oil. The presence of flavor compounds in olive oil is closely related to its sensory quality. Hexanal, trans ‐2‐hexenal, 1‐hexanol, and 3‐methylbutan‐1‐ol are the major volatile compounds of olive oil. Volatile flavor compounds are formed in the olive fruit through an enzymatic process. Olive cultivar, origin, maturity stage of fruit, storage conditions of fruit, and olive fruit processing influence the flavor components of olive oil and therefore its taste and aroma. The components octanal, nonala, and 2‐hexenal, as well as the volatile alcohols propanol, amyl alcohols, 2‐hexenol, 2‐hexanol, and heptanol, characterize the olive cultivar. There are some slight changes in the flavor components in olive oil obtained from the same oil cultivar grown in different areas. The highest concentration of volatile components appears at the optimal maturity stage of fruit. During storage of olive fruit, volatile flavor components, such as aldehydes and esters, decrease. Phenolic compounds also have a significant effect on olive oil flavor. There is a good correlation between aroma and flavor of olive oil and its polyphenol content. Hydroxytyrosol, tyrosol, caffeic acid, coumaric acid, and p ‐hydroxybenzoic acid influence mostly the sensory characteristics of olive oil. Hydroxytyrosol is present in good‐quality olive oil, while tyrosol and some phenolic acids are found in olive oil of poor quality. Various off‐flavor compounds are formed by oxidation, which may be initiated in the olive fruit. Pentanal, hexanal, octanal, and nonanal are the major compounds formed in oxidized olive oil, but 2‐pentenal and 2‐heptenal are mainly responsible for the off‐flavor.