Antioxidant quantification in different portions obtained during olive oil extraction process in an olive oil press mill

BACKGROUND Different antioxidant compounds are generally transferred from olives to olive oil during the production process. This work characterized the principal total bioactive compounds (tocopherols and phenols) in olives, olive oil and by-products of four cultivars grown in Calabrian areas (southern Italy), considering the effect of harvesting period. Antioxidant capacity, total and individual phenolic compounds were also analysed. RESULTS Drupes, olive paste, pomace and olive wastewater showed similar phenolic compounds, while olive oil possessed a different composition, suggesting that phenols are not only transferred from drupe to oil, but also they change during oil production. Tocopherols varied among cultivars and harvesting period: generally, they were more abundant in samples produced in the first harvesting period. Qualitative and quantitative differences in phenolic composition and antioxidant activity were significantly found among cultivars in all the matrices. CONCLUSION The highest amount of total phenolic antioxidants ended up in olive wastewater with variability due to the olive cultivar, while only a small part of them finished in the oil. This work shows evidence that the availability of bioactive compounds in different portions from the olive oil extraction belong to different varietal origins. In particular, new information was acquired on Ottobratica Calipa, a new olive clone, that produced an olive oil with an interesting antioxidant amount. (c) 2020 Society of Chemical Industry

Automated summary

This study characterized the transfer and changes of bioactive compounds in olives during olive oil production process. Significant differences were found in phenolic composition and antioxidant activity among cultivars in different matrices. This research provides new insights into the availability of bioactive compounds in different portions from olive oil extraction and the antioxidant potential of different olive varieties.