Elisabeth Borges Gonçalves

Influência das condições de cultivo na composição da semente e do óleo de gergelim

Effect of cultivation conditions on the composition of sesame seed and oil Fourteen selected sesame genotypes were grown in Patos, Paraiba State, Brazil and Barbalha, Ceara State, Brazil, and the trials were at a randomized block design with five replicates under non-irrigated and irrigated conditions, respectively. Seeds were evaluated for oil yield and chemical composition, while defatted meal was analyzed for amino acids content. The fatty acids and sterols profiles were also evaluated, as well as the characteristics for identity and oil quality. The differences observed between genotypes in the same area were small. However, significant differences (p <0.05) between the areas for oil content and protein were observed, with higher oil content found for genotypes in Barbalha, where the crop was irrigated. Higher amounts of stearic (C18: 0) and oleic acids (C18: 1) were observed for the oil from Patos, while for linoleic acid (C18:2) a higher content was found in Barbalha oil. As for sterols, campesterol, stigmasterol and delta 5 avenasterol were more abundant for samples from Barbalha, and sitosterol for samples from Patos (p <0.05). Some figures observed for some fatty acids, sterols, density and refractive index diverged from the identity characteristics described in Codex Alimentarius (2001), reinforcing the need to set up a national database that can support future changes in this standard.

Desenvolvimento do perfil sensorial e avaliação sensorial/instrumental de suco de maracujá

Palavras-chave: SUMMARY SENSORY PROFILE DEVELOPMENT AND SENSORY/INSTRUMENTAL PASSION FRUIT JUICE EVALUATION. The most important tropical fruits used in juice production are passion fruit and mango. They are especially liked due to their intense aromas. Aroma and flavor are results of many constituents that are present in different concentrations, which are very sensitive to changes during thermal treatment used in the juice production. This work aimed at developing the sensory profile and evaluating the changes that may occur during the passion fruit juice processing. Three passion fruit juices were analyzed: the raw material (pulp), which was pasteurized, kept in tambour and frozen; the ready-to-drink (formulated with sugar and water); and the pasteurized at 98 C, 30s. The sensory profile was composed of 13 attributes The quantitative descriptive analysis design comprised two factors, i.e. type of juice and panelists. The results were also analyzed using principal components analysis. Significant differences were found among the three juices except for the attribute passion fruit aroma and sweet aroma. the artificial aroma, cooked aroma, fermented aroma and fermented flavor were significantly higher (p<0.05) on the processed passion fruit juice. The first two principal components accounted for 57% of the variance. There were significant differences among the three juices regarding the colour parameters, except for the haze. The frozen juice kept in tambour was darker than both the formulated juice and the pasteurized juice. The red color of the frozen juice kept in tambour and the formulated juice was similar. On the other hand, the red color for the pasteurized juice was less intense. However the yellow colour was higher on the formulated juice, presenting lower values on the pasteurized juice and on the frozen juice kept in tambour.

Extração de ácido clorogênico de farelo de girassol desengordurado

The culture of sunflower (Helianthus annuus L.) has been consolidated in different regions of Brazil, and presents interesting characteristics on agronomic aspects, oil composition and protein quality. The defatted sunflower meal has been used to feed, but browning limits its use for human consumption. Sunflower meal contains chlorogenic acid, a potent antioxidant, which in turn is oxidized by polyphenol oxidase, producing compounds that darken the meal and reduce the nutritional quality of protein. In this research chlorogenic acid extracts were obtained from defatted sunflower meal, using methanol or ethanol as solvent, at temperatures of 25, 40 and 60°C and contact times of 30 and 60 minutes in a three classification criteria experiments. There were significant differences between solvent, time and temperature (P<0.05). The highest removal efficiency of chlorogenic acid was of 40%, when methanol was used. Chlorogenic acid extracts obtained have potential for use as antioxidant.

EFEITO DA ASSOCIAÇÃO DE PECTINASE, INVERTASE E GLICOSE ISOMERASE NA QUALIDADE DO SUCO DE BANANA

The association of 0,03 % v/w pectinase (Clarex), 0,6 % v/w invertase (Invertase-S) and 0,5 % w/w glucose isomerase (Taka-sweet) in industrialized banana (Musa cavendishii) pulp, under conditions of hydrolysis 40oC, 15 minutes, was observed and compared to other three enzymatic treatements: 0,03 % v/w pectinase (Clarex); 0,03 % v/w pectinase (Clarex) associated to 0,6 % v/w invertase (Invertase-S); and 0,03 % v/w pectinase (Sigma) associated to 0,03 % cellulase (Sigma) to determine the quality using a group of physical, physico-chemical, chemical, microbiological and sensory properties of the banana juices obtained. These properties had not differ significantly in function of pectinases and celulase employed. The addition of invertase had increased sweetness and decreased viscosity in juice. On the other side, the addition of glucose isomerase in inverted juice was not able in increasing significantly fructose content.

Incerteza em resultados analíticos e verificação de conformidade de qualidade de alimentos

This paper discusses the validity of estimators of uncertainty (dispersion, variance and its functions such as precision, standard deviation, and others) of measurements to be used to assess compliance. Estimates of uncertainty in analytical methods measurement were shown describing inconsistent trends in mycotoxins, sodium, grasses oils, and calibration curves for carotenoids mycotoxins. The data were certified by proficiency tests, precision experiments (collaborative studies), and calibration routines. The uncertainty of sampling, was considered, and its invalidity can be concluded. Considering the system of generation of uncertainty as a whole, a systematic estimation for foods and foods processing using standard or specific sampling plans is suggested. Moreover, stochastic rules for verifying compliance in foods and other products were established.

Efeito dos complexos enzimáticos clarificantes Clarex e CEC1-CTAA sobre a qualidade do suco de banana

The effect of the clarifier enzymatic complexes Clarex and CEC1-CTAA, used in the proportion 0.03% v/w in industrialized banana (Musa cavendishii) pulp, at the conditions of gentle hydrolysis 40 degree Celsius, 15 minutes, was observed to determine the quality here represented by indicators such as yield, viscosity, Brix, pH, centesimal composition, counts of moulds and yeasts and of mesophilics, and sensorial properties of color, aroma, flavor and body by both clarified banana juices. The juice clarified by Clarex was significantly (p < 0.01) more yellow, less grey, less opaque and less viscous than that obtained with CEC1-CTAA. There was no significant difference between the means of aroma of fresh banana and flavor in these juices. Furthermore, the values obtained for flavor for both juices were judged good (6.72 and 6.05 for the juices clarified with Clarex and CEC1- CTAA, respectively), because they were up the middle of the scale (from 0 to 10).

Verificação intralaboratorial da performance obtida em método de determinação de ocratoxina A por purificação em coluna de imunoafinidade e cromatografia líquida de alta eficiência usando café

Ochratoxin A is a food contaminant which can appear in several foods and can be harmful not only to human health, but also to the economy. In order to quantify properly an analite, even when using standard methods, it is necessary to check the validation method requirements. Therefore, a single laboratory validation of the method using immunoaffinity column and high performance liquid chromatography in spiked samples of ground green coffee beans was conducted. The evolution of the measurements along the analyte was sigmoid, as expected, and the range showed botton between 0.489 and 1.59, and top between 220 and 300 μg.kg-1, top. Linear regression was not rejected in this range and there was no external significant interference in the model. The intercept was in the origin and the linear coefficient did not differ significantly from 1.00 (p < 0.05). The standard deviations depended on the concentrations of ochratoxin A, similarly to studies in the literature, and the estimated values of the relative standard deviation obtained were in accordance with the values from those studies. Therefore, the laboratory proved competence in this measurement process, especially for green coffee beans.

Porção servida, heterogeneidade e seus efeitos em medidas sensoriais de dureza em ervilhas em conserva e biscoitos tipo aperitivo

The amount of material served to panelists and heterogeneity in foods, have ever been a trouble to the sensory analyst. They used to be regarded as interference in results and, sometimes, could explain no difference found in products or non realistic differences. In order to study these aspects, experiments were carried out with pods in brine and little biscuits employing the degree of difference test. The first experiment (Exp. I), with pods, showed no difference when employing one or five grains. Of course, to employ one grain can not be recommended. The other two experiments, Exp. II and Exp. III, with pods (the second) and little biscuits (the third) had not confirmed increasing of variability in results which could be regarded as related to heterogeneity of materials, and more, there was no evidence of great effects of heterogeneity on the observed averages. Then, the amount of material served to panelists and the heterogeneity in materials could not change the conclusions obtained from these experiments.