The effect of milling on proteins in model Queso Fresco cheeses

Raw milk Queso Fresco (QF) made in Mexico contains contaminating bacterial strains that are not permitted in US foods. There is interest in developing a pasteurized milk version of Mexican Queso Fresco to be sold in the US. Milling is one of many manufacturing factors that may influence protein integrity. The aim of this study is to assess the effect of milling procedures on protein composition and cheese functional properties in a model QF, made without starter cultures. Mass spectrometric and gel electrophoretic analyses of aged milled cheeses show minimal changes in protein content without differences among the milling techniques. In these novel QF-like cheeses, eight weeks of aging, regardless of milling type, results in cheeses that is very similar to the non-aged samples. Aged cheeses with minimal proteolysis imply an extended shelf life and therefore, model cheeses from this study, relative to Mexican raw milk cheeses, would stay fresher in American households and supermarkets longer.