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.

Estimation of Serpa cheese ripening time using multiple linear regression (MLR) considering rheological, physical and chemical data

“…4e) induced an effect of micelle demineralization (Ca bonds) and consequent dissociation, which were also responsible for cheese softening. This phenomenon causes a progressive dissociation of para κ particles into small casein aggregates and, therefore, in the protein links of the cheese matrix (Ramkumar et al 1998; Boutrou et al 2002; Hassan et al 2004). Therefore, a reduction of the solid-like properties can be observed in samples presenting low pHs (28–42 d; Fig.…”

Towards the classification of cheese variety and maturity on the basis of statistical analysis of proteolysis data—a review

“…During the manufacture of cheese as well as in the days following the manufacture of dry-salted cheese, the cheese structure is set up as pH-dependent interactions take place between the caseins and between the caseins and minerals (Boutrou & Gagnaire, 2001;Boutrou et al, 2002), and the caseins become more hydrated (Creamer, 1985;Guo & Kindstedt, 1995;Ramkumar, Campanella, Watkinson, Bennett, & Creamer, 1998). Recent studies have used nuclear magnetic resonance to explore changes in water distribution associated with increasing protein hydration in the days following cheese manufacture (Kuo, Gunasekaran, Johnson, & Chen, 2001) and during ripening (Godefroy, Korb, Creamer, Watkinson, & Callaghan, 2003).…”

“…The changes in cheese texture and physical properties occur mainly as a result of proteolysis, and the influence of proteolysis on cheese texture has been widely studied (e.g. de Jong, 1976de Jong, , 1977de Jong, , 1978Creamer & Olson, 1982;Lawrence & Gilles, 1987;Luyten & van Vliet, 1996;Lane, Fox, Johnston, & McSweeney, 1997;Watkinson et al, 1997Watkinson et al, , 2001Ramkumar et al, 1998;Watkinson & Jackson, 1999;Verdini & Rubiolo, 2002).…”

Invited Review: Perspectives on the Basis of the Rheology and Texture Properties of Cheese

“…In model cheese curds that were made with pH values between 5.45 to 6.05 (Ramkumar et al, 1998) or where the pH of Mozzarella was increased by exposure to an ammonia atmosphere (Kindstedt et al, 2001), there was an increase in the elastic modulus and apparent viscosity with increasing pH. Presumably, in cheese made with a higher pH value there was more residual Ca phosphate associated with CN.…”