Development and Nutritional Evaluation of Novel Plant-Based Meat Analogues from Legume Blends Infused with Zobo (Hibiscus sabdariffa) Calyces

Abstract

Background: Global concerns over environmental sustainability, health, and food security have spurred growing interest in plant-based meat analogues—products designed to replicate conventional meat in appearance, texture, taste, and nutritional value. While traditional alternatives such as tofu, tempeh, and seitan have long existed, recent innovations are focused on advanced formulations that harness a diverse range of plant protein sources. Aim: This study investigated the nutritional and sensory qualities of meat analogues produced from selected leguminous seeds. Methodology: Four legumes—soybeans, mucuna, African yam beans, and cowpeas were processed and evaluated for plant-based meat analogue production. Cowpea and soybean seeds were wet dehulled and soaked for 24 hours, while African yam beans and mucuna seeds were mechanically dehulled and soaked for 32 hours. Each seed type was blended into a paste using a 90:10 (w/v) Roselle (zobo) calyx infusion to enhance colour. Binder and oil were added during kneading, and the mixture was cooked via extrusion. The formulation included 70% legume protein, 20% binder, and 10% fat. The meat analogues were evaluated alongside a commercial sausage (control) for proximate composition, mineral and vitamin content, amino acid profile, and sensory attributes using standard methods. Results: Proximate values ranged from 3.25–5.30% (moisture), 3.18–3.90% (ash), 0.73–1.22% (crude fibre), 7.29–9.34% (fat), 40.09–42.80% (protein), and 38.70–47.71% (carbohydrates). Mineral contents (mg/100g) included magnesium (0.06–0.39), zinc (0.01–0.02), iron (0.10–2.45), calcium (0.26–0.62), and potassium (1.23–1.48). Vitamins ranged from 5.36–6.63 µg/g (carotenoids), 0.18–0.61 µg/100g (vitamin A), 0.17–0.54 mg/100g (folate), 0.31–1.66 mg/100g (niacin), and 0.67–1.46 mg/100g (riboflavin). The meat analogues were rich in essential amino acids, with sufficient levels to meet daily needs. Although methionine and tryptophan were comparatively lower, the cowpea-based analogue showed the best amino acid balance.  Sensory scores showed no significant differences (P > 0.05) between the analogues and the control in taste, aroma, appearance, mouthfeel, and texture. Overall acceptability ranged from 7.01 to 8.45. Conclusion: These results support the use of legume-based analogues as nutritious and acceptable alternatives to conventional meat products. These findings highlight the viability of developing plant-based meat alternatives using locally available legumes for improved nutrition and food sustainability.