The effect of herbal Lippia javanica extracts on the bioactive content, functional properties, and sensorial profile of biofortified-orange maize based fermented maheu

Abstract

Lippia javanica is commonly used to treat respiratory ailments because of its rich phytochemical profile, however its importance as a food additive in maheu production is not known. The study was aimed at determining the effect of herbal Lippia javanica extract (L.J.E) on the bioactive content, functional properties, and sensorial profile of biofortified-orange maize based fermented maheu. The prepared orange maize gruels were mixed with 5 %, 10 %, and 15 % v/w L.J.E and fermented spontaneously for 24 h. Total polyphenols (TP), antioxidant activity (AOA), β-carotene, vitamin A and vitamin C content were analysed using Folin-Ciocalteu reagent, 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity, ABTS (2,2′-azinobis-3-ethyl-benzothiazoline-6-sulphonate), HPLC, retinol activity equivalent (RAE) conversion, and dichlorophenolindophenol titration method respectively. Physiochemical properties, mineral content and product acceptability were analysed using standard AOAC methods. The β-carotene, vitamin A, and vitamin C range was 0.8–1.1 µg/g, 3.55–3.90 µREA/100g and 6.3–11.1 mg/100g respectively. TP, AOA, total antioxidant activity range was 8.2–19.4 mg GAE/g, 28.1–41 EC50mg/L and 31.3–48.3AE/100g respectively. The pH, total soluble sugars, and titratable acidity was 3.6–3.9, 4–4.5 % and 0.08–0.16 %. Minerals present in maheu were zinc (0.8–1.1mg), iron (2.6–3.1mg), magnesium (93.2–97.1mg), calcium (80.1–89.4mg), and potassium (72.5–82mg). Maheu with 15 % v/w L.J.E had better improved bioactive content, functional properties and sensorial profile.