Formulations of Rancid and Winey-Vinegary Artificial Olfactory Reference Materials (AORMs) for Virgin Olive Oil Sensory Evaluation

Abstract

Sensory assessment of virgin olive oil (“panel test”) is the only sensory method included in international regulations of edible oils and its application is compulsory. Even if its application has been a success in quality control, improving the quality of virgin olive oils over the last 30 years, at present, there is no reference material (RM), in the strict sense of the term, to be used as a validated standard for sensory defects of virgin olive oil with which tasters can be trained. Usually, real samples of virgin olive oils assessed by many panels for the International Olive Council (IOC) ring tests are used as materials of reference in panel training and control. The latter are highly representative of the main perceived defects, but availability is limited, samples are not homogeneous year after year, and other secondary defects can be present. Thus, in order to provide solutions, this work describes an analytical procedure for implementing olfactory formulations that emulate rancid and winey-vinegary defects found in virgin olive oils with the aim of providing reproducible RMs that can be prepared on demand. A strategy for designing RMs for aroma is presented and the optimization process to obtain the best formulation is described. Under the criteria of representativeness, verified with the advice of the IOC, aroma persistence, and simplicity in formulation, two RMs for winey-vinegary and rancid were obtained by diluting acetic acid and ethanol (winey-vinegary defect) and hexanal (rancid defect) together with other compounds that are used to modify aroma and avoid non-natural sensory notes.

Potential of the Oxidized Form of the Oleuropein Aglycon to Monitor the Oil Quality Evolution of Commercial Extra-Virgin Olive Oils

“…Regarding VOOsmhp, even if they exceeded the limit for storage (Figure 5B), except for two samples, S1, S3, S4, S5, and S6 stayed under the limit until the tenth month (Figure 5B). The general lower accumulation of (E)-2-decenal in VOOsmhp is in line with (E, E)-2,4 decadienal data, confirming that higher VOO polyphenols attenuate the accumulation of secondary volatiles products linked to the "rancid" defect [5,8,38,42,43].…”

Fortified Cold-Pressed Oils: The Effect on Sensory Quality and Functional Properties

“…There are many efforts to increase the reliability and accuracy of sensory analyses in the research of edible oils to detect oxidized odor. One example of such effort is the formulation of artificial olfactory reference materials for virgin olive oil sensory evaluation [31]. Individual volatiles responsible for oxidized odor can be detected by gas chromatography, the mixture of volatiles contributing to the oxidized odor can also be detected by means of sensory analysis allowing separation of the rancid samples from those that are still sensorially acceptable.…”