EFFICIENCY OF THE IONIC GELATION PROCESS FOR MICROENCAPSULATION OF BIFIDOBACTERIUM LONGUM 5¹A

In recent decades, the consumer market demand for healthier food products and practical consumption has been growing. In this scenario, probiotic foods have been gaining more and more popularity due mainly to their health-promoting effects on the digestive system. In order for the balance of the intestinal microbiota and other desirable effects to be achieved, it is necessary that probiotic microorganisms are present at adequate levels in the food for consumption, as well as after the digestion stage. Both food processing operations and the digestive process present challenging conditions for the survival of probiotics, such as pH, temperature, and oxireductive potential. In this context, several microencapsulation techniques have been evaluated and employed in order to protect and ensure the viability of these microorganisms. The ionic  gelation technique, in particular, has great potential  for application in view of its practicality, low cost and possibility of using different protective materials, such as sodium alginate. The use of this technique for the microencapsulation of the probiotic strain Bifidobacterium longum 5¹A, however, is still unknown, and is the objective of this study. The activation of the microorganism occurred in MRS broth (Man, Rogosa and Sharpe), which was centrifuged, added sodium alginate at a concentration of 3% and sprayed in a 1.6% calcium lactate solution. The gelled microspheres obtained were subsequently frozen at -60°C and lyophilized. The Bifidobacterium longum 5¹⁰ strain was counted in the culture broth before and after centrifugation, in the sodium alginate gel and after lyophilization. The results were expressed in CFU/g after pour plate plating, with overlay, in an anaerobic jar. The probiotic microorganism presented counts of approximately 1.91 x 10⁹ and 1.11 x 10¹⁰ CFU/mL in the culture broth before and after centrifugation, respectively. The gelled microspheres presented a total count of 3.52 x 10⁹ CFU/mL, with an encapsulation efficiency (EE) of 95%, while the lyophilized microcapsules presented 4.93 x 10⁹ CFU/g, resulting in an EE corresponding to 96%. The results indicate that the encapsulation process of this strain by ionic gelation using sodium alginate as wall material was satisfactory, allowing its use as a simple, accessible and low-cost technique, presenting itself as a promising alternative for the pharmaceutical and functional food industries.