scholarly journals Changes in the Antioxidant Properties of Extra Virgin Olive Oil after Cooking Typical Mediterranean Vegetables

Antioxidants ◽  
2019 ◽  
Vol 8 (8) ◽  
pp. 246 ◽  
Author(s):  
Jessica del Pilar Ramírez-Anaya ◽  
Ma. Claudia Castañeda-Saucedo ◽  
Manuel Olalla-Herrera ◽  
Marina Villalón-Mir ◽  
Herminia López-García de la Serrana ◽  
...  

Extra virgin olive oil (EVOO), water, and a water/oil mixture (W/O) were used for frying, boiling and sautéeing Mediterranean vegetables (potato, pumpkin, tomato and eggplant). Differences in antioxidant capacity (AC) (2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric iron (FRAP), 2,2-azinobis-(3-ethylbensothiazoline)-6-sulphonic acid (ABTS)), total phenolic content (TPC) and individual phenols (high-performance liquid chromatography (HPLC)) in unused and used EVOO and water were determined. The water used to boil tomatoes showed the highest TPC value, whilst the lowest was found in the EVOO from the W/O used for boiling potatoes. After processing, the concentrations of phenols exclusive to EVOO diminished to different extents. There was a greater transfer of phenols from the vegetable to the oil when eggplant, tomato and pumpkin were cooked. W/O boiling enriched the water for most of the phenols analysed, such as chlorogenic acid and phenols exclusive to EVOO. The values of AC decreased or were maintained when fresh oil was used to cook the vegetables (raw > frying > sautéing > boiling). The water fraction was enriched in 6-hydroxy-2,5,7,8–tetramethyl-chroman-2-carboxylic acid (Trolox) equivalents following boiling, though to a greater extent when EVOO was added. Phenolic content and AC of EVOO decreased after cooking Mediterranean diet vegetables. Further, water was enriched after the boiling processes, particularly when oil was included.

Author(s):  
Ramírez-Anaya Jessica del Pilar ◽  
Castañeda-Saucedo Ma.Claudia ◽  
Olalla-Herrera Manuel ◽  
Villalón-Mir Marina ◽  
López-García de la Serrana Herminia ◽  
...  

Extra virgin olive oil, water, and water/oil mixture (W/O) were used to fry, boil and sautée Mediterranean vegetables. We determined the variations between unused and used water and oil for the contents of total (TPC) and individual phenolic compounds measured by HPLC, and the antioxidant capacity (AC) by DPPH, FRAP and ABTS methods. The highest TPC value was found in water used to boil tomato, whereas the lowest in the EVOO from the W/O used for boiling potatoes. The TPC decreased in the processed EVOO, whereas the water was enriched after boiling. After processing, the concentrations of phenols exclusive to EVOO diminished with differentiated behavior, from complete elimination of hydroxytyrosol and tyrosol after sautéeing and W/O boiling, to conservation of pinoresinol. The transfer of phenols such as chlorogenic, gallic, dihydroxybenzoic, hydroxybenzoic and hydroxyphenylacetic acids, as well as luteolin, apigenin and vanillic acid from the vegetable to the oil was frequent when eggplant, tomato and pumpkin were cooked. The cooking water was enriched in most of the phenols analysed, as the case of chlorogenic acid and phenols exclusive to EVOO after W/O boiling. The values of AC in the fresh oil decreased or were maintained after being used to cook the vegetables. With some exceptional increases in the oil used for frying (p<0.05). The cooking techniques were classified in decreasing order according to the AC as follows: raw>deep frying>sautéing>boiling. This pattern was more consistent with DPPH results (from potato, eggplant and pumpkin) than in those of ABTS (pumpkin) and FRAP (eggplant). The water fraction recovered from boiling was enriched in Trolox equivalents being higher when EVOO was added. Phenolic content and AC in the EVOO decreased after cooking Mediterranean Diet vegetables, whereas the water was enriched after the boiling processes, particularly when oil was included.


Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 877
Author(s):  
Anallely López-Yerena ◽  
Antonia Ninot ◽  
Núria Jiménez-Ruiz ◽  
Julián Lozano-Castellón ◽  
Maria Pérez ◽  
...  

The ancient ‘Corbella’ olive variety from the center-north of Catalonia is being recovered to obtain quality extra-virgin olive oil (EVOO) with unique organoleptic properties. The aim of this work was to determine the effect of agronomic and technical factors on the phenolic fingerprint of EVOO and to establish the optimum harvesting time and crushing and malaxation conditions for ‘Corbella’ olives. Therefore, three different ripening indices (0.3, 1.2, and 3.2) and three crushing temperatures (10, 18, and 25 OC) were studied. Additionally, a factorial design to optimize the phenolic concentration of the EVOO was developed, applying a range of sieve diameters (4 and 6 mm), and malaxation time (30 and 60 min) and temperature (27, 32, and 37 °C). The phenolic profile was analyzed by ultra-high performance liquid chromatography coupled to mass spectrometry in a tandem detector. The level of secoiridoids, the major phenolic compounds in the oil, was higher when using olives harvested earlier. Oleuropein aglycone and ligstroside aglycone were degraded during crushing at high temperatures, resulting in the formation of oleacein and oleocanthal. The best processing conditions in terms of total phenolic content were found to be 30 min of malaxation at 37 OC, the crushing size not having any affect.


Molecules ◽  
2020 ◽  
Vol 25 (21) ◽  
pp. 5000
Author(s):  
Nikolaos Kokras ◽  
Eleni Poulogiannopoulou ◽  
Marinos G. Sotiropoulos ◽  
Rafaella Paravatou ◽  
Eleni Goudani ◽  
...  

The aim of this study was to determine the cognitive and behavioral effects of extra virgin olive oil total phenolic content (TPC) and Sideritis (SID) extracts in female mice, and identify the associated neurochemical changes in the hippocampus and the prefrontal cortex. All animals received intraperitoneal low or high doses of TPC, SID or vehicle treatment for 7 days and were subjected to the Open Field (OF), Novel Object Recognition (NOR) and Tail Suspension Test (TST). The prefrontal cortex and hippocampus were dissected for analysis of neurotransmitters and aminoacids with high performance liquid chromatography with electrochemical detection (HPLC-ED). Both TPC doses enhanced vertical activity and center entries in the OF, which could indicate an anxiolytic-like effect. In addition, TPC enhanced non-spatial working memory and, in high doses, exerted antidepressant effects. On the other hand, high SID doses remarkably decreased the animals’ overall activity. Locomotor and exploratory activities were closely associated with cortical increases in serotonin turnover induced by both treatments. Cognitive performance was linked to glutamate level changes. Furthermore, TPC reduced cortical taurine levels, while SID reduced cortical aspartate levels. TPC seems to have promising cognitive, anxiolytic and antidepressant effects, whereas SID has sedative effects in high doses. Both extracts act in the brain, but their specific actions and properties merit further exploration.


Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2041 ◽  
Author(s):  
Vasilisa Pedan ◽  
Martin Popp ◽  
Sascha Rohn ◽  
Matthias Nyfeler ◽  
Annette Bongartz

Olive oil is not only known for its pungent, bitter, and fruity taste, but also for its health potential, which is often hypothesized to depend on its phenolic compounds. One hundred extra virgin olive oil samples (monocultivaric as well as blends of varieties) were assessed with regard to their sensory properties and phenolic compound composition. Nineteen phenolic compounds have been determined and correlated with sensory data. In all olive oil samples, oleocanthal and oleacein were the most abundant phenolic compounds, with average amounts of 77.9 mg/kg and 41.8 mg/kg, respectively. The highest correlation coefficient between a sensory descriptor and the phenolic compounds was found for the bitter taste sensation and the total phenolic content with r = 0.72 and in particular, for 3,4-DHPEA-EA, with r = 0.57. Intensity plots were assessed for the three main sensory descriptors fruitiness, bitterness, pungency, and for the quality factor harmony, which is associated with the degree of ripeness aroma of olive oil. Positive correlations for the aroma descriptors freshly cut grass, leaves, and nuts, and the phenolic compounds were especially observed for oleoside 11-methylester and vanillic acid. The present study provides a comprehensive database of phenolic compounds in olive oils from six different varieties and seven countries.


Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2449 ◽  
Author(s):  
Panagiotis Diamantakos ◽  
Triada Giannara ◽  
Maria Skarkou ◽  
Eleni Melliou ◽  
Prokopios Magiatis

The phenolic fraction of the extra virgin olive oil (EVOO) has been studied over the past two decades because of its important health protective properties. Numerous studies have been performed in order to clarify the most crucial factors that affect the concentration of the EVOO’s phenolic fraction and many contradictory results have been reported. Having as target to maximize the phenolic content of EVOO and its healthy properties we investigated the impact of harvest time, malaxation temperature, and malaxation duration on the concentration of individual phenols in extra virgin olive oil. Olive oil was prepared in a lab-scale olive mill from different varieties in Greece. The extraction process for cultivar (cv) Koroneiki samples was performed at five different harvest periods from the same trees with three different malaxation temperatures and five different malaxation duration times (N = 75). Similar types of experiments were also performed for other varieties: cv Athenolia (N = 20), cv Olympia (N = 3), cv Kalamata (N = 3), and cv Throubolia Aegean (N=3) in order to compare the changes in the phenolic profile during malaxation. The quantitative analysis of the olive oil samples with NMR showed that the total phenolic content has a negative correlation with the ripening degree and the malaxation time. The NMR data we collected helped us to quantitate not only the total phenolic content but also the concentration of the major phenolic compounds such as oleocanthal, oleacein, oleokoronal, and oleomissional. We noticed different trends for the concentration of these phenols during malaxation process and for different malaxation temperatures. The different trends of the concentration of the individual phenols during malaxation and the completely different behavior of each variety revealed possible biosynthetic formation steps for oleocanthal and oleacein and may explain the discrepancies reported from previous studies.


2020 ◽  
Vol 10 (1) ◽  
pp. 04-09
Author(s):  
Evangelos Giannakopoulos ◽  
Georgios Salachas ◽  
Dimitrios Zisimopoulos ◽  
Sofia-Anna Barla ◽  
Electra Kalaitzopoulou ◽  
...  

Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3654
Author(s):  
Antonio Francioso ◽  
Rodolfo Federico ◽  
Anna Maggiore ◽  
Mario Fontana ◽  
Alberto Boffi ◽  
...  

Extra virgin olive oil (EVOO) phenols represent a significant part of the intake of antioxidants and bioactive compounds in the Mediterranean diet. In particular, hydroxytyrosol (HTyr), tyrosol (Tyr), and the secoiridoids oleacein and oleocanthal play central roles as anti-inflammatory, neuro-protective and anti-cancer agents. These compounds cannot be easily obtained via chemical synthesis, and their isolation and purification from EVOO is cumbersome. Indeed, both processes involve the use of large volumes of organic solvents, hazardous reagents and several chromatographic steps. In this work we propose a novel optimized procedure for the green extraction, isolation and purification of HTyr, Tyr, oleacein and oleocanthal directly from EVOO, by using a Natural Deep Eutectic Solvent (NaDES) as an extracting phase, coupled with preparative high-performance liquid chromatography. This purification method allows the total recovery of the four components as single pure compounds directly from EVOO, in a rapid, economic and ecologically sustainable way, which utilizes biocompatible reagents and strongly limits the use or generation of hazardous substances.


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