Francine Ferreira Padilha

Extração, secagem por atomização e microencapsulamento de antocianinas do bagaço da uva "Isabel" (Vitis labrusca)

Objetivou-se obter neste trabalho um corante natural (antocianina), na forma de po a partir do bagaco de uva da cultivar Isabel (Vitis labrusca), onde foram realizados estudos de extracao e encapsulamento. Empregou-se o metodo de extracao por imersao mediante tecnica de planejamento experimental, onde as variaveis avaliadas foram pH da solucao de extracao (1-2), volume de etanol (100-250 mL), tempo de extracao (3-7 h) e temperatura de extracao (15-35oC). A concentracao maxima de antocianinas totais obtidas foi de 300 mg/100 g de bagaco de uva (umidade 5%) nos niveis inferiores de pH (1,0) e tempo (3 horas) e superiores de temperatura (35oC) e volume de etanol (250 mL). Os extratos foram secos por atomizacao. A melhor condicao para o encapsulamento e a secagem foi quando utilizaram-se proporcoes iguais de maltodextrina e goma arabica.

A Study of the Effects of Aeration and Agitation on the Properties and Production of Xanthan Gum from Crude Glycerin Derived from Biodiesel Using the Response Surface Methodology

The effects of aeration and agitation on the properties and production of xanthan gum from crude glycerin biodiesel (CGB) by Xanthomonas campestris mangiferaeindicae 2103 were investigated and optimized using a response surface methodology. The xanthan gum was produced from CGB in a bioreactor at 28xa0°C for 120xa0h. Optimization procedures indicated that 0.97xa0vvm at 497.76xa0rpm resulted in a xanthan gum production of 5.59xa0gxa0L−1 and 1.05xa0vvm at 484.75xa0rpm maximized the biomass to 3.26xa0gxa0L−1. Moreover, the combination of 1.05xa0vvm at 499.40xa0rpm maximized the viscosity of xanthan at 0.5xa0% (m/v), 25xa0°C, and 25xa0s−1 (255.40xa0mPaxa0s). The other responses did not generate predictive models. Low agitation contributed to the increase of xanthan gum production, biomass, viscosity, molecular mass, and the pyruvic acid concentration. Increases in the agitation contributed to the formation of xanthan gum with high mannose concentration. Decreases in the aeration contributed to the xanthan gum production and the formation of biopolymer with high mannose and glucose concentrations. Increases in aeration contributed to increased biomass, viscosity, and formation of xanthan gum with greater resistance to thermal degradation. Overall, aeration and agitation of CGB fermentation significantly influenced the production of xanthan gum and its properties.

Produção de biopolímero sintetizado por Sphingomonas capsulata a partir de meios industriais

Com este trabalho, avaliou-se a producao de biopolimero sintetizado por Sphingomonas capsulata ATCC 14666, utilizando-se os meios industriais melaco bruto e pre-tratado e residuo de proteina texturizada de soja (PTS). Foram testadas diferentes concentracoes de meios industriais (2,66, 4, 6 e 8%), cujas condicoes de fermentacao utilizadas foram 28o ± 2oC, 208 rpm, 72 h. Os ensaios foram realizados em triplicata e os resultados foram avaliados estatisticamente mediante o teste de Tukey. As melhores produtividades foram obtidas para melaco pre-tratado 8% (0,290 gL-1h-1), seguida de extrato aquoso de residuo de PTS 6% (0,240 gL-1h-1) e melaco bruto 8% (0,190 gL-1h-1). A qualidade reologica das gomas foi demonstrada atraves da leitura de viscosidade aparente de solucoes aquosas e salinas a 25 e 60oC.

Microorganisms screening for limonene oxidation

Limonene is a monoterpene obtained in large amounts from essential oils and is used as a raw material for the synthesis of flavors and fine chemicals. Several pathways or routes for the microbial degradation of limonene making use of the cytochrome P450-dependent monooxygenases have been described. In this study, we present a fermentative screening of microorganisms in order to verify their ability to perform the desirable conversion. In parallel, the PCR technique was used to select the microorganisms that contain the limC gene, which is responsible for the conversion of carveol to carvone. The microorganisms selected by PCR were not able to bioconvert limonene. From this result, we can suppose that these strains do not have the gene that codifies the enzyme responsible for the transformation of limonene into carveol. The results obtained in the fermentative screening showed that 4 microorganisms were able to bioconvert limonene into carveol. In addition, the amplification results showed the presence of fragments of 800 pb, expected for the limC gene. Therefore, the results obtained in the bioconversion and evaluation of the limC gene did not allow a correlation showing that these strains do not contain all the enzymes responsible for the conversion of limonene to carvone.

Chemical markers and antifungal activity of red propolis from Sergipe, Brazil

The aim of this study was to analyze the physicochemical properties and antifungal activities of the red propolis samples from Sergipe, Brazil, and also evaluate their variability throughout the year. The characterization of the hydroalcoholic extract (HPE) of the red propolis samples was performed monthly from October 2009 to September 2010. The concentrations of the bioactive compounds varied during the year, but their chromatographic profiles were similar. Four compounds were identified by comparison with authentic standards. Formononetin was one of the predominant compounds in all propolis extracts. In our study, it was observed that all the propolis samples inhibited the growth of Candida species. Multivariate analysis confirmed the variations in chemical composition and color of the HPEs throughout the year. The biological activities of the HPEs were statistically significant (p<0.05), and all samples exhibited antifungal properties.

Production and Rheological Characterization of Biopolymer of Sphingomonas capsulata ATCC 14666 Using Conventional and Industrial Media

This work was aimed at the production and rheological characterization of biopolymer by Sphingomonas capsulata ATCC 14666, using conventional and industrial media. The productivity reached the maximum of 0.038 g/L·h, at 208 rpm and 4% (w/v) of sucrose. For this condition, different concentrations of industrial medium were tested (2.66, 4, 6, and 8%). The best productivity was obtained using pretreated molasses 8% (w/v) (0.296 g/L·h), residue of textured soybean protein 6% (wt/v) (0.244 g/L·h) and crude molasses 8% (w/v) (0.192 g/L·h), respectively. Apparent viscosity presented similar results when compared with those in the literature for other biopolymers.