In vitro evaluation of genistein bioaccessibility from enriched custards

The suitability of custards with genistein incorporated in the fat phase of the milk to become a new ‘functional food’ with good bioaccessibility was evaluated. Intestine bioaccessibility was mainly attributed to the incorporation of genistein into micelles and did depend on fat concentration. In terms of bioaccessibility, a milk fat content of 3% was found to be the optimum. Saliva and pepsin significantly affected the bioaccessibility of genistein in the mouth and the stomach but they did not have an effect on intestine bioaccessibility. The use of carboxymethylcellulose instead of starch as thickening agent significantly reduced bioaccessibility. Similar bioaccessibilities and structure breakdown properties were found among the waxy maize and the tapioca pregelatinized starches, which convert the latest in a good alternative when a cold custard preparation is required. Values of bioaccessibility up to 92% were obtained, so it is concluded that custards are a useful carrier for genistein.