Microencapsulation of Lactobacillus acidophilus and Lactiplantibacillus plantarum in alginate and gelatin: study of production, characterization and stability aiming application in food
Functional Foods, Probiotics, Encapsulation, Emulsification O/W
Probiotics are defined as viable microorganisms, which ingested regularly, provide numerous benefits to health. However, cell viability can be compromised by exposure to storage conditions and the digestive process. Thus, encapsulation appears as a technological solution capable of promoting protection, controlled release, and preservation of bioactive effects. In this context, the present study aimed to produce, characterize and evaluate the stability of microparticles based on sodium alginate and swine gelatin containing Lactobacillus acidophilus NRRL B-4495 and Lactiplantibacillus plantarum NRRL B-4496. The encapsulation was performed by emulsification oil/water (O/W), using Tween 20 as surfactant. The encapsulates were characterized by Scanning Electron Microscopy (SEM), Laser Diffraction, and Fourier Transform Infrared Spectroscopy (FTIR). In addition, the particles were evaluated for encapsulation efficiency, water dispersibility, and thermal behavior. For encapsulated in gelatin, the micrographs showed irregular particles with smooth surfaces, containing microorganisms in their structure, unlike the base alginate encapsulated. The FTIR indicated the chemical interactions only between the constituents of the gelatin-based formulations, with the formation of new vibrational bands, in addition to bands characteristic of probiotics. The gelatin-based formulation containing L. plantarum showed particle size of 22.86 μm (0.01) and polydispersion index of 0.6 (0.1). L. acidophilus and L. plantarum encapsulated in gelatin had encapsulation efficiencies of 89.65% (4.2) and 81.08% (9.7) (p>0.05), respectively. On the other hand, alginate-based particles did not favor the viability of probiotics (0.0 log CFU/g). Probiotics encapsulated in gelatin showed dispersibility in water in the range from 60.9 to 57.6% (p>0.05). Finally, the thermal analysis indicated stability at a temperature below of 54 ºC, which guarantees the crystallization of the microparticles. Therefore, it is suggested that the microencapsulation of gelatin by emulsifying O/W is a proper and favorable strategy for the protection of probiotic bacteria, enabling future applications in the food area.