The polyphenol-rich baobab fruit (Adansonia digitata L.) reduces starch digestion and glycemic response in humans

• DOI: 10.1016/j.nutres.2013.08.002
• Publication Date: 2013-09-09T12:00:20Z
• Authors: Shelly A. Coe; Miriam Clegg; Mar Armengol; Lisa Ryan
• Keywords: Adult; Blood Glucose; 2. Zero hunger; 0301 basic medicine; Plant Extracts; Polyphenols; Starch; Bread; Satiation; Postprandial Period; Young Adult; 03 medical and health sciences; Adansonia; Glucose; Glycemic Index; Fruit; Dietary Carbohydrates; Humans; Digestion; Female; Single-Blind Method; Energy Metabolism

The baobab fruit (Adansonia digitata L.) is found throughout regions of Africa and is becoming increasingly recognized for its high nutrient and polyphenol content. Polyphenols have been beneficial for their effects on reducing the glycemic response (GR) and for improving various other metabolic parameters. Based on previous research, it was hypothesized that the baobab fruit extract would reduce starch digestion in vitro and would show potential for reducing the GR and for increasing satiety and diet-induced thermogenesis in humans. Six extracts of baobab from 6 different locations in Africa were measured for their antioxidant and polyphenol content using the ferric ion-reducing antioxidant power and the Folin-Ciocalteu methods, respectively. Baobab extract was baked into white bread at different doses to determine the optimal dose for reducing starch breakdown and sugar release from white bread after an in vitro digestion procedure. In vivo, baobab extract was consumed in solution at both a low-dose (18.5 g) and a high-dose (37 g) aqueous drink in 250 mL of water along with white bread, and resulting GR, satiety, and postprandial energy expenditure were measured. All extracts in this study were shown to be good sources of polyphenols. Baobab fruit extract added to white bread at 1.88 % significantly (P < .05) reduced rapidly digestible starch from white bread samples. In vivo, the baobab fruit extract at both low and high doses significantly (P < .05) reduced GR, although there was no significant effect on satiety or on energy expenditure.