Whey valorization using transgalactosylation activity of immobilized β-galactosidase

Whey represents a significant dairy industry by-product that has recently received due attention based on the rich nutrient composition and significant transformation potential. Hereby, we investigated a possibility of whey lactose bioconversion into prebiotic compounds, galacto-oligosaccharides (GOS) using beta-galactosidase transgalactosylation activity. The results showed that whey could be successfully used for GOS synthesis, since the highest GOS concentration (around 62 g L-1) was obtained batchwise using 40% (w/w) sweet whey powder solution under optimum conditions (50 degrees C, pH 4.5). Nevertheless, an efficient immobilized preparation using methacrylic Lifetech ECR8409 immobilization carrier was developed, enabling additional process improvement and ensuring at least 4 reaction cycles with unchanged yields and 2.5- fold enhanced productivity in comparison to the soluble enzyme. Therefore, this study provides a valuable contribution to the efficient and economical valorization of whey, which can be further on utilized as functional food and feed constituent.