In Vitro and In Vivo Characterisation of Lactiplantibacillus plantarum LAB12 in Pea Protein-Alginate Microcapsules

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 ( 9 log CFU g-1) in simulated intestinal fluid (at pH 6.8 for 240 min). Whilst retaining their intrinsic cholesterol lowering effect, microencapsulation conferred additional advantages to L. plantarum LAB12 in terms of lowering serum triglyceride and increasing HDL cholesterol in zebrafish fed with high-cholesterol diet (HCD). Overall, our findings strongly imply the potential use of Alg-PPi10 as an effective medium that confers thermal protection and facilitates pH-sensitive release of cholesterol-reducing L. plantarum LAB12. This will allow the diverse applications L. plantarum LAB12 across health, food and agro-feed industries amongst others.