Integrated Study of Qualitative Olive and Oil Production from Three Important Varieties Grown in Calabria (Southern Italy)

Influence of environmental growth temperature on tocopherol and sterol oil concentrations in olive fruit

BACKGROUND

Tocopherols and sterols are minor components of virgin olive oils that contribute to oil quality. Based on observations at different geographical locations, it has been suggested that environmental temperature during fruit growth affects tocopherol and sterol oil concentrations in olive fruit. However, controlled experiments have not been conducted to directly assess their responses to temperature. In this study, a manipulative experiment using open-top chambers (OTCs) was performed in the field to evaluate the responses of these oil components to a moderate air temperature increase during oil accumulation in young trees of two olive cultivars (Arbequina, Coratina). The two temperature levels in the OTCs were a control about 1 °C above ambient temperature (T0) and a heated treatment (T+) with a target temperature of 4 °C above T0.

RESULTS

Total tocopherol and sterol oil concentrations in olive fruit were generally higher in the T+ temperature treatment than in the control at the end of the oil accumulation period. The increase in total tocopherols in T+ appeared to be related to a decrease in fruit oil concentration with heating. Individual sterols showed both significant increases and decreases due to T+, and some differences in response occurred between the two cultivars.

CONCLUSION

These findings provide evidence that growth temperature affects tocopherol and sterol oil concentrations in olive fruit at the end of the oil accumulation period. Cultivars should be carefully chosen for new olive-growing regions, and the results could be relevant for global warming scenarios in existing growing regions. © 2021 Society of Chemical Industry.

Characterization of Olive Oils Obtained from Minor Accessions in Calabria (Southern Italy)

The valorization of minor accessions of olive is potentially a good way to improve the qualitative production of a specific territory. Olive oils of four minor accessions (Ciciarello, Tonda di Filogaso, and Ottobratica Calipa and Ottobratica Cannavà clones) produced in the same area of the Calabria region were characterized for the principal qualitative analyses at two drupe harvesting periods (October and November). Good quality in terms of free acidity, peroxides, spectrophotometric indexes, and fatty acid composition was observed in olive oils produced at both drupe harvesting times, with the exception of those of Tonda di Filogaso, which showed a free acidity level over the legal limit for extra virgin olive oil in the second harvesting time. All of the olive oils possessed at both production periods averagely abundant total polyphenols (460–778 mg/kg) and tocopherols (224–595 mg/kg), and the amounts changed in the experimental years for expected different environmental variations. Ottobratica Cannavà and Ottobratica Calipa clones showed some peculiar qualitative characteristics (free acidity, peroxides, fatty acid composition, and total polyphenols), distancing themselves from the principal variety of reference, Ottobratica.

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. © 2020 Society of Chemical Industry.

n-Alkanes and n-Alkenes in Virgin Olive Oil from Calabria (South Italy): The Effects of Cultivar and Harvest Date

n-Alkanes and n-alkenes are components of the unsaponifiable fraction of an olive oil. These were analysed by GC on-column analysis and are here proposed as an additional tool to certify the origin, authenticity, traceability and chemical quality of olive oil produced in the Reggio Calabria province (South Italy). Nine cultivars were studied: Cassanese, Coratina, Itrana, Leccino, Nociara, Ottobratica, Pendolino, Picholine and Sinopolese grown in the region of Calabria (South Italy). n-Alkanes in the range from 21 to 35 chain carbon atoms and alkenes in the range from 23:1 to 25:1 chain carbon atoms were found with the following elution order: heneicosane (C21), docosane (C22), tricosene (C23:1), tricosane (C23), tetracosene (C24:1), tetracosane (C24), pentacosene (C25:1), pentacosane (C25), hexacosane (C26), eptacosane (C27), octacosane (C28), nonacosane (C29), triacontane (C30), entriacontane (C31), dotriacontane (C32), tritriacontane (C33), tetratriacontane (C34), pentatriacontane (C35). The oil of all cultivars showed a decreasing trend in total n-alkane and n-alkene content, with the oil of Sinopolese showing the highest content, varying from 328.50 to 214.00 mg/kg. Odd-chain alkanes predominated over even-chain n-alkanes, and tricosane, tetracosane and pentacosane were the most represented alkanes. Cultivar and harvest date significantly influenced the n-alkane and n-alkene content. These findings can be useful to distinguish different olive cultivars and to decide the fruit harvest date for the oil of the Reggio Calabria province (South Italy). A daily quantity of 30 g of olive oil of the Sinoplese cv (the one with the highest n-alkane and n-alkene content) was found to be in accordance with the suggestions of the European Agency for the evaluation of medicinal products Committee for veterinary medicinal products and biogenic hydrocarbons intake for the human diet.