Bioaccessibility of Mineral Nutrients in Plain Green Spanish-Style Manzanilla Table Olives Packaged in Nutrient Salt Mixtures

Abstract

Table olives are high in salt, which can negatively impact cardiovascular health. It is essential to reduce their salt content to mitigate such risk. The objectives of the study were to develop an appropriate protocol to determine mineral bioaccessibility in green Spanish-style Manzanilla table olives and to use it to evaluate, for the first time, the effects of replacing 50% NaCl in the packaging brine with KCl, CaCl2, and MgCl2 on this characteristic. After testing, Miller’s protocol with a post-digestion re-extraction was chosen. The mineral bioaccessibility found was as follows: Na, 93–98%; K, 94–100%; Ca, 19–27% (the lowest accessibility); Mg, 78–91% (moderately accessible); and non-added P, 55–67%. Bioaccessible amounts (mg/100 g pulp) of added minerals in runs were 151–503 for K, 53–109 for Ca, and 54–143 for Mg. The bioaccessible mineral vs. salt concentrations were modelled and plotted using RSM, illustrating the possible predictions from the tested range of combinations. The bioaccessibility of Ca and Mg was approximately 70% and 15% lower than the values indicated on the label based on the chemical analysis. The results discourage Ca fortification in packaging and suggest including bioaccessibility, markedly influenced by the food matrix, on the label for accurate nutritional information.