Investigating gum arabic and soy protein isolate as wall material for encapsulation of five strains of Lactobacillus

Encapsulation technology is a suitable tool to protect probiotics in carrier food products and gastrointestinal tract. In the current investigation, the potential of gum arabic, soy protein isolate and their blend as wall material for the encapsulation of five Lactobacillus spp. viz. L. acidophilus, L. bulgaricus, L. casei, L. plantarum and L. rhamnosus by freeze drying was studied. The impact of various encapsulating materials on the encapsulation efficiency, water activity, particle size, thermal properties and morphology of encapsulates was investigated. The results revealed that microparticles have low water activity (0.25-0.37), high encapsulation efficiency (81.94 to 93.03 %) and particle size ranged between 112.34 and 147.79 μm. Scanning electron microscopy indicated a porous morphology and irregular shape of probiotic powder. The absorption bands in the FT-IR spectra between 2854 and 1088 cm^-1, 2927-109 cm^-1 and 2930-1071 cm^-1 confirm the successful encapsulation of probiotics. The encapsulated probiotics showed high lysozyme tolerance (76.00 to 92.16 %) and high cell surface hydrophobicity (58 to 85 %) as compared to free cells. This improves probiotic stability, survivability, and functional properties, making them ideal for developing functional food products. These encapsulated probiotics are well-suited to withstand gastrointestinal conditions and deliver health benefits to consumers.