Rosinelson da Silva Pena

Comportamento higroscópico da farinha de pupunha (Bactris gasipaes)

Avaliou-se o comportamento higroscopico da farinha de pupunha obtida por secagem em estufa a 70°C. Obteve-se dados de equilibrio de adsorcao de umidade a 15°C e 35°C, atraves de um metodo estatico, onde recipientes de 500mL, contendo solucoes saturadas de sais, foram utilizados como ambientes geradores de umidades relativas constantes, na faixa de 11% a 97%, aos quais foram submetidas amostras do produto. A partir dos dados de equilibrio foram construidas isotermas de adsorcao de umidade, sendo observadas isotermas do tipo III e, ainda, que a umidade de equilibrio diminui com o aumento da temperatura. Determinou-se o calor isosterico de adsorcao para diferentes niveis de umidade de equilibrio e a umidade equivalente a monocamada, observando-se valores inferiores a 5g H2O/100 g s.s. Verificou-se a aplicabilidade do modelo GAB na predicao de dados de equilibrio do produto. De acordo com os resultados obtidos, a farinha de pupunha apresenta baixa higroscopicidade, ou seja, baixa afinidade por moleculas de agua.

Comportamento higroscópico do açaí e cupuaçu em pó

Neste trabalho, isotermas de adsorcao e dessorcao do acai (Euterpe oleracea Mart.) e do cupuacu (Theobroma grandiflorum Schum.) em po foram determinadas experimentalmente com o auxilio de higrometro AQUAlab3TE da Decagon nas temperaturas de 15, 25 e 35 °C. As curvas obtidas apresentaram um comportamento do tipo III, caracteristico de materiais ricos em carboidratos. Os dados experimentais de adsorcao e dessorcao dos produtos foram ajustados, por analise de regressao nao-linear, usando o aplicativo STATISTICA para Windows 5.1B, aos modelos matematicos de Handerson, Oswin, GAB e BET-modificado. Os modelos de Oswin e GAB foram os que melhor se ajustaram aos dados experimentais de sorcao de umidade para o acai e cupuacu em po, respectivamente. Determinou-se ainda a monocamada para os dois produtos e o calor de dessorcao para o acai em po.

Bioactive amines and phenolic compounds in cocoa beans are affected by fermentation

Cocoa is the target of increased scientific research as it is one of the richest source of bioactive compounds. The formation of bioactive amines and their changes in cocoa beans during seven days of traditional fermentation was investigated for the first time. In addition, total phenolic compounds, anthocyanins contents and the scavenging capacity against ABTS radical were determined to monitor the fermentation process. Only two biogenic amines (tryptamine and tyramine) and two polyamines (spermidine and spermine) were detected in cocoa beans during fermentation. Fermentation was characterized by three stages: i) high levels of tryptamine, phenolics, and scavenging capacity; ii) high contents of spermine, total biogenic amines and total polyamines; and iii) the highest spermidine levels and total acidity, but the lowest total phenolic compounds and anthocyanins contents. The scavenging capacity of cocoa beans during fermentation correlated with total phenolic compounds and anthocyanins contents.

Adsorption capacity of phenolic compounds onto cellulose and xylan

The interaction between three phenolic compounds (catechin, caffeic acid and ferulic acid) onto two dietary fibres (cellulose and xylan) has been evaluated to inquire possible interferences on the biodisponibility of phenolic compounds. The adsorption kinetics were performed using solutions containing 100 mg/L of phenolic compounds during a contact time ranging between 10 and 120 minutes at pH 2.0, 4.5, and 7.0. After the kinetics, isotherms were obtained using phenolic compounds concentration ranging between 10 and 80 mg/L during 60 minutes, at pH 2.0 and 7.0 and temperature of 36 °C. Results indicate that adsorbed quantities mainly changed in function of pH, however the maximum adsorption was only of 0.978 mg of caffeic acid/g of xylan at pH 2 and after 60 min. Redlich-Peterson model were able to predict the adsorption isotherms of all phenolic compounds onto cellulose, except for caffeic acid at pH 7.0. The low adsorption capacities observed suggest that both dietary fibres are unable to compromise the biodisponibility of phenolic compounds, especially in the small intestine, where they are partially absorbed.

Rheological behavior of Brazilian Cherry (Eugenia uniflora L.) pulp at pasteurization temperatures

Neste trabalho, foi estudado o comportamento reologico da polpa de pitanga na faixa de temperatura de pasteurizacao de 83 a 97 °C. Os resultados indicaram que a polpa apresentou comportamento pseudoplastico e o modelo de Herschel-Bulkley foi considerado o mais adequado para representar o comportamento reologico do produto nas temperaturas estudadas. Os indices de comportamento de fluido (n) variaram na faixa de 0,448 a 0,627. O efeito da temperatura sobre a viscosidade aparente pode ser descrito pela equacao analoga a de Arrenhius, observando-se a diminuicao da viscosidade aparente da polpa de pitanga com o aumento da temperatura.

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.

Qualidade física e sensorial de biscoitos doces com fécula de mandioca

This research evaluated the substitution of 5, 10 and 15% of wheat flour for cassava starch in sweet cookies production. Both, flour and starch were submitted to the physicochemical, rheological and differential thermal analysis (DTA). The produced cookies were compared through sensory

Physicochemical properties of three sugary cassava landraces

This study evaluates the physical and physicochemical properties of three sugary cassava (Manihot esculenta Crantz) landraces: Sao Francisco Bag 3, Manicueira 62, and Castanhal Iracema. These three landraces showed high estimated productivity (≥3.93kg plant-1) and had a high sugar content (≥3.92g 100g-1 of root), making them viable for use in syrup production, especially the Sao Francisco Bag 3 landrace (4.76g 100g-1). The Manicueira 62 landrace had the highest starch content (4.40g 100g-1). The three sugary cassava landraces exhibited high levels of cyanide (>195mg kg-1), indicating the need for processing prior to consumption.

CARACTERIZAÇÃO FÍSICA, FÍSICO-QUÍMICA E POTENCIAL TECNOLÓGICO DE FRUTOS DE CAMAPÚ (Physalis angulata L.)

O objetivo deste estudo foi investigar o potencial tecnologico de frutos de camapu. Para isso foram determinadas as caracteristicas fisicas, fisico-quimicas e os teores de vitamina C, carotenoides totais, compostos fenolicos totais e a capacidade de sequestrar radicais livres atraves do metodo DPPH (2,2-difenil-1-picril hidrazil). Alguns dos resultados observados foram: solidos soluveis de 12°Brix; pH de 4,11; Aw de 0,97; teor de proteinas de 0,95% ; 6,45% de acucares totais e 4,12% of acucares redutores; 25 mg.100g -1 de vitamina C; 3,99 μg.g -1 de carotenoides totais; 61,70 mg GAE. 100g -1 para compostos fenolicos totais e a capacidade antioxidante de IC 50 : 93,01 e 92,8 μ g .mL -1 para extracao aquosa e metanolica respectivamente . Os resultados obtidos mostraram teores consideraveis de fenolicos totais e atividade antioxidante mediana para os frutos de camapu, comparaveis a outras frutas ja amplamente comercializadas no brasil. O objetivo deste estudo foi investigar o potencial tecnologico de frutos de camapu. Para isso foram determinadas as caracteristicas fisicas, fisico-quimicas e os teores de vitamina C, carotenoides totais, compostos fenolicos totais e a capacidade de sequestrar radicais livres atraves do metodo DPPH (2,2-difenil-1-picril hidrazil). Alguns dos resultados observados foram: solidos soluveis de 12°Brix; pH de 4,11; Aw de 0,97; teor de proteinas de 0,95% ; 6,45% de acucares totais e 4,12% de acucares redutores; 25 mg.100g-1 de vitamina C; 3,99 μg g-1 de carotenoides totais; 61,70 mg GAE. 100g-1 para compostos fenolicos totais e a capacidade antioxidante de IC50: 93,01 e 92,8 μg.mL-1 para extracao aquosa e metanolica respectivamente. Os resultados obtidos mostraram teores consideraveis de fenolicos totais e atividade antioxidante mediana para os frutos de camapu, comparaveis a outras frutas ja amplamente comercializadas no Brasil.

Optimization and characterization of gelatin from kumakuma (Brachyplatystoma filamentosum) skin

ABSTRACT Fish industry residues are used due to their easy transformation into several products and because they have nutrients with high biological value, being rich in proteins and fatty acids. The gelatin extraction process from the skin of kumakuma (Brachyplatystoma filamentosum) using sodium hydroxide was optimized and the product was characterized. The optimized conditions established in the process were 6 h extraction at 58°C, with yield and gel strength at 19.7% and 244.3 g, respectively, which is considered acceptable for foods. The maximum desirability condition was 0.998. When the technological properties of the gelatin extracted from fish skin was compared with commercial gelatin, a difference (p < 0.05) was observed for all parameters analyzed, but within the appropriate range for gelatin. The gelatin obtained from kumakuma skin may be a new alternative to replace gelatin from mammals, besides contributing to less fish residue released into the environment.