scholarly journals Long-Term Preservation of Total Phenolic Content and Antioxidant Activity in Extra Virgin Olive Oil: A Physico-biochemical Approach

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


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 ◽  
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.


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.


Planta Medica ◽  
2016 ◽  
Vol 81 (S 01) ◽  
pp. S1-S381
Author(s):  
MA Ghareeb ◽  
T Mohamed ◽  
AM Saad ◽  
LA Refahy ◽  
MA Sobeh ◽  
...  

2019 ◽  
pp. 49-59
Author(s):  
Nu Linh Giang Ton ◽  
Thi Hoai Nguyen ◽  
Quoc Hung Vo

Avocado peel has been considered as a potential source of natural antioxidants in which phenolics are among the most important compounds. Therefore, this study aims to optimize the extraction process of phenolics using response surface methodology and evaluate the corresponding antioxidant activity. From the quadratic model, the optimal condition was determined including the ethanol concentration 54.55% (v/v), the solvent/solute ratio 71.82/1 (mL/g), temperature 53.03 oC and extraction time 99.09 min. The total phenolic content and the total antioxidant capacity at this condition with minor modifications were 26,74 ± 0,04 (mg GAE/g DW) and 188.06 ± 1.41 (mg AAE/g DW), respectively. The significant correlation between total phenolic content and total antioxidant capacity was also confirmed. Key words: response surface methodology, central composite rotatable design, total phenolic content, total antioxidant capacity, avocado peel


2020 ◽  
Vol 50 (3) ◽  
pp. 460-469
Author(s):  
Damir Zyaitdinov ◽  
Alexandr Ewteew ◽  
Anna Bannikova

Introduction. Bioactive compounds are a very popular topic of modern food science, especially when it concerns obtaining polyphenols from cereals. The antiradical, antioxidant, and anti-inflammatory properties of these ingredients allow them to inhibit and prevent coronary, artery, and cardiovascular diseases, as well as several types of cancer. Encapsulation is an effective technology that protects bioactive ingredients during processing and storage. In addition, it also prevents any possible interaction with other food constituents. The research objective was to obtain effective tools of controlled delivery of bioactive compounds. The study featured whey protein as a wall material in combination with maltodextrin to encapsulate the bioactives from oat bran. Study objects and methods. The processed material was oat bran. The technology of its biotransformation was based on ultrasound processing and enzymatic hydrolysis. The antioxidant properties were determined using a coulometer of Expert – 006-antioxidants type (Econix-Expert LLC, Moscow, Russia). Separation and quantitative determination of extract were followed using a Stayer HPLC device (Akvilon, Russia) and a system column Phenomenex Luna 5u C18(2) (250×4.6 mm). The total phenolic content was measured by a modified Folin-Ciocalteu method. To prepare microcapsules, whey protein concentrate (WPC) and maltodextrin (MD) solutions were mixed at ratios 6:4, 4:6, and 5:5. After that, the mixes were treated by ultrasonication and 10% w/w of guar gum solution as double wall material. The encapsulation efficiency (EE) was determined as a ratio of encapsulated phenolic content to total phenolic content. A digestion protocol that simulates conditions of the human gastric and intestinal tract was adapted to investigate the release kinetics of the extracts. Results and discussion. Ferulic acid is the main antioxidant in cereals. Its amount during extraction was consistent with published data: 9.2 mg/mL after ultrasound exposure, 9.0 mg/mL after enzymatic extraction, and 8.6 mg/mL after chemical treatment. The antioxidant activity of the obtained polyphenols was quite high and reached 921 cu/mL. It depended on the concentration of the preparation in the solution and the extraction method. The polyphenols obtained by ultrasonic exposure and enzyme preparations proved to have a more pronounced antioxidant activity. The highest EE (95.28%) was recorded at WPC:MD ratio of 60:40. In vitro enzymatic hydrolysis protocol simulating digestion in the gastrointestinal tract was used to study the effect of capsule structural characteristics on the kinetics of polyphenol release. The percentage of o polyphenols released from capsules ranged from 70% to 83% after two hours of digestion, which confirmed the effectiveness of microencapsulation technology. Conclusion. The research confirmed the possibility of using polyphenols obtained by the biotechnological method from oat bran as functional ingredients. Eventually, they may be used in new functional products with bifidogenic properties. Whey protein can be used to encapsulate polyphenols as the wall material of microcapsules.


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