Proximate, Mineral, and Vitamin Composition of Psidium guajava (Guava) Roots: Nutritional Profiling and Potential Applications as a Functional Food Ingredient

Abstract

Medicinal plants are valuable sources of bioactive compounds with significant therapeutic potential. Psidium guajava (guava), a widely used tropical medicinal plant, is well-known for its phytochemical richness. However, while the leaves and fruits have been extensively studied, the roots remain underexplored. This study aimed to determine the proximate composition, mineral content, and vitamin profile of Psidium guajava root extract to evaluate its nutritional potential and applications as a functional food ingredient. Fresh guava roots were collected, air-dried, powdered, and extracted using methanol by maceration. Proximate analysis was carried out according to AOAC (2005) methods. Mineral contents (Ca, Mg, K, P, Fe, Zn, Cu, Mn) were determined using atomic absorption spectroscopy, while vitamin levels were analyzed using standard spectrophotometric and titration methods. Results showed exceptionally high crude fiber content (52.83 ± 0.21%), moderate carbohydrate (18.60 ± 0.14%) and protein (11.58 ± 0.44%), low fat (0.20 ± 0.01%), and ash (4.48 ± 0.14%). Mineral analysis revealed an extraordinarily high calcium level (11.148 ± 40.647 mg/100g), along with potassium (4.168 ± 0.083 mg/100g), phosphorus (2.162 ± 0.012 mg/100g), magnesium (0.792 ± 0.011 mg/100g), and trace amounts of iron, zinc, manganese, and copper. Vitamins detected include vitamin E (11.58 ± 0.44 µg/100g), vitamin C (0.454 ± 0.024 mg/100g), and vitamin A (1.036 ± 0.078 µg/100g). The findings demonstrate that Psidium guajava roots possess a unique nutritional profile rich in dietary fiber and calcium. This supports its potential use as a natural dietary supplement and functional food ingredient for promoting digestive and bone health, while providing baseline data for further nutraceutical development.