Determination of Rennet Clotting Time by Texture Analysis Method

Abstract

In this study, texture analysis method was used for the determination of rennet flocculation time (t floc ) and rennet clotting time (t clot ) of rennet-induced reconstitued milk samples with different CaCl 2 concentrations. The rennet flocculation time (RFT) and rennet clotting time (RCT) were also determined by using the Berridge test and sensory evaluation. The hardness value versus renneting time curves derived from texture analysis gave a good modified exponential relationship for each CaCl 2 concentration and the curves were used to calculate flocculation time and clotting time parameters. It was found that the parameters (t floc and t clot ) appeared strongly correlated with RFT and RCT, respectively. Texture analysis was proved as a suitable method to control the rennet-induced coagulation and determine the rennet clotting time. It was also determined that enrichment of milk with CaCl 2 leaded to a decrease in flocculation and clotting times and an increase in rate of clotting and gel hardness.