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The Effect of Homogenization, Condensation and Variations in the Fat’ Content of a Milk upon the Keeping Quality of its Milk Powder

1925; Elsevier BV; Volume: 8; Issue: 6 Linguagem: Inglês

10.3168/jds.s0022-0302(25)93983-5

1529-9066

George E. Holm, George R. Greenbank, E.F. Deysher,

Microencapsulation and Drying Processes

There is considerable difference of opinion with respect to the relative keeping quality of milk powders manufactured by dit~erent processes. Coutts (1), also Palmer and Dahle (2), have noted that the drum process produced powders superior in keeping quality to powders manufactured by the spray processes. Palmer and Dahle have attempted to explain these results on the basis of the physical structure of the powders, Showing that in a spray powder air is occluded in the milk particles and therefore the fat in this powder is subjected to the action of oxygen from within as well as upon the outer surface. These authors also suggest that homogenized fat in a powder produces a condition favorable for accelerated oxidizing action of air due to the increase surface area. The present writers (3), though having no experiments to prove that drum powders had a better keeping quality than spray powders, accepted the observations made by the above mentioned authors, but maintained also that the quality of the fat largely determined the keeping quality of the powder manufactured. Later experiments by Dahle and Palmer (4) do not fully substantiate their former conclusions. They maintain that a spray powder, which contains its fat in a finer state of division, and therefore exposes the greatest surface to the action of air, seems to possess the best keeping quality in this case. They also intimate that a spray powder owes its superior keeping quality to closer pacldng because of its fineness, and also to the smaller air cells occluded within the granules. The lack of the latter condition