Somatic cell recovery by microfiltration technologies: a novel strategy to study the actual impact of somatic cells on cheese matrix
Résumé
The actual impact of the somatic cells in the dairy technology is still ill-defined, because the increase in
milk somatic cell count, usually correlated with mastitis factors, impairs the raw milk composition,
through mainly unwanted proteolysis and lipolysis. This study used microfiltration technologies for
recovering high quantity of somatic cells and for clarifying their role in cheese quality. Three series of
Swiss-type cheeses were manufactured by adding 0 (control), 4 105 and 9 105 somatic cells mL 1.
These cells were traced for the first time during the cheese making process by using adapted flow
cytometry and real-time quantitative PCR. Proteolysis and lipolysis indices were measured throughout
ripening time. Only a weak increase in lipolysis (þ28%) and proteolysis (þ8%) was observed in the
highest somatic cell count cheese, despite 73% of the cells trapped within the cheeses. Our approach
gives a new view of somatic cell role in cheese milk alteration.