Comparative efficiency of Geotrichum candidum microcapsules prepared with alginate and in combination with other polymers: In vitro evaluation.

Microencapsulation is utilized to protect probiotics, such as Geotrichum candidum, ensuring their survival, stability, and targeted release. The encapsulation efficiency depends on factors such as the type and concentration of the polymers and the encapsulation method. In this study, G. candidum was encapsulated using alginate (Alg) combined with starch (AlgS) or xanthan (Alg-X) and coated with chitosan aand chitosan nanoparticles (AlgC, Alg-S-C, Alg-X-C, Alg-CN, Alg-S-CN, and Alg-X-CN) using a simple extrusion technique. The structural characteristics and surface morphology of the microcapsules were analyzed using Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). Encapsulation efficiency (EE) and pH and temperature tolerances were assessed using in vitro assays. SEM results showed that the Alg-CN microcapsules were notably spherical and smooth, in contrast to the irregular and rough textures of the uncoated forms. Notably, Alg-CN exhibited the highest EE (99.3 %), followed by Alg-C (96.6 %) and Alg-X-CN (96.03 %). Moreover, chitosan-coated microcapsules, particularly Alg-CN, demonstrated superior viability at various pH levels and after exposure to 60 °C, along with extended shelf life at room temperature and 4 °C. These findings suggest that a 2 % alginate and 0.4 % chitosan combination is optimal for preserving G. candidum's viability in various applications.