ABSTRACT The use of natural antioxidants extracted from plants is an alternative to the application of synthetic antioxidants. In this study, we evaluated the oxidative stability of soybean oil after the addition of Curcuma longa L. leaf extracts compared to its oxidative stability with the synthetic antioxidant butylated hydroxytoluene (BHT Different concentrations (0.5%, 1.0%, and 1.5%) of ethanolic extract of Curcuma longa L. leaves were added to the oil, and the mixture was heated at 60 ±2 °C for 12 days. Several parameters of oxidative stability, including the peroxide index (PI), thiobarbituric acid reactive substances (TBARS), and conjugated dienes and trienes, were analyzed every three days. The results were promising, the oils to which the Curcuma longa L. leaf extract was added showed a reduction in all parameters, indicating oxidative deterioration under the influence of the concentration of the extract and the duration of treatment. The extract was less effective at low concentrations (0.5%), the parameters did not vary considerably. The PI was low in all treatments until the third day. The PI of the soybean oil treated with 1.5% extract was lower than that after treatment with the synthetic antioxidant and the blank treatment on days 6 to 12. The highest production of TBARS was observed in the blank treatment on days 6 to 12, and the lowest values of TBARS were recorded in the soybean oil treated with 1.5% extract. For the same concentration, the conjugated dienes varied from 2.05 to 8.6, and the trienes from 0.57 to 1.59.

RESUMO O uso de antioxidantes naturais de plantas tem sido uma abordagem alternativa aos antioxidantes sintéticos. O objetivo desse trabalho foi avaliar a estabilidade oxidativa do óleo de soja com adição de extrato de folhas de Curcuma longa L. em comparação com antioxidante sintético hidroxitolueno butilado (BHT). Ao óleo, adicionou-se o extrato etanólico de folhas de Curcuma longa L. nas seguintes concentrações 0.5%, 1.0%, 1.5%, submetidos a aquecimento a 60 °C ±2, por um período de 12 dias. Analises dos parâmetros da estabilidade oxidativa: índice de peróxido (IP), substâncias reativas ao ácido tiobarbitúrico (TBARS), dienos e trienos conjugados foram feitas a cada 3 dias. Os resultados foram promissores, os óleos com extrato de folha de Curcuma longa L. apresentou redução de todos os parâmetros indicativos de deterioração oxidativa, com influência da concentração e do tempo de estudo. A concentração 0,5% foi menos efetiva, os parâmetros não sofreram grandes variações. O IP foi menor em todos os tratamentos até o 3° dia, no óleo de soja com extrato de 1.5% o valore de índice de peroxido foi menor que o antioxidante sintético e o branco nos dias (6 a 12). Quanto ao TBARS a maior produção foi observada no branco nos dias (6 a 12) e os menores valores de TBARS foram evidenciados no óleo de soja com extrato 1.5%, para a mesma concentração os dienos conjugados variaram entre 2.05 a 8.6, e os trienos de 0.57 a 1.59.

RESUMO Pão de queijo (PQ) é um produto sem glúten, produzido a partir de amido de mandioca azedo. Apresenta casca crocante e miolo macio, lembrando uma estrutura extrudada. O amido de milho ceroso (AMC) é conhecido pela sua qualidade tecnológica e não foram encontrados estudos para sua aplicação na produção de PQ. Neste sentido o presente trabalho objetivou investigar o uso de AMC e de AMC fermentado, utilizando polvilho azedo de mandioca como inóculo, e seco ao sol (AMCF) na substituição do amido convencional (0, 25, 75, e 100%) e seus efeitos no desenvolvimento da massa, cor e propriedades de textura. Os dados foram analisados por ANOVA e teste de Tukey (p≤0.05%) e os resultados foram comparados com um produto comercial A melhor formulação foi caracterizada quanto sua composição proximal, aceitação sensorial e pela intenção de compra e os dados são apresentados pelas suas médias e desvio-padrão. Os parâmetros que diferiram estatisticamente foram as coordenadas de cor para o vermelho, capacidade de expansão, volume específico. Com 100% de AMCF a melhor formulação foi microbiologicamente segura. A composição proximal apresentou valores menores quando comparados com os valores da Tabela Brasileira de Composição de Alimentos. O produto pode ser considerado com boa aceitação, já que apresentou notas maiores que 7,79 para textura, aparência, sabor e intenção de compra. O AMCF pode ser considerado como um bom substituto para o polvilho azedo de mandioca.

ABSTRACT Brazilian cheese bread (CB) rolls are gluten-free bread made from sour cassava starch. They are soft in the center and have crispy crust, reminding of the extruded structure. Although native waxy maize starch (WMS) has higher technologic quality, it has not been used in CB rolls; therefore, this study aimed to investigate the use of WMS and the backslopping fermentation process plus sun drying in WMS to replace sour cassava starch (0, 25%, 75%, and 100%) and the effects on dough development, color, and textural properties. Data were analyzed using variance and Tukey test (p ≤ 0.05%), and the results were set against a commercial product from cassava starch. The better formulation was characterized by proximal composition, sensorial acceptance, and willingness to buy, and data were presented as means and standard deviation. The different statistic parameters included color to redness coordinate, baking expansion capacity, specific volume, hardness, fracturability, and chewiness. The best formulation had 100% of sundried WMS and was microbiologically safe. The proximal composition had lower values than that obtained from the Brazilian Food Database. The product was considered satisfactory as it had a score of more than 7.79 to texture, appearance, and flavor with higher willingness to buy (92.5%). The backslopping fermentation plus SWMS was considered a potential replacement for sour cassava starch.

Abstract The objective of this work was to elaborate fermented extracts using rice bran and broken rice grains (proportion 8:92) with probiotic bacteria and different concentrations of waxy maize starch (WMS) in order to obtain products with low level of syneresis and desirable physical-chemical characteristics, and to evaluate the content of phenolic compounds, antioxidant capacity and chemical composition of the extract selected and flavored with strawberry aroma and strawberry syrup. A randomized design was used with five treatments (0, 4, 8, 12 and 16 g 100 g–1 of WMS) and four replications. The fermented rice extract had increased soluble solids (from 12.97 to 14.23 °Brix) and total acidity (from 0.29 to 0.30 g 100 g–1), whereas total soluble sugars (from 9.24 to 8.73 g 100 g–1) and syneresis (from 10.16 to 0.99 g 100 g–1) decreased with gradual increments of waxy maize starch. The fermented rice extract containing 12 g 100 g–1 WMS reduced the syneresis by 89% compared to the control without waxy maize starch. The fermented rice extract with 12 g 100 g-1 of waxy maize starch flavored with strawberry aroma and strawberry syrup shows high nutritional value, antioxidant capacity, content of total phenolic compounds, and marketing potential, particularly for consumers with special needs, such as those allergic to lactose or soybean proteins, as an alternative food ready for consumption.

As lipases são um importante grupo de enzimas com diversas aplicações na indústria alimentar, química e farmacêutica, além de ter grande interesse para o tratamento de efluentes com alto teor de lipídios. Objetivou-se, neste trabalho, isolar, caracterizar e selecionar bactérias lipolíticas produtoras de lipase, a partir de efluentes residuais aquosos, assim como estudar a cinética da atividade enzimática do extrato obtido via fermentação submersa. Os resultados obtidos foram promissores, sendo possível isolar e caracterizar 23 microrganismos potencialmente produtores de lipase, sendo a maioria das bactérias Gram Positivas, porém após a etapa de fermentação em meio líquido, os Gram Negativos apresentaram as maiores atividades enzimáticas (56,72 U.L-1 para a bactéria ETE 2A` e 81,99 U.L-1 para a R2B). No estudo cinético da atividade enzimática com a bactéria selecionada (R2B), das seis variáveis (temperatura, pH, meio mínimo mineral, óleo de soja, glicose, e nitrato de sódio), a temperatura foi a que mais influenciou na atividade enzimática, tendo efeito positivo, e os melhores resultados foram obtidos a 40 °C. Concluiu-se que o extrato enzimático obtido, a partir de resíduos ambientais, poderão ser utilizados no próprio tratamento do efluente e contribuir na redução dos impactos ambientais.

Lipases are an important group of enzymes with various applications in the food, chemical and pharmaceutical industry, besides having great interest for the treatment of effluents with high lipid content. The objective of this study was to isolate, characterize and select lipolytic bacteria that produce lipase from aqueous waste effluents and to study the enzymatic activity kinetics of the extract obtained via submerged fermentation. The results obtained are promising, being possible to isolate and characterize 23 lipase-producing microorganisms, mostly gram-positive bacteria, but after the fermentation step in a liquid medium, gram negative bacteria showed the highest enzymatic activity (56.72 U.L-1 for STP 2A` bacterium and 81.99 U.L-1 for R2B). In the enzymatic activity kinetic study with the selected bacterium (R2B), among the six variables (temperature, pH, minimal mineral medium, soybean oil, glucose and sodium nitrate), temperature was the one that most positively influenced the enzymatic activity, and the best results were obtained at 40°C. It was concluded that the enzyme extract obtained from environmental waste may be used to treat the effluent and contribute to reduce environmental impacts.

Potato pulp waste (PPW) drying was investigated under different experimental conditions (temperatures from 50 to 70 °C and air flow from 0.06 to 0.092 m³ m- 2 s- 1) as a possible way to recover the waste generated by potato chip industries and to select the best-fit model to the experimental results of PPW drying. As a criterion to evaluate the fitting of mathematical models, a method based on the sum of the scores assigned to the four evaluated statistical parameters was used: regression coefficient (R²), relative mean error P (%), root mean square error (RMSE), and reduced chi-square (χ²). The results revealed that temperature and air velocity are important parameters to reduce PPW drying time. The models Midilli and Diffusion had the lowest sum values, i.e., with the best fit to the drying data, satisfactorily representing the drying kinetics of PPW.