Impact of pH on the texture of cultured Cream cheese: firmness and water phase characteristics

This study explored the effect of pH on the firmness and water phase properties of Cream cheese, a soft unripened acid-coagulated cheese. Sections of cultured Cream cheese manufactured with locust bean gum were randomly exposed to NH3 from 1 to 10 min to increase the pH from 4.6 ca 6.1. Specimens from the treatment with the highest pH were exposed to HCl for up to 10 min to reverse pH. The cheeses were analyzed for pH and firmness and then centrifuged to obtain the expressible serum. The effect of pH on the viscosity of the serum and the Ca content of the water phase was investigated. Firmness drastically decreased with the increase of pH and subsequently increased when the pH was reversed. Concomitantly, the amount of expressible serum decreased with pH and then increased when reversing cheese pH. Interestingly, the serum viscosity and calcium content of the water phase were not affected by pH, indicating that the textural changes observed were not caused by changes in the Ca distribution or the stabilizer function, but rather from changes in the hydration of the casein-matrix. Higher pH appears to promote water-casein interactions, increasing water holding capacity and softness of the cheese.