Effects of Milk Somatic Cell Count on Cottage Cheese Yield and Quality

Abstract

Eight Holstein cows in midlactation were selected for low milk somatic cell count (SCC) and the absence of the pathogens that cause mastitis. Milk collection and cottage cheese manufacture from low SCC milk were replicated on each of 4 d (control period). Each cow was infused with 1000 cfu of Streptococcus agalactiae. One week after infusion, milk from the same eight cows was collected and commingled. On each of 4 d, cottage cheese was made from milk with high SCC (treatment period). A mass-balance protocol, accounting for protein and total solids, was used to determine recoveries in whey, wash water, and uncreamed curd. Actual yields, yields adjusted for composition, and theoretical yields of uncreamed curd were calculated. Mean milk SCC for the periods with the low SCC (control) and the high SCC (treatment) were 83 x 10(3) and 872 x 10(3) cells/ml, respectively. The recovery of protein in the uncreamed curd was higher during the low SCC period than during the high SCC period (75.85% vs. 74.35%). High SCC and the associated higher proteolytic activity caused higher protein loss in the whey and wash water and more curd fines. The percentage of total solids recovery in uncreamed curd was higher for high SCC milk because the lactose content of the high SCC milk was 0.27% lower than that of the low SCC milk. The moisture content of the curd was higher for the high SCC milk (82.75% vs. 83.81%). Proteolysis during refrigerated storage was faster in cottage cheese made from high SCC milk. The yield efficiency of uncreamed curd, adjusted for composition based on 81% moisture, was 4.34% lower for the cottage cheese curd made from high SCC milk.

Polymorphonuclear proteolytic activity and milk composition change

“…Whatever the technology, most authors showed a negative impact on cheese yield, casein loss into whey, slower rate of curd formation with high SCC milk [1,7,15,34,66]. In a recent review, Barbano [6] showed that the variations in milk SCC explain about half of the variation in milk plasmin and casein damage; other causes of variation (stage of lactation, health history and number of lactation) may interact with high SCC to produce a decrease in cheese yield efficiency.…”

“…Cheddar cheese [7] Cheddar cheese [1] Cottage cheese [34] Swiss-type cheese [15] Early lactation milk …”

Heritability and repeatability of milk coagulation properties predicted by mid-infrared spectroscopy during routine data recording, and their relationships with milk yield and quality traits

“…Improvement of these traits can be achieved through selection for correlated traits such as milk protein content and composition (Bonfatti et al, 2011;Jensen et al, 2012), milk acidity (Ló pez et al, 1998; -E-mail: martino.cassandro@unipd.it Ná jera et al, 2003) and somatic cell count (SCC; Politis and Ng-Kwai-Hang, 1988;Klei et al, 1998). Moreover, genetic variants at the protein loci have been demonstrated to exert an effect on MCP (Kü barsepp et al, 2005;Comin et al, 2008).…”

Relationships between ruminant management and sensory characteristics of cheeses: a review

“…The effects of mastitis on clotting and whey drainage as well as on cheese yield have been comprehensively described by a number of authors, in cows' [5,10,25,52,66,88,103], goats' [49] and ewes' milk alike [98,102]. Milks with high SCC coagulate slowly and drip-dry poorly.…”

“…Lastly, concerning the influences of late lactation or mastitis milks (high in SCC) on cheese sensory properties, it has been suggested by Klei et al [66] that growth of lactic acid bacteria may be inhibited by the antibacterial compounds contained in white blood cells.…”