Unmasking Sensory Defects of Olive Oils Flavored with Basil and Oregano Using an Electronic Tongue‐Chemometric Tool

Abstract

Olive oil price and consumers' preference depend on the commercial grade classification that can decrease if any sensory defect is perceived leading to an economic loss. Enriched oils, obtained by incorporating dried aromatic herbs, spices, or essential oils, which is a common practice in the Mediterranean region, are commercially available. This practice may conceal the fraudulent purpose of masking the perception of sensory defects. The detection of this type of fraud is a difficult task, requiring sensory analysis. Thus, in this study, extra-virgin and lampante olive oils, the latter classification being due to the perception of an intense winey-vinegary defect, were deliberately enriched with different amounts of basil-dried herbs and oregano-dried herbs. Sensory analysis showed that, depending on the aromatic herb and on the added amount (0.011-0.110 g herb per kg oil), the defect intensity could be masked leading to an erroneous classification of flavored lampante oils as flavored virgin oils. In contrast, the electronic tongue-chemometric approach could unmask the defect in flavored oils (predictive sensitivities: 70-78%) and semiquantitatively discriminate flavored oils according to the added levels of basil or oregano (predictive sensitivities: 93-100%). The electronic tongue approach showed satisfactory unmasking performance when compared with the sensory panel, and so, its future application as a quality control tastesensor device for disclosing olive oil sensory defects masked by the incorporation of flavoring agents may be forseen.

Kinetic study of the microwave‐induced thermal degradation of cv. Arbequina olive oils flavored with lemon verbena essential oil

“…This trend was contrary to that previously observed by Cherif et al (2021) for cv. Arbequina also flavored with lemon verbena EO or in other studies (Baiano et al, 2009; Caponio et al, 2016), but similar to the trends reported by other researchers (Bobiano et al, 2019; Tarchoune et al, 2019) for different flavoring agents (e.g., fruits, leaves, dry or fresh spices, EO, or aromatic herbs). No obvious effect could be found regarding the microwave heating impact on the PV of the studied unflavored and flavored olive oils.…”

“…Finally, higher extinction coefficients ( K 232 and K 268 ) were observed for higher flavoring levels as well as for greater heating times, pointing out a possible pro‐oxidant behavior enhanced by the thermal degradation due to the rise of both factors, with a rise of primary and secondary oxidation products. In the literature, contradictory effects have been reported regarding the oils' flavoring effect, being described both increasing (Baiano et al, 2009; Caponio et al, 2016; Sacchi et al, 2017) and decreasing (Bobiano et al, 2019; Tarchoune et al, 2019) trends of the evaluated quality parameters with the increase of the flavoring levels. It should be noticed that a similar increasing tendency of the extinction coefficients during the microwave heating has been previously reported in the literature for different unflavored olive oils (Kishimoto, 2019; Malheiro et al, 2009; Sevim et al, 2018).…”

“…Arbequina oils. In the literature, both increasing and decreasing trends have been reported, depending on several factors such as the type and level of flavoring agent, the type and quality of the olive oil, and the storage conditions (Baiano et al, 2009; Bobiano et al, 2019; Farhoosh & Hoseini‐Yazdi, 2014; Khemakhem et al, 2015; Taoudiat et al, 2018; Tarchoune et al, 2019; Veloso et al, 2020). Concerning the microwave heating time‐period, it had an obvious negative impact on the OS, DPPH, TPC, TCC, and chlorophyll content, leading to a marked decrease of their values, mainly for heating times between 5 and 15 min.…”

Kinetic-thermodynamic study of the oxidative stability of Arbequina olive oils flavored with lemon verbena essential oil

“…The observed temperature decreasing effect is in accordance with the literature data for olive oils (Farhoosh & Hoseini-Yazdi, 2014;Heidarpour & Farhoosh, 2018;Veloso et al, 2020). Similar decreasing trends were also reported found for olive oils flavored with lemon, dried chili pepper, hot pepper, rosemary, sweet lime/orange, oregano or basil (Baiano et al, 2009;Bobiano et al, 2019;Caporaso, Paduano, Nicoletti, & Sacchi, 2013;Khemakhem et al, 2015). Opposite findings (i.e., higher OS values for higher content of the flavoring agent) were also reported in the literature, which are in general linked to higher TRC values (Ayadi et al, 2009;Farhoosh & Hoseini-Yazdi, 2014;Sousa et al, 2015;Veloso et al, 2020).…”

“…Similar findings were reported in the literature, for oils flavored with fruits, spices or aromatic herbs, which flavoring processes in general increased the PV, K 232 and/or K 268 (Baiano et al, 2009;Caponio et al, 2016;Sacchi, Medaglia, Paduano, Caporaso, & Genovese, 2017). Opposite trends, i.e., a significant decrease of the PV, K 232 and/or K 268 or no significant change of the parameters' values, were reported after olive oils flavoring with different aromatic herbs, EO, rosemary leaves or olive leaves (Bobiano et al, 2019;Sousa et al, 2015;Tarchoune et al, 2019). However, as pointed out by Taoudiat, Djenane, Ferhat, and Spigno (2018), the above-mentioned changes (decrease or increase) may only be observed after a minimum storage period (after a 60-days period).…”