The influence of brine concentration on chemical composition and texture of Iranian White cheese

The effect of brine concentration on composition, proteolysis development measured by free tyrosine-tryptophan content, microstructure monitored using scanning electron micrographs, and theological behavior measured in uniaxial compression test and small amplitude oscillatory shear were studied. Three treatments of Iranian White cheese were made by immersing cheese curds in brines with different salt concentrations (9%, 13%, and 17%). The higher the brine concentration, the higher were the salt, fat and protein contents and lower was the moisture content. The treatment; therefore, led to a significant increase in salt-in-moisture and a decrease in the ratio of moisture to protein. It also increased the values of fracture stress and storage modulus. The concentration of free tyrosine-tryptophan decreased as salt-in-moisture of cheese increased. When the moisture content of the treatments decreased, fat did not replace the moisture on an equal basis, so the total filler volume (fat and moisture) was decreased. The decrease in the ratio of filler to protein in treatments ripened at stronger brines could mainly account for the increased firmness. The cheeses ripened in weaker brines (9% and 13%) especially that in the weakest had a dense microstructure with large protein aggregates; while, the cheese ripened in the strongest brine (17%) had a casein network with more homogenous protein aggregates permeated by holes and fissures corresponding to discrete fat globules and/or pools of coalesced fat globules. (c) 2006 Published by Elsevier Ltd.