Diffusion of Salt, Fatty Acids, and Esterases in Mozzarella Cheese

Diffusion rates of sodium chloride, butanoic acid, octanoic acid, and pregastric esterase in Mozzarella cheese were estimated. Solutions of sodium chloride, butanoic acid, octanoic acid, and carbon-14 labeled pregastric esterase were absorbed into chromatography paper, these "paper wicks" were placed between two slabs of cheese, and rates of migration of the solutes in cheese were measured. The approximate equilibration times of sodium chloride, butanoic acid, and octanoic acid over a 1.5 cm-thiek section of Mozzarella cheese were 7, 28, 160 days. Pregastric calf esterase did not migrate during 11 wk of diffusion, probably because of its high molecular weight. Diffusion of sodium chloride, the smallest molecule evaluated, was equivalent across or parallel to the fibrous structure of Mozzarella cheese. Butanoic acid applied to the paper wick as a water or octanol solution migrated at equal rates, suggesting that butanoic acid should migrate freely through either water or fat phases of cheese.