(P04-020-24) African Baobab (Adansonia digitate L.) Seeds Are a Promising Source of Bioactive Peptides

Objectives: Information is sparse in the literature on the utilisation of functional components of baobab seed protein. This research aims to extract and characterise the functionalities of bioactive peptides from African baobab seeds. 

Methods: Protein from baobab seed was isolated using the isoelectric point method and the Baobab protein isolate (BPI) was enzymatically hydrolysed using alcalase enzyme (50^oC, pH 8) to obtain baobab protein hydrolysate (BPH). The BPH was subjected to Reverse-Phase High Performance Liquid Chromatography (RP-HPLC), to detect and quantify the organic compounds and other bioactive components; and to further obtain peptide fractions from the BPH. The peptide fractions were evaluated for antidiabetic potential using alpha-amylase and alpha-glucosidase inhibitory activity at concentrations ranging from 10 to 50 ug/mL.

Results: Baobab seed protein hydrolyste with a 45% degree of hydrolysis was obtained. Organic acids detected in the BPH were citric, malic, ascorbic and benzoic acids, with peak area and compound weights 26.09 and 23.58, 20.00 and 21.54, 6.96 and 5.33, 2.61 and 3.02, and 1.74 and 2.93 %, respectively. Other bioactive compounds detected are polyphenolic compounds which include Quercetin, (-)-Epicatechin, procyanidin, (+)-Catechin, Chlorogenic acid, and Luteolin, with peak area and compound weights 15.65 and 16.24, 13.01 and 4.61, 7.13 and 5.87, 4.35 and 3.97, 1.57 and 1.83, and 0.87 and 1.02 %, respectively. Four peptide fractions with molecular weight ranges 1.0 – 2.50 (Fraction A), 2.50 – 5.00 (Fraction B), 5.00 – 7.50 (Fraction C), and 7.50 – 10.00 (Fraction D) KDa were obtained from BPH. Alpha-amylase activities for BPI and BPH were 5.05 – 69.40, and 7.58 – 65.30 % while higher activities, which increased in a concentration-dependent manner were observed in fractions A-D, highest in fraction B (45.12 – 104.00%). Similarly, significant alpha-glucosidase activities with a concentration-dependent increase were observed in all samples but lowest in BPI (7.11 – 98.00) and highest in fraction B (22.54 – 116.20%).

Conclusions: African baobab seeds are a rich source of bioactive peptides which contains organic acids and polyphenols, with significant antidiabetic potential, and could be utilised as ingredients in functional foods and nutraceuticals.

Funding Sources: The research did not receive any external funding.