The tropical fruits velvet tamarind (Dialium guineense Willd), African locust beans (Parkia biglobosa Jacq.) and baobab (Andansonia digitata L.) are part of sub-Saharan Africa culture and are used as foods, usually as raw materials for beverage production, or even for medicinal purposes, being an important nutrient and bioactive compound source [1,2]. This research focused on nutritional composition and bioactive compounds in the fruit pulps and seeds of these Guinean-origin plant species.
Sugars were quantified using high-performance liquid chromatography with a refractive index detector (HPLC-RI) [3]. The profile determination and quantification of organic acids and phenolic compounds were performed using HPLC-PDA (photodiode array detector) [4]. Protein (Kjeldahl) and fat (Soxhlet) content [5,6] and antioxidant capacity (DPPH, FRAP) [4] were also determined. The fatty acids of the lipid phase were identified and quantified via gas chromatography with a flame ionisation detector (GC-FID) [6]. Elemental analysis was carried out using X-ray fluorescence [6]. Total, soluble and insoluble dietary fibre were determined enzymatically only in the fruit pulps [6]. Amygdalin [7,8], a toxic compound, was analysed via HPLC-PDA in the seeds and not detected.
The fatty acid profiles of the seeds are quite different, with African locust beans standing out for their high polyunsaturated content and baobab for its high monounsaturated content.
Several bioactive compounds were quantified, such as vitamin C, various hydroxycinnamic acids (caffeic, coumaric, chlorogenic, ferulic) hydroxybenzoic acids (gallic, vanillic, p-hydroxybenzoic), and polyphenols (quercetin, catechin, epicatechin, rutin, naringin, procyanidin, kaempferol), as well as fatty acids from the ω-3 and ω-6 series.
Velvet tamarind had the highest antioxidant capacity, African locust beans had the highest sugar, potassium, iron and copper content and baobab had the highest vitamin C, calcium and soluble and total dietary fiber content. Generally, fruit pulps are richer in sugars and organic acids and seeds in protein and fat.
