Microencapsulated Lactobacillus rhamnosus GG as a probiotic strain in dry fermented sausages

The viability of probiotics in food matrices and their survival through the digestive system remain key challenges in functional food development. This study aimed to microencapsulate Lactobacillus rhamnosus GG (ATCC 53103) using rice bran protein, bovine serum albumin, and carrageenan as wall materials, followed by their application in Milano-type salami. A 2² Full Factorial Design was employed to evaluate the effects of wall protein material (1.5–2.5%, w/v) and probiotic concentration (0.6–1.4%, w/v) on encapsulation efficiency (EE). The highest EE (99.7%) was obtained with a blend of 1.5% protein and 0.6% probiotic concentration, while increasing both variables significantly reduced EE. Microcapsules were characterized through physicochemical, thermal, and morphological analyses. Scanning electron microscopy revealed smooth surfaces with concavities in high-efficiency formulations, whereas lower EE microcapsules exhibited rough surfaces and cracks. Thermal analysis demonstrated that microencapsulation enhanced probiotic thermal stability. FTIR-ATR spectra confirmed wall materials and L. rhamnosus interactions, with spectral shifts supporting successful entrapment. In vitro digestibility assay indicated a 2-log CFU/g reduction in viable probiotic cells under gastrointestinal conditions, compared to 3-log CFU/g in free cells, demonstrating microencapsulation’s protective effect. Probiotic viability, when applied to fermented salami, was maintained at 10¹⁰ CFU/g after simulated maturation and digestion. The sensory analysis did not differ between the control and probiotic-enriched formulations. These findings highlight the efficacy of the proposed microencapsulation system in enhancing probiotic viability and stability in dry-fermented meat products, supporting its application in functional foods.