EFFECTS OF DASHER TYPE AND REVOLUTION NUM BER OF DASHER ON DEEMULSIFIED FAT OF ICE-CREAM

Ice cream of desired taste and good mouthfeel is produced by employing specially designed formulation and a contrived production method. On production, it is important to control a fat de-emulsification rate an d distribution of fat globules, ice crystal size, air cells and unfroz en matrix. We have investigated the relationship between fat de-emulsi fication, and a type and the revolution number of a dasher. Ice cream consisting of vegetable fat 9.0%, M.S.N.F. 9.5% and total solids 38.0% was prepared by freezing the mix in a CREPACO continuous freezer. Con ditions were varied as follows. The dasher type was 15 dasher, or 80 d asher, the mix flow rate was 65 l/h and the revolution number of the d asher was 110 rpm and 220 rpm. The particle size distribution of fat g lobules was measured by a Laser diffraction particle size analyzer. Th e fat de-emulsification rate was determined from the difference betwee n the particle size distribution of fat globules measured in ice cream mix and an ice cream solution prepared by diluting ice cream at 5 sim ilar to 10 degrees C with 5 volumes of ion exchange water. Melting res istance was examined by the meltdown method. The fat de-emulsification rate increased when a dasher of larger was employed and this resulted improved melting resistance. Also, the fat de-emulsification rate inc reased using a higher revolution number and this resulted in improved melting resistance. Dryness of ice cream increased when a dasher of la rger volume and higher revolution number were used. The particle size distribution of fat globules changed when the fat de-emulsification ra te increased i.e. fat globules of below 1.2 mu m in diameter decreased and, un-expectedly, the proportion of fat globules of ranging from 7 to 15 mu m in diameter increased.