β-D-Galactose is widely used in the food and pharmaceutical industries. It serves as a key component in the synthesis of lactose, which is essential in infant formula and dairy products for nutritional value. In biotechnology, β-D-Galactose is employed as an inducer in gene expression systems, particularly in the gal operon of E. coli, enabling controlled production of recombinant proteins. It is also used in diagnostic applications to assess bacterial fermentation patterns in microbiology. Additionally, it plays a role in the development of glycoconjugate vaccines and other therapeutic agents due to its involvement in cell surface recognition processes.