What You Need to Know
The casein proteins in Parmesan unfold at temperatures above 30 °C, reducing their emulsifying ability and causing phase separation. At 20–25 °C, the proteins remain soluble and, together with basil polyphenols, adsorb to oil droplets, lowering interfacial tension and forming a stable emulsion. A slight acidity (~pH 4.5) further enhances protein solubility and stabilizes the mixture.
The Science
Primary Reaction
Emulsification of olive oil droplets in an aqueous phase via protein and polyphenol stabilization