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The health benefits of extra virgin olive oil (EVOO) are related to its chemical composition and the presence of bioactive compounds with antioxidant properties. The aim of this study was to evaluate antioxidant compounds (pigments, coenzyme Q10 (CoQ10) and phenolic compounds) and antioxidant properties of EVOO from the same region comparing different cultivars (Hojiblanca and Arbequina), harvest year and crop stage. Antioxidant properties of oils were studied before and after a gastrointestinal digestion process, by in vitro assays (DPPH, ABTS and FRAP) and antioxidant markers in Caco-2 cells (reactive oxygen species production). The content of bioactive compounds measured was significantly affected by cultivar and harvest year (except for carotenoids) and by the crop stage (except for coenzyme Q10). Higher amounts of coenzyme Q10 were observed in Hojiblanca than in Arbequina EVOO. Total phenol content and antioxidant properties were also different depending on cultivar and harvest year and the in vitro digestion process strongly improved antioxidant marker values. Antioxidant potential in bioaccessible fractions was mainly related to the content of coenzyme Q10 and phenolic compounds in EVOO. Chemometric analysis showed that the oils were clearly classified by cultivars, harvest and crop stage, according to the chemical composition and antioxidant activity analyzed in the present study

In this report, we investigated for the first time the total polyphenols content (TPC) and antioxidant activity before and after digestion of Carapichea ipecacuanha root infusion, better known as ipecac, prepared at different concentrations. An in vitro digestion system coupled to a Caco-2 cell model was applied to study the bioavailability of antioxidant compounds. The ability of ipecac bioaccessible fractions to inhibit reactive oxygen species (ROS) generation at cellular level was also evaluated. The findings revealed that water volume of 50 mL g-1 of sample provided the maximum yield of extraction of TPC and antioxidant activity. Polyphenols increased in content and activity after digestion and they were highly bioavailable (75% of intestinal absorption). Polyphenols were also present in the residual parts which indicate a possible local activity. Results also suggest that ipecac infusion could represent a promising source of effective bioavailable antioxidants to be exploited in functional foods field.

The effect of the experimental conditions on assessing the global volatile profile of extra virgin olive oils (EVOO) by headspace solid-phase micro-extraction/gas chromatography-mass spectrometry (HS-SPME/GC–MS) is studied to obtain maximization of the total peak areas of the compounds. Response Surface Methodology (RSM) is applied to Arbequina EVOO, and the influence of oil quantity, extraction time, and extraction temperature on the total area and extraction of the major desirable compounds is analyzed. The experimental data are adequately fitted into second-order polynomial models with non-significant lack of fit (p > 0.05) and coefficients of determination (R and R -adjusted) higher than 0.88 and 0.78, respectively. A strong similarity is found between the predicted and experimental values. Furthermore, the surface plots show that the extraction of the volatile compounds is favored with increasing extraction temperature, time, and oil quantity. The extraction conditions to obtain the maximum response of “green” volatile compounds from Arbequina olive oil by HS-SPME placed in 50 mL vials are 4.6 g of oil, 43 min, and 59 C. Practical Applications: The findings of the present work show that specific conditions of HS-SPME/GC–MS affect the extraction of volatile compounds from cv. Arbequina olive oil and establish the optimum extraction parameters to more efficiently determine the global profile of this fraction, taking into account the organoleptic characteristics of the cultivar. The results also contribute to the knowledge of the volatile profile of the monovarietal olive oil cv. Arbequina, which is one of most cultivated and consumed types of olive oil worldwide.

The capability of determining the phenolic and volatile profiles of olive oils is of major relevance since these compounds are known to greatly influence the gustatory and olfactory positive attributes of olive oils. An electronic tongue with multiple linear regression models was used to evaluate both profiles based on olive oils potentiometric data generated during a single assay. The proposed electronic tongue-chemometric procedure enabled the quantification of flavonoids, phenolic acids and phenol alcohols of Arbequina extra-virgin olive oils with a similar accuracy of UPLC-MS (0.93 ± 0.03 ≤ R ≤ 0.98 ± 0.08 for the repeated K-fold cross-validation procedure). Also, it was verified that the potentiometric device should not be applied to evaluate volatile compounds in solution (0.80 ± 0.14 ≤ R ≤ 0.94 ± 0.05 for the repeated K-fold cross-validation procedure), showing a lower accuracy than HS-SPME-GS-MS. The overall satisfactory results showed that electronic tongue could be used as a practical sensing instrument to generate a chemical profile of the compounds known to influence the positive sensory attributes of olive oils.