Alda Verônica Souza Livera

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.

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.

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.

Bebida à base de flocos de abóbora com inulina: características prebióticas e aceitabilidade

Os resultados fisico-quimicos demonstram que as formulacoes pouco diferiram quanto a composicao centesimale que a ingestao 200mL/dia contribui, em media, com 10,8%, 36,0%, 10,2%, 12,6%, 37,1% e 126,4% daRecomendacao de Ingestao Diaria de energia, proteinas, carboidratos, lipideos, fibra alimentar e carotenoides,respectivamente. Os resultados microbiologicos comprovaram a inocuidade do produto; os sensoriais que asformulacoes obtiveram uma aceitacao em torno de 70% e os dados da avaliacao do efeito prebiotico sugeremmaior estudo sobre o tema.

MODIFICAÇÃO DA CONCENTRAÇÃO DE AMIDO RESISTENTE EM FEIJÃO MACASSAR (Vigna unguiculata L. WALP) POR TRATAMENTO HIDROTÉRMICO E CONGELAMENTO

Considering the importance of the functional properties of resistant starch for health, the high consumption of the macassar bean in the northeast of Brazil and the effects of the thermal process and storage on the structure of the starch, this work was implemented to evaluate the influence of different hydrothermal treatments (cooking under pressure and whithout pressure) and of storage at 20oC for 15 and 30 days, on the formation of resistant starch in the macassar bean, in two stages of maturation (green and dryed). To analyse the combined factors, a factorial design type 23 was realized with three independent variables (factors) and one dependent variable (response). All the variables exercised significant effects on the production of the resistant starch and the highest formation was registered for the dried bean due to the previous hydration before cooking without pressure, as well as the 30 day frozen storage. Concerning the physics analysis after the hydrothermic treatments there are transformations in the cristalinity patterns and in the morphologic aspect of the beans.

Influence of heat treatment on the sensory and physical characteristics and carbohydrate fractions of french-fried potatoes (Solanum tuberosum L.)

The aim of this study was to analyze the impact that heat treatment with salts and freezing processes on the sensory, instrumental, and physico-chemical characteristics of fried potatoes of the Monalisa cultivar. The potatoes were blanched in distilled water (P); sodium chloride solution (B1); calcium chloride solution (B2), and a solution with both of these salts (B3). They were then pre-cooked and frozen for 24 hours and for 30 days. After frying, sensory characteristics were analyzed (color, texture, flavor, oiliness), along with overall preference and instrumental determinations of texture, color, and oil content. Further tests were conducted on the sample with the best results in the sensory analysis (B1), along with sample P as a control, to determine granule microstructure, carbohydrate fractions, glycemic index, and glycemic load. Blanching B3, despite reducing oil absorption and providing less oiliness, obtained lesser overall preference. Freezing for 30 days increased the lightness, except for when sodium chloride was used, which intensified the color yellow. The use of sodium chloride did not interfere with the type of starch granules, nor with the formation of resistant starch; however, longer freezing time reduced the glycemic index and concentrated the dietary fiber content. All samples exhibited low glycemic index and moderate glycemic loads.

Phisicochemical, sensory, and microbiological evaluation and development of symbiotic fermented drink

The goal of this study was to develop a symbiotic lacteous drink, evaluate its physicochemical and sensory characteristics, and verify the viability of Lactobacillus acidophilus in the drink. The milk serum-based drink consisted of 50% milk serum containing 10% saccharose, 25% powdered milk, 15% yacon pulp, and cultures of Lactobacillus acidophilus-La 5E and Bifidobacterium bifidum BB12. It was stored for up to 21 days under refrigeration. The milk serum-based drink was analyzed for protein, ether extract, total dietary fiber, total frutans, carbohydrate content, color, pH, acidity, and contamination by coliforms, and Salmonella sp. Coliforms and Salmonella sp were not detected, and L. acidophilus and B. bifidum provided satisfactory probiotic counts up to 21 days of storage under refrigeration. Lactobacillus acidophilus resistance to gastric acids and bile salts was detected only up to seven days of storage when evaluated in vitro. Sensory analysis and purchase viability were evaluated by consumers at 0, 7, 14, and 21 days of storage. Based on the analytical results and consumer evaluation, the drink was acceptable up to seven days of storage.