Vukosavljević Predrag
Antioxidant activities of herbs, fruit and medicinal mushroom Ganoderma lucidum extracts produced by microfiltration process
Faculty of Agriculture, Institute for Food Technology and Biochemistry, Belgrade-Zemun (1,3,4,6)
Institute of Chemistry, Technology and Metallurgy, Belgrade (2)
Faculty of Technology, Leskovac (5)
This paper presents kinds of extraction and cross-flow filtration of composition of 46 healthful and aromatic herbs, 8 fruits and fungi Ganoderma lucidum. Those extracts are part of Bitter 55, which have significant antioxidant capacity. Antioxidative activities of plant extracts have been determined by DPPH test using method of Blois. Bitter 55 which was kept at the green bottle in the dark has EC50 = 141.07 μl/ml and it was stable during 150 days.
Investigations of hydrodynamic permeability ceramic membranes for microfiltration
Faculty of Technology and Metallurgy, University of Belgrade, Belgrade (1)
Faculty of Agriculture, Belgrade-Zemun (2,4)
Chemical Engineering Department, Loughborough University, Loughborough, Leicestershire, UK (3)
This paper introduces the results of experimental investigations on the influence of operating parameters, such as feed flow rate, temperature, pressure difference in the microfiltration through the ceramic Kerasep membrane. The results confirmed earlier work on the same laboratory device for microfiltration. and they are the main condition for determination of kinetics juice clarification. Apart from investigations on the influence of operating parameters, the influence of membrane moisture on microfiltration was observed.
Change of juice color during raspberry processing in fruit juice and fruit juice concentrate
Faculty of Agriculture, Belgrade-Zemun (1,2,3,4,5)
A change of anthocyanins under different conditions of enzymatic treatments, clarification and concentration was determined. A pectin preparation Klerzyme®120, manufactured by DSM, France, specific for "sour fruits" with pH below 3.2, was used for maceration and depectinization. Experiments were carried out by a laboratory hydraulic press. Raw raspberry juice was clarified either by membranes separation processes or by traditional treatments using gelatin and bentonite.
Change of anthocyanins content during raspberry extraction
Faculty of Agriculture, Belgrade-Zemun (1,2,3,4)
Change in anthocyanins content under different conditions of extraction enzymatic maceration and heat treatment of two raspberry cultivars (Villamette and Meeker) was determined. Experiments were carried out on a laboratory hydraulic extractor. During extraction commercial operating conditions were emulated using a "Bucher" extractor (pressure 180-200 bar 1-3 pulp shakings).
Application of ultrafiltration to apple juice clarification
Faculty of Agriculture, Belgrade-Zemun (1,2,3,4)
Raw depectinized apple juice was clarified in a laboratory scale ultrafiltration (UF) system using ceramic tubular membranes (Tech-Sep Carbosep) with a molecular weight cut-off of 300,000, 50,000, and 30,000 daltons. The experiments have been carried out over a wide range of transmembrane pressures (100-400 kPa), temperatures (293-328 K), and feed flow rates (100-900 mL/min). Permeate flux significantly decreased with time until a steady state was established.