Formulating iron-enriched fruit juices with milk may improve uptake of the mineral, suggests new research that offers a way of boosting iron intake for people at risk of deficiency.

Spanish researchers report that milk may increase iron uptake from iron-fortified fruit juices by up to four times, and exceeded uptakes observed when juices were formulated with casein proteins, according to findings published in the Food Chemistry.

"The addition of milk to fruit beverages exerted a positive effect on iron retention, transport and uptake versus fruit beverages, and this effect was greater than in the case of caseinophosphopeptides added to soluble fractions of fruit beverages," wrote the researchers, led by Reyes Barbera from the University of Valencia.

"The addition of caseinophosphopeptides to soluble fractions f fruit beverages improved iron transport," they added.

Iron deficiency remains the leading nutrient deficiency in both developed as well as developing countries. It affects around one in five women in the UK.

Fortifying foods with iron also poses several challenges for the food industry, most notably with regards to effects on colour, taste, and the shelf-life of the food.

However, the researchers stressed that additional studies are needed to confirm the results, especially in humans. It should also be clarified which caseinophosphopeptides favour iron bioavailability, they said.

"In addition, studies are required on the addition of functional ingredients to fruit beverages with the purpose of favouring iron bioavailability," wrote Barbera and co-workers.

Study details

Using different fruit juice concentrates, including grape concentrate, orange concentrate, and apricot puree, the researchers prepared fruit juices enriched with iron sulphate at a level of 3 milligrams of 100 ml fruit beverage, with or without skimmed milk.

A comparison was made with juices formulated with caseinophosphopeptides, and measurements of iron retention, transport and uptake Caco- 2 cells.

The study showed that milk improved the retention, transport and uptake of iron in the fruit juices, even more than when CPPs were added to soluble fractions of fruit beverages.

"Iron supplementation increased iron retention, transport and uptake - the effect being more notable in samples with milk," noted Barbera and co-workers.

Source: Food Chemistry
Volume 119, Issue 1, Pages 141-148
"Addition of milk or caseinophosphopeptides to fruit beverages to improve iron bioavailability?"
Authors: M.J. Garcia-Nebot, A. Alegria, R. Barbera, G. Clemente, F. Romero