Implications of blanching on nutrients and biochemical profile of African spinach and its potential in formulation of functional bread

Purpose African spinach is known to be rich micronutrients and phytochemicals. However, most of these components are lost during processing depending on processing procedures employed. This study aims to investigate the effects of steam blanching and hot-aqueous blanching on the nutritional and bioactive contents of African spinach as well as its potential as a functional ingredient in bread making. Design/methodology/approach Freshly harvested Africa spinach was destemmed, wet-cleaned, divided into five portions and pretreated using steam and aqueous-thermal techniques. The blanched leaves were evaluated for biochemical and bioactive contents using standard procedures. The leaves were also used to enrich bread at 5% inclusion, and the bread was evaluated. The significant differences among means were evaluated at a 5% significant level using the Duncan Multiple Range Test. Findings The protein of 17.2%–26.4%, ash (5.7%–10.2%), calcium (82.7–105.4 mg/100 g), iron (8.2–16.4 mg/100 g) and pyridoxine (0.09–0.22 mg/100 g) were obtained for blanched leaves, while protein (27.9%), ash (12.2%), calcium (120 mg/100 g), iron (20.9 mg/100 g) and pyridoxine (0.23 mg/100 g) were obtained for unblanched leaves. There was a significant ( p = 0.03) loss in nutrient composition due to blanching. Bioactive compounds include 10-methylnonadecane (3.85–4.11 mg/100 g), ferulic acid (10.09–15.50 mg/100 g), epicatechin (103.62–132.096 mg/100 g) and luteolin (2.38–2.80 mg/100 g. The bioactive compounds were associated with potential biological properties such as antioxidant, anti-inflammatory, neuroprotective and cardioprotective. The functional bread showed higher nutrients than 100% wheat bread, and all the enriched bread samples had good sensory scores. Originality/value Using African spinach as enrichment in bread making could reduce malnutrition and incidents of ill health in low-income homes and thus improve food security.