Degradation mechanisms tannins

Some microorganisms degrading condensed tannins have been isolated and described, but no reports on the mechanism of the depolymerization process, or the enzymes involved in biodegradation, have appeared. It must be stressed that condensed tannin degradation may be associated with other... 

In 1913, Knudson (17) reported that tannic acid (the commercial name of the Chinese gall tannin) could be degraded by a strain of Aspergillus niger previously the French scientist Pottevin (in 1900) had named this enzyme tannase (10). Since then, most of the progress on elucidating the mechanisms of hydrolysable tannin biodegradation has occurred since 1960. 

Fortifying foods with minerals and vitamins is becoming more and more common. Mineral deficiency is one of the most important nutritional problems in the world. The best method to overcome this problem is to make use of an external supply, which may be nutritional or supplementary, like the fortification of foods with highly bioavailable mineral sources. Major interests of mineral encapsulation are linked to the fact that this technique enables to reduce mineral reactions with other ingredients, when they are added to dry mixes to fortify a variety of foods, and it can also incorporate time-release mechanisms of the minerals into the formulations. For example, iron is the most difficult mineral to add to foods and ensure adequate absorption, and iron bioavailability is severely affected by interactions with food ingredients (e.g., tannins, phytates, and polyphenols). Additionally, iron catalyses the oxidative degradation of fatty acids and vitamins (Schrooyen et al., 2001). 

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