Researchers from the University of Buenos Aires report that fortification of the pumpkin mesocarp with ferrous sulfate did not affect the taste of the food, and that the iron remained biologically available.
“Pumpkin (Cucurbita moschata Duchesne ex Poiret) mesocarp tissue showed to be an adequate fiber-rich food matrix for iron supply and a promising raw material for functional food product development,” wrote lead author Marina de Escalada Pla.
The results are published online ahead on print in the Journal of Food Engineering.
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 color, taste, and the shelf-life of the food.
“Iron compounds highly soluble in acidic water like ferrous sulfate, contribute to high iron bioavailability,” explained the researchers. “Nevertheless, these kinds of compounds are highly reactive and can produce undesirable off-flavor changes in foods.”
The researchers report that addition of the iron salt increased slightly the acidity of the pumpkin tissue, but did not have an impact on the microbiological parameters.
Concerns over color and taste that are common iron-fortified foods were unfounded in this study, suggest the authors, since no “significant changes in the organoleptical behavior of the product” was observed. In other words, no changes to the texture (firmness) of the pumpkin tissue, or the color of the food were recorded.
A nine-person panel was recruited to evaluate the effect of the ferrous sulfate on the taste of the pumpkin, and compared to an unfortified control.
The panelists scored both products approximately the same and the researchers concluded “that both products presented the same acceptability”.
An in vitro digestion model was used to test if the iron would be biologically available if the pumpkin was eaten. The model included pepsin and pancreatin and bile salts.
“Following hydrolysis with pancreatin (pH 8.00), the iron content in the supernatant increased […]; thus, a proportion of the iron intake was able to be absorbed in the stomach, while the rest, entrapped by pumpkin tissue, could be completely liberated at the gut,” wrote the researchers.
“Comparing the latter value with those obtained in the tissue before digestion, it could be concluded that all the iron present in the pumpkin product was available,” they added.
Source: Journal of Food EngineeringPublished online ahead of print, doi: 10.1016/j.jfoodeng.2008.11.013“Pumpkin (Cucurbita moschata Duchesne ex Poiret) mesocarp tissue as a food matrix for supplying iron in a food product”Authors: M.F. de Escalada Pla, C.A. Campos, L.N. Gerschenson, A.M. Rojas