The objective of this study was to investigate the effect of complexation of epigallocatechin-gallate (EGCG) to a caseinate-stabilized oil-water interface on the bioefficacy of EGCG. The bioaccessibility, anti-proliferative activity, and intestinal uptake of EGCG are reported. Higher amount of EGCG was present in digested emulsions compared to their equivalent solutions after digestion. The incorporation of EGCG in sodium caseinate emulsions improved its bioaccesibility and this was confirmed by cytotoxicity assays on Caco-2 cells. Intestinal absorption of EGCG was also studied with in vitro transport experiments. It was difficult to obtain a quantitative measurement of the EGCG in the basolateral fraction, but the fractions showed a clear anti-proliferative activity. These results would suggest the use of a cytotoxicity assay on cell cultures to estimate the extent of intestinal absorption of the bioactive catechin EGCG. The findings demonstrated that sodium caseinate-stabilized emulsions can be used as a platform for delivery of EGCG.

This work was funded by the Natural Sciences and Engineering Research Council of Canada (NSERC). The authors thank DSM Nutritional Products (Ayr, Ontario, Canada) for donating the green tea extract. Authors participate in the EU COST Action INFOGEST. Also authors would like to thank Dr. Tracey Campbell at the mass spectrometry facility of Centre for Microbial Chemical Biology at McMaster University.

Peer reviewed