Effect of Milk Protein Standardization Using Different Methods on the Composition and Yields of Cheddar Cheese

Abstract

Two sets of Cheddar cheese were made in which the milk protein level (%, wt/wt) was increased from 3.3 (Control A, CA) to 3.6 (set A) or from 3.3 (control B, CB) to 4.0 (set B) by the addition of phosphocasein (PC), milk protein concentrate (MPC), or freshly prepared ultrafiltered milk retentate (UFR). The cheeses were denoted CA, PCA, MPCA, and UFRA from set A, and CB, PCB, MPCB, and UFRB, from set B, respectively. The level of cheese moisture decreased significantly on increasing milk protein level from 3.3 to 3.6 or 4.0% (wt/wt), but was not affected significantly by the method of protein standardization. The percentage milk fat recovered to cheese increased significantly on increasing the level of milk protein from 3.3 to 3.6% (wt/wt) with PC, and from 3.3 to 4.0% (wt/wt) with PC, MPC, and UFR. Increasing milk protein level from 3.3 to 4.0% (wt/wt) with PC significantly increased the percentage of milk protein recovered to cheese. Actual cheese yield increased significantly with milk protein level. The yield of cheese per 100 kg of milk normalized to reference levels of fat (3.4%, wt/wt) and casein (2.53%, wt/wt) indicated no significant effects of protein content or standardization treatment on yield. However, the moisture-adjusted yield per 100 kg of milk with reference levels of fat and casein increased significantly on increasing the protein content from 3.3 to 3.6% (wt/wt) with MPC and from 3.3 to 4.0% (wt/wt) with PC, MPC, and UFR.

Pre-treatment of cheese milk: principles and developments

“…PC and MPC have rennet coagulation properties similar to those of milk at similar protein concentration and ionic strength [33,74,78]. In a comparative study, increasing milk protein content through standardisation with UFR, MPC or PC resulted in enhanced rennet coaguability, reduced gelation time and increased curd firmness but there was no significant effect of protein type [52].…”

“…Increased yield results from reduced losses of fat and casein particles in whey and better retention of whey proteins in the aqueous phase of cheese. Furthermore, standardisation of milk protein to higher than normal levels enables increased plant throughput without installation of extra cheese vats [52].…”

“…Decreased levels of primary proteolysis were possibly due to reduced plasmin activity or to addition of chymosin on a volume basis, rather than on a casein basis. Increased moisture-adjusted yield may be due to a high level of whey protein denaturation in the MPC and thus a high level of protein recovery in the MPC-fortified cheese [52]. Standardisation of milk protein content using PC, UFR or MPC resulted in significantly increased fat recovery and yield of cheese per unit weight of milk, normalised to reference levels of casein and fat [52,56].…”

“…Standardisation of milk protein/casein levels, by concentration of milk solids or by producing a protein rich fraction which may be subsequently added to milk prior to cheese manufacture, may be used to reduce some negative defects associated with a seasonal milk supply [5,52], such as variable protein/casein contents which result in poor curd-forming properties and in variations in yield and in composition and consistency of resultant cheeses [3,83,109]. Increased yield results from reduced losses of fat and casein particles in whey and better retention of whey proteins in the aqueous phase of cheese.…”

“…Protein standardisation may be achieved by: use of low-concentrated retentate (LCR) produced by UF or RO of cheesemilk; enrichment of casein by MF; or addition of phosphocasein powder (PC) or milk protein concentrate (MPC) [52], typically followed by cheese manufacture using conventional equipment [98]. Addition of denatured microparticulated whey proteins to cheesemilk may also be used to ameliorate defects associated with reduced fat cheese [34,134].…”