The colorimetric determination of lactic acid in silage

Abstract

5 g. of silage is extracted with 100 ml. of boiling distilled water for 5 min., 0.5 g. solid Ca(OH)2 added, and filtered. To 1 ml. of 1:10 dilution of filtrate is added 1 ml. of 0.8 [image] CuSO4, 1 g. Ca(OH)2, 8 ml. of water, shaken for 20 minutes and filtered. The lactic acid in 1 ml. of filtrate is then estimated by the method of Barker and Summerson (Jour. Biol. Chem. 138: 535. 1941). Silage specimens taken at random showed that the lactic acid content fell rapidly with rise in pH.