FILTRATION AND DRYING STUDY OF ALCOHOL EXTRACT OF DE-OILED SOY-LECITHIN

摘要

De-oiled soy lecithin is divided in to two major parts i.e.alcohol soluble phosphatidylcholine (PC) fraction and alcohol insoluble phosphatidylinositol (PI) fraction.Both the fractions are highly desired for their variety of applications in fields such as medicine, cosmetics and food applications.Separation and purification of PC and PI fractions to their utmost purity is still a challenge to industries for the reason of its source and molecular and structural complexity. The present study deals with the filtration of the PI rich fraction followed by drying of the cake for its further purification and value addition. The filtration of PI rich fraction was carried out under constant pressure conditions followed by the cake drying in a vacuum tray dryer. The average specific cake resistance (αav) as a function of operating pressure was studied and it showed little variation with respect to the applied pressure differential. The initial solvent content in the cake after filtration was approx.1kg solvent kg dry solid-1 which was subsequently reduced to 0.04 kg solvent/kg dry solid. The drying kinetics of the cake in vacuum tray dryer was studied at different drying temperatures with constant as well as variable vacuum. The drying rate curve showed prominently the falling rate period with the effective solvent diffusivity in the range of 5.4×10-10 m2s-1 to 1.18×10-9 m2s-1 within the temperature range of 40oC to 60oC. The temperature dependence of the effective solvent diffusivity was described by an Arrhenius type relationship and the activation energy was found to be 39.28 kJmol-1.