Abstract
The manometric determination of malic acid is specific, rapid and more convenient than other methods of analysis and, by introduction of 0.5 to 1 ml sample, it extends well over the whole range of concentrations of malate found in grape musts and wines. No preliminary treatment, such as the removal of tartrate and sugars, is necessary and the sample is directly introduced into the Warburg flask. The method has been tested for additional carbon dioxide evolution from fermentation concomitant with malate decarboxylation and from decarboxylation of oxalo-acetate, pyruvate and fumarate and no interference from these side reactions with the analysis was detected.
The effect of ethanol on the enzyme system has been investigated. It was found to have no inhibitory influence on the decarboxylation unless the overall concentration exceeded 24 per cent by volume. The accuracy of the method was confirmed by determining malic acid in samples of grape must and wine containing incremental additions of the pure compound.
- Copyright 1962 by the American Society for Enology and Viticulture
Sign in for ASEV members
ASEV Members, please sign in at ASEV to access the journal online.
Sign in for Institutional and Non-member Subscribers
Log in using your username and password
Pay Per Article - You may access this article (from the computer you are currently using) for 2 day for US$10.00
Regain Access - You can regain access to a recent Pay per Article purchase if your access period has not yet expired.