Variação na qualidade do azeite em cultivares de oliveira

O cultivo de oliveira (Olea europaea L.) no sul de Minas Gerais tem apresentado resultados promissores quanto à produção de frutos. No entanto, há necessidade de verificar seu valor nutritivo e a qualidade do azeite oriundo dos frutos das cultivares potencialmente produtivas. Objetivou-se com este trabalho determinar a composição centesimal dos frutos, as características químicas e o perfil de ácidos graxos dos azeites extraídos de diferentes cultivares de oliveira, com a finalidade de selecionar os materiais com potencial agroindustrial. Foram avaliadas 32 cultivares de oliveira com seis anos de idades quanto à composição centesimal (teores de umidade, lipídeos, proteínas e cinzas, tanto na polpa quanto no caroço dos frutos); composição química e perfil de ácidos graxos dos azeites. Observaram-se nas cultivares MGS ASC315, Cerignola, MGS GRAP561 e MGS GRAP575 maiores valores de lipídeos. Além disso, as análises indicaram que o caroço possui quantidades significativas de lipídeos, embora sempre inferiores às quantidades presentes na polpa. Os índices de acidez em ácido oleico, peróxidos e refração absoluta estão de acordo com a resolução da ANVISA, podendo ser inicialmente classificados como azeite de oliva extravirgem ou virgem. De modo geral, todos os ácidos graxos presentes nos azeites possuem valores satisfatórios, destacando a cultivar MGS GRAP084, com maior concentração de ácido oleico, principal ácido responsável pelos benefícios à saúde

LC-ESI-MS characterization of phenolic profiles Turkish olive oils as influenced by geographic origin and harvest year

The purpose of this investigation was to evaluate and compare the differences in the phenolic fractions and antioxidant properties of virgin olive oils from the Nizip yaglik and Kilis yaglik olive varieties cultivated in native and different olive growing areas of Turkey. The phenolic composition of olive oils was carried out by HPLC-DAD and identifications were made by LC-MS. Fourteen phenolic compounds were identified and among these compounds elenolic acid, tyrosol and hydroxytyrosol were the most dominant. Based on the results, there was no difference in distribution of phenolic compounds, but the total phenolic content in oil from native regions was higher than in oil from Bornova regions. The antioxidant capacity of olive oil extracts was determined by two different methods, including DPPH and ABTS. In both methods, antioxidant capacity values were higher in oil from native regions. © 2013 AOCS.110O602, ZF-2010-D24Acknowledgments The authors thank the Scientific and Technical Research Council of Turkey (TUBITAK) and Cukurova University Research Fund (ZF-2010-D24) for financial support for this research project (Project No. 110O602)

Characterization of the Volatile, Phenolic and Antioxidant Properties of Monovarietal Olive Oil Obtained from cv. Halhali

Volatile and phenolic compositions of olive oil obtained from the cv. Halhali were investigated in the present study. Fruits were harvested at the optimum maturity stage of ripeness and immediately processed with cold press. Simultaneous distillation/extraction (SDE) with dichloromethane was applied to the analysis of volatile compounds of olive oil. Sensory analysis showed that the aromatic extract obtained by SDE was representative of olive oil odour. In the olive oil, 40 and 44 volatile components were identified and quantified in 2010 and 2012 year, respectively. The total amount of volatile compounds was 18,007 and 19,178 µg kg-1 for 2010 and 2012, respectively. Of these, 11 compounds in the 2010 and 12 in the 2012 harvest presented odour activity values (OAVs) greater than 1, with 1-octen-3-ol, ethyl-3-methyl butanoate, (E)-2-heptenal and (E,Z)-2,4-decadienal being those with the highest OAVs in olive oil. The high-performance liquid chromatographic method coupled with diode-array detection was used to identify and quantify phenolic compounds of the olive oil. A total of 14 phenolic compounds in both years were identified and quantified in olive oil. The major phenolic compounds that were identified in both years were hydroxytyrosol, tyrosol, elenolic acid, luteolin, and apigenin. Antioxidant activity of olive oil was measured using the DPPH and ABTS methods. © 2013 AOCS