Spray-Dried Microencapsulation of Lacticaseibacillus Rhamnosus GG (ATCC 53103) in Cross-Linked Alginate Enriched with...

The development of non-fermented probiotic products in powders requires strategies to ensure their viability and metabolic activity under adverse conditions. In this study, a cross-linked alginate matrix was used to encapsulate Lacticaseibacillus rhamnosus GG (ATCC 53103) using the spray-drying technique. The matrix was supplemented with the following encapsulating agents: chia seed mucilage (CM), flaxseed mucilage (FM) and inulin. Response surface methodology was used to evaluate the effects of the type and concentration of encapsulating agent and CaHPO₄ concentration on probiotic survival after spray drying. Furthermore, encapsulated L. rhamnosus GG viability was evaluated during storage of two supplemented powdered food products (flan dessert and soup). After encapsulation, L. rhamnosus GG showed reductions of 0.2 and 0.7 logarithmic cycles when the matrix was supplemented with CM (0.4%, w/v) and FM (0.4%, w/v), respectively, in combination with CaHPO₄ (0.5%, w/v). Under these conditions, L. rhamnosus GG survival rates reached 98% and 93%, respectively. Furthermore, microcapsules of L. plantarum, B. infantis and B. longum showed high survival (> 90%) rates. L. rhamnosus GG microcapsules supplemented with FM resisted heat stress, reaching a survival rate of 78%. Regarding stability in powdered food matrices, L. rhamnosus GG encapsulated viability was affected by storage temperature. After 90 days at 4 °C, both products reached high counts (> 9 Log CFU/g of dry product). In contrast, at 25 °C, they did not exceed 4.5 Log CFU/g of dry product. Both CM and FM can be effective alternatives as encapsulating agents in spray-drying and cold storage processes.