Vitamin Studies XX. The Effect of Various Methods of Pasteurization on the Vitamin B and the Vitamin G Content of Cow's Milk

Abstract

Experiments are described in which raw certified milk, produced by the college dairy herd, was fed to rats with and without supplementation with potent preparations of vitamins B and G. At three different periods during the year these experiments were repeated, at which times the raw milk was pasteurized by four methods, viz., (1) ordinary pasteurization at 62-63° C. for 30 minutes; (2) same as (1) except that pasteurization was conducted under reduced pressure; (3) same as (1) except that the milk was aerated; and (4) boiled for 10 minutes under a reflux condenser. The pasteurized milks were also fed to rats in the presence and in the absence of potent preparations of vitamins B and G and comparisons were made with raw milk from which the pasteurized milks were made. It was found that the raw milk contained appreciable quantities of vitamins B and G and that 3 mls. per day were sufficient to furnish at least one Sherman unit of each of the vitamins. It was found that vitamin B was the limiting, factor when 3 mls. of raw milk were fed as the sole source of vitamins B and G but the data indicate that the B potency was not limited to the extent that has been reported by certain investigators. It was observed that the vitamin B and G potency of the raw milk was remarkably constant throughout the year. Three separate sets of experiments showed greater loss of vitamin B and vitamin G when the milk was pasteurized under diminished pressure. This was contrary to expectations and will be investigated in the near future. Some loss of vitamins B and G occurred in all methods of pasteurization but less destruction occurred when milk was boiled for 10 minutes under a reflux condenser. Although the maximum destruction of either vitamin B or vitamin G, as a result of any one of the four methods of pasteurization, was about 38 per cent (calculated from differences in growth response), the destruction of these vitamins under carefully controlled plant operation need not be as great as indicated above. It is suggested that the relative requirements for vitamin B and vitamin G by the rat vary with the age of the rat, the evidence suggesting that the requirement for vitamin B is greater in the young rat and that the need for vitamin G seems to be greater as the rat matures. © 1934, American Dairy Science Association. All rights reserved.