Solvent Extraction of Polyphenolics from the Indigenous African Fruit Ximenia caffra and Characterization by LC-HRMS

Abstract

Indigenous and non-commercial fruits can be an important source of antioxidant polyphenols; however, the identity and content of polyphenols from non-commercial fruits are often poorly described. The study aimed to extract, identify, and quantify polyphenols from the skin of the indigenous Africa fruit Ximenia caffra, using solvent extraction. Three solvents (hexane, acetone, and 70% v/v ethanol) over three extraction times (30, 60 and 120 min) were used in a 32 full factorial experimental design to determine effects on polyphenol recovery, and individual polyphenolics were characterised using liquid chromatography high-resolution mass spectrometry (LC-HRMS). Ethanol was the most effective extraction solvent, and extracts had high levels of total phenolics and flavonoids (65 mg gallic and 40 mg catechin equivalents per gram dry sample respectively), and high antioxidant activity (18.2 mg mL−1 ascorbic acid equivalents). LC-HRMS positively identified 16 compounds, of which 14 were flavonoids including flavonoid glycosides, and indicated that concentrations of some flavonoids decreased for extraction times beyond 60 min. It was concluded that the fruit of Ximenia caffra is rich in natural polyphenolic antioxidants; the present work identified and quantified a number of these, while also establishing suitable solvent extraction conditions for the recovery of these potentially high-value compounds.

Ultrasound-Assisted Extraction of Two Types of Antioxidant Compounds (TPC and TA) from Black Chokeberry (Aronia melanocarpa L.): Optimization of the Individual and Simultaneous Extraction Methods

“…The polarity of the extraction solvents has been proposed as one of the critical aspects that results in different extraction efficiency [29]. TPC and TA are moderately polar compounds that can be found in most berries.…”

Nutritional, Antioxidant and Quality Acceptability of Smoothies Supplemented with Moringa oleifera Leaves

“…However, the fact that a similar trend was not obtained for the flavonoid contents and considering the generally low values obtained for the total flavonoid content compared to the total phenolic content might suggest the presence of more phenolic compounds in the fruit and vegetables used. Polyphenolic compounds, including phenolic and flavonoid compounds, are parts of the bioactive components in food which possess health promoting properties such as anti-inflammatory, antidiabetic and antihypertensive properties, which have been the focus of many research studies [1,[13][14][15]. Percentage (mean ± standard deviation, n = 3) of (A) total phenolic and (B) total flavonoid contents of smoothies (TPC and TFC).…”

Nutritional, Antioxidant and Quality Acceptability of Smoothies Supplemented with Moringa Oleifera Leaves

“…However, the fact that similar trend was not obtained for the flavonoid contents and considering the generally low values obtained for the total flavonoid content compared to the total phenolic content might suggest the presence of more phenolic compounds in the fruits and vegetable used. Polyphenolic compounds including phenolic and flavonoid compounds are parts of the bioactive components in food which posse health promoting properties such as antiinflammatory, antidiabtes, antihypertensive which have been the focus of many research studies [1,[12][13][14] Studies [2,15] have reported the roles of antioxidant in preventing or ameliorating the effects of free radical which have been implicated in many diseases including diabetes, hypertension, cancer etc. Phenols and flavonoid compounds are bioactive components of foods with health promoting properties including antioxidative and anti-inflammatory properties [16].…”