Functional yak milk ice cream by incorporating Latilactobacillus sakei microcapsules using milk protein–hyaluronic acid–chitosan multilayer systems

Yak milk is a nutrient-rich dairy material with various bioactive properties, yet yak milk ice cream remains unexplored. This study aimed to develop the probiotic yak milk ice cream by incorporating microencapsulated Latilactobacillus sakei J15 ( Lb. sakei J15) with different coating layers (1–4 layers) prepared via layer-by-layer assembly using casein-hyaluronic acid or β-lactoglobulin-hyaluronic acid conjugates and chitosan. Compared with the non added probiotic and free-probiotic cell samples, the addition of Lb. sakei microcapsules significantly modulated the viscosity, survival rates in various condition, and melting temperature of ice cream. During simulated gastrointestinal digestion, the microencapsulated probiotics maintained a high viability of 67.6%, significantly higher than the 41.2% survival rate of free cells. Notably, yak milk ice cream with three-layer microcapsules exhibited the most pronounced reduction in melting temperature (Tpeak as low as 3.11°C) and retained the highest viable count after 60 days of frozen storage. Furthermore, microencapsulation effectively enhanced flavor richness and sensory acceptance by reducing astringency while increasing umami perception. These results demonstrate that multilayer microencapsulation is an effective strategy to improve both probiotic delivery and the overall quality of functional yak milk ice cream.