The susceptibility of probiotics to high temperature and low pH remains a major challenge in food industries. Numerous commercially available probiotic products were reportedly presented with lower probiotic viability than claimed. To confer health benefits to the host, it is essential that probiotic strain remains viable at optimal amount during food processing procedures, storage and passage through the gastrointestinal tract. This study addressed these issues by immobilising Lactiplantibacillus plantarum LAB12 isolated from tempeh (fermented soybean) in a polymeric matrix made up of alginate (Alg, 0.5% w/v) and denatured pea protein isolate (PPi, 1-10% w/v) using the emulsion/acidification technique. Alg supplemented with 10% PPi (Alg-PPi10) appeared to be optimally small (<
350 µm), substantiated by the improved surface smoothness and uniform dispersion of probiotics in the Alg-PPi core. The findings indicated that microencapsulation enhanced thermal stability of L. plantarum LAB12. The microencapsulated L. plantarum LAB12 remained highly viable (80%) despite exposure to 100 °C for 5 min. The microencapsulated cell number during storage at 4 and 25 °C for 8 weeks was greater than 7 log CFU g