Mineral Bioaccessibility of Pistachio-Based Beverages: the Effect of Lactic Acid Bacteria Fermentation

Abstract

The aim of this work was to study the effects of two LAB strains on the bioaccessibility (BA) of minerals after the fermentation of pistachio-based beverages. The beverages were made with two varieties of pistachio (Argentina, AP and Italian, IP). Aliquots were inoculated with 10-6 CFU of two different LAB strains and fermented for 24 h at 28°C. Six types of beverages were obtained: two controls (AP-c and IP-c), two fermented with LAB1 (AP-f1 and IP-f2) and two fermented with LAB2 (AP-f2 and IP-f2). The contents of minerals, phytic acid, and ascorbic acid were evaluated. To determine the BA of minerals, the samples were subjected to a simulated gastrointestinal digestion with equilibrium dialysis in the intestinal stage. The IP presented higher contents of Ca and Fe than the AP ones. The ascorbic acid content was higher for AP than for IP, and increased in both beverages after fermentation, obtaining a 70% increase in IP-f1. Phytic acid content was higher for AP than for IP, and decreased after fermentation to a greater extent when fermented with LAB1 (50% reduction). In all the cases, mineral BA was higher in fermented samples, being BA values dependent on the pistachio variety and the LAB strain. Negative correlations (p<0.05) were observed between the BA of Ca and Mg with phytic acid content. The fermentation of the pistachio beverages with LAB allowed increasing the BA of minerals, improving the nutritional quality of the pistachio-based beverage.