Eh and pH gradients in Camembert cheese during ripening: Measurements using microelectrodes and correlations with texture

This study investigated the use of microelectrodes to continuously and simultaneously monitor pH and redox potential (Eh) gradients in Camembert cheeses from the rind to the core, as a function of ripening time (15 and 35 days). Cheeses were shown to be heterogeneous throughout their mass. An Eh gradient existed from the rind to the core. The surface was oxidizing (+ 330 to + 360 mV) and the core was reducing and became more so in the course of ripening (-300 to -360mV). A relationship between firmness and Eh was shown. pH gradients were in line with those previously described in the literature and related to ammonium and lactate gradients. Gradients evolved from the rind to the core (pH 7.7 to 5.2 at 15 d and 7.5 to 6.8 at 35 d). These findings showed that both the Eh and pH constituted control parameters for cheese ripening. (C) 2007 Elsevier Ltd. All rights reserved.