Leaves of a new variety of Stevia rebaudiana with a high content of rebaudioside A were pretreated with ethanol. The ethanolic extract showed high antioxidant potential and 39 compounds were identified, by UPLC/HRMS, among them one not yet mentioned in the literature for stevia leaves. From the in natura leaves and pretreated leaves, the conditions of aqueous extraction of steviol glycosides were investigated using response surface methodology. The aqueous extracts obtained were purified by ion exchange chromatography techniques and membrane separation methods. The recuperation of steviol glycosides was 4.02g for pretreated leaves and 2.20g for in natura leaves. The level of purity was, respectively, 87% and 84.8%. The results obtained demonstrate that pretreatment increases the yield and purity level of stevia sweeteners by the use of environmentally friendly methodologies and the final product presented acceptable sensory characteristics.

The aim of this study was to determine the composition and antioxidant potential of leaves of a new variety of Stevia rebaudiana (Stevia UEM-13). Stevia leaves of UEM-13 contain rebaudioside A as the main glycoside, while most wild Stevia plants contain stevioside. Furthermore can be multiplied by seed, which reduces the cost of plant culture techniques as other clonal varieties are multiplied by buds, requiring sophisticated and expensive seedling production systems. Ethanol and methanol were used in the extraction to determine the bioactive compounds. The methanolic extract was fractionated sequentially with hexane, chloroform, ethyl acetate and isobutanol, and the highest concentration of phenolic compounds and flavonoids was obtained in the ethyl acetate fraction (524.20 mg galic acid equivalent/g; 380.62 µg quercetin equivalent/g). The glycoside content varied greatly among the fractions (0.5% -65.3%). Higher antioxidant potential was found in the methanol extract and the ethyl acetate fraction with 93.5% and 97.32%, respectively. In addition to being an excellent source for obtaining of extracts rich in glycoside, this new variety can also be used as raw material for the production of extracts or fractions with a significant amount of antioxidant activity and potential to be used as additives in food.

ABSTRACT. Organizations responsible for public health throughout the world have been increasingly concerned with the feeding of the populations, by encouraging a nutritious and balanced diet in order to decrease the occurrence of chronic diseases, which are constantly related to an inadequate diet. Still, consumers are increasingly seeking convenient products due to the modern lifestyle. This being so, cereal bars have been an option when the issue is low calorie fast food and source of fiber. This study aimed at developing a cereal bar with high dietary fiber, iron, vitamins A and E, in order to easily enable adult population to achieve the daily recommendation for such nutrients. Eight formulations plus the focal point were prepared through experimental planning; sensory analysis was conducted with 110 tasters for each block and texture. Afterwards, we performed proximate analysis for all three formulations presenting the best sensory results. After statistical analysis and comparison with the means of products available in the market, it was possible to conclude that the product developed had great acceptance and fiber level more than double of mean values for commercial products.Keywords: cereal bars, functional food, dietary fiber.Desenvolvimento de barra de cereais com alto valor nutricional por planejamento experimental RESUMO. Organizações responsáveis pela saúde pública ao redor do mundo vêm se preocupando cada vez mais com a alimentação das populações incentivando a procura por alimentos nutritivos e balanceados, com o objetivo de diminuir os índices de doenças crônicas cada vez mais relacionadas à alimentação incorreta. Entretanto, os consumidores, em função do estilo de vida moderno, buscam cada vez mais a conveniência nos produtos. Neste contexto, as barras de cereais têm sido uma opção para o alimento rápido, com baixo valor calórico e como fonte de fibras. O objetivo deste estudo foi desenvolver uma barra de cereais com alto teor de fibra alimentar, ferro, vitaminas A e vitamina E, para que se atinja a recomendação diária desses nutrientes para a população adulta de maneira viável no dia a dia. Foram realizadas oito formulações mais o ponto central por meio de planejamento experimental, realizaram-se análises sensoriais com 110 provadores em cada bloco e de textura. Posteriormente, foi feita a análise centesimal das três formulações que apresentaram melhores resultados sensoriais. Após análise estatística dos resultados e comparação com as médias dos produtos disponíveis no mercado foi possível concluir que o produto desenvolvido apresentou elevada aceitação e teor de fibras de mais que o dobro da média dos produtos comerciais.Palavras-chave: barra de cereais, alimento funcional, fibra alimentar.

ResumoNa produção de extrusados de milho, a indústria usualmente emprega o grits, que consiste no milho limpo, degerminado e moído em granulometria média. Entretanto, visando à redução dos custos de produção, fabricantes de snacks extrusados de milho vêm utilizando o fubá em substituição ao grits, devido ao menor custo apresentado por este. O objetivo deste trabalho foi verificar a influência da granulometria do milho sobre o índice de expansão dos snacks, sua textura e aceitação sensorial. Para isso, foram utilizadas três diferentes granulometrias do milho moído, sendo: grits, fubá mimoso e fubá mimoso fino. O índice de expansão radial foi analisado pela razão entre o diâmetro médio do snack e o diâmetro da matriz utilizada, a textura foi analisada em texturômetro, modelo Texture Analyser TA-XT Plus (Stable Micro Systens). A partir dos resultados obtidos, houve a confirmação da influência da granulometria nos parâmetros físicos, entretanto, não ocorreu alteração na aceitação do produto, indicando, desta forma, ser viável a substituição do grits pelo fubá na produção de snacks sob o ponto de vista do produto final. Palavras-chave: Extrusão; Milho; Granulometria. SummaryIn order to produce extruded corn snacks, industry has usually employed grits (clean, degerminated corn, milled to a medium particle size). However, aiming at reducing production costs, extruded corn snack producers have been replacing grits by corn flour due to lower costs. The objective of this study was to assess the influence of corn particle size on the snack expansion rate, texture and sensory acceptance. Thus, three different milled corn particle sizes were used in this study: grits, mimoso corn flour and fine mimoso corn flour. The expansion rate was analyzed from the ratio between the mean snack diameter and the diameter of the matrix used, and the texture was analyzed using aTA-XT Plus Texture Analyser (Stable Micro Systems) with the WB-12 probe. The results obtained proved the influence of particle size on the physical parameters, but there was no change in product acceptance, indicating the feasibility of replacing grits by corn flour to produce snacks, when considering the final product.

Abstract:Cookies are bakery products rich in fat and sugars. Lipids have in general important nutritional and technology factors, but excessive intake can bring health risks. The reduced caloric value and lipid content is a common demand among biscuits consumers, which come to own up to 60% fat. This study aimed at developing formulations of cookies with partial replacement (Standard-0%, R1-25%, R2-50% and R3-75%) of fat by inulin as well as evaluating physical, physicochemical and sensory characteristics. Through the present study, it was observed that the partial replacement of fat by inulin in the production of cookies was effective in reducing the percentage of total lipids in the final product, with maximum reduction of 86% in formulation R3, without changing the parameters for moisture, crude fiber and instrumental color. Once insulin was increased, the size of the cookies after baking decreased, therefore increasing the crispness of the cookies made from the formulation with the highest level of replacement, represented by R3, which negatively impacted the sensory evaluation of flavor and purchase intention for the product, while formulation R2, with 50% fat replacement by inulin, presented similar results to the standard product, being the formulation with the greatest sensory acceptance and physical characteristics. Therefore formulation R2 was been good in nutritional and sensorial performance, and then it is best formulation.