title: Proteolysis, lipolysis, volatile compounds and sensory characteristics of Hispánico cheeses made using frozen curd from raw and pasteurized ewe milk.
abstract: Hispánico cheese, manufactured from a mixture of cow and ewe milk, is representative of cheese varieties made using milk from more than one animal species in Mediterranean countries. The shortage of ewe milk production in autumn hinders the uniformity of Hispánico cheese composition throughout the year. To surmount this inconvenience of ewe milk seasonality, curds made in spring from raw and pasteurized ewe milk were stored frozen and used four months later for the manufacture of Hispánico cheese. Experimental cheeses were made by mixing fresh curd from pasteurized cow milk with thawed curd from raw or pasteurized ewe milk, and control cheese from a mixture of pasteurized cow and ewe milk in the same proportion. Characteristics of experimental and control cheeses throughout a 60-d ripening period were investigated. On the one hand, the experimental cheese containing frozen curd from raw ewe milk showed the highest counts of staphylococci, Gram-negative bacteria and coliforms, the highest levels of aminopeptidase and esterase activity, and the highest concentrations of free amino acids, free fatty acids, alcohols and esters. On the other, the experimental cheese containing frozen curd from pasteurized ewe milk had concentrations of free amino acids, free fatty acids and volatile compounds similar to those of control cheese, with the only exception being a higher level of ketones. Flavour intensity reached the highest scores in the experimental cheese containing frozen curd from raw ewe milk, followed by the experimental cheese containing frozen curd from pasteurized ewe milk. Flavour quality scores of both experimental cheeses were similar, and lower than those of control cheese.
authors.affiliation: Departamento de Tecnología de Alimentos, INIA, Madrid, 28040 Spain.
authors.forename: Rocío
authors.initials: R
authors.lastname: Alonso
authors.forename: Antonia
authors.initials: A
authors.lastname: Picon
authors.forename: Pilar
authors.initials: P
authors.lastname: Gaya
authors.forename: Manuel
authors.initials: M
authors.lastname: Nuñez
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002611:Cheese / Q000032:analysis* / Q000382:microbiology; D005230:Fatty Acids, Nonesterified / Q000032:analysis; D005260:Female; D005511:Food Handling / Q000379:methods; D005519:Food Preservation / Q000379:methods*; D005615:Freezing; D007659:Ketones / Q000032:analysis; D008066:Lipolysis; D008892:Milk / Q000201:enzymology; D061352:Pasteurization; D010447:Peptide Hydrolases / Q000032:analysis; D059748:Proteolysis; D012677:Sensation; D012756:Sheep; D013649:Taste; D055549:Volatile Organic Compounds / Q000032:analysis*
chemical_list: D000596:Amino Acids; D005230:Fatty Acids, Nonesterified; D007659:Ketones; D055549:Volatile Organic Compounds; D010447:Peptide Hydrolases