Bioactive Compound Yield and Antioxidant Capacity ofHelicteres hirsutaLour. Stem as Affected by Various Solvents and Drying Methods

Abstract

Different parts of Helicteres hirsuta Lour. (H. hirsuta L.) have been used as traditional medicines, however limited studies have been conducted on the preparation of dried material or the extraction of bioactive compounds. This study aimed to determine the effect of various solvents and drying methods on the bioactive compound yield and antioxidant capacity of the H. hirsuta L. stem. The results showed that water was the best solvent for obtaining the highest levels of phenolics and flavonoids, whereas methanol was the solvent of choice for saponin extraction. Among assessed drying methods, hot-air drying at 80C revealed as the best method to maintain the bioactive components (phenolics of 8.99 mg GAE/g, flavonoids of 9.60 mg CE/g and saponins of 15.18 mg ESE/g), and DPPH, ABTS, and FRAP antioxidant activities. Thus hot-air drying at 80C is recommended for preparation of dried H. hirsuta L. stem for further processing steps. Practical Applications The optimal drying condition to prepare dried H. hirsuta L. stem is hot-air drying at 80C, a simple and fast drying method, and the most suitable solvent for extraction of antioxidant components from dried H. hirsuta L. stem is water; a cheap, accessible, and environmentally friendly solvent. These conditions can be applied for isolating and purifying bioactive compounds for further application in the food and pharmaceutical industries.