# The efficacy of three double-microencapsulation methods for preservation of probiotic bacteria

## TL;DR

This study compares three methods to preserve probiotic bacteria using double microencapsulation, finding that spray drying best maintains bacterial viability and properties.

## Contribution

The study introduces a double-coating microencapsulation method using alginate and chitosan, showing spray drying's superior efficacy in preserving probiotic bacteria.

## Key findings

- Spray drying produced smaller, spherical particles with higher LAB viability after 6 months of storage.
- Encapsulated LAB retained probiotic properties like acid-bile tolerance and antibacterial activity.
- Double-coating microencapsulation shows potential for probiotic applications in livestock.

## Abstract

Lactic acid bacteria (LAB) are used as a probiotic alternative to antibiotics in livestock production. Microencapsulation technology is widely used for probiotic preservation. A variety of microencapsulation protocols have been proposed and compared based on chemicals and mechanical procedures. This study aimed to develop a double-encapsulated coating from alginate (1.5%) and chitosan (0.5%) by extrusion, emulsion, and spray drying methods using the LAB strains Lactobacillus plantarum strains 31F, 25F, 22F, Pediococcus pentosaceus 77F, and P. acidilactici 72N, and to monitor the basic probiotic properties of the encapsulated prototypes. The final products from each microencapsulation protocol were analysed for their appearance, probiotic properties and viable cell count. Using the spray drying method, particles smaller than 15 μm in diameter with a regular spherical shape were obtained, whereas the other methods produced larger (1.4–52 mm) and irregularly shaped microcapsules. After storage for 6 months at room temperature, the LAB viability of the spray-dried particles was the highest among the three methods. In all the LAB strains examined, the encapsulated LAB retained their probiotic properties in relation to acid-bile tolerance and antibacterial activity. This study highlights the efficacy of double-coating microencapsulation for preserving LAB properties and survival rate, and demonstrates its potential for probiotic application in livestock farms.