Some Observations on the Nutritional Value of Dialyzed Whey Solids

Abstract

Partial substitution of whey proteins for casein, in a formula resembling human milk, detrimentally affects the growth of rats. Removal of a considerable portion of minerals from whey by means of dialysis results in a more favorable growth response. On a diet containing dialyzed whey, the rats grow 12.8% better per gm of food intake than on the same diet containing undialyzed whey. If the minerals removed from the whey by dialysis are reintroduced to the dialyzed whey after ashing, the rats' growth again is impaired. This proves that 1 or more of the inorganic constituents, rather than an organic compound, affects detrimentally the nutritional value of whey. On a diet in which 53% of casein is replaced by dialyzed whey lactalbumin, rats show 14.5% greater efficiency in conversion of food to body tissue than rats fed on a corresponding formula containing milk proteins only. This experimental result is in agreement with previous work whereas the results with undialyzed whey seemed to dispute the well established biological superiority of lactalbumin over casein.