Control of oxidation-reduction potential during Cheddar cheese ripening and its effect on the production of volatile flavour compounds.
In cheese, a negative oxidation-reduction (redox) potential is required for the stability of aroma, especially that associated with volatile sulphur compounds. To control the redox potential during ripening, redox agents were added to the salted curd of Cheddar cheese before pressing. The control cheese contained only salt, while different oxidising or reducing agents were added with the NaCl to the experimental cheeses. KIO3 (at 0·05, 0·1 and 1%, w/w) was used as the oxidising agent while cysteine (at 2%, w/w) and Na2S2O4 (at 0·05 and 0·1%, w/w) were used as reducing agents. During ripening the redox potential of the cheeses made with the reducing agents did not differ significantly from the control cheese (E h ≈ -120 mV) while the cheeses made with 0·1 and 0·05% KIO3 had a significantly higher and positive redox potential in the first month of ripening. Cheese made with 1% KIO3 had positive values of redox potential throughout ripening but no starter lactic acid bacteria survived in this cheese; however, numbers of starter organisms in all other cheeses were similar. Principal component analysis (PCA) of the volatile compounds clearly separated the cheeses made with the reducing agents from cheeses made with the oxidising agents at 2 month of ripening. Cheeses with reducing agents were characterized by the presence of sulphur compounds whereas cheeses made with KIO3 were characterized mainly by aldehydes. At 6 month of ripening, separation by PCA was less evident. These findings support the hypothesis that redox potential could be controlled during ripening and that this parameter has an influence on the development of cheese flavour.
School of Food and Nutritional Sciences,University College Cork,Cork,Ireland.
Veronica
V
Caldeo
Teagasc Food Research Centre,Moorepark,Fermoy,Cork,Ireland.
John A
JA
Hannon
Department of Life Sciences,University of Limerick,Castletroy,Limerick,Ireland.
Dara-Kate
DK
Hickey
School of Food and Nutritional Sciences,University College Cork,Cork,Ireland.
Dave
D
Waldron
Department of Life Sciences,University of Limerick,Castletroy,Limerick,Ireland.
Martin G
MG
Wilkinson
Teagasc Food Research Centre,Moorepark,Fermoy,Cork,Ireland.
Thomas P
TP
Beresford
School of Food and Nutritional Sciences,University College Cork,Cork,Ireland.
Paul L H
PL
McSweeney
D000818:Animals; D002611:Cheese / Q000032:analysis / Q000382:microbiology; D005511:Food Handling / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D016877:Oxidants; D010084:Oxidation-Reduction; D019163:Reducing Agents; D012965:Sodium Chloride; D013649:Taste; D055549:Volatile Organic Compounds / Q000032:analysis* / Q000737:chemistry
D016877:Oxidants; D019163:Reducing Agents; D055549:Volatile Organic Compounds; D012965:Sodium Chloride
Cheddar cheese; Oxidation-reduction potential; redox agents; volatile flavour compounds