Infusion Variables Affecting Bioactive Compound Yield in Dry Scent Leaf (Ocimum gratissimum Linn.) Tea

Abstract

Abstract

Scent leaf (Ocimum gratissimum Linn.) is widely utilized in traditional medicine and culinary applications due to its rich content of bioactive phytochemicals. However, limited information is available on the optimization of infusion variables for maximizing bioactive compound extraction when prepared as herbal tea. This study evaluated the effects of particle size, infusion temperature, and soaking duration on the extraction of bioactive compounds from dried scent leaf tea. Dried leaves were milled and sieved into particle sizes of 0.30, 0.60, and 1.18 mm. Infusions were prepared using 2 g of dry scent leaf in 25 mL distilled water at temperatures of 30, 50, and 70 °C with soaking durations of 3, 5, and 7 minutes. Total dissolved solids (TDS) were used as an indicator of extraction yield. Results showed that extraction efficiency increased with increasing temperature and decreasing particle size. The highest extraction yield (0.87 mg L⁻¹ TDS) was obtained at 70 °C using a particle size of 0.30 mm and a soaking duration of 7 min. Nutritional evaluation of the optimized infusion revealed appreciable levels of carbohydrates (9.95%), protein (4.18%), potassium (120.5 ppm), phytate (2.32 mg 100 g⁻¹), and vitamin C (12.94 mg 100 g⁻¹). The infusion contained relatively low amounts of crude fibre (0.07%), magnesium (8.67 ppm), saponin (0.42 mg 100 g⁻¹), and vitamin A (205.92 µg 100 g⁻¹). The findings demonstrate that optimized infusion conditions significantly enhance extraction yield and nutritional quality of scent leaf tea, supporting its potential as a functional herbal beverage.