Enhancement of Carotenoid Profile and Beta‐Carotene Bioavailability in African Locust Bean Pulp–Supplemented Instant Kunu Beverage

Abstract

This study evaluated the effects of African locust bean pulp (ALBP) supplementation on carotenoid profile and beta‐carotene bioavailability in rats fed with instant kunu beverage. Based on preliminary studies, a freeze‐dried kunu beverage was developed with the substitution of 5%–25% ALBP for millet. A 100% millet‐based kunu served as a control. Established procedures were used to determine the carotenoid profile and retinol equivalence (RE) of the beverage. Beta‐carotene bioavailability was assessed in an animal study model involving 36 male weanling albino rats. ANOVA (at α 0.05) was used to analyze the data generated. The carotenoid profile of kunu was enhanced with lutein ranging between 4.54 and 7.43 μ g/g, alpha‐carotene (0.19 and 15.22 μ g/g), 13‐ cis (0.16 and 3.36 μ g/g), trans (0.45 and 8.50 μ g/g), 9‐ cis (0.53 and 1.64 μ g/g), and TBC (total beta‐carotene) (4.28 and 12.74 μ g/g) and RE of alpha‐carotene (0.05–1.80 μ g/g), beta‐carotene (0.15–2.10 μ g/g), and total provitamin A carotenoid (pVAC) content (0.20–3.80 μ g/g), respectively. Improvements were observed in serum and liver retinol and protein of rats, up to 20% inclusion of ALBP compared to the control group. The linear regression analysis from plots of feed carotene contents against carotene concentrations of serum and liver showed bioavailability of 6.61% and 6.67% for serum and liver, respectively. These findings showcased the level of beta‐carotene absorption and utilization. The similarity in values of serum and liver bioavailability indicates consistent systemic distribution and uptake from diet. Therefore, substitution of 20% ALBP for millet in kunu and similar beverages is recommended, as the product can potentially serve as a functional food against vitamin A deficiency (VAD). Further works should include shelf‐life determination, the effect of processing methods, a consumer acceptance study, and clinical trials to validate the efficacy in humans.