Inulin is a polysaccharide frequently used as a sugar or fat replacer in the food industry, which offers the advantage of a functional effect similar to those of dietary fibers. By cooling or freezing an inulin concentrated solution, a more concentrated solution precipitates as a paste-like substance, while the liquid phase forms a diluted solution. In this work, the effect of storage temperature of inulin concentrated solution as well as temperature on the rheological behavior of liquid and precipitated phases obtained from a process of phase separation were evaluated. The precipitated phase of inulin was evaluated under two conditions: pure and formulated with encapsulating agents. It was observed that a reduction in storage temperature resulted in a higher inulin precipitation, which produced higher apparent viscosity values for the precipitated phase. All the samples analyzed had a shear-thinning rheological behavior.

Osmotic dehydration is a process that enables partial removal of water by direct contact of a product with a hypertonic medium. This prompts two major simultaneously countercurrent flows: water flow from the product to the surrounding solution and solutes flow into the product. Leakage of the product solutes (sugars, organic acids, mineral, etc.) is quantitatively negligible, but may be important for the organoleptic and nutritional values of the product. Osmotic pretreatment improves nutritional, sensorial and functional properties of the dehydrated food without changing its integrity. It also improves the texture as well as stability of the pigment during dehydration and the storage of dehydrated product. The aim of this work was to evaluate the osmotic dehydration of sweet potato (Ipomoea batatas) using salt and sucrose solutions. The osmotic process was carried out at different sucrose concentrations (40-60%w/w), salt concentrations (0-10%w/w) and solution temperatures (30-50°C). A non-exponential two parameters model was used to describe the water loss and gain of solids kinetics. The mathematical models were fitted to the experimental data. Values of effective diffusivity calculated from these models varied from 4.07 to 11.19 x 10 m/s for water loss and from 0.91 to 13.06 x 10 m/s for solids gain.

The tomato is a very perishable fruit, necessitating the removal of water for its preservation. The drying of solids is a common form of preservation, allowing the foodstuff to be kept for a longer period than would otherwise have been possible (Hawlader et al., 1991). In addition, dried food can be stored and transported at a relatively low cost. However, water removal leads to a serious decrease in food nutritive and organoleptic values, such as lignified texture, slow or incomplete rehydration, and loss of juiciness characteristics of fresh fruit and vegetables. Moreover, color and smell are affected in a negative way. It is generally known that dried food of the best quality is obtained by means of freeze-drying, but this is one of the most expensive methods. For these reasons, efforts are being made to perfect the convection drying process. The preliminary treatment of the raw material is of crucial importance. The utilization of an osmotic prestep can have important advantages in terms of product quality and cost (Lenart, 1996).

O Agaricus blazei e um cogumelo comestivel e conhecido no Brasil como Cogumelo do Sol, Cogumelo de Deus ou Cogumelo Piedade. Popularmente, esta especie e utilizada para cobater o estresse fisico e psicologico, a osteoporose e a ulcera gastrica e para estimular a imunidade. Os cogumelos possuem umidade ao redor de 90% e sao altamente pereciveis, de modo que ha uma necessidade de processa-los, para aumentar sua vida de prateleira. Assim, o presente trabalho teve como objetivo estudar a cinetica de secagem de cogumelo Agaricus blazei com e sem pre-tratamento osmotico. A desidratacao osmotica foi realizada em solucao de 10% de NaCl p/p, com as seguintes condicoes de processo: agitacao de 80rpm, temperatura de 20oC e tempo de processo de 60 minutos. Os experimentos de secagem convectiva foram conduzidos em um secador de leito fixo de bandejas, com temperatura do ar variando de 40 a 80oC e velocidade do ar de 1,0 a 2,5 m/s. Os dados experimentais foram ajustados nos modelos de Fick, exponencial e de Page, na qual o coeficiente de determinacao do desvio relativo medio entre os valores experimentais e os valores preditos foram calculados para cada experimento, para se avaliar o modelo que apresentou melhor ajuste. assim, observou-se que o modelo de Page foi o que apresentou melhor ajuste dentre as equacoes analisadas, podendo ser utilizado para predicao da cinetica de secagem do cogumelo. Os valores de difusividade efetiva, calculados atraves do modelo de Fick, ficaram na faixa de 4,13E-10 a 13,48E-10 M²/s para o cogumelo in natura e de 5,38E-10 a 14,80E-10 m² para o cogumelo desidratado osmoticamente. Os dados experimentais apresentaram tambem um bom ajuste ao modelo exponencial, na qual a constante de secagem da equacao variou de 2,17E-04 a 6,6E-04 s-¹ para o cogumelo sem pre-tratamento e de 2,78E-04 a 7,25E-04 s-¹, para o cogumelo desidratado osmoticamente.