Physical Chemistry of Foods
How does one make an oil-in-water emulsion that is stable during storage but that can be whipped into a topping? The first quest ...
particulars of the system determine the boundary conditions for application of a theory and thereby the final result. All of thi ...
microbiology—to solve problems and to predict changes that will occur during manufacture, storage, and use of foods. 1.2 ABOUT T ...
Next we come tophase transitions. Chapter 14 mentions the various phase transitions that may occur, such as crystallization, gas ...
text; no full account of literature sources, but a discussion of selected references at the end of each chapter. Worked out exam ...
Finally, we have equations that describe an experimentally established correlation; such relations are generally not meant to pr ...
chapter. It can also be read in advance to see what topics are being discussed. BIBLIOGRAPHY Several textbooks of physical chemi ...
2 Aspects of Thermodynamics Chemical thermodynamics can provide the food scientist with important quantitative knowledge. It tre ...
2.1 CONCEPTS Physical chemists call the part of the universe that they want to consider the systemand the remainder the surround ...
EntropyðSÞis a measure of disorder; it is given by S¼kBlnO ð 2 : 1 Þ where kB is the Boltzmann constant ð 1 : 38? 10 ^23 J?K^1 ...
FIGURE2.1 EnergyðUÞand entropy. Depicted for a given number of molecules or particles in a given two-dimensional space. ...
system will change until it has obtained the lowestGibbs energy: G:HTS ð 2 : 4 Þ Unless mentioned otherwise, we will always mea ...
which equals 6020 J?mol^1. Consequently, the change in entropy of water molecules going from the solid to the liquid state equa ...
2.2.1 The Chemical Potential In a homogeneous mixture each component i has a chemical potentialmi, defined as the partial molar ...
by m 2 ¼m^72 þRTlnx 2 ð 2 :6aÞ Note in Figure 2.2a that at high concentration of ethanol the activity of the solvent (water) is ...
pressure are constant, it is convenient to use the activity. The activity rather than the concentration enters in relations on t ...
It may further be noted that the volume of a mixture of two components is generally not equal to the sum of the volumes of each. ...
tion, these reactions are generally chosen such that the reacting solute will be completely consumed, and a concentration result ...
FIGURE2.3 ActivitiesðaÞof sucrose and water in binary mixtures as a function of the mole fractionðxÞ. The broken lines give the ...
dissociate into two species—commonly ions—have an effective molarity that is about twice the nominal one, etc.; this effective c ...
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