ABSTRACT
The history of enzymes is closely connected with our increased knowledge in the elds of foodstuff chemistry and technology. It started around 1526 with Paracelsus’s studies of fermentation products. The assay of the enzyme characteristics of a certain food is carried out to determine its degree of freshness (as is the case with the oxidative enzymes found in vegetables), to detect particular treatments such as pasteurization (easily monitored in milk by measuring the levels of phosphatases and lactoperoxidase), or to see whether decay or microbial contamination has started.*
Enzyme levels can be easily measured by observing the action they have on their substrates, since most of these enzyme-catalyzed reactions have an absolute specicity. The rst satisfactory
* This review is an update of Chapter 10, “Enzymes” by R. Muñoz and A. Ros Barceló of Handbook of Food Analysis, Volume 1 (1996).
