Pectin-interactions and in vitro bioaccessibility of calcium and iron in particulated tomato-based suspensions

摘要

In this study, the pectin structure-function relationship in tomato-based suspensions was explored. Particularly, electrostatic pectin-interactions were investigated and these interactions were subsequently linked to the in vitro bioaccessibility of Ca and Fe-ions in tomato-based suspensions. Process tomatoes were either treated at high-pressure (HP) or blanched at high temperature (HB). Ca2+ mediated pectin-pectin interactions in reconstituted HP tomato-based systems were stronger than in reconstituted HB tomato-based systems. These interactions were influenced by the molecular structure of pectin present in the serum fraction of the tomato suspensions, and improved with increasing Ca2+ concentration and pH. Investigation of the essential mineral content showed that HP and HB tomato-based suspensions contained similar amounts of Ca and Fe-ions (9.8 +/- 0.8 and 0.39 +/- 0.1 mg/100 g of puree, respectively). The Ca and Fe-ions in HB tomato-based suspensions were two times more bio-accessible than the Ca and Fe-ions in HP tomato-based suspensions. Finally, it could be concluded that the bioaccessibility of Ca and Fe-ions decreases with increasing electrostatic pectin-interactions. (C) 2015 Elsevier Ltd. All rights reserved.