Investigation of different methods on extraction of bioactive components of licorice

In this M.Sc. thesis, the extraction conditions of licorice bioactive components (glycyrrhizic acid, liquiritin and formononetin) by conventional and ultrasonic methods (methanol:water ratio, extraction temperature, extraction time, ultrasound power) were optimized according to the response-surface method. Also, time-dependent kinetic parameters of extracts which obtained conventional extraction method in water were determined. Bioactive components of extracts obtained by conventional method were enriched by ultrafiltration technique and enriched extracts were powdered by spray drying technology. The optimization of the extraction conditions was carried out according to the amount of bioactive components in the extract. The results of the research showed that the amount of bioactive components in the extract decreased with increasing methanol content in extract and water was the most suitable solvent. As a result of extraction with ultrasound assisted performed using water, the amount of glycyrrhizic acid in the extract was determined between 0.522-1.046 g/100 g DM, the amount of liquiritin was between 0.901-2.310 g/100 g DM and the amount of formononetin was determined between 0.106-0.173 g/100 g DM and the optimum conditions of extraction were given as 90 ˚C, 77 minutes and 653 Watts. According to the results of the research, the duration of ultrasound assisted extraction can be reduced by approximately 40%. As a result of the extraction kinetics study using water by the traditional method, the Two-site kinetic model is the best expression of the extraction of licorice components; The fast (K1) and slow (K2) extraction coefficients in the model were 0.0270 min-1 and 4.5064 min-1 for liquiritin, 0.0531 min-1 and 2.0335 min-1 for formononetin, 0.0530 min-1 and 2.0490 min-1 for glycyrrhizic acid, respectively. It was concluded that the amount of bioactive components in the retentant parts of the extracts passed through membranes having separation limits of 10, 30, 50 and 100 kDa was increased by ultrafiltration method and this increase was obtained in membranes having maximum separation limit of 10 kDa. The drying efficiency of licorice powder obtained by spray drying was between 50.77-71.52% and the highest yield was obtained by drying at 140 ° C using 100% (Maltodextrin) MD. The water activity values of powder products obtained were between 0.23-0.28, 93% above solubility values, and mass density values were between 385.46-435.86 kg / m3. At 140 ˚C, 1: 1 ratio of MD: Whey protein (PSP) as a result of spray drying using the highest percentage of bioactive components of the licorice was obtained.