|Authors: ||V. Demopoulos, E. Karkoula, P. Magiatis, E. Melliou, A. Kotsiras , C. Mouroutoglou|
|Keywords: ||organoleptic assessment, phenolics, intensity, health benefits|
It is known that the organoleptic attributes of pungency and bitterness in olive oil are attributed to phenolic compounds.
Recent research has demonstrated that oleocanthal, a secoiridoic phenolic, is a naturally occurring anti-inflammatory and neuroprotective agent, and that it elicits a throat stinging sensation through a specific TRPA1 receptor.
Oleacein, a hydroxytyrosol derivative is considered as the most powerful antioxidant in olive oil and although it differs from oleocanthal only by one additional phenolic hydroxyl, organoleptically it is associated more with bitterness and less with pungency.
The present study examined the correlations between oleocanthal and oleacein concentrations and the intensity of pungent and bitter sensations in a group of 21 virgin olive oil samples of the ‘Koroneiki’ cultivar, produced in a specific geographic region of Greece (Messini). The qualitative and quantitative determination of the chemical compounds was carried out by a new method based on quantitative 1H-NMR in CDCl3 at 600 MHz after extraction of olive oil with acetonitrile.
The concentrations of the studied compounds ranged for oleocanthal between 34.6-154.6 mg/L (mean value 94.5±31.8 mg/L) and for oleacein between 11.5-191.9 mg/L (mean value 63.3±36.1 mg/L). The organoleptic assessment of the samples was performed by a trained sensory panel according to the IOC method.
The values of the positive attributes were distributed between 0.40-2.65 (mean value 1.45±0.72) for bitterness, 1.50-3.70 (mean value 2.62±0.56) for pungency and 0.40-3.60 (mean value 2.14±0.82) for fruitiness.
The results showed that there is a positive correlation (r=0.79, p≤0.05) between the concentration of oleocanthal and oleacein, and the intensity of pungency and bitterness, suggesting that virgin olive oils with intense organoleptic attributes may offer more health benefits.
Moreover, a proposal for a new index for describing and quantifying the positive organoleptic attributes of virgin olive oils is discussed.
Download Adobe Acrobat Reader (free software to read PDF files)