Alginate-Pereskia aculeata flour conjugates for the microencapsulation of Lacticaseibacillus rhamnosus GG

Pereskia aculeata (ora-pro-nobis – OPN) has emerged among plant-based bioactive compounds due to its proven health-promoting effects. This study aimed to encapsulate Lacticaseibacillus rhamnosus GG using external ionic gelation with a composite matrix of OPN flour and sodium alginate (ALG), evaluating viability, stability, and interaction separately and together under different conditions. Encapsulated probiotics were assessed after 60 days of storage at 2 °C, 22 °C and 35 °C, and gastrointestinal simulation. OPN flour facilitated bacterial proliferation with a generation time of 6 h 79 min. Encapsulation efficiency exceeded 94 % for ALG and ALG/OPN microcapsules, with diameters ranging from 2 to 4 mm and 1–5 mm, respectively. Scanning electron microscopy revealed that ALG/OPN microcapsules exhibited spherical or elliptical structures with homogeneous surfaces, while ALG-only capsules displayed slight deformations. ALG/OPN microcapsules showed increased antioxidant activity (21.39 % DPPH inhibition) and excellent probiotic viability during 60 days of storage at 22 °C and 15 days at 35 °C. Under gastrointestinal simulation, ALG/OPN preserved 6.9 log CFU/g, compared to 1.0 log CFU/g for free and ALG-only capsules. This study provides the first evidence supporting using P. aculeata flour as an effective material for probiotic encapsulation.