Nowadays, as processes for producing fat powder, in general, two processes are known, that is, a process for producing fat powder comprising spray-drying a fat or oil which has been emulsified into an oil-in-water type emulsion with water, an emulsifying agent and a hydrophilic base (spray-drying method); and a process for producing fat powder comprising atomizing a molten fat or oil in the atmosphere at a temperature which is lower than the melting point of the fat or oil (spray-cooling method). Among them, by the spray-drying method, stable, free-flowing fat powder can be obtained regardless of the melting point or S.F.I. (Solid Fat Index) of the fat or oil used because the surface of the fat or oil is coated with the hydrophilic base. However, there are many problems such as energy cost for evaporating water, deterioration of flavor of the fat at high temperature, and loss of volatile flavor by volatilization. To the contrary, in the spray-cooling method, although such problems as the above energy cost and deterioration of the flavor are not present, there is a marked disadvantage in that it is difficult to powder a fat or oil having a low S.F.I. and, even if it is powdered, the resulting powder has a low fluidity since the fat or oil containing unsaturated fatty acids segregates on the surface of the powder to make it adhesive. Due to this marked difference in fluidity, fat powder obtained by the spray-drying method has been predominantly and widely used in the fields such as various mixes for bread, cakes and cookies, instant milk powder, soup powder, fodder powder and the like.
However, recently the consumers' have demanded products of a higher grade and genuine taste, thus, the excellent flavor peculiar to fat powder obtained by the spray-cooling method has been reevaluated. Nevertheless, the improvement of the fluidity of products obtained by the spray-cooling method is strongly needed.
Heretofore, as a process for improving fluidity of fat powder, 10 to 50% by weight of wheat flour, starch and sugar have been added to the powder. Further, in Japanese Pat. Kokoku No. 50-14650 entitled "Process for Producing Fat Powder", there is disclosed a process of melting a starting fat or oil material at a temperature of at highest 15.degree. C. higher than the melting point thereof; cooling it to a temperature of the range between the solidifying point and the melting point of the fat or oil and lower than one third from the bottom of the range; forming a stable b-type crystal nucleus completely by maintaining it at this temperature for 2 to 30 minutes; and then heating to a temperature of at highest 10% higher than the melting point (1st crystalization step); and followed by spraying it into a crystalization chamber maintained at -15.degree. C. to -30.degree. C.; aging the powder obtained at 0.degree. C. to 10.degree. C. for 0.5 to 10 minutes successively in an aging chamber (2nd crystalization step); and mixing the powder with powder of non-oil soluble natural solid material. However, in order to practice this process, an extremely complicated adjustment of the starting liquid material and strict control of the temperature are required and, therefore, many difficulties in operation must be overcome, if it is to be produced on an industrial basis.