ABSTRACT

Bitter leaf scientifically known as Vernonia amygdalina, is a traditional medicine that has been highly regarded for its broad-spectrum therapeutic potential. It is commonly used to treat a variety of ailments, including gastrointestinal disorders, fever, malaria, and hypertension. The research was carried out to study the effect of two drying methods, sun drying and oven drying on the chemical composition and sensory properties of Vernonia Amygdalina. Samples were dried separately using hot air oven at (36.30℃) and under the sun respectively, and then analyzed for their content of minerals and phytochemicals using the standard methods. The result showed significant differences (p<0.05) in the chemical composition between the two drying methods. The proximate analysis were higher for sun dried samples in moisture 6.73mg/100g, crude protein 14.65mg/100g, fat 1.35mg/100g, crude fibre 3.79mg/100g, ash 10.53mg/100g, carbohydrate 62.97mg/100g and energy value 322.57mg/100g. The corresponding values for the oven dried samples were 5.74mg/100g for moisture, 13.96mg/100g for crude protein, 1.62mg/100g for fat, 3.62mg/100g for crude fibre, 10.81mg/100g for ash, 64.26mg/100g for carbohydrate and 377.42mg/100g for energy value. Minerals were generally higher in the sun-dried samples, with values of 71.66mg/100g for calcium, 8.28mg/100g for potassium, 40.75 mg/100g for magnesium, and 25.66mg/100g for sodium. In contrast, the oven dried samples contained 68.24mg/100g for calcium, 9.84mg/100g for potassium, 37.92mg/100g for magnesium, and 24.97mg/100g for sodium. The results of phytochemical analysis showed significantly higher values (p<0.05) in sun dried samples with alkaloid at 9.83%, flavonoid at 4.07%, and saponin at 4.62%. The oven dried samples contained 7.64% alkaloids, 4.62% flavonoids, and 3.54% saponins. The results of sensory properties were generally higher in the sun-dried samples, with values of 4.65% for appearance, 3.00% for taste, 4.26% for aroma, 3.85% for texture and 3.87% for general acceptability. The oven dried samples contained 3.80% for appearance, 2.00% for taste, 3.45% for aroma, 2.75mg/100% for texture and 3.00% for general acceptability. The higher values obtained in the sun dried samples were attributed to the higher dry matter content, which leads to a more concentration and increased density of the minerals and phytochemical content of Vernonia Amygdalina. Based on the results of this study, it is recommended that sun drying be considered a more effective method for preserving and enhancing the nutritional and medicinal value of Vernonia Amygdalina.