Two-step aging dynamics in enzymatic milk gels

In this study, the authors take advantage of the emergence time-resolved mechanical spectroscopy to investigate the formation and aging of enzymatic milk gels, made of soft natural colloids. By coupling rheometric measurements with structural characterizations, they reveal two sequential steps in the aging process. First, the open particulate network rapidly matures into a compact network, increasing gel elasticity and evolving the viscoelastic spectrum. Second, the microstructure ``freezes'' at a critical time, after which aging proceeds through contact-driven mechanisms. This two-step aging process is crucial for industrial cheese processing and contrasts with the aging of hard particle colloidal gels, where the overall network structure remains constant throughout aging.