Influence du teneur du calcium sur les proprietes de texture de fromage

Abstract

The effect of pH using different concentrations of Glucono-β-lactone (GDL) and the addition of calcium chloride on the textural and rheological properties of rennet-induced casein gels from ultrafiltered milk was investigated. Addition of CaCl2 and a decrease of pH between the values ~6,8 and 6, resulted a denser, stronger curd. As pH decreased under 6 to ~5,5, the level of colloidal calcium phosphate decreased concomitantly, giving less cross-links in the casein networks, less values of hardness of the gels and so explaining the textural changes in the structure of casein gel that also attest a little process of syneresis. So, a higher concentration of GDL resulted soft gel with large pores, presumably because some of the strands in the gel network were weak enough to break. No conclusive explanation could be given for the effects of CaCl2 concentration and pH on the properties of acid casein gels.