C. Druaux et al., EFFECTS OF PHYSICOCHEMICAL PARAMETERS OF A MODEL WINE ON THE BINDING OF GAMMA-DECALACTONE ON BOVINE SERUM-ALBUMIN, Food chemistry, 53(2), 1995, pp. 203-207
To understand the effect of temperature, pH and the composition of alc
oholic beverages in flavour-protein interactions, the binding of gamma
-decalactone to bovine serum albumin (BSA) was investigated using the
equilibrium dialysis method. Thermodynamic analysis revealed that the
affinity of aroma compound for BSA is higher at 10 degrees C than at 2
0 and 30 degrees C, while the number of binding sites (n = 6-7) is not
modified at the three temperatures. pH did not have any appreciable e
ffect on flavour binding in the presence of ethanol, but it was observ
ed that a decrease of 1.8 pH unit reduces binding by 40% in its absenc
e. The presence of ethanol has no effect on the number of binding site
s and on the standard free energy (Delta G degrees) of the interaction
s. On the other hand, the binding constant (k) was 4.8-fold higher in
water than in model wine (pH 3.5, ionized compounds, 10% w/w ethanol);
so, the affinity of volatile compound was clearly lower in the model
wine than in water.