Preparation and Performance Evaluation of Freeze-Dried Yogurt Blocks Containing Microcapsules of Lactiplantibacillus plantarum

Freeze-drying has been widely utilized to extend the shelf life of yogurt. However, the poor viability of probiotics during freeze-drying and storage is a key challenge, limiting the application of freeze-dried yogurt products. This study aimed to investigate the effect of microencapsulation on the physicochemical and microbial properties of freeze-dried yogurt blocks. Protein-based microcapsules encapsulating Lactiplantibacillus plantarum (L. plantarum) were prepared by emulsification. Three formulations of yogurt blocks were prepared: control yogurt blocks, yogurt blocks with free L. plantarum, and yogurt blocks with microencapsulated L. plantarum. This study demonstrated that microencapsulation effectively improved the viability of L. plantarum in yogurt blocks during freeze-drying and storage with viable counts maintained above 7 log CFU/g. Microcapsule incorporation significantly enhanced the moisture content, protein content, water activity, and instrumental texture of the products. Instrumental color, electronic nose, and electronic tongue analyses revealed that freeze-drying and microencapsulation resulted in similar characteristic profiles to those of fresh yogurt. These results indicate that microencapsulation is a promising strategy for developing stable, room-temperature-storable functional dairy products with improved properties and probiotic stability.