The present study aimed to assess the drying kinetics of black rice and fit different mathematical models (empirical and diffusive) to the experimental data, and evaluate the effect of drying air temperature on the physical-chemical and bioactive compounds quality of black rice. Drying air temperatures ranged from 40 to 80 ºC and the drying air speed was 1.5 m/s. Physical-chemical characterization of the product was based on the following parameters: moisture, water activity, ashes, total protein content, pH, total acidity, lipids, total carbohydrates, total anthocyanins, flavonoids, total phenolic compounds and antioxidant activity. Among the empirical models, Page showed the lowest mean squared deviations (MSD) and highest coefficients of determination (R2). For the diffusion model, the values of effective mass diffusivity and convective heat transfer coefficient increased with increasing drying air temperature, and the Biot number indicated that the first-type boundary condition would also describe well the drying process. Physical-chemical parameters and bioactive compounds differed between the temperatures used, and the temperature of 60 ºC led to the best relationship between drying time and preservation of product characteristics.

This study aimed to develop red rice flours in order to provide alternatives to replace conventional flours in the production of gluten-free foods for people who suffers from celiac disease. To obtain the flour, red rice grains were dried at temperatures of 40, 50, 60, 70, and 80 C and air velocity of 1.5 m/s. Mathematical models (empirical and diffusive) were fitted to the experimental data obtained and, subsequently, the dehydrated grains were ground to obtain the flour, which was subjected to physicochemical and bioactive characterization to verify the impact of the applied temperatures on the final product quality. It was found that the Page model is more reliable to describe the drying kinetics of red rice, since it showed higher coefficients of determination (R 2) and lower chi-square (χ 2). The diffusion model showed satisfactory fit, with coefficient of determination (R 2) higher than 0.99 and chi-square (χ 2) lower than 0.0146659. Higher drying rate was found at the temperature of 80 C, but cracks were observed in the grains and there was greater degradation of anthocyanins. The pH, total titratable acidity, and flavonoids did not differ between the temperatures applied. Lower values of moisture content, water activity, total phenolic compounds, and antioxidant activity were obtained in the grains subjected to temperature of 80 C. Therefore, the temperature of 40 C was the one that ensured greatest conservation of all bioactive compounds analyzed and greater antioxidant activity for all three methods. Practical applications: The diffusion model provides a realistic and physical interpretation of the drying operation, stimulating the correct time needed to reduce the moisture content of the material, of initial value at the equilibrium value. In this way, it is possible to save energy and reduce the degradation of bioactive compounds promoted by thermal damage, which material is submitted, in addition to aiming at the optimization of drying equipment projects. 1 | INTRODUCTION Rice (Oryza sativa L.) has several types of cultivars and is a widely consumed food in the world, with different colors, such as white, black, red, and brown. Red rice is thus called because of the reddish color of the pericarp of the grains, which in turn is due to the accumulation of tannins and anthocyanins (Agostineto, Fleck, Rizzardi,

The aim of this study was to evaluate the influence of the use of different types of sugar and sweetener (sucralose) on pineapple jelly with cinnamon on its physicochemical quality of the product. For the preparation of the jelly, we used pineapple pulp, cinnamon tea, pectin, citric acid and the addition of different types of sugar: crystal, brown sugar, raw sugar and sweetener. The jellies (F1, F2, F3 e F4) were evaluated for the following physico-chemical parameters: water activity, moisture content, soluble solids content (SST), titratable total acidity (ATT), ratio (SST / ATT), ashes, pH, reducing sugars, non-reducing sugars and total sugars, lipids and vitamin C. We concluded that the use of pineapple and cinnan for the preparation of different flavors of jelly is an excellent alternative because these are well accepted fruits and they have high nutritional value. The use of different kinds of sugar and sweetener (sucralose) in the preparation of pineapple and cinnamon jelly is a good option for consumers who want to ingest quality products with lower sucrose content. The elaborated jellies presented values of moisture, soluble solids content and hydrogen ionic potential according to the quality identity standard for jelly, required by current legislation. All the samples were adequate to physico-chemical parameters and the F1 jelly had the highest level of ascorbic acid.

The jellies constitute an important alternative for the processing of fruits, adding greater economic and nutritional value. The objective of this study was to evaluate the effects of different concentrations of pulp, sugar and maltodextrin on the physical-chemical and textural characteristics of kiwifruit jelly with lemon grass tea. Factorial design 23 was used with 3 replicates at the central point, resulting in 11 experiments with variation of sugar percentages (30, 40 and 50%), pulp (50, 60 and 70%) and maltodextrin (5, 10 and 15%). Water content, moisture content, total soluble solids (TSS), total titratable acidity (TTA), ashes, pH, reducing sugars, non-sugars were evaluated for the following physico-chemical parameters: reducers, total sugars, lipids and vitamin C. Regarding the texture profile, the following parameters were evaluated: hardness, cohesiveness, chewing, gummy and adhesiveness. It was found that among the analyzed variables, the ones that were considered as significant and/or predictive according to ANOVA and the F test were: (moisture, total solids, carbohydrates and vitamin C), through the graphs of the surfaces of responses observed that the percentage of pulp and maltodextrin used was proportional to the increase in moisture content, vitamin C, total solids and carbohydrates. The G2 experiment presented the lowest values of moisture and water activity, and higher carbohydrate contents, total solids and cohesiveness, in which it was formulated with the sugar concentration (-1) and pulp and maltodextrin (+1). The development of kiwi jelly with lemon grass tea is an excellent alternative for the use of the raw material, since it is a product with high nutritional value, stability during storage and potential for consumer acceptance.

The objective of this study was to perform the kinetics of peach drying and to adjust the experimental data obtained to empirical and diffusive mathematical models to evaluate the effect of temperature on the physical-chemical quality of the final product. The drying experiments were performed in an air circulation dryer with a velocity of 1.5 m s-1, the drying kinetics were performed at temperatures of 60, 70 and 80 °C. Among the mathematical models applied, the Page model was the one that best fit the experimental data, because it presents greater efficiency in the description of the drying process. The decrease in the drying rate from the initial time to the end of the process was observed, increasing the temperature of the air caused a reduction in the drying time. It was verified through the analytical solution of the diffusion equation with infinite wall geometry that the increase of the drying temperature caused the increase of the diffusivity and convective coefficient of heat transfer. Through the Biot number, it can be stated that the first-type boundary condition would also describe the process satisfactorily. The fresh peach slices present high water content and water activity and the drying effect caused significant differences in all physical-chemical parameters analyzed.

O Brasil é um país no qual possui uma grande diversidade de frutas, com um destaque no cultivo de uva, principalmente na região nordeste, porém devido a elevada exportação da fruta, boa parte considerada imprópria é descartada. Com isso o presente estudo objetivou elaborar uva passa da cv. Arra 15’® a partir da secagem em estufa e air fryer com a aplicação de um pré-tratamento químico, e caracterizar quanto as propriedades físico-químicas. As uvas in natura foram pré-tratadas com NaOH 1% a 95 ºC durante 30 segundos, secas em estufa e air fryer. A fruta foi caracterizada quanto à umidade, sólidos solúveis totais, pH, acidez total e cor. Os processos de secagem utilizados reduziram a umidade, obtendo assim a uva passa. O modelo de logaritmo se ajustou melhor aos dados experimentais. Com o aumento da temperatura houve o aumento da difusividade, e a partir da solução analítica da equação de difusão apresentou valores baixos de número de Biot, indicando que a condição de contorno utilizada (terceiro tipo) não descreveu de forma satisfatória o processo. Com isso conclui-se que estes resultados são importantes pois demostram que o processamento foi eficiente e possibilitou a obtenção da uva passa com boas características nutricionais.

Os Blends constituem-se como uma importante alternativa para o processamento de frutas, agregando maior valor econômico e nutricional ao produto. Objetivou-se através do presente estudo o desenvolvimento de um blend liofilizado à partir das polpas de kiwi e maracujá, avaliar as suas características físico-químicas. O blend das duas frutas (in natura e liofilizado) foram carcaterizados quanto aos seguintes parâmetros físico-químicos: teor de umidade, atividade de água, sólidos solúveis totais (SST), acidez total titulável (ATT), ratio (SST/ATT), pH, e vitamina C. O blend liofilizado foi determinado as seguintes propriedades físicas: solubilidade, densidade aparente e compactada, índice de Carr e Fator de Hausner. Através do processo de liofilização as amostras apresentaram menor teor de umidade e de atividade de água, indicando maior estabilidade do produto durante o armazenamento. Foi observado também o aumento dos seguintes parâmetros: acidez total titulável, sólidos solúveis totais e ratio. Com relação as propriedades físicas do blend liofilizado, o mesmo apresentou-se com média solubilidade, boa fluidez e de baixa coesividade. Portanto, o desenvolvimento do blend de kiwi e maracujá é uma excelente alternativa para o aproveitamento da matéria-prima, por se tratar de um produto que apresentará elevado valor nutricional.

The objective of this work was to perform the chemical and physical characterization of the kino bark (Cucumis metuliferus) as well as to evaluate through mathematical modeling the drying kinetics at different temperatures. The barks were characterized in natura for water content, total and soluble solids, water activity, ashes, pH, total titratable acidity, Ratio and ascorbic acid. The drying kinetics at 60, 70, 80 and 90 °C were determined by adjusting the data to twelve mathematical models using the coefficient of determination (R2) and the mean square deviation (DQM) as adjustment criteria. The kino barks showed high water content and water activity, with relatively low acidity and ash parameters and satisfactory contents of ascorbic acid, total and soluble solids. Ten of the models tested presented satisfactory adjustments to the drying kinetics data, highlighting the Page and Diffusion Approximation models, with R²> 0.999 and DQM <0.091.