Response Surface Methodology-Based Optimization for Enhancing the Viability of Microencapsulated Lactobacillus plantarum in Composite Materials

Probiotics have gained prominence and consumer appreciation due to their potential health benefits. However, maintaining their viability and stability during gastric transit remains a challenge. This study aims to enhance the viability of microencapsulated Lactobacillus plantarum in composite microcapsules exposed to simulated gastric juice. The independent variables investigated were low-acyl gellan gum (LAG), bacterial cellulose (BC), and calcium concentrations. The microcapsules were prepared using the internal ionic gelation method. The resulting microcapsules exhibited a uniform size distribution, with a diameter of approximately between 15 to 120 μm, making them suitable for food applications. Response surface methodology (RSM) based on the Box–Behnken design was successfully employed to optimize the concentrations of LAG, BC, and calcium. Under optimal conditions—0.63% w/v LAG, 17.91% w/v BC, and 25.12 mM Ca—the highest L. plantarum viability reached 94.28% after exposure to simulated gastric juice, with an R² value of 99.64%. These findings demonstrate the feasibility of developing multicomponent microcapsules that effectively protect probiotic bacteria against gastric fluids, offering a promising alternative for the food industry in designing probiotic-enriched food systems.