Phenolic compounds of ‘Galega Vulgar’ and ‘Cobrançosa’ olive oils along early ripening stages

Abstract

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.

Seeking for sensory differentiated olive oils? The urge to preserve old autochthonous olive cultivars

“…Verdeal was the poorest, with 140 mg/kg in 2016 and 172 mg/kg in 2017. These results agree in general with the ones obtained for different cultivars in different parts of the world, with average amounts varying from 50 to 500 mg/kg of olive oil, and also for the Portuguese cultivars (Galega Vulgar and Cobrançosa) (Peres et al, 2016) suggesting that the amount of vitamin E highly depends on the olive cultivar (Beltrán et al, 2010;Reboredo-Rodríguez et al, 2016;Tura et al, 2007) but also influenced by other factors like maturation process and agro-climatic conditions. In the present work, the severe drought observed during the year 2017 (data not shown) probably promoted the synthesis of these antioxidants, perhaps as a protection of the plant against the increased environmental stress (Beltrán et al, 2005).…”

“…Tura et al, 2007). And, for Verdeal Transmontana and Redondal, are in the same order of the values obtained for the two most common cultivars in Portugal (Galega Vulgar and Cobrançosa) (Peres et al, 2016). The TP content seemed to be significantly influenced by olive cultivar (Pvalue < 0.0001), ranging from 75 to 135 mg CAE/kg of olive oil in 2016 and from 164 to 363 mg CAE/kg of olive oil in 2017, with the highest values consistently observed in cv.…”

“…Redondal, with 34.9 and 29.6 for 2016 and 2017, respectively. Peres et al (2016) obtained values in the order of 17.8 and 8.3, respectively for the Galega Vulgar and Cobrançosa cultivars. In general, the C 18:1 /C 18:2 ratio followed the order Redondal ˃ Verdeal Transmontana ˃ Verdeal ˃ Lentisca ˃ Rebolã ˃ Madural, highly consistent with the results observed for the OS.…”

GxE Effects on Tocopherol Composition of Oils from Very Old and Genetically Diverse Olive Trees

“…Cobrançosa, with reported amounts of 99–313 mg/kg of olive oils, being these values dependent from the storage conditions of the olive fruits before extraction (Pereira et al, ), olive fly attack (Pereira et al, ), decreasing along the fruit ripening (Matos et al, ), and increasing with the addition of olive leaves during extraction (Malheiro et al, ). Also, Peres et al () reported that olive oils extracted from olives of cv. Cobrançosa and other typical cultivar (cv.…”

An effective HPLC‐based approach for the evaluation of the content of total phenolic compounds transferred from olives to virgin olive oil during the olive milling process

“…Olive fruits are very rich in phenolic compounds, with the exact composition depending on different variables, the more relevant of which are cultivar, climatic conditions and degree of maturation . Nevertheless, it is well known that only a minor part of this phenolic fraction passes in the olive oils during the extraction process, mainly depending on their predominant hydrophilic nature and the enzymatic activities .…”