Instituto Politécnico de Castelo Branco, Escola Superior Agrária, 6001-909 Castelo Branco, Portugal.
Universidade de Lisboa, Instituto Superior de Agronomia, LEAF, Tapada da Ajuda, 1349-017 Lisbon, Portugal.
Food Chem. 2016 Nov 15;211:51-8. doi: 10.1016/j.foodchem.2016.05.022. Epub 2016 May 5.
In this study, the lipophilic and hydrophilic phenol composition of virgin olive oils (VOO) obtained from olives from two of the most important Portuguese cultivars ('Galega Vulgar' and 'Cobrançosa'), harvested at different ripening stages and under two irrigation schemes (rain fed and irrigated), was evaluated. Phenolic alcohols (hydroxytyrosol and tyrosol), phenolic acids and derivatives and flavonoids (luteolin and apigenin), as well as tocopherols were quantified. Lipophilic (>300mgkg(-1)) and hydrophilic phenols (>600mgkg(-1)) were present in high contents in both VOO, for early ripening stages. Gamma-tocopherol content is higher in 'Galega Vulgar' VOO. Total phenols showed a decrease between ripening index 2.5 and 3.5. The dialdehydic form of elenolic acid linked to hydroxytyrosol (3,4-DHPEA-EDA), also known as oleacein, was the major phenolic compound identified in both oils. The concentration of free hydroxytyrosol and tyrosol in both VOO is very low while their esterified derivatives, like 3,4-DHPEA-EDA and p-HPEA-EDA, are much more abundant.
本研究评估了两个葡萄牙主要橄榄品种（“Galega Vulgar”和“Cobrançosa”）橄榄果实的初榨橄榄油（VOO）的亲脂性和亲水性酚类成分，这些橄榄在不同成熟阶段和两种灌溉方案（雨养和灌溉）下收获。测定了酚醇（羟基酪醇和酪醇）、酚酸及其衍生物和类黄酮（叶黄素和芹菜素）以及生育酚的含量。亲脂性（>300mgkg(-1)) 和亲水性酚类（>600mgkg(-1)) 在两个 VOO 中均在早期成熟阶段含量较高。“Galega Vulgar”VOO 中的γ-生育酚含量较高。总酚含量在成熟指数 2.5 和 3.5 之间呈下降趋势。与羟基酪醇结合的橄榄酸的二醛形式（3,4-DHPEA-EDA），也称为橄榄苦苷，是两种油中鉴定出的主要酚类化合物。两种 VOO 中游离羟基酪醇和酪醇的浓度非常低，而它们的酯化衍生物，如 3,4-DHPEA-EDA 和 p-HPEA-EDA，则更为丰富。
