AGGLOMERATION OF FAT GLOBULES DURING THE FREEZING PROCESS OF ICE-CREAM MANUFACTURING

It has already been reported that the size of fat globules increased a nd de-emulsification occurred during the ice cream manufacturing proce ss, when drawing temperature is lowered and dasher capacity, dasher sp eed and overrun are increased. This paper shows the changes in fat glo bules in ice cream during the freezing process as observed by a laser microscope at 400 times magnification. Most of the fat globules disper se as small particles of diameter about 1.0 mu m in the ice cream mix. However, after the freezing process, most of the fat globule particle s were 1.0-5.0 mu m in diameter at a drawing temperature of -3.5 degre es C. The fat globules grew to 20 mu m in diameter at a drawing temper ature of -4.5 degrees C, and huge particles of 40 mu m were observed a t a drawing temperature of -5.5 degrees C. At an overrun of 30%, most of the fat globules were about 1.0 mu m and there was no difference co mpared with the fat globules in ice cream mix. Fat globules increased in size as the overrun increased, 5-20 mu m at an overrun of 60%, 20 m u m at 100%, and 50 mu m at 140%.