Microencapsulation of Kluyveromyces marxianus and Plantago ovata in cheese whey particles: Protection of sensitive cells to simulated gastrointestinal conditions

Abstract

Cheese whey proteins are natural vehicles for biological agents that are used as an inexpensive and effective coating material in the encapsulation of probiotics. In this work, the yeast Kluyveromyces marxianus, of probiotic potential, was associated with the prebiotic Plantago ovata (Psyllium) in particles coated with cheese whey. The efficiency of encapsulation, gastrointestinal tract (GIT) viability, particle morphology, and adhesion to enteral cells were analyzed. K. marxianus was encapsulated in different formulations with alginate (alg), psyllium (psy), and cheese whey (cw) through an extrusion process associated with vibrational technology. Yeasts encapsulated in different wall materials [alginate-psyllium-cheese whey (alg-psy-cw), alginate (alg), alginate-psyllium (alg-psy), and alginate-cheese whey (alg-cw)] were adequately protected, resulting in high cell viability (11.32, 9.77, 9.13, 10.95 log CFU.g−1, respectively). Regarding the bioavailability assay after three months of storage under refrigeration (±4 °C), cells encapsulated in wall material alg-psy-cw demonstrated the best viability (>6 log CFU.g−1). Encapsulated yeasts showed greater resistance to acidic conditions when exposed to simulations of the gastrointestinal tract, demonstrating a lower diffusion rate in the formulation made with wall material alg-psy-cw (10.03 log CFU.g−1). The adhesion rate to Caco-2 cells was high (±3,166 yeasts/100 Caco-2 cells). Finally, the developed product in this study was found to be suitable for incorporation in functional foods, as well as in pharmaceutical products, demonstrating its biotechnological potential.