Effect of two co-microencapsulation methods on the viability of the Lactobacillus plantarum ATCC 14917 and the release and bioaccessibility of iron

Abstract

Co-microencapsulation is an innovative approach for delivering two or more bioactive components to their site of action. This study aimed to evaluate the effect of two co-microencapsulation methods on the viability of the Lactobacillus plantarum ATCC 14917 during storage (24 °C and 4 °C) and under simulated gastrointestinal conditions, focusing on the release and the bioaccessibility of iron in vitro. Co-microencapsulation of L. plantarum and iron was performed using extrusion and spray-drying, using alginate (2%), chitosan (1%), and maltodextrin (0% and 5%) as wall materials. The microcapsules were characterized in terms of probiotic encapsulation yield, iron encapsulation efficiency, morphology (by scanning electron microscopy), and functional groups (by Fourier transform infrared spectroscopy). Both encapsulation methods exhibited high encapsulation yield values (87.43% – 98.90%). However, the spray-drying method with 5% maltodextrin leads to a higher survival rate at 4 °C, with a viability loss rate of -0.010 day-1. This negative value indicates an increase in the probiotic viability due to the use of maltodextrin as an energy source. Similarly, this treatment resulted in bacterial growth of 0.12 log CFU/g under intestinal conditions and the lowest viability reduction of 0.32 log CFU/g under gastric conditions. Maltodextrin enhanced probiotic viability both during storage and under simulated gastrointestinal conditions. Furthermore, the spray-drying method also promoted greater and faster iron release under gastric (85% – 98%) and intestinal (51.67%) conditions, as well as higher iron bioaccessibility (74.13%). These findings suggest that co-microencapsulation of L. plantarum and iron via spray-drying with maltodextrin has significant potential for the development of functional foods containing viable probiotic bacteria while ensuring the timely release of iron with superior bioaccessibility, thereby offering health benefits.