OPTIMIZATION OF EXTRACTION AND DRYING PROCESSES OF JUGLONE FROM WALNUT LEAVES (JUGLANS REGIA L.)

The influencing factors on the process of juglone extraction from walnut leaves (Juglans regia L.), as well as the dynamics of extraction, were studied using the method of mathematical planning of an experiment according to Box–Wilson. Based on the research results, it was established that for maximum extraction of juglone, walnut leaves must be crushed to a raw material particle size of no more than 6 mm and then extracted three times with 90% ethanol at a temperature of 20–30 °C at the first contact of the phases - 5 hours, with the second – 3 hours, with the third – 2 hours. To purify the extract, liquid-liquid extraction has been proposed, in which the concentrated extract is diluted with water and juglone is extracted four times with ethyl acetate to remove hydrophilic impurities. For effective drying of the alcohol solution of juglone, a filler was used, for which microcrystalline cellulose was selected in a mass ratio of the dry residue of the dried solution - microcrystalline cellulose 1 : 2. To uniformly mix biologically active substances with microcrystalline cellulose, as well as remove residual amounts of ethyl acetate, a method has been proposed that consists of concentrating the ethyl acetate extract to constant weight, dissolving the thick mass with ethanol, evaporating the alcohol solution to half the volume, mixing the alcohol solution with microcrystalline cellulose and drying the resulting masses. Based on the results of experiments on selecting the type of drying apparatus for drying a mass containing juglone, drying with forced air ventilation at a temperature of 60±2 °C was proposed. Using the method of mathematical planning of a Latin square experiment using a 3×3 scheme, the optimal mode of a dryer with forced air ventilation was found. It has been established that the mass of a mixed alcohol solution of juglone with microcrystalline cellulose must be dried in a drying unit with forced air ventilation under the following conditions: the thickness of the layer of the dried mass on the dryer tray is 10 mm, the supplied air speed is 15 m/s and the process duration is 6 hours. A technology has been developed for obtaining a dry extract with anthelmintic action from walnut leaves, providing a 10.8% yield of dry extract to the mass of raw materials containing at least 0.9% juglone.