Rheological behavior of blueberry

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)The physical and physicochemical characteristics of blueberry (Vaccinium myrtillus) fruits produced in Brazil were analyzed. Rheological properties were measured at 5, 25, 45 and 65 degrees C, on a stress controlled rheometer equipped with grooved a stainless-steel parallel-plate in a shear rate range of 0-300 s(-1), with the objective of determining the influence of temperature on the rheological properties. The pseudoplastic behavior with yield stress was well described by the Ostwald-de-Waele (Power Law), Herschel-Bulkley (HB) and Mizhari Berk models. The yield stress and behavior index decreased with the increase in the temperatures for 5, 25, and 45 degrees C whereas for the temperature of 65 degrees C the effects were the opposite exhibiting elevated values. The viscosity decreased with an increase in temperature, and the Arrhenius equation described adequately the effect of temperature on the apparent viscosity of the puree, in which the activation energy (Ea) determined at a shear rate of 100 s(-1) was 9.36 kJ.mol(-1).294732737UNICAMPFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Nutrisaude Industria e Comercio de Frutas LtdaFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Morphological and Physicochemical Characterization of Commercial Maltodextrins with Different Degrees of Dextrose-Equivalent

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Maltodextrins show increasing industrial applications depending on the extent of the starch hydrolysis. This paper reports a relationship between morphological and physico-chemical characteristics of different maltodextrins (A, B, and C) in order to establish appropriate uses. The moisture content of the maltodextrins varied from 2.82 to 6.47% and true and bulk density, average particle size, and porosity of the maltodextrins ranged from 1.14-1.44 g/mL, 0.33-0.49 g/mL, 39.44-289.17 m, and 59.70-67.58%, respectively. Spherical, irregular, and filamentous shapes conduct to low values of wetting times. The increase in the DE level of maltodextrins from the same botanical source caused a decrease in the dissolution time. Results demonstrated that products obtained by supplier B showed the best performance and regularity in the dissolution/dispersion characteristics in water meanwhile maltodextrins manufactured by supplier A would be favored by an agglomeration process.132411425Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [03/08377-4, 03/001105-9

Optimization of the jet steam instantizing process of commercial maltodextrins powders

Several food powders are submitted to agglomeration in order to enhance their appearance, flowability, and above all, their wettability. This work evaluates the wet agglomeration process of maltodextrins of different degrees of dextrose-equivalent, DE 5-20, following a sequential strategy of experimental designs in order to produce granules with low dissolution time. Initially, a 2((5-1)) fractional factorial design was carried out with the independent variables steam pressure (1.5-1.9 bar), feed powder rate (1.6-2.0 g/s), drying air temperature (100-120 degrees C), sucrose and glucose addition (0-10% w/w). The results indicate that an increase in the DE degree increases the number of significant independent variables (p <= 0.05). The same levels used in the (2(5-1)) fractional factorial design performed previously were adopted in a 2(3) central composite design that was composed of 11 experimental runs. The surface response analysis indicated that the region of interest for lower dissolution time was found with a steam pressure of 1.7 bar, feed powder rate at 1.8 g/s and two possible drying air temperature (93 degrees C or 127 degrees C). The dissolution times of the agglomerates were substantially lower than of the original powder. The different characteristics obtained for the agglomerated maltodextrins could be attributed to the influence of their molecular mass and, consequently, of the glass transition temperature. (C) 2007 Elsevier Ltd. All rights reserved.86344445

Nutritive evaluation of a non-conventional leafy vegetable (Pereskia aculeata Miller)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Pereskia aculeata Miller is a native cactus that can be found in Brazil and is called 'ora-pro-nobis' (OPN). Many people from poor communities consume the dark green leaves of OPN as a vegetable. The objective of the present work was to evaluate the nutritional components in terms of proximate composition, minerals, vitamins, protein content and their in vitro protein digestibility. OPN leaves showed remarkable levels of total dietary fiber (39.1% dry basis), minerals (calcium, magnesium, manganese and zinc) and vitamins (vitamin A, vitamin C and folic acid). Among amino acids, tryptophan was the most abundant (20.5% of the total amino acids) and sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed small peptides, inferior to 6.5 kDa, and four major bands (61 kDa, 53 kDa, 33 kDa, and 15 kDa). The protein digestibility corrected amino acid score showed the lowest value of sulfur-amino acids (Met+Cys) . OPN leaves could be considered a good source of minerals, vitamins and amino acids, and may serve as a potential functional ingredient.60148160Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)UNICAMPFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [06/57880-9