Edible flowers from Theobroma speciosum: Aqueous extract rich in antioxidant compounds

Abstract

Theobroma speciosum, known as "cacauí" in Brazil, is considered a prominent unconventional food plant. The objective of this work was to evaluate the chemical profiles, antioxidant capacity and minerals of the aqueous extract and fractions from its flowers. The identified compounds were sugars, organic acids and phenolics compounds such as citric, malic and protocatechuic acids, quercetin, quercetin pentoside and quercetin-3-O-glucoside. The extract was rich in phenolic compounds (640 mg GAE g^-1). Furthermore, fractions also presented phenolic compounds from 170.7 to 560.7 mg GAE g^-1 (mainly protocatechuic acid, quercetin and derivatives), which influenced on the high antioxidant capacity in DPPH, ABTS, FRAP and co-oxidation β-carotene/linolenic acid assays. Flowers presented potassium (115 ± 2 μg mL^-1), magnesium (18.4 ± 0.2 μg mL^-1), phosphorus (7.0 ± 0.0 μg mL^-1) and calcium (3.1 ± 0.1 μg mL^-1). Moreover, the flowers aqueous extract represents a new promising food source rich in antioxidant compounds.

Keywords: Cacauí; Citric acid, PubChem CID: 311; DI-HRMS; Malic acid, PubChem CID: 525; Malvaceae; NMR; Phenolics compounds; Protocatechuic acid, PubChem CID: 72; Quercetin, PubChem CID: 5280343; Quercetin-3-O-glucoside, PubChem CID: 5280804; Unconventional food plant.