Effects of High Pressure Treatment on Volatile Profile During Ripening of Ewe Milk Cheese

Abstract

The effect of high-pressure treatment on the volatile profile of ewe milk cheeses was investigated. Cheeses were submitted to 200, 300, 400 and 500 MPa at 2 stages of ripening (after 1 and 15 d of manufacturing) and volatile compounds were assayed at 15 and 60 d of ripening. High-pressure treatment altered the balance of volatile profile of cheeses, limiting the formation of acids, alcohols, ketones, aldehydes, and sulfur compounds and enhancing the formation of 2,3-butanedione. In general, cheeses pressurized at 15 d of ripening were more similar to untreated cheeses than those treated at 1 d. Cheeses treated at 300 MPa after 1 d of manufacturing were characterized by higher levels of free amino acids, ethanol, ethyl esters, and branchedchain aldehydes, whereas cheeses treated at 500 MPa after 1 d of manufacturing had lower microbial populations, showed the highest abundance of 2,3-butanedione, pyruvaldehyde, and methyl ketones, and the lowest abundance of alcohols.

Changes in the volatile profile of a raw goat milk cheese treated by hydrostatic high pressure at different stages of maturation

“…It is probable that the increase in methyl ketones in cheese treated at day 1 could be caused because some ketones did not undergo reduction of alcohols, since lower levels of alcohols were found in HP-treated cheeses than control ones. Consistent with these findings, Juan et al (2007) reported that HP treatment at !400 MPa applied on the first day of ripening of pasteurized ewes' milk cheese could affect the enzyme activity responsible for degrading methyl ketones to alcohols, thus increasing levels of methyl ketones and decreasing alcohols. On the other hand, HP could also facilitate the production of methyl ketones from FFA, although additional studies are needed for clarifying this hypothesis.…”

“…Some researchers have studied the changes in the volatile composition of HP-treated raw ewes' milk cheese; e.g., Arqués, Garde, Fernández-García, Gaya, and Núñez (2007) reported the variation of volatile compounds of La Serena cheese HP-treated at two different stages of ripening (days 2 and 50), while Juan, Barron, Ferragut, and Trujillo (2007) investigated the effects of HP (treatment at 200, 300, 400 or 500 MPa) on volatile profile of pasteurized ewes' milk cheeses applied at two stages of ripening (after 1 and 15 days of manufacturing). As far as we are aware, only one paper has studied the fraction volatile of a goat milk cheese treated by HP at 400 MPa for 5 min at two stages of ripening, i.e., 21 and 60 days (Saldo et al, 2003).…”

High Hydrostatic Pressure Processing of Cheese

“…Chymosin is much less barotolerant in cheese than plasmin, being stable to HHP treatments from 50 to 400 MPa when held between 10 and 100 min at temperatures from 2 to 30 °C (Messens and others 1999; Trujillo and others 2000b; O’Reilly and others 2002a; Huppertz and others 2004; Rynne and others 2008), although Saldo and others (2002a) reported that residual coagulant activity was reduced to about half the value of control cheese after HHP treatments of 400 MPa for 5 min at 14 °C applied to Garrotxa cheese on the 1st day of ripening. Juan and others (2007a) observed a similar result in treatments of 400 MPa applied for 10 min at 12 °C postmanufacture on semi‐hard ewes’ milk cheese. Chymosin activity reduced by 62% compared to control cheese at day 15 of ripening.…”

“…Most of these enzymes require autolysis of starter bacteria to be released into the cheese matrix, since they are intracellular enzymes. Results from different studies have shown that pressure‐induced lysis is strain dependent and that HHP treatments can increase the autolysis of starter culture cells and affect aminopeptidase activity in cheese (Malone and others 2002; Juan and others 2007a). Juan and others (2008) reported autolysis of starter bacteria ( L. lactis ssp.…”

Effect of high-pressure treatment on the volatile profile of a mature raw goat milk cheese with paprika on rind

“…Some researchers have studied the changes in the volatile composition of ewe milk cheese HP-treated: e.g., Arqués et al (2007) reported the variation of volatile compounds of La Serena cheese HP treated at two different stages of ripening (days 2 and 50); and Juan, Barron, Ferragut, and Trujillo (2007) investigated the effects of HP on volatile profile during ripening of ewe milk cheese: cheeses were submitted to 200, 300, 400 and 500 MPa at 2 stages of ripening (after 1 and 15 days of maturation) and volatile compounds were assayed at 15 and 60 days of ripening. As far as we know only one paper has studied the fraction volatile of a goat cheese treated by HP at 400 MPa for 5 min at two stages of ripening, 21 and 60 days (Saldo et al, 2003).…”