Influence of lipid matrix in the bitterness perception of virgin olive oil

Bitterness is a characteristic organoleptic property of virgin olive oil, related to the presence of phenolic compounds. Although in other fat foods the influence of the degree of unsaturation on their sensorial properties has been investigated, to our knowledge this aspect has not yet been studied in virgin olive oil. The present work evaluates the influence of lipid matrix unsaturation degree in the perception of bitterness in olive oil. Two polyphenol-free lipid matrices of olive oil, of very different fatty acid composition, were fortified at different levels with the same phenolic extract, obtained from a very bitter virgin olive oil. To evaluate differences between them, organoleptic characterisation and 'triangular tests' were carried out. Matrices with more-monounsaturated fatty acids showed a more intense green taste and astringency, whereas an almond flavour characterised the more-polyunsaturated matrices at the same spiking levels. Likewise, pungency and bitterness were more pronounced in monounsaturated matrices than in polyunsaturated ones. Considering these results, it can be concluded that the composition of the lipid matrix plays a key role in the perception of bitterness in virgin olive oil, since polyunsaturated matrices produce milder sensations and are less bitter than monounsaturated ones. (c) 2007 Elsevier Ltd. All rights reserved.