Alessandra Santos Lopes

Estabilidade da polpa de pitanga sob congelamento

Amongst tropical fruits, the pitanga (Eugenia uniflora L.), still little studied, shows great sensory appeal and excellent vitamin quality, due to its high carotenoid level. The objective of this study was to evaluate the stability of pitanga pulp during frozen storage (-18°C) with respect to the following parameters: pH, total titratable acidity, soluble and total solids, total and reducing sugars and sensory acceptance determined after 0, 30, 60 and 90 days, and total carotenoid contents and instrumental colour measured after 0, 15, 30, 45, 60 and 90 days. The reaction kinetics for the degradation of the colour parameter a* adjusted better to a 1 order kinetic model (R2 =91.69%), whereas the total difference in colour (DE*) adjusted better to a zero order kinetic model (R2 =91.91%). In the sensory analysis, the attribute of appearance varied significantly (p<0.05) after 90 days of frozen storage. Thus there was a marked fall in sensory acceptance and in the positive attitude towards buying of the nectar formulated with pitanga pulp stored for 90 days at -18°C.

Caracterização de farinhas de tapioca produzidas no estado do Pará

Tapioca flour is a typical food produced from cassava starch (Manihot esculenta Crantz), widely consumed in the Amazon Region. The aim of this study was to characterize two tapioca flours produced in Para State, Brazil one in the West Region and other in Bragantina Area. Both tapioca flour presented distinct particle-size distribution and significant difference (P 0.05) for majority of the physico-chemical and technological parameters. Flour from West Region presented high moisture (10.7%), this due the greater capacity of water adsorption, attributed at its high specific area (smaller particle-size). The optical microscopy with polarized light and the technologic properties of the products did not showed a standard process for the production of tapioca flour.

Características físicas e físico-química da casca de mangostão em três períodos da safra

In this work, it was evaluated the physical characteristics of fruit and physiochemical of the mangosteen peel, harvested in different periods (beginning, middle and end). The physical characteristics of fruits range significantly (p<0.05) from the beginning to the end, and it was observed that the fruits average weight, ranged from 91.33 to 50.82 g and the peel consists of an average from 72.12 to 76.86% of the total fruit weight. The physiochemical characterization shows that the peel possesses high moisture content (64.5 to 66%), total fibers (24.9 to 29.1%), high water activity (0.96 - 0.98), low energy value (24.8 to 34.7 Kcal/ 100g) and expressive content of total anthocyanins (25.9 to 63.9 mg/100g), mainly in the intermediate harvest period.

Production and Characterization of Sugary Cassava Syrup

Abstract A group of cassava landraces that occur naturally in Amazonia (Manihot esculenta Crantz) are known as mandiocaba or sugary cassava because they have high free sugar content, making them a possible feedstock for the production of syrup. The objective of the study was to evaluate the technological viability of obtaining sugary cassava syrup and to characterize the physical and physicochemical properties of the product. The yield of the syrup (80 °Brix) obtained from the manipueira (liquid obtained by crushing and filtering the cassava) concentration was 262.72 g per plant. The reducing sugars represented 77.26% of total sugars, the density was 1.4210 g cm–3 at 20°C, and the volumetric expansion coefficient was 38.6 m K–1. The Newtonian behavior and activation energy (≥69.65 kJ gmol–1) were similar to that of honey found in the literature.

Influência do uso simultâneo de ácido ascórbico e azodicarbonamida na qualidade do pão francês

The aim of this work was to evaluate the simultaneous use of ascorbic acid and azodicarbonamide in a bakery product by using the response of the surface methodology. The experimental design (22) responses were the specific volume and total count of the external and internal characteristics of French bread. The action of ascorbic acid on the increase of the specific volume of French bread had significant linear and quadratic effects (p < 0.05 or near values). For azodicarbonamide, the quadratic effect was observed, and there was no interaction effect between the two studied oxidants agents. The application of ascorbic acid and azodicarbonamide using concentrations above 75 mg.kg -1 of wheat flour and 30mg.kg -1, considering the studied levels, provided French bread production with a higher specific volume.

Determinação dos Teores de Cu, Fe, Mn e Zn por FAAS em Raízes de Mandioca ( Manihot esculenta Crantz) da Amazônia Oriental

O objetivo deste estudo foi determinar a quantidade de micronutrientes Fe, Zn, Mn e Cu de nove amostras de raizes de mandioca por espectrometria de absorcao atomica com chama (FAAS) utilizando ferramentas quimiometricas como a analise exploratoria multivariada sem supervisao para tentar explicar possiveis diferencas nas suas caracteristicas quimicas e teste de Tukey para verificar a significância estatistica dos valores medios. Quatro amostras foram obtidas de um comercio local, cultivadas sem qualquer informacao sobre as condicoes ambientes de plantio ou colheita. As outras cinco amostras pertencem a um banco ativo de germoplasma (BAG) em condicoes de plantio e ambientes conhecidas. O teor de Fe variou de 0,54 a 5,24 mg/kg; Zn de 0,38 a 6,55 mg/kg; Cu de 0,04 a 0,89 mg/kg e Mn de 0,16 a 0,41 mg/kg. As amostras comerciais apresentaram resultados esperados para todos os elementos estudados, enquanto as amostras de BAG apresentaram vantagens na absorcao de ferro e zinco. As amostras do comercio local nao apresentaram ferro em sua composicao, mas foram as unicas que apresentaram manganes em sua composicao. Tal caracteristica foi, portanto, um parâmetro essencial para distinguir as amostras comerciais das outras amostrasis. O conhecimento das condicoes de plantio sao essenciais para assegurar provaveis fatores exogenos que podem causar variacoes na absorcao de micronutrientes. Esses fatores devem ser considerados como influentes na absorcao de micronutrientes em amostras de mandioca.