What are complexing agents and anti-foaming agents?

Germany

These are categories of food additives. Food additives are substances added intentionally to foodstuffs to perform certain technological functions. They are grouped by their function.

Complexing agents, also called “sequestrants” are substances which form chemical complexes with metallic ions. Sequestrants are used e.g. to stabilize fats and oils which undergo rancidity and reversion in the presence of the metals copper and iron. By chelating (sequestering) metals, oxidation is slowed or entirely prevented. Calcium-Dinatrium-EDTA E385 is the most used one.

“Anti-foaming agents” are substances which prevent or reduce foaming; e.g. when jams are boiled, E 471 (Mono- and diglycerides of fatty acids) are often used as an anti-foaming agent.

Food additives and flavorings
http://europa.eu.int/comm/food/fs/sfp/flav_index_en.html

Backgrounder on food additives
http://www.eufic.org/en/quickfacts/food_additives.htm