Changes in phenolic compounds during ripening in Gemlik variety olive fruits obtained from different locations

Abstract

The phenolic compounds, total phenolic content, and antioxidant activity of Gemlik variety olive fruits obtained from four different locations in Turkey on five different harvesting dates (HDs) were investigated. The determination of phenolic compounds in olive flesh methanolic extracts was done by high performance liquid chromatography (HPLC) analysis. The total phenolic content and antioxidant activity values were estimated using Folin-Ciocalteu reagent and 2,2-diphenyl-1-picodrylhydrazyl reagent methods, respectively. Among 11 phenolic compounds identified, vanillic acid and hydroxytyrosol are the most abundant ones. In general, olive fruits from the Umurbey location had higher levels of phenolic compounds. The antioxidant activities of the olives were related to their phenolic content, and the olive fruits from the Umurbey location had a mean antioxidant activity 66.52% higher than that of other olives. There were differences among the quantities of phenolic compounds, the total phenolic contents, and the antioxidant activities of the olive fruits depending on HDs and location.Keywords: olive fruits; phenolic compounds; harvesting dates; vanillic acid Para esta investigación, se analizó la presencia de compuestos fenólicos, el contenido total de fenólicos y la actividad antioxidante de aceitunas tipo Gemlik obtenidas de cuatro lugares diferentes de Turquía en cinco fechas de cosecha (FC) distintas. Para determinar los compuestos fenólicos presentes en los extractos metanólicos de la pulpa de aceituna se utilizó el análisis con cromatografía líquida de alta resolución (HPLC). El contenido fenólico total y los valores asociados a la actividad antioxidante fueron estimados usando los métodos reactivos Folin-Ciocalteu y 2,2-diphenyl-1-picodrylhydrazyl, respectivamente. Entre los once compuestos fenólicos identificados, los más abundantes fueron ácido vanílico y hidroxitirosol. En general, las aceitunas cosechadas en Umurbey mostraron niveles más elevados de compuestos fenólicos. Asimismo, se observó que las actividades antioxidantes de las aceitunas se relacionan con su contenido fenólico. En este sentido, la actividad antioxidante promedio de las aceitunas de Umurbey fue 66,52% más elevada que la de las demás aceitunas. A partir de esta investigación puede concluirse que existen diferencias en lo que respecta a las cantidades de compuestos fenólicos, los contenidos totales de fenólicos y las actividades antioxidantes de las aceitunas, vinculadas a su FC y a su lugar de origen.

Response Surface Methodology‐Based Optimized Ultrasonic‐Assisted Extraction and Characterization of Selected High‐Value Components from Gemlik Olive Fruit

“…In the present study vanillic acid is detected as the major (2.45 %) while p-hydroxyphenol as the minor (0.35 %) phenolic bioactives among other characterized phenolics. This result is in agreement with that investigated by Uylaşer et al (2015) who reported that vanillic acid was the highest (at un-ripened/green stage of olive) among others samples harvested from Mudanya (571.05 mg/kg FW), Umurbey (2071.37 mg/kg FW), Cagrisan (971.30 mg/kg FW) and Kumla (485.25 mg/kg FW) locations. [23] Furthermore, Benlarbi et al (2018) reported that vanillic acid, in green olive fruits from Algerian cultivars, ranged from 27.55 to 211.01 mg/100 g with highest amount in Sigoise and the lowest in Dahbia cultivars.…”

Effect of Bactrocera oleae on phenolic compounds and antioxidant and antibacterial activities of two Algerian olive cultivars

“…Globally, the phenolic amounts determined were in the range previously reported by other authors for different cultivars. 36,39,40 Oleuropein, besides being biologically active, is also responsible for the bitter-taste of raw olive fruits. 41 Curiously, the cultivar with higher contents of this compound (Limli) was less attacked by B. oleae.…”

Characterization of virgin olive oils obtained from minor Tunisian varieties for their valorization

“…Significant differences were found between varieties and according to the region (p ≤ 0.01). Uylaşer [19] observed differences in both quantitative and qualitative fractions of phenolic compounds from the studied olive fruit samples obtained from different locations.…”