Biophenolic Compounds Influence the In-Mouth Perceived Intensity of Virgin Olive Oil Flavours and Off-Flavours.

Alessandro Genovese,Raffaele Sacchi,Antonello Paduano,Ferdinando Mondola

doi:10.3390/molecules25081969

Abstract

In this study, the influence of phenolic compounds on the sensory scores attributed to extra virgin olive oil (EVOO) by panel test was investigated. Two model olive oils (MOOs) with identical concentrations of volatile compounds, differing only in the amount of biophenols (297 vs. 511 mg kg−1), were analysed by two official panels and by SPME-GC/MS. Six other MOOs set up by the two previous models were also tested and analysed. They were formulated separately with the addition of three off-flavours (‘rancid’, ‘winey–vinegary’ and ‘fusty–muddy’). While high levels of EVOO phenolic compounds did not produce any effect on the headspace concentration of volatile compounds, they did affect the scores of both positive and negative sensory attributes of EVOO, due to the well-known in-mouth interactions between EVOO phenols, saliva and volatile compounds. In particular, a decrease of about 39% in the positive fruity score was found in the presence of a higher concentration of phenols. Regarding EVOO off-flavours, the higher level of phenolic compounds decreased by about 23% the score of ‘fusty–muddy’ defect and increased the score of ‘winey–vinegary’ defect about 733%. No important effect of EVOO phenolics on the perceived intensity of the ‘rancid’ defect was found. These findings could be helpful in explaining some discrepancies of panel test responses observed during extra virgin olive oil shelf life.

Highlights

These findings could be helpful in explaining some discrepancies of panel test responses observed during extra virgin olive oil shelf life
The positive attributes ‘bitterness’ and ‘pungency’ in-mouth are evaluated in extra virgin olive oil (EVOO) by sensory assessors and, they are not considered important in the quality classification of olive oil, they are very desirable [3,5,6]
The free acidity, peroxide value, K232, K270 and ∆K of the two samples remained within the legal limits of the category of extra virgin olive oil [1], showing no difference between the two model olive oils (MOOs)

Summary

Introduction

The quality of extra virgin olive oil (EVOO) is defined by several chemical indices (acidity, peroxide value, UV and alkyl esters), but the sensory perception of its flavour is the ultimate determinant [1,2,3].Sensory assessment identifies mainly positive attributes and defects in the oil, and it is critical for the oil’s quality classification according to the International Olive Council [4] and the EU legislation [1].to be classified as “extra virgin” (highest quality), olive oil must have the presence of ‘fruity’notes in its flavour and the absence of any unpleasant sensations, defined as defects or off-flavours.The four main frequent off-flavours of virgin olive oil are ‘musty’, ‘winey’, ‘fusty–muddy’ and ‘rancid’.The positive attributes ‘bitterness’ and ‘pungency’ in-mouth are evaluated in EVOO by sensory assessors and, they are not considered important in the quality classification of olive oil, they are very desirable [3,5,6].The bitterness and pungency are mainly related to the quali-quantitative presence of phenolic compounds in EVOO [7,8], characterised by different health functions [6]. The quality of extra virgin olive oil (EVOO) is defined by several chemical indices (acidity, peroxide value, UV and alkyl esters), but the sensory perception of its flavour is the ultimate determinant [1,2,3]. Sensory assessment identifies mainly positive attributes and defects in the oil, and it is critical for the oil’s quality classification according to the International Olive Council [4] and the EU legislation [1]. The positive attributes ‘bitterness’ and ‘pungency’ in-mouth are evaluated in EVOO by sensory assessors and, they are not considered important in the quality classification of olive oil, they are very desirable [3,5,6].

Objectives

Methods

Results