Vivianne Montarroyos Padilha

Avaliação do tempo de secagem e da atividade de óxido-redutases de yacon (Smallanthus sonchifolius) sob tratamento químico

Scientific evidences acknowledged the yacon (Smallanthus sonchifolius) like a promise source of fructans, as inulin and fructooligosaccharides - FOS, meanwhile, the presence of phenolic coumpounds became this susceptible to enzimatic browning reaction. This project aimed to evaluate the use of chemical agents in yacon processing to obtain flour in a way that inhibits enzymatic darkening of the product besides determining the enzymatic activity in these treatments. Samples of yacon without chemical inhibitions, yacon treated with 1.0g 100g-1 calcium chloride for 30 seconds and yacon treated with 0.5g 100g-1 potassium metabisulfite for 5 minutes were dried at 55oC in a ventilated greenhouse and the proportions of humidity and drying curves were determined. The peroxidase activities and polyphenol oxidase enzymes were checked before and after being dried with an enzymatic darkening possible biochemist marker of this tubercle. Regarding humidity Parameter all the three treatment were equivalent, but treatment 2 (calcium chloride) reduced the humidity in lower time. Before and after the thermal treatment the enzymatic activity was higher in treatment 3 (potassium metabisulfite). The thermal action did not inhibit completely polyphenol oxidase and peroxidase. The treatment with calcium chloride at 1.0g 100g-1 for 30 minutes to obtain yacon flour was the one with better result despite the fact that it did not inhibit completely peroxidase and polyphenol oxidase enzymes activity, offering a better drying time better material of row firmness , facilitating the process for obtaining the meal.

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.

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.

Perfil sensorial de bolos de chocolate formulados com farinha de yacon (Smallanthus sonchifolius)

This study evaluated the use of yacon flour in the formulation of chocolate cakes by investigating its influence on the sensory quality and chromaticity of the product. The following samples were prepared and analyzed: sample P (standard cake without yacon flour), sample A (20% of yacon flour), and sample B (40% of yacon flour). The Quantitative Descriptive Analysis (QDA) was used for the sensory analysis with 15 trained panelists who evaluated 9 sensory attributes (color, crumb structure, aroma, sweet taste, chocolate flavor, residual taste, humectancy, tenderness, and overall quality). The physical analysis of the cake was made by color characterization. The data were subjected to sensory analysis of variance ANOVA and the Duncans test for comparison between the averages, at 5% level of significance. To verify the correlations between the samples and attributes, the Principal Components Analysis (PCA) was performed. In the PCA, the sum of the principal components 1 and 2 was 83.3%, i.e., the variability between the samples was explained by these two components. The results showed that the addition of 40% of yacon flour resulted in higher scores for aroma (10.16), sweet taste (7.60), chocolate flavor (10.52), tenderness (11.44), and overall quality (11.64). With regard to the attribute crumb structure, there was no significant difference between the scores of cakes P, A, and B. Regardless of the amount of yacon flour added, the sensory profile of the chocolate cakes was influenced. Particularly, the cake with the highest content of yacon flour was attributed the highest scores.