Total acid that can be titrated

from Wikipedia, the free encyclopedia

If in wine - or fruit juice analysis of acid is mentioned, one speaks of the total titratable acid . The value determined by titration does not, however, correspond to the total acid calculated as the sum of the individual acids. The titratable total acidity also does not correlate with the pH value . The part of the acids buffered by potassium , magnesium or calcium is neither recorded by titration nor by sensors. In principle, during a titration, the base capacity is determined up to a defined pH value (usually the transition point of a certain indicator ), i.e. the amount of alkali required to "neutralize" all acids in this buffered system. The base capacity determined in this way is then converted to a carboxylic acid occurring in the drink with the help of a table or formula and, depending on the liquid examined, stated as “ tartaric acid ” or “as citric acid ” or “as malic acid ” . Even if another acid occurs in larger quantities in this drink, see acid (wine) .

When the total acid is determined by chromatography , on the other hand, the concentration of all acids is measured regardless of the extent of the buffering . Both the total acid determined with the chromatograph and the pH value are thus a significantly poorer measure of acid perception than the total acid that can be titrated. Tartaric acid and citric acid , for example, lower the pH value significantly more than malic acid , lactic acid or succinic acid .

literature

Individual evidence

  1. ↑ Roland Bill and Manuela Oettli: The determination of the titratable total acid in wine ( Memento from March 24, 2016 in the Internet Archive ) Topic beverage analysis In: Swiss journal for fruit and viticulture. (SZOW), Wädenswil, No. 13, 2000.