Prediction of water activity, a(w), in cook-soak equilibrated intermediate moisture meats

The relationship between the moisture content and water activity, a(w), of several meat samples adjusted to intermediate moisture water activities by cook-soak equilibration in glycerol solutions containing 9·5% sodium chloride was determined. Within experimental error the relationship was found to be unique for all the lean meats studied. It was also found that a modification of the Grover method (Grover, 1947) in which a(w) is determined from the well established relationship between a(w) and sucrose equivalent, E(s), was an excellent predictor of the final a(w) of the ssystem. E(s) was calculated from E(s) = E(1)X(1) + E(1)X(2) + … etc. where E(1) are specific constants for each humectant and X(1) and X(2) are given as weight of humectant in the system/weight of water in the system. E values of 9·0 and 2·2 for sodium chloride and glycerol were applicable for initial salt concentrations of 0 to 20 (w/w)_and glycerol concentrations of 0 to 90% (w/w) The method was equally applicable to propylene glycol (E value 3·2)/salt systems and sorbitol (E value 1·0)/salt systems.