Optimization of the synthesis process of β‐galactosidase/carboxymethylchitosan‐silica biocatalyst powders, stabilized with lyoprotectants for potential dietary applications

Abstract

Abstractβ‐galactosidase dosing and transport powders offer benefits for people with specific digestive deficiencies. They can be produced by immobilization in solid materials by sol–gel methods. The challenge is to maintain enzyme activity under processing conditions. The objective here is to design and optimize the calcium chloride and carboxymethylchitosan concentrations at 25°C and 7.3 pH for preparing active β‐galactosidase powders. This optimization was performed using a Response Surface Methodology with Central Composite Design, selecting lyoprotectants for preserving activity during the lyophilization. Glucose, galactose, maltose, sucrose, and β‐cyclodextrin lyoprotectants were assayed in different weight proportions. The optimal conditions to obtain a biocatalyst with maximum expressed activity were 473 mM CaCl2 and 402 ppm carboxymethylchitosan, obtaining a biocatalyst with 57.8% ± .7% recovered activity and 92.3% ± 2.1% immobilization yield. The galactose, maltose, and sucrose in a 1:5 ratio increased 1.2 times the expressed activity of this biocatalyst, protecting the active site during lyophilization due to favorable interactions with the enzyme as shown by docking analysis.Practical applicationsThis work shows the implementation of production methodologies of mixed enzyme‐mineral biocatalysts, based on the experimental, statistical, and docking studies of β‐galactosidase interactions with mono‐, di‐ and polysaccharides under ionic and thermal stress. The obtained powders could be candidates as dietary supplements of calcium, silicon minerals, and β‐galactosidase.