Fac-simile Scheda Linee di Ricerca - Federalimentare

4. Derossi A., De Pilli T., Severini C., McCarthy M.J. 2008. Mass transfer during osmotic dehydrationof apples. J. Food Eng. 86 (4): 519-528.Osmotic dehydration processes are widely applied to obtain high quality intermediate moisture food. The studyof dehydration kinetics and mass transfer mechanisms is very important for understanding and controlling theosmotic dehydration process. The internal changes and kinetics of both moisture change and mobility duringosmotic dehydration of apples is reported. The effective diffusion coefficient of water was not constant duringthe dehydration treatment. Initially the effective diffusion coefficient calculated using a Fickian-based modelwas 2x10 -10 m 2 /s and increased to 5x10 -10 m2/s during treatment. Moreover, results showed the existence of anosmotic dehydration front that moves from the surface to the core of apple samples. It was not possible to explainthe osmotic treatment process using only diffusion-based mechanisms. All layers of cells appear to be involvedin the moisture transport process at the same time.5. Derossi A., Giuliani R., Severini C. 2007. Study on relationships between food kinetic stateand some reactions of food degradation. Italian Food and Beverage Technology 47(10): 21-24.It is well known that food matrixes may exist as high viscous glass, rubbery or liquid states. Glassy state is definedas an amorphous very high viscosity and kinetically stable system; instead rubbery state is defined as anamorphous low viscosity and kinetically unstable system. Concerning food, moisture content is the most importantcomponent that can act as plasticizer, modifying the glassy transition temperature (T g ). Traditionally a foodin glassy state (T < T g ) will be considered stable because the translational mobility of water is considered to benon-existent. Instead a food stored at T > T g will be in an unstable state and all reaction degradation will occur inshort time. Some scientists studied the effect of moisture content on kinetic state of food and on degradation rate,but literature concerning the effect of glassy or rubbery state on the rate of degradation reactions is not exhaustive.We put a question: which would be the rate of reaction of some degradation if a food is at T > T g + Ti°C?This work will attempt to answer, dealing with the eventual connections between food kinetic state and rate ofsome degradation reactions.SISTAL - SOCIETA’ ITALIANA DI SCIENZE E TECNOLOGIE ALIMENTARIDipartimento di Scienze e Tecnologie Agroalimentari, Università degli Studi della TusciaVia San Camillo de Lellis, 01100 ViterboTel.: 0761- 35 74 94/7 , Fax: 0761- 35 74 98, e-mail: mmoresi@unitus.it155