Goat cheese yield and recovery of fat, protein, and total solids in curd are affected by milk coagulation properties

摘要

The aims of the present research were to quantifythe effects of each coagulation trait, traditional milkcoagulation properties [MCP: rennet coagulation time(RCT), curd-firming time (k_(20)), and curd firmnessat 30 min (a30)], and modeled curd-firming over time(CF_t) parameters [estimated rennet coagulation time(RCTeq), curd-firming instant rate constant (k_(CF)), andpotential curd firmness (CFP)] directly on the following:(1) recovery of 3 milk components in the curd(%REC), (2) 3 measures of cheese yield (%CY), and(3) 3 daily cheese yield traits (dCY) from goat milk.Cheese-making traits were analyzed using 2 mixed differentmodels, the first to test MCP and the secondto test CF_t parameters. Pearson correlations werealso calculated. Significant and favorable relationships(negative for time intervals and positive for CF measures)were found between the traditional MCP andthe CF_t parameters and %REC and %CY traits. Theeffects of milk fat and protein contents were particularlyimportant on all cheese-making traits, with theonly exception being the effect of fat content on waterretention in cheese (%CY_(WATER)). We found an optimumvalue of milk k_(20), associated with the highest recoveryof components and cheese yield in solids (%CY_(SOLIDS)).In addition, a lower level of curd water retention and anincreased fresh curd yield (%CY_(CURD)) were associatedwith greater recovery of fat. The collection of all availableinformation during the process of milk coagulationand curd-firming allowed us to discover the effect ofRCT_(eq) on %REC traits and %CY_(SOLIDS), which had notpreviously been revealed for traditional RCT. Moreover,higher k_(CF) values were associated with increased%CY_(CURD) and %CY_(SOLIDS). Given that CF_t parametersshowed a high level of independence from one another,these can also be easily used and characterized in futureapplications at the industry level. Information providedby traditional and modeled coagulation propertiescould efficiently support the goat dairy industry andlay the foundations for a quality payment scheme forgoat milk.