Characterization and storage stability of microencapsulated Lactobacillus helveticus in sweetened condensed Milk: Impacts of wall material composition on product quality and probiotic viability

The high osmotic pressure in sweetened condensed milk severely inhibits probiotic viability, resulting in its insufficient use in probiotic applications. In this study, we systematically evaluated casein (CS), sodium hyaluronate (SH), and sodium alginate (SA) as microencapsulants for Lactobacillus helveticus in sweetened condensed milk, and assessed various CS:SA and CS:SH ratios to optimize both microbial viability and product quality. Through multimodal analysis of rheological properties (dynamic modulus and viscosity), thermal stability, physicochemical parameters (water activity and sugar/acid content), and color evolution, the CS:SH (1:1) formulation demonstrated stable microstructural integrity, enhanced volatile flavors, and preserved sensory characteristics while maintaining probiotic viability, which proved to be optimal for L. helveticus microencapsulation. Our findings establish a viable microencapsulation approach for hypertonic food applications that effectively balances probiotic viability and product shelf stability.