Microcalorimetric Determination of the Global Heat Generated Between Dry Yeast Used for Elaboration of Bread and Sucrose, Glucose, and Fructose Solutions

摘要

By means of a batch type heat conduction calorimeter, heat generated is determined when a commercial dry yeast, used for the elaboration of bread, is placed in contact with low concentration sucrose, glucose, and fructose solutions. The weight of the dry yeast varies between 50 and 200 mg for each of the solutions of sugar.The determinations are carried out for sucrose solutions that range form 0.042 to 0.155 g sugar mL~(-1) water; for the glucose and fructose, the lowest concentrations of 0.042 and 0.043 g sugar mL(-1) water were tried, respectively.The obtained results show that, as the weight of yeast and the concentration of the solution of sugar is increased, heat increases. The values obtained for the generated global heat of the process are between 3.44 and 126.75 KJ mol~(-1).