Lewis is an assistant professor of animal and food science at UW–River Falls who specializes in dairy processing. Her research interests include processing interventions to improve dairy protein functionality, dairy food byproduct enhancement and utilization, high-pressure technologies, and nanoparticles, emulsions and foams. Lewis’s position is funded by the Dairy Innovation Hub.
Of the proteins in milk, casein proteins are the most abundant (ca. 80% of total milk proteins). Casein proteins orient themselves into a micellar structure (i.e., a spherical protein quaternary structure) with the more hydrophobic proteins shielded within the core. The previously funded project titled “Optimization of casein nanoparticle formation using high pressure homogenization and processing aids” identified optimized ways to dissociate the casein micelle into smaller proteins. These proteins, being more exposed, are likely to have altered interactions with enzymes, such as those encountered during digestion or cultured dairy product manufacture. An expedited digestion of proteins would be appealing to certain groups of people such as athletes, who desire immediate protein bioavailability post-workout, or infants, who have been shown to digest proteins at a slower rate. Therefore, the objectives of the present work are (1) to evaluate the hydrolysis kinetics of milk proteins in dissociated samples vs. native samples using a variety of proteolytic digestion enzymes and (2) to determine the gelation properties of dissociated samples upon exposure to traditional coagulation procedures (i.e., rennet, acid, and ginger-based coagulation).