An Approach for Using Non-purified β-Galactosidase: The Potential of β-Galactosidase in Kluyveromyces marxianus Cell Microparticles with Different Wall Materials

β-Galactosidase is an enzyme of significant commercial importance, widely used in industry for various purposes as lactase, among others. Enzyme microencapsulation is used to protect the target agent; therefore, this method improves the applicability of enzymes in different aspects. Considering these aspects, this study aimed to immobilize Kluyveromyces marxianus cells that express β-galactosidase enzymatic activity through microencapsulation by spray drying. Encapsulation used sodium alginate (SA), maltodextrin DE10 (MD), Arabic gum (AG), and isolated soy protein (ISP) to form microcapsules. The drying parameters were drying air temperature of 90 °C, atomization flow of 40 L/min, inlet air flow of 1.65 m³/min, and feed solution flow of 0.600 L/h. Among the wall materials evaluated, MD emerged as the most suitable for forming microparticles due to its low loss of activity during storage, low moisture content, and water activity, in addition to high solubility, yield, and retention of enzymatic activity. They demonstrated excellent retention of activity during storage and the second longest half-life at 30 °C and pH 7.0. ISP exhibited the longest half-life for the enzyme at 30 °C and pH 7.0. Control had a longer half-life when stored at 35 and 40 °C and stability at pH 7.3 and 30 °C. In addition, it maintained 72% of post-immobilization activity. The results of this study conclusively demonstrated that the microencapsulation process can be considered a viable tool to immobilize K. marxianus cells, as it effectively maintained the activity of the β-galactosidase enzyme without the need for purification of the enzyme.