Study on the effect of formalin as a preservative on different constituents of raw milk samples during storage.

Cows' milk was mixed with formalin at 0.4 or 0.6% and stored in sealed glass bottles for 1 yr at 37 degree C. During storage there were no significant changes in fat and lactose contents, although there was an increase in titratable acidity (from 0.17% before addition of formalin to 0.22% immediately after addition, and 0.32% after 12 months). It is concluded that 0.4% formalin is suitable for preservation of milk samples