Cherry tomato samples were osmotically dehydrated in different hypertonic NaCl solutions (with or without sucrose) at two different concentrations. Mass transfer kinetics were modelled according to Peleg, Fick and Page equations. The Peleg equation presented the best fitting for water loss and Page model showed the best predictive capacity for salt gain data. The effective diffusivity determined using FickÕs second law applied to a spherical geometry was found to be in the range of 0.43 Â 10 À9-1.77 Â 10 À9 m 2 /s for water loss and 0.04 Â 10 À9-0.54 Â 10 À9 m 2 /s for salt gain. Increased solution concentration resulted in higher water loss and salt gain. An addition of sucrose to osmotic solutions decreased the driving force of the process.

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*A quem a correspondência deve ser enviada ResumoForam determinados o rendimento do filé e a composição físico-química da tilápia quanto ao teor de umidade, proteína, cinza, lipídeos e atividade de água. Para as análises, foram utilizados 19 exemplares de tilápia com peso médio e comprimento de 989,6 g e 38,9 cm, respectivamente. Os peixes foram pesados, medidos (comprimento, largura e espessura) e após a filetagem calculou-se o rendimento. Foi realizada a determinação da composição físico-química, que apresentou teores de: 77,13% de umidade; 2,60% lipídios; 19,30% proteína; 1,09% cinza; e atividade de água de 0,983. As relações de peso filé/peixe e peixe/resíduo apresentaram boas correlações lineares. Foi realizada também a análise microbiológica do peixe in natura; a matéria-prima estava dentro dos limites exigidos pela legislação brasileira, portanto apta para o processamento e/ou consumo. Palavras-chave: composição centesimal; filetagem; subprodutos da filetagem; pescado. AbstractThe fillet yield of Thai-style tilapia and its physicochemical composition, including moisture content, protein, ash lipids and water activity, were determined. The analysis involved 19 specimens of tilapia with average weight and length of 989.6 g and 38.9 cm, respectively. The fish were weighed, measured (length, width and thickness), filleted, and the yield was calculated. The chemical composition presented the following contents: 77.13% moisture, 2.60% lipids, 19.30% protein, 1.09% ash, and 0.983 water activity. The fillet/fish to fish/residue weight ratios presented good linear correlations. The raw fish was also subjected to a microbiological analysis, which indicated that it met the safety limits established by Brazilian legislation and was therefore safe for processing and consumption. Keywords: approximate composition; filleting; filleting by-products; fish.Composição físico-química, microbiológica e rendimento do filé de tilápia tailandesa (Oreochromis niloticus) IntroduçãoA tilápia apresenta requisitos típicos dos peixes preferidos do consumidor, tais como carne branca de textura firme, sabor delicado e fácil filetagem, não tendo espinha em "Y" e nem odor desagradável 22 . Possui também características que a colocam no pódio das principais espécies cultiva das comercialmente, como: facilidade de reprodução e obtenção de alevinos, a possibilidade de manipulação hormonal do sexo para produção de machos, aceitação de diversos alimentos, excelente crescimento em cultivo intensivo e resistência às doenças. Assim, as linhagens de tilápia do Nilo, existentes no Brasil, possuem duas origens, a tilápia de Bouaké, originária da Costa do Marfim, região oeste da África e a tilápia tailandesa ou chitralada, originária da Tailândia, que, por sua vez, tinha importado do Japão, e cujo estoque teve origem no Egito, região leste da África 14 .No Brasil, a expansão da tilápia tem sido impulsionada pela demanda de mercado por sua boa aceitação pela população, quanto ao sabor, valor nutritivo e preços baixos. O grande interesse pela tilápia ...

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The aim of this work was to study and to model the drying kinetics of fresh and osmotically pre-treated papaya cubes (Carica papaya L.) using the diffusional model (FickÕs second law) adapted to a cubic geometry, and an empirical two parameters model. The osmotic pre-treatment was carried out in an incubator at constant temperature and agitation. The drying process was carried out in a fixed bed dryer at two different temperatures and air velocities. At the beginning of the drying process of fresh papaya, drying rate was influenced by both air velocity and air temperature. But lose to the equilibrium condition, the drying rate was affected only by the air temperature. The physico-chemical changes in the papaya cubes during osmotic pre-treatment caused differences in the drying rate in the subsequent air drying process when compared to fresh papaya cubes. The effective diffusivities of water, calculated by diffusional model, were of the order of 10 À9 m 2 /s.

Osmotic dehydration of cashew apple in sucrose and corn syrup solids solutions as influenced by temperature (30-50 C), sugar syrup concentration (40-60% w/w) and immersion time (90-240 min) was studied through response surface methodology. Responses of water loss (%) and solid gain (%) were fitted to polynomials, with multiple correlation coefficients ranging from 0.92 to 0.99. The fitted functions were optimised for maximum water loss and minimised incorporation of solids in order to obtain a product resembling non-processed fruit. Three optimum sets were selected for each solute and the ascorbic acid content was determined. The ascorbic acid losses were similar to those reported for osmotic dehydration processes.

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The effect of different osmotic pretreatments on cashew apple drying kinetics and product quality were investigated. The osmotic pretreatment was carried out in an incubator at constant temperature and agitation. The drying process was conducted in a fixed bed dryer at different temperatures and constant air velocity. Experimental data were fitted successfully using the Page and the two-term exponential models for dried fresh and pretreated fruit, respectively. It was found that drying rates of osmosed fruits decreased owing to the presence of infused solutes. Evaluation of the final product was performed by means of ascorbic acid content, water activity and sensorial test. The osmotic pretreated samples showed the highest vitamin C losses and the lowest water activity. The samples pretreated in sucrose solution had the highest acceptance.