33-4 |
Methods and applications of microcalorimetry in food |
P. LEPARLOUER, Thermal Consulting, 35 chemin de Crépieux BP142, Caluire, 69643, France The calorimetric techniques, and especially DSC, are more and more used for the characterization of food ingredients (fatty compounds, starch, proteins, …) such as glass transition, melting, crystallization, denaturation,… However, even if the DSC technique is a powerful technique, it can not solve all the problems of analysis, mainly due to lack of sensitivity, small amount of sample under investigation and no possibility of mixing two compounds (liquid or powder). The very high sensitive calorimetry opens a new way of determination when the DSC technique is no more adapted. This technique uses very high sensitive detectors (semiconductors) and allows to work on large amounts of sample (volume available : 1 cm3). Very weak thermal effects such as denaturation of proteins in diluted state, gelification of polysaccharides, are detectable. This calorimetric technique is also adapted for mixing simulations. As the mixing operations are very varied in the food industry, many types of determinations can be carried out : dilution, dissolution, wetting, reaction… Running an enzymatic reaction is one of the interesting applications of the very high sensitive calorimetry. The calorimetric technique is used in the scanning temperature mode, but also for isothermal determination. This mode is especially helpful for the determination of the isothermal retrogradation of starch. Examples of the applications of the very high sensitive calorimetry will be given in the field of animal and vegetable proteins, enzymes, hydrocolloids, starch and dairy products
Session 33, Applications of calorimetry in food and biological materials
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