Proteolysis texture and microstructure of low-fat Tulum cheese affected by exopolysaccharide-producing cultures during ripening



The objective of the study was to determine the effects of exopolysaccharide (EPS)-producing or non-EPS-producing starters on proteolysis, physical and microstructural characteristics of full-fat or low-fat Tulum cheeses during ripening. For this purpose, Tulum cheese was manufactured using full- or low-fat milk with EPS-producing and non-EPS-producing starter cultures. Chemical composition, proteolysis, texture profiles and microstructure of the cheeses were studied during 90 days of ripening. Urea-PAGE of water-insoluble and RP-HPLC peptide profiles of water-soluble fractions of the cheeses showed that the use of starters resulted in different degradation patterns in all cheeses during ripening. Although β-casein exhibited similar degradation patterns in all cheeses, small differences are present in αs1-casein degradation during ripening. Reducing fat in Tulum cheese changed the RP-HPLC peptide profile of the cheeses. The use of EPS-producing cultures improved the textural characteristics and changed the microstructure and proteolysis of low-fat Tulum cheese.