hour the temperature of the main inlet air was 160 u00b0 c while the outlet air temperature was maintained at 86 u00b0 c for the integrated fluid bed the temperature was 65 u00b0 c and for the first and the second stage of the external fluid bed the temperature was 45 u00b0 c and 20 u00b0 c respectively silicon dioxide e551 was added as free flowing agent at a percentage of 0 9 by weight of final product at the outlet of the external vibrating fluid bed the same method as described in example 1 was used for processing the greek style strained yogurt serum the yogurt serum of 5 3 by weight total solids was initially concentrated to 15 4 by weight it was afterwards concentrated to a percentage of 47 by weight the concentrated yogurt serum exiting the flash cooler of the evaporator had a temperature of 45 u00b0 c the monohydrate lactose crystals in average size of less than 45 microns were added at the temperature of 30 u00b0 c the crystallized serum had 71 degree of crystallization and the product 39 s average crystal size was less than 10 microns for the spray drying of the product the high pressure nozzles were of type tcsc 39 the feed inlet to the dryer was 1300 kg h and the temperature of the main inlet air was maintained at 155 u00b0 c silicon dioxide e551 was added as free flowing agent at a percentage of 0 8 by weight of final product at the outlet of the external vibrating fluid bed after the aforementioned processing method the produced greek style strained yogurt serum powder had the following typical composition however as discussed in the background section past attempts to process the serum derived from the.