The mineral profile affects the coagulation pattern and cheese-making efficiency of bovine milk

摘要

Natural variations in milk minerals, their relationships,and their associations with the coagulation processand cheese-making traits present an opportunityfor the differentiation of milk destined for high-qualitynatural products, such as traditional specialties or ProtectedDesignation of Origin (PDO) cheeses. The aimof this study was to quantify the effects of the nativecontents of Ca, P, Na, K, and Mg on 18 traits describingtraditional milk coagulation properties (MCP),curd firming over time (CF_t) equation parameters,cheese yield (CY) measures, and nutrient recoveries inthe curd (REC) using models that either included oromitted the simultaneous effects of milk fat and caseincontents. The results showed that, by including milkfat and casein and the minerals in the statistical model,we were able to determine the specific effects of eachmineral on coagulation and cheese-making efficiency. Ingeneral, about two-thirds of the apparent effects of theminerals on MCP and the CF_t equation parameters areactually mediated by their association with milk composition,especially casein content, whereas only onethirdof the effects are direct and independent of milkcomposition. In the case of cheese-making traits, theeffects of the minerals were mediated only negligiblyby their association with milk composition. High Cacontent had a positive effect on the coagulation patternand cheese-making traits, favoring water retention inthe curd in particular. Phosphorus positively affectedthe cheese-making traits in that it was associated withan increase in CY in terms of curd solids, and in allthe nutrient recovery traits. However, a very high Pcontent in milk was associated with lower fat recoveryin the curd. The variation in the Na content in milkonly mildly affected coagulation, whereas with regardto cheese-making, protein recovery was negatively associatedwith high concentrations of this mineral. Potassiumseemed not to be actively involved in coagulationand the cheese-making process. Magnesium contenttended to slow coagulation and reduce CY measures.Further studies on the relationships of minerals withcasein and protein fractions could deepen our knowledgeof the role of all minerals in coagulation and thecheese-making process.