Does the addition of caseinophosphopeptides or milk improve zinc in vitro bioavailability in fruit beverages?

The influence of caseinophosphopeptides (CPPs) added to fruit beverage versus milk based fruit beverage upon zinc retention, transport, and uptake, as well as the influence of Fe supplementation, were studied using a combined simulated gastrointestinal digestion/Caco-2 cell system. Zinc retention, transport, and uptake of milk based fruit beverage was 4- to 5-fold greater than that of fruit beverages with or without CPPs - no statistically significant differences being observed in relation to the presence or absence of CPPs. Possibly, a slow release of CPPs throughout the digestive tract, as can be expected to take place during the digestion of casein. has a more beneficial effect than the addition of preformed CPPs upon Zn availability. A significantly negative Fe x Zn interaction in relation to Zn retention and uptake was observed in fruit beverages. This should be taken into account in the formulation of such beverages, where the supplementing of both of these mineral elements is common practice. (C) 2009 Elsevier Ltd. All rights reserved.