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Green glass (GG), ultraviolet grade absorbing glass (UVAGG), and multilayer (plastic-coated paperboard aluminium foil) (MLP) packagings were used for storing two commercially extra virgin olive oils (EVOOs) with different phenolic and volatile compound contents to evaluate their effect on oil quality evolution over 10 months of light exposure. Quality parameters such as free acidity, peroxide value, spectrophotometric indices, antioxidant and volatile compositions as well as sensory characteristics were evaluated; packaging material type and initial antioxidant composition significantly influenced EVOOs' resistance to oxidation, and consequently their quality. Compared with GG or UVAGG, MLP provided superior protection against oxidation; oils stored in MLP containers retained their characteristics within the regulatory limits and contained more antioxidants and fewer 'rancid' defect and related volatile compounds., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

The quality evolution of 14 extra-virgin olive oils (EVOOs), with different initial polyphenol and oleic acid (64.6-77.7%) levels, was determined during real-time storage in dark conditions at room temperature for 22 months. EVOOs with low (<20-200 mg/kg), medium (450-700 mg/kg), and high polyphenolic levels (750-1400 mg/kg) were used. We found high correlations among peroxide values, K 232 , K 270 , and storage time. Oleuropein derivatives decreased by 98%, 89%, and 85% in EVOOs with low, medium, and high polyphenolic levels, respectively, with the highest depletion occurring in those with the lowest initial concentrations. Besides having higher α-tocopherol protection from oxidative phenomena, EVOOs with the highest phenolic fractions showed lower head space accumulations of off-flavour volatile substances and thus demonstrated the best retention of sensory and health benefits. We propose that the shelf life of EVOOs can be determined from their initial levels of oleuropein derivatives., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The potential of a phenolic extract (PE) from olive vegetation water (OVW) to limit the negative effects of frying was tested after adding it at different concentrations to a refined olive oil (RO). Its efficacy was also compared to ROs containing butylated hydroxytoluene (BHT) and an extra virgin olive oil (EVOO) with a high polyphenol content. Analyses of the oils collected after 30min, 1, 2, 4, 6, 8, 10 and 12h of frying at 180°C, demonstrated that degradation of the polyphenols was proportional to the original content; at a concentration of at least 400mg/kg of polyphenols, PE was able to reduce oxidation of the tocopherols and the emission of low-molecular-weight aldehydes better than BHT and with similar results to the EVOO. In addition, secoiridoid oxidative compounds were examined by high-performance liquid chromatography/triple quadrupole tandem mass spectrometry with electrospray ionisation., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

In recent years, the temperature of processed olives in many olive-growing areas was often close to 30 °C, due to the global warming and an early harvesting period. Consequently, the new trends in the extraction process have to include the opportunity to cool the olives or olive paste before processing to obtain high quality EVOO. A tubular thermal exchanger was used for a rapid cooling treatment (CT) of olive paste after crushing. The results did not show a significant difference in the oil yield or any modifications in the legal parameters. The cooling process determined a significant improvement of phenolic compounds in all the three Italian cultivar EVOOs analyzed, whereas the volatile compounds showed a variability largely affected by the genetic origin of the olives with C 6 aldehydes that seem to be more stable than C 6 alcohols and esters. [ABSTRACT FROM AUTHOR]