title: Pyroglutamic acid in cheese: presence, origin, and correlation with ripening time of Grana Padano cheese.
abstract: Pyroglutamic acid is present in many cheese varieties and particularly in high amounts (0.5 g/100 g of cheese) in extensively ripened Italian cheeses (Grana Padano and Parmigiano Reggiano) that are produced with thermophilic lactic acid bacteria as starters. The mechanism of pyroglutamic acid formation in cheese seems to be mostly enzymatic, as demonstrated by the presence of only L-pyroglutamic acid enantiomer. Thermophilic lactobacilli are involved in pyroglutamic acid production, as suggested by the low pyroglutamic acid content found in Bagos, a ripened Italian mountain cheese produced without addition of starter. Because milk pasteurization did not influence the pyroglutamic acid content in the ripened Grana Padano cheese, the formation of pyroglutamic acid mainly depends on the whey starter microflora rather than that of raw milk. Pyroglutamic acid concentration is linearly correlated (R2 = 0.94) with the age of Grana Padano cheese.
authors.affiliation: Istituto Sperimentale Lattiero Caseario, Lodi, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Mucchetti
authors.forename: F
authors.initials: F
authors.lastname: Locci
authors.forename: M
authors.initials: M
authors.lastname: Gatti
authors.forename: E
authors.initials: E
authors.lastname: Neviani
authors.forename: F
authors.initials: F
authors.lastname: Addeo
authors.forename: A
authors.initials: A
authors.lastname: Dossena
authors.forename: R
authors.initials: R
authors.lastname: Marchelli
mesh_terms: D000818:Animals; D002611:Cheese / Q000032:analysis* / Q000382:microbiology; D005511:Food Handling; D006358:Hot Temperature; D007778:Lactobacillus / Q000378:metabolism; D008892:Milk; D011761:Pyrrolidonecarboxylic Acid / Q000032:analysis*; D013291:Streptococcus / Q000378:metabolism; D013997:Time Factors
chemical_list: D011761:Pyrrolidonecarboxylic Acid