Coffee with ginger - interactions of biologically active phytochemicals in the model system.

This study evaluated the interactions between antiradical and anti-inflammatory compounds from coffee and ginger. Results obtained for whole plant material extracts were compared with those for chlorogenic and caffeic acids (the main hydroxycinnamic acids of plant material). All the tested samples showed the ability to scavenge free radicals and to inhibit lipoxygenase (LOX) activity. Both of these activities increased after simulated gastrointestinal digestion. Aromatic additives, such as ginger, are able to change the antioxidant properties of coffee extract and antioxidant interactions may be identified using two methods. Antiradical phytochemicals from coffee and ginger acted synergistically - isoboles adopted a concave form, while after digestion in vitro an additive reaction was observed; in turn, chemical standards acted antagonistically. Water extractable LOX inhibitors acted antagonistically; however, after digestion in vitro synergism was observed. The same kind of interaction was determined for standard compounds. These results were confirmed by IF (interaction factor) analysis.