Nonete Barbosa Guerra

Características químicas e físico-químicas de pequis da Chapada do Araripe, Ceará

O objetivo deste trabalho foi avaliar a qualidade do pequi. Para isso, frutos maduros colhidos de trinta e cinco pequizeiros (Cariocar coriaceum Wittm.) nativos, provenientes da Chapada do Araripe, Estado do Ceara, foram avaliados quanto as suas caracteristicas quimicas e fisico-quimicas. Na polpa do fruto, foram determinados pH, acidez total titulavel (ATT), solidos soluveis (°Brix), acucares soluveis totais (AST), relacao °Brix/acidez, atividade de agua, proteina, carboidratos totais e valor energetico total; na polpa e amendoa, umidade, lipidios, cinzas e minerais (Ca, Mg, P, K, Cu, Fe, Mn, Na e Zn). As plantas apresentaram grande variabilidade para a maioria das caracteristicas avaliadas. As maiores variabilidades foram observadas para a acidez, acucares totais e proteina. Em relacao aos minerais, a maior variabilidade foi observada para o cobre na polpa e sodio na amendoa. A menor variabilidade foi detectada para a atividade de agua, pH e umidade da polpa, em ordem crescente. Seis plantas destacaram- se por apresentarem percentagem de lipidios (polpa e amendoa) superiores a media deste estudo. A composicao em minerais variou entre as amostras (onze plantas), destacando-se, em termos quantitativos, o potassio na polpa e o fosforo na amendoa. A amendoa e mais rica em minerais do que a polpa. A polpa do pequi, face as caracteristicas de baixa acidez, alto pH e alta atividade de agua, apresenta-se propicia ao desenvolvimento de microrganismos patogenicos e a deterioracao. Alem disso, a presenca de nutrientes, temperatura e a disponibilidade de oxigenio sao fatores importantes que devem ser considerados durante o processamento e armazenamento por favorecerem a oxidacao dos lipidios. Os resultados demonstram a importância nutricional do pequi, principalmente de sua amendoa, pelo elevado teor de lipidios e minerais.

Atividade antioxidante de extratos de coentro (Coriandrum sativum L. )

The antioxidant activity of different extracts of coriander (Coriandrum sativum), isolated and/or combined with itself and BHT, was investigated. The etheric, ethanolic and aqueous extracts obtained by sequential extraction were evaluated for antioxidant action in a b-carotene/acid linoleico model system and the active compounds identified. The antioxidant synergistic effect between aqueous and etheric extracts was evaluated using factorial 22 plan. The antioxidant action of the extracts aqueous, etheric and ethanolic was 69.83%, 61.89% and 40.50%, respectively. Phenolic compounds were detected in two first extracts and carotenoids in the etheric. Combining different concentrations of etheric and aqueous extracts, the percentage of inhibition of the oxidation was inferior to that of the isolated ones, demonstrating that was no synergistic effect that occurred when the aqueous extract was associated with BHT. The ability of the aqueous and etheric extracts in delaying the oxidation can be attributed, respectively, to its phenolic and carotenoids constituent. The aqueous extract can be considered as an antioxidant potential, whose action can together be intensified to the employed being with BHT.

Effect of the addition of inulin on the nutritional, physical and sensory parameters of bread

The present work evaluated the effect of the addition of inulin on sensory, nutritional and physical parameters of white bread. Three formulations containing 0%, 6% and 10% of inulin were produced. Physical analyses of mass, volume, specific volume, density, centesimal composition, glycemic index (GI) and qualitative descriptive sensory analyses, were carried out. The reduction in bread volume seen with 10% inulin was higher than that reported in the literature. Bread weight did not differ statistically. There was an 85% reduction in fat content for bread with 6% inulin and 86% for bread containing 10% inulin. Glycemic index in bread containing 10% inulin was lower than bread with 6% inulin and equal to inulin-free bread. A level of 6% inulin added to bread was regarded to yield good sensory quality.

Polpa de fruta congelada: efeito do processamento sobre o conteúdo de fibra alimentar

The effects of the process utilized to obtain frozen fruit pulp on the quality of dietary fibers were evaluated, using ripe samples of acerola, cashew, guava, soursop, mango, sweetsop, pitanga, sapoti and grapes. The results obtained showed that the technological process used reduced significantly the fiber percentual of the fruit, determined by gravimetric non-ensymatic method particularly the guava, followed by the grapes, soursop, saoti, cashew, sweetsop and acerola. With the exception of mango and pitanga, all the frozen pulps tested do not seem to substitute, in terms of quantity of dietary fiber, the in natura fruit in the diet of healthy individuals. Considering the fact that these losses are variable, depending on the characteristics of the fruit which was processed, the inclusion of frozen pulps in the human diet in substitution to fruits will depend on quality control studies which may lead to a classification of the components of the mentioned fraction.

Modificações do método gravimétrico não enzimático para determinar fibra alimentar solúvel e insolúvel em frutos

OBJETIVES: Modifications in the treatment of samples and operational sequence of the gravimetric non enzymatic method were carried out in order to simplify it and allow the quantification of soluble and insoluble quantities of the total dietary fiber. METHODS: Lyophilization influence was first evaluated in guava samples and afterward in samples of acerola, mango, sugar apples, sapodilla and grapes. The mentioned fruits and also pineapple, cashew, passion fruit and strawberry were tested for the modifications intrinsic in the methodological sequence. RESULTS: The average total dietary fiber for guava, both lyophilized and non-lyophilized, were: 10.50% ±0.97 and 10.53% ±0.88, respectively, revealing good method reproducibility and no significant differences among the treatments applied to guava and other fruits. Differently from what was found in the determination of the insoluble dietary fiber, which had a variation of 99.6% for cashew and 54.0% for acerola, the data generated for soluble dietary fiber were disregarded, due to the dispersiveness found. CONCLUSION: Those results show that the samples do not depend on lyophilization and that the quantification of soluble dietary fiber needs further adjustments of the precipitation stage.

Caracterização física de frutos do pequizeiro nativos da chapada do Araripe-CE

The study aimed to characterize physically pequi fruits (Caryocar coriaceum Wittm.) of native trees from Chapada do Araripe, situated south of the state of Ceara, in order to quantify the variability among plants and identify genotypes to food industry and breeding programs. Fruits of 35 plants were characterized for 24 physical parameters in the whole fruit, rind, almonds, pulp and seeds. The results (average of 25 fruits) were evaluated via descriptive statistics (measures of central trend and data variability) and methods of multivariate analysis (cluster analysis and main component analysis). The fruits from the plants numbers: 01, 02, 03, 05, 07; 14, 22 and 26 showed the best characteristics for processing. The cluster analysis resulted in the identification of five groups of plants with similar phenotypic characteristics. The results showed that there is considerable variability in the specie.

Análise de componentes principais de pães de forma formulados com farinha de yacon (Smallanthus sonchifolius (Poepp.) H. Rob.)

O yacon, tuberculo de origem andina, vem sendo cada vez mais aplicado na tecnologia de alimentos, em virtude de suas propriedades funcionais, por ser fonte de inulina e fruto-oligossacarideos, considerados prebioticos. Foram preparadas tres formulacoes de paes, sendo uma padrao e duas testes contendo farinha de yacon, denominadas de amostra P (pao padrao, sem farinha de yacon), amostra A (pao com 6% de farinha de yacon e 3% de gordura) e amostra B (pao com 11% de farinha de yacon sem adicao de gordura). Para a avaliacao sensorial foi realizada a Analise Descritiva Quantitativa (ADQ), utilizando-se 11 provadores treinados, os quais definiram 10 atributos sensoriais (aroma, cor, porosidade e uniformidade do miolo, sabor, textura, umectância, untuosidade, adesividade e qualidade global). Tambem foi realizada analise fisica dos paes, por meio da caracterizacao cromatica. Os resultados da ADQ foram analisados por analise de variância e testes de medias de Duncan, a 5% de significância. Os resultados da ADQ foram representados graficamente por analise multivariada de analise de componentes principais (ACP). Nao houve diferenca entre as amostras A e B em relacao aos atributos porosidade, textura, sabor e qualidade global. A amostra A obteve media maior em atributos sensoriais indesejaveis como aderencia, enquanto a amostra B apresentou maior media para o atributo umectância, devido ao maior teor de yacon. Na ACP, a soma de componentes principais 1 e 2 foi de 97,59%, ou seja, a variabilidade entre as amostras foi quase totalmente explicada por estes dois componentes. Os resultados obtidos demonstram o grande potencial para o desenvolvimento de novos produtos utilizando alimentos fontes de prebioticos, como os frutanos do yacon.

Caracterização físico-química do grândulo do amido do feijão caupi

This work aimed at characterizing the starch of the cowpea bean in the stages of maturation in which it is consumed both chemically and physically. The unripe and ripe grains of the cowpea bean (Vigna unguiculata L. Walp) were submitted to determine the centesimal composition: protein by Kjeldahl, lipids by Soxleth, moisture at 105°C, ashes at 550°C, alimentary fiber by gravimetric-enzymatic method, total carbohydrates by difference, total starch, reductor glicids and non reductor by oxid-reduction in Fehling solution. The isolated starch of the distinct samples was analyzed as to the resistant starch (based in the use of amylolytic enzymes), amylose and amylopectin (by spectrophotometry) and typification (X-ray diffraction). The results obtained showed that the fractions of carbohydrates differed according to the stage of maturation of the grains. The starch of the unripe bean showed a higher content of resistant starch (RS) type 2 in relation to total starch and low content of amylose. Maturation influenced the crystallinity patterns, type C was found for the unripe bean and type A for the ripe bean. The stage of the maturation influenced the qualitative and quantitative aspects of the constituents of the beans. The morphologic aspect of the granules of starch was not influenced by the stage of maturation of the grains. The unripe bean showed a percentage of soluble alimentary fiber compatible with the FDA standards.

Antioxidant capacity of anthocyanins from acerola genotypes

Anthocyanins from 12 acerola genotypes cultivated at the Active Germplasm Bank at Federal Rural University of Pernambuco were isolated for antioxidant potential evaluation. The antioxidant activity and radical scavenging capacity of the anthocyanin isolates were measured according to the β-carotene bleaching method and 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay, respectively. The antioxidant activity varied from 25.58 to 47.04% at 0.2 mg.mL-1, and it was measured using the β-carotene bleaching method. The free radical scavenging capacity increased according to the increase in concentration and reaction time by the DPPH assay. At 16.7 μg.mL-1 concentration and after 5 minutes and 2 hours reaction time, the percentage of scavenged radicals varied from 36.97 to 63.92% and 73.27 to 94.54%, respectively. Therefore, the antioxidant capacity of acerola anthocyanins varied amongst acerola genotypes and methods used. The anthocyanins present in this fruit may supply substantial dietary source of antioxidant which may promote health and produce disease prevention effects.

Glycemic profile and prebiotic potential "in vitro" of bread with yacon (Smallanthus sonchifolius) flour

The purpose of this study was to elaborate bread with yacon flour at two different levels (6% and 11%) and to analyze their proximate composition, their glycemic indices and their prebiotic potentials in vitro. Bread with 6% and 11% of yacon flour presented, simultaneously, low and moderate glycemic index. As for the prebiotic potentials, it was evident the presence of probiotic bacteria, particularly Lactobacillus. The results showed that, the addition of yacon flour on bread rendered products from low to moderate GI, with prebiotic potential, low fat and high fiber contents, according to the Brazilian food legislation.