Metabolomic and chemometric profiles of ten southern African indigenous fruits

Abstract

Using UPLC-QTOF/MS, metabolites were identified in 10 indigenous fruits from South Africa. Metabolomic-chemometric analysis showed chlorogenic acid scored highest for the discrimination of three different fruit clusters. Heat maps showed patterns and groupings based on the metabolite concentrations. The highest concentrations of quercetin 3-O-α-l-arabinopyranoside (401.09 mg/kg), delphinidin 3-galactoside (57.80 mg/kg), procyanidin B-type dimer (527.07 mg/kg) and epicatechin (1349.46 mg/kg), was in Englerophytum magalismontanum (Transvaal milkplum). Syzygium cordatum (Water berry) had the highest concentrations of quercetin 3-galactoside and methyl gallate 3-O-beta-d-glucopyranoside, Ficus capensis (Cape fig) the most 3-CQA and 5-CQA, and Parinari curatellifolia (Mobola plum) had the highest FRAP (9.5 mmol TEAC/g) and DPPH (14.2 IC50 µg/mL) scavenging activities. When compared to eight other indigenous fruits, Ximenia caffra (Sour plum), and Landolphia kirkii (Sand apricot vine), showed the highest inhibition of carbohydrate hydrolysing enzymes. Correlation analysis identified candidates responsible for each biological activity in these fruits, proving their utility as functional ingredients.