The effects of pH and time on rheological changes during early cheese maturation

Abstract

Changes in rheological properties of cheese curd during the initial stages of ripening, with pH (5.45-6.05) and with time (2-14 days), were evaluated using a small strain oscillatory test and a newly designed large strain deformation test. The new test method developed for evaluation of grated cheese employed extrusion flow technique and was carried out using the Instron universal Testing Machine. The values for the storage modulus (G′) measured using the small strain test increased with an increase in the pH of cheese curds from 5.45 to 5.90. The results from the large strain test showed essentially similar trends. The samples of curd also showed an increased solid-like behaviour as the pH increased and appeared to become more elastic with time during the two-week period of analysis.