Multivariate approaches for stability control of the olive oil reference materials for sensory analysis – part II: applications

Abstract

The similarity indices have been calculated to build multivariate control chart with two olive oils certified reference materials that have been used as examples to monitor their stabilities. This methodology with chromatographic data could be applied in parallel with the 'panel test' sensory method to reduce the work of sensory analysis. © 2018 Society of Chemical Industry.

Volatile Profile of Two-Phase Olive Pomace (Alperujo) by HS-SPME-GC–MS as a Key to Defining Volatile Markers of Sensory Defects Caused by Biological Phenomena in Virgin Olive Oil

“…It must be always borne in mind that IOC reference oils are usually real samples used for proficiency interlaboratory tasting, and thus, they are not stable over time and not reproducible over the years and cannot be considered definitive reference standards for specific defects. 46 Consequently, we defined a further marker for defects of biological origin in oils with low-intensity fusty/muddy sediment defects (the Σ Fu-VOO in Table 3 ). The VOCs for this marker were those ones present in concentrations lower than 150 ng/g in all the analyzed olive oils, greater than 1 ng/g in the VOO, and lower than 1 ng/g in at least 3 out of the 4 EVOO samples; they were represented by a prevalence of esters (10, two of which acetates) followed by 4 alcohols, 1 ketone, and 1-hydroxyketone.…”

“…As highlighted by the bar chart in Figure C, the marker was clearly able to differentiate the fusty IOC reference samples from all the other samples; it was also able to discriminate the highly defective (i.e., the lampante ones) from the EVOO samples, but it was not able to distinguish the EVOO from the VOO samples (Figure D). It must be always borne in mind that IOC reference oils are usually real samples used for proficiency interlaboratory tasting, and thus, they are not stable over time and not reproducible over the years and cannot be considered definitive reference standards for specific defects . Consequently, we defined a further marker for defects of biological origin in oils with low-intensity fusty/muddy sediment defects (the Σ Fu‑VOO in Table ).…”

Virgin Olive Oil Volatile Compounds: Composition, Sensory Characteristics, Analytical Approaches, Quality Control, and Authentication

“…Harmonization of panels (interlaboratory or interpanel approaches) or developing suitable chemical/ statistical tools for screening out samples easy to classify (i.e., samples far from boundaries of EVOO/VOOx and VOOx/LOO) are needed to support the Panel Test in VOO classification, and many efforts have been spent over years by EU researchers in this direction. 14,53,115,116,120,121,152,166,167 For panels' harmonization, the use of reference standard materials (RMs) for each VOO defect is needed: up to now, real samples saved after proficiency interlaboratory testing organized by some bodies such as the IOC are used. However, real samples are not reproducible and not stable over time; thus, they may be characterized by different nuances of each attribute.…”

“…However, real samples are not reproducible and not stable over time; thus, they may be characterized by different nuances of each attribute. 167 This is why researchers are spending efforts in developing RMs. 53,64,115,167 Analysis of VOCs followed by suitable statistical tools is one of the most explored ways to pursuit the goal of supporting the Panel Test in VOO classification (Table 3).…”

“…167 This is why researchers are spending efforts in developing RMs. 53,64,115,167 Analysis of VOCs followed by suitable statistical tools is one of the most explored ways to pursuit the goal of supporting the Panel Test in VOO classification (Table 3). 16,53,116,120,144,152 Suitable methods have to be built using real commercial samples.…”