Protective effect of oligosugar alcohols against thermal denaturation of horse mackerel myofibrillar protein and its relation to sweetness

The protective effect of oligosugar alcohols against thermal denaturation of myofibrillar protein from horse mackerel was investigated as a function of the molecular weight and the number of OH group of the sugar alcohols, and its relation to sweetness was discussed. The results obtained were as follows; 1) The protective effect was studied as E or E' = Delta log K-D/C (M or %), where the K-D is the first order rate constant for thermal inactivation of Ca-ATPase with or without varied concentrations (C) of sugar alcohol. The E(M-1) generally increased and E'(%(-1)) decreased with the increase in the molecular weight as well as the number of OH groups of the sugar alcohol. 2) The protective effect given with a branched oligosugar alcohol was similar to that of linear oligosugar alcohol having approximately the same molecular weight. 3) There was a good correlation between the E value and the logarithmic value of the molecular weight or the number of OH group of the sugar alcohols. 4) Dependencies of the E' value or the sweetness level on the logarithmic value of the number of OH group were close to each other. 5) A good correlation between the level of sweetness by sugar alcohols and the E' value of the same sugar alcohols was therefore demonstrated. It was thus found that the dependency of the E' and the sweetness on the logarithmic number of OH group of sugar alcohol was very similar.