315. The effects of commercial processing and of storage on some nutritive properties of milk. Comparison of full-cream sweetened condensed milk and of evaporated milk with the original raw milk

Abstract

1. Full-cream unsweetened condensed milk (evaporated milk) and full-cream sweetened condensed milk (condensed milk) were prepared simultaneously on several occasions each time from a common bulk of raw milk. Heat treatment in the preparation of evaporated milk is, of course, much more severe than with condensed milk.(a) There was no loss of vitamin A, carotene or riboflavin in either of the processes.(b) The mean loss of vitamin C as compared with the raw milk was 10% for condensed and 60% for evaporated milk.(c) The vitamin B₁losses were 3·5 and 27% respectively.(d) Tests on rats showed that the biological values and true digestibilities of the proteins of the raw, condensed and evaporated milks were respectively 85·6 and 94·2, 84·6 and 98·8, 84·1 and 93·7. The differences in biological value are without statistical significance but the digestibility of the condensed milk was significantly higher than that of the other two milks.