Cow milk coagulation: process description, variation factors and evaluation methodologies. A review

Introduction. For dairy producers who want to transform their milk, the ability of milk to coagulate is an important parameter. It makes it possible to transform milk into cheese. Therefore, it is necessary to understand the coagulation process and the techniques to measure it in order to achieve the best transformation performance. The objective of this review is to describe the milk coagulation process, the factors influencing it and the methods for measuring the coagulation of milk at lab level. Literature. The processing of milk into cheese involves three steps: coagulation, dewatering and refining. Coagulation is a key step which involves the use of rennet and depends on several parameters (pH, calcium content, temperature, etc.). Some milks never coagulate. To measure the coagulation ability of milk and identify different parameters in milk coagulation properties, the Formagraph, the computerized renneting meter and the Optigraph have been developed (reference methods). Equations have been developed using infrared spectrometry to predict the parameters obtained by the reference methods. Conclusions. The milk coagulation mechanism is known. However, the issue of non-coagulating milk persists and represents a real challenge in terms of yield. The use of infrared is a faster alternative to reference methods that measure the coagulation properties of milk, but still requires an improvement in prediction equations. Coagulation du lait : description du processus, facteurs de variation et évaluation des méthodologies (synthèse bibliographique) Introduction. Pour les producteurs laitiers qui souhaitent transformer leur lait, l’aptitude à la coagulation du lait est un paramètre important. Elle permet en effet de transformer le lait en fromage. Dès lors, il convient de bien comprendre son processus et les techniques pour la mesurer afin d’obtenir le meilleur rendement de transformation. L’objectif de cette revue bibliographique est de décrire le procédé de coagulation du lait, les facteurs qui l’influencent et les méthodes pour mesurer la coagulation du lait au niveau du laboratoire. Littérature. Le processus de transformation du lait en fromage implique trois étapes : la coagulation, l’égouttage et le raffinage. La coagulation utilisant la présure est l’étape clé. Elle dépend de nombreux facteurs (pH, teneur en calcium, température, etc.). Certains laits ne coagulent jamais. Pour mesurer l’aptitude du lait à la coagulation, le Formagraph, le Computerized Renn