Flavor, Profile and the ‘Sting’
The intricate chemistry behind the flavor of olive oil continues to baffle researchers, leading to extensive ongoing research in this field. The following insights only scratch the surface of this complex topic! In certain foods, intense flavors can stem from a single compound. For example, the chemical cinnamaldehyde imparts a strong cinnamon aroma. It would be convenient to pinpoint a single chemical that predicts the taste quality of olive oil, eliminating the need for taste testers and relying solely on a simple test. However, olive oil contains thousands of chemical compounds, with hundreds likely contributing to its flavor profile through intricate interactions.
Exploring Naturally Occurring Aroma Compounds in Extra Virgin Olive Oil
The distinct and delicate flavor of premium extra virgin olive oil is attributed to a diverse array of chemical compounds. Through gas chromatography and mass spectrometry, researchers have identified aldehydes, alcohols, esters, hydrocarbons, ketones, furans, and other compounds in high-quality olive oil. More than a hundred such compounds have been recognized, collectively shaping the unique sensory characteristics that define extra virgin olive oil.
These flavors and aromas arise from compounds like hexanal (green and grassy), trans-2-hexenal (green and bitter), as well as 1-hexanol and 3-methylbutan-1-ol, which are primary volatile compounds in olive oil. Many of these flavor components break down if milling temperatures are too high.
Phenolic compounds significantly influence olive oil flavor, with a notable correlation between aroma/flavor and polyphenol content. Hydroxytyrosol, tyrosol, caffeic acid, coumaric acid, and p-hydroxybenzoic acid mainly impact the sensory attributes of olive oil. Oxidation leads to the formation of various off-flavor compounds, potentially initiated in the olive fruit itself. Major compounds like pentanal, hexanal, octanal, and nonanal emerge in oxidized olive oil, while 2-pentenal and 2-heptenal are key culprits of off-flavors.
There's often confusion about whether oleic acid, which is present in olive oil, causes the peppery sensation and coughing. However, different olive oils with identical oleic acid levels can exhibit varying degrees of pepperyness. Studies aiming to predict flavor profiles based on oil chemistry have been conducted extensively. In "The Handbook of Olive Oil" by Harwood and Arapicio, studies highlighted by the authors reveal that aglycons contribute to the bitter and pungent attributes, along with tyrosol and possibly alpha-tocopherol. Phenols are linked to astringent qualities, and it's likely the combination of bitterness and astringency that triggers coughing.
A fascinating related discovery: Chemists, including Gary Beauchamp, published an article in Nature on September 1, 2005, demonstrating that oleocanthal, the pungent compound in some oils causing a throat-stinging sensation, shares properties with anti-inflammatory compounds like ibuprofen.