عنوان مقاله [English]
Introduction: Nature has always been an excellent source of many therapeutic compounds providing with numerous medicinal plants and microorganisms producing beneficial chemicals. The growing demand for medicinal species indicates the emergence of a market with high potential for consumption, requiring a consistent and readily available supply of high-quality raw material. Medicinal properties of plants are mainly related to the ingredient contents. Achieving the maximum ingredient contents is one of the most important goals of the production and processing of medicinal plants. The post-harvesting process of medicinal plants has great importance in the production chain, because of its direct influence on the quality and quantity of the active ingredients in the product sold. Drying is the most common processing method affecting the quality and quantity of ingredients after harvesting. Several factors such as temperature, duration, air flow, relative humidity, sample size and plant texture affect the amount and type of these compounds. The choice of the optimal drying air temperature is a central economic and ecological criterion. Although most experimental studies state that increasing temperature was related to the reduction active ingredient contents, but also, there are differences in temperature sensitivity between species. Increasing temperature was leaded decreasing time of drying especially large samples. Glycyrriza glabra (fabaceae family) is ligneous perennial shrubs plant. This plant is considered one of the most important export medicinal plants, which has medicinal properties. The medicinal properties of this plant are mainly related to glycyrrhizic acid and water-soluble extract. This plant was used in foods as sweetening and in both traditional and herbal medicine. This plant was considered to have strong pharmacological activities, such as anti-inflammatory, anti-ulcer, antibacterial, regulating blood lipids and blood glucose levels, neuroprotection, anti-osteoporosis, phytoestrogen and anticancer. In this study, the effect of temperature and root size was evaluated on glycyrrizic acid and water soluble extract.
Materials and Methods: Gathered licorice root were chopped in large size (10 cm length, 10mm diameter), medium size (5 cm length, 7mm diameter), and small size (2 cm length, 5mm diameter). All samples were dried in room temperature (natural drying), and oven (50 and 70 degree centigrade). Glycyrrhizic acid solution were prepared European pharmacopeia and were injected HPLC apparatus. To prepare water soluble extract, water poured on prepared licorice root powder. After 24 hours keeping steady, sample was shaked off with shaker apparatus 8 hours and keeping steady again18 hours. Ready mixture was filtered and heated in 105 degrees centigrade until it reached constant weight. Water soluble extract and glycyrrhizic acid were measured to determine effect drying temperature and size sample on the amount of them.
Results and Discution: Based on the results of this research, temperature did not have a significant effect on the amount of glycyrrhizic acid in small dried samples, but in medium samples, an increase in temperature was led to a significant decrease in glycyrrhizic acid, and in large samples, an increase in temperature was led to significant increase in glycyrrhizic acid. Water-soluble extract showed similar behavior glycyrrhizic acid. Finally, drying large size licorice root in 70 degrees centigrade introduced as the best conditions for drying licorice root.