Afonso Mota Ramos

Qualidade da manga e polpa da manga Ubá

Uba mango (Mangifera indicates L. var. Uba) has excellent flavor qualities and a tasty, yellow and succulent pulp. It contains a high content of soluble solids, around 14 °Brix, acidity of 0.2% as citric acid and ratio 70, besides being rich in potassium and vitamins A and C. The fruit has soft and short fibers, and can be consumed fresh or be industrialized, especially for the production of pulp and juice. This variety possesses an excellent industrialization yield, by greatly reducing processing, with a consequent reduction in the final production costs. Uba mango supplied to a pulp and juice agroindustry in the Zona da Mata Mineira area had its quality determined through fruit and pulp analyses. During the 2003/2004 harvest period, the Dirty Mangos (DM), as were denominated the fruits that arrived at the industry, presented an average initial count of 7.34 log CFU mesophyllic aerobics/mango. After cleaning, the fruits were called Clean Mangos (CM), and had an average of 5.62 log CFU/mango, presenting an average reduction of 1.72 log cycles. In the 2004/2005 harvest period, the DM presented an average initial count of 7.02 log CFU mesophyllic aerobics/mango and the CM, an average of 5.76 log CFU/mango, with an average reduction of 1.52 log cycles. The mango pulp presented values for pH, total soluble solids, total acidity, total soluble solids/total acidity ratio, total solids and total soluble sugars, in accordance with the legislation requirements. The color coordinates presented values indicating that the pulp has a yellow-orange characteristic color.

ASPECTOS COLOIDAIS DA ADESÃO DE MICRO-ORGANISMOS

The ability of bacteria to attach to surface and develop into a biofilm has been of considerable interest to food industry. Electrostatic, Lifhistz-van der Waals and Lewis acid-base forces are usually considered responsible for the interactions at the interface of the bacterial adhesion. The study of microbial adhesion thermodynamic is important because it represents the reflection of microbial surface and food processing surface physicochemical characteristics. This review examines the most important aspects involved in bacterial attachment to a surface with emphases in thermodynamics of adhesion process.

Pro-Apoptotic Activities of Polyphenolics From Açai (Euterpe oleracea Martius) in Human SW-480 Colon Cancer Cells

This study aimed to evaluate the cell growth inhibition activity of açai (Euterpe oleracea Mart.) polyphenolic extract against colon cancer HT-29 and SW-480 cells and the nonmalignant CCD-18Co colon fibroblast cells. Results showed that açai polyphenolic extract (5–20 mg/L) inhibited preferentially the growth of SW-480 cells with no toxicity in CCD-18Co cells, and this was accompanied by reduction of H2O2-induced reactive oxygen species (ROS) generation. The mechanisms involved in SW-480 cell growth-inhibition by açai polyphenolic extract included the downregulation of NF-κB proinflammatory transcription factor and the nuclear factor-kappa B targets intracellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). Furthermore, prooncogenic specificity proteins (Sp) were downregulated as well as Sp-targets Bcl-2, vascular endothelial growth factor, and survivin. This was accompanied by activation of mitochondrial proapoptotic pathway involving increase of cytochrome c, cleavage of caspase-3, and decrease of PARP-1. Results strongly suggest that açai polyphenolic extract has antiinflammatory and cytotoxic activities in colon cancer cells and can be effective as natural colon cancer chemopreventive agents.

Minimally processed yellow melon enriched with probiotic bacteria

The demand for healthy diets with fresh foods, especially minimally processed fruits and vegetables, resulted in a variety of products available to consumers...

Modelagem matemática da secagem em camada delgada de bagaço de uva fermentado

The objective of this work was to determine the drying characteristics of fermented grape pomace in a hot air-dryer, to evaluate the descriptive capacity of known mathematical models of thin-layer drying, and to establish the values of effective diffusivity and activation energy. Drying experiments were conducted at 50, 60, 70, 80 and 90oC, with 1.0 m s-1 air-drying velocity. Ten different mathematical models for thin-layer drying were compared, according to the values of coefficient of determination (R2), chi-square (χ2), residual mean square root (RMSR), and relative mean error (P) estimated by the drying curves. The effects of drying temperature on the coefficients and constants were predicted by the regression models. The modified Page model was selected to represent the behavior of thin-layer drying of grape pomace. The mean values of effective diffusivity varied from 1.0091 x 10-9 m2 s-1 to 3.0421 x 10-9 m2 s-1, at the evaluated temperatures. Effective diffusivity dependence on temperature was described by the Arrhenius equation, with activation energy of 24.512 kJ mol-1.

Campo elétrico pulsado

Pulsed electric fields of high intensity (HIPEF) is a non-thermal food conservation to replace traditional thermal pasteurization. Compared to thermal processing, the HIPEF as well as being effective in removing microorganisms and inactivate enzymes also minimize the loss of flavor, color, texture, nutrients and labile components of food. The aim of this work was to gather bibliographic data current HIPEF on the subject, covering: experimental setup, effects of dielectric breakdown of food, effect on microorganisms, enzymes and constituents of food. The data found in the literature indicate treatment of HIPEF as a promising alternative for food conservation and it could be used as a single technology or in addition to thermal processing.

Perfil dos consumidores de hortaliças minimamente processadas de Belo Horizonte

Consumers food consciousness has increased, however, time for preparing healthy food has decreased. Therefore, the market of minimally processed vegetable has increased rapidly, giving rise to the appearance of fresh products that can be prepared and consumed faster than conventional foods. Thus, the objective of this work was to establish the behavior and profile of minimally processed vegetable consumers in supermarkets of Belo Horizonte, Minas Gerais State, Brazil. Based on the answers to a survey, the consumers profile was traced, highlighting preferences, habits, complaints and demands. The survey was conducted with consumers of five supermarkets which sell minimally processed vegetables (MPV). Consumers were chosen randomly when they were buying in November 2004. Of two hundred and forty six interviewed persons, 23% were consumers of MPV. The main reasons for consumption were: easiness and feasibility (46%); short preparation time (21%) of meals and hygiene (11%) of the products; and the main reasons against consumption were: the high price of the precuts (31,9%); easy to prepare and/or to choose (23%) and distrusting (17,8%) the offered products. The major consumers were those with a better education. Comparing the overrating of MPV with other vegetables, a variation of 2,4 (potato) to 39,5 times (carrots) was found. On average the overrating found in markets for eleven MPV was of 10 times.

Kinetics of Peroxidase Inactivation in Carrot Juice Treated with Pulsed Electric Fields

UNLABELLED Peroxidase activity accounts for quality losses in many plant-based foods. The paper provides insight into the inactivation kinetics of peroxidase (POD) in carrot juice treated with pulsed electric fields (PEF). Juice samples were subjected to electric field intensities of 20 to 35 kV/cm for 300 to 2000 μs. Up to 93% of the initial activity was inactivated after treating at 35 kV/cm for 1500 μs. POD activity inactivation correlated well with the increase in energy density input. A first-order fractional conversion model best fitted the experimental results. Other kinetic approaches such as the Fermis model can be used to estimate residual POD activity values in treated juices as a function of electric field strength. PRACTICAL APPLICATION Pulsed electric fields (PEF) are a processing technology that can be used for the pasteurization of liquid food products. Peroxidase activity inhibition is required in carrot juices to prevent undesirable quality losses, such as discoloration, flavor changes, and loss of nutrients. The most significant processing parameters ruling POD inactivation in PEF-treated carrot juice are identified and mathematical modeling of experimental data is conducted.

The use of cashew apple residue as source of fiber in low fat hamburgers

The main purpose of this study was to produce hamburgers with partial substitution of the meat with cashew apple residue powder. The powder residue was obtained after the extraction of the pulp and dehydration in stove with air circulation. Three formulations of hamburgers with increasing concentration of the residue as well as a control sample were prepared. The formulated products with cashew apple residue powder presented lower humidity and proteins and 35% lipid reduction. However, there was an increase in carbohydrates and pH with the addition of the powder from the cashew apple residue. Some formulations showed an improvement of the final product yield. The total dietary fiber value was between 0 and 7.66%, with higher content of insoluble dietary fiber. The addition of up to 10.70% of the residue did not cause significant sensory changes in the flavor of the samples. The production of hamburgers with a partial substitution of cow meat with the cashew apple residue could be a feasible option since it resulted in product with high nutritional quality that is rich or have high dietary fiber content and is low in fat.

Effect of temperature and concentration on the physical properties of watermelon pulp.

Density and viscosity are important physical properties since they are the properties most used in calculations involving fluid transport. The main objectives of the present study were to examine the rheological behaviour and determine the density of watermelon pulp at different temperatures (10, 20, 30, 40, 50 and 60 °C) and concentrations (8, 17, 26 and 35 °Brix) and to obtain models to describe the alterations in these physical properties as a function of temperature and concentration. A Searle concentric cylinder rheometer was used to study the rheological behaviour and the density was determined using pycnometers. The models used in this work were fitted by nonlinear regression. It was concluded that the watermelon pulp behaved as a pseudoplastic non-Newtonian fluid at all the temperatures and concentrations used and that the Ostwald-de-Waele model could be used to describe this behaviour. Models were found that described the simultaneous effect of temperature and concentration on the density and viscosity of watermelon pulp, and these could be very useful in the food industry.