Evolution of the volatile components of raw ewes' milk Castellano cheese Seasonal variation
Fifteen batches of Castellano cheese were made in different seasons of the year from raw ewes' milk without the addition of starter cultures. The volatile fraction of the cheeses, its evolution during ripening and the seasonal differences were studied by using purge and trap extraction and GC-MS analysis. Concentrations of aldehydes such as 2-propenal, hexanal and 2-methyl-1-butanal, 1- and 2-alkanols, 2-alkenols, and most classes of esters increased significantly with ripening time, while that of 2,3-butanedione decreased from 60 to 180d. Branched chain aldehydes were more abundant in cheeses made in summer. 2-Propenal and 2-methyl ketones were more abundant in 180-d-old cheeses made in autumn. Alcohols were quantitatively the main chemical class found in the volatile fraction of Castellano cheese. Primary alcohol concentrations were significantly higher and 2-butanol significantly lower in autumn cheeses. α-Pinene, toluene and 3-methyl-1-heptene concentrations were higher in summer cheeses. Discriminant analysis classified all the cheeses at 60 and 180d of ripening correctly for the season of manufacture. Principal component analysis showed a positive correlation between 2-methyl-ketones, 2-pentanol and 2-propanol with the Micrococcaceae counts at 60d, and the gram-negative bacteria and coliform counts in 1-d-old-cheese. Ethyl esters and ethanol correlated positively with lactic acid bacteria counts and odour quality. © 2003 Elsevier Ltd. All rights reserved.
| Main Authors: | , , , |
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| Format: | journal article biblioteca |
| Language: | English |
| Published: |
Elsevier
2004
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| Subjects: | Volatile compound, Rawewes’ milk, Castellano cheese, Ripening, Seasonal variation, |
| Online Access: | http://hdl.handle.net/20.500.12792/1403 http://hdl.handle.net/10261/293448 |
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