Evaluation of phenolic composition and antioxidant activity changes in olive flowers during development using HPLC/DAD and LC‐MS/MS

Abstract

Olive fruit and leaves have been extensively studied for their chemical compositions and biological activities. However, less attention has been given to its flowers. The present research was achieved on Tunisian olive flowers. It aimed at studying the effects of flower development on phenolic compounds and antioxidant activity. The extracts were analyzed using high performance liquid chromatography coupled to diode array detection (HPLC/DAD) and coupled to mass spectrometry (LC-MS/MS). The HPLC/DAD analysis indicated that oleuropein aglycon (from 1.158 to 3.746 g/kg), followed by hydroxytyrosol (from 0.168 to 1.581 g/kg) and oleoside (from 0.143 to 1.325 g/kg) were the predominant phenolics in olive flowers extracts during development stages. Twenty compounds have been identified, revealing the complex profile of olive flowers, composed, in order of abundance, by secoiridoids, phenolic alcohols, lignans, flavonoids and phenolic acids. Total phenolic contents increased from 2.455 to 8.541 g/kg Gallic acid equivalent per kg of fresh flowers during all steps of the flower development. A correlation between antioxidant activity and total phenolic contents was determined.

Development of Fortified Citrus Olive Oils: From Their Production to the Nutraceutical Properties on the Cardiovascular System

“…MS/MS of both parent ions are in agreement with fragmentation profile of luteolin and apigenin, respectively[53]. Both flavones were previously reported in olive oil[47,54]. Peak 15 (tR = 54.9 min) was detected only in Citrus oil samples, suggesting it originated by Citrus peels.…”

Development of Fortified Citrus Olive Oils: From Their Production to Their Nutraceutical Properties on the Cardiovascular System

“…MS/MS of both parent ions are in agreement with fragmentation profile of luteolin and apigenin, respectively [ 55 ]. Both flavones were previously reported in olive oil [ 49 , 56 ]. Peak 15 ( t R = 54.9 min) was detected only in Citrus oil samples, suggesting it originated from Citrus peels.…”

Olive Fruit and Leaf Wastes as Bioactive Ingredients for Cosmetics—A Preliminary Study

“…However, further studies are necessary to clarify the candidate compounds responsible for these effects. In this sense, olive leaf composition has been studied by different authors [13][14][15][16][17], reporting the richness in bioactive compounds belonging to phenolic compounds, such as hydroxytyrosol, catechin, rutin, verbascoside, luteolin and oleuropein [18]. These compounds have been associated with antioxidant, anti-inflammatory, antiobesity or chemopreventive effects [15,[19][20][21][22][23][24], among other activities.…”