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A Biochemical Study of Irradiated Milk

1932; Elsevier BV; Volume: 15; Issue: 6 Linguagem: Inglês

10.3168/jds.s0022-0302(32)93438-9

1529-9066

A Anderson, Howard O. Triebold,

Radiation Effects and Dosimetry

Recently O'Brien, Davis and Armstrong 1 have described a method for irradiating milk with ultraviolet light.Their source of light is an arc from carbon electrodes vf special composition and has an energy emission, in the wave length region from 2,800 to 3,100 £ngstrom units, 1,260 times that of bright sunlight.There is very little energy emitted at Wave lengths shorter than 2,800 A. They point out that radiation of wave lengths between 2,800 to 3,100 A. is very effective in producing anti-rachitic potency, while radiation of wave lengths less than 2,800 A. is destructive to vitamin A, causes protein coagulation and produces a bad odor and taste in the milk.The apparatus in which the milk is irradiated is essentially a glass cylinder.The carbon arc is in the center of this cylinder and the milk flows down the inside of the cylinder in a thin fihn in such a way that each particle of milk receives a uniform dosage of light.Feeding experiments which they have conducted show that the vitamin D potency of irratiated milk is increased 16 times, while the vitamin A potency is 86 per cent. of that in the original milk.They also report bacteriological studies showing a decided reduction in the bacterial count after irradiation.In the present paper a biochemical study of milk and butter from milk irradiated by the above process is reported.Since it was anticipated that effects of irradiation would be slight, the milk used in the following work was given a much longer exposure to ultraviolet light than is the usual practice.This was accomplished by passing it thru the irradiating process eight times.In this way it was hoped that any effects of ultraviolet light would be greatly exaggerated and therefore more easily detected by the methods employed.The samples of certified milk were irradiated at a plant located near Erie, Pennsylvania.Uniform samples of irradiated and nonirradiated milk were cooled, placed in thermos bottles and shipped to our laboratory at State College, arriving the following morning in good condition. EXPERIMENTAL Chemical Composition of MilkThe object of this phase of the work was to determine what changes in chemical composition, if any, take place during irradiation.Several sets