Study of the Feasibility of Using Food-Grade Lactose as a Viable and Economical Alternative for Obtaining High-Purity β-Lactose

β-lactose is an anomer of interest for the pharmaceutical and food industries due to its techno-functional properties; however, its production is often costly and complex. In this study, the feasibility of using food-grade lactose (F-αL) to produce β-lactose was evaluated as an accessible and cost-effective alternative. For this purpose, the physicochemical characterization of this lactose was carried out through X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA), Modulated Differential Scanning Calorimetry (MDSC), Fourier Transform Infrared Spectroscopy (FTIR), and Raman Spectroscopy. The mutarotation process was also performed using alcoholic KOH solutions. Physicochemical characterization confirmed that commercial lactose consists mainly of α-lactose monohydrate, which is an ideal precursor for β-lactose production. Likewise, the conversion process efficiently yielded β-lactose, validating the feasibility of using food-grade lactose in this process, with a residual α-lactose content below 10%, indicating a high conversion efficiency. Thus, food-grade lactose emerges as a viable alternative for producing high-purity β-lactose. This finding represents a 90% reduction in production costs of this anomer, promoting the development of high-quality products in the pharmaceutical and food sectors.