Migration of water-soluble nitrogenous compounds of Feta cheese from the cheese blocks into the brine

The migration of water-soluble nitrogenous compounds of Feta cheese from the cheese into brine was monitored over a 5-month period, and the nature of the compounds diffusing into the brine was investigated. Reversed-phase high-performance liquid chromatography analysis of the water extract of Feta cheese and of the brine showed that both contained serum proteins and various peptides; the chromatographic profiles changed with the age of the cheese. Also, differences between chromatograms of the water extract of the cheese and the brine at the same age were observed. It seems likely that the parameters driving the solubility of peptides in 120 g L−1 trichloroacetic acid (size and hydrophobicity) also determine their potential for diffusion into the brine. Amino acids also migrate into the brine, with the hydrophobicity and shape of the side chain governing their diffusing ability.