Gil Eduardo Serra

Evaluation of paraffins biodegradation and biosurfactant production by Bacillus subtilis in the presence of crude oil

Bacillus subtilis experiments for surface tension evaluation were accomplished with culture medium containing 0.4% nitrate ions and 4% glucose basic nutrient in the presence of crude oil. Surfactin production was observed by surface tension reduction of the culture broth. Surfactin was isolated from Bacillus subtilis fermented broth, by acid-precipitation followed by extraction with chloroform-methanol. Evaluation of the linear alkanes composition was performed by capillary gas chromatography. We observed a significant reduction of the surface tension of the fermented broth indicating that the biosurfactant production was not inhibited by the crude oil presence, and that the light paraffins might have been consumed.

Potencial tecnológico do galactomanano de sementes de faveiro (Dimorphandra mollis) para uso na indústria de alimentos

The use of seed gums has brought a lot of benefits to the food industry, improving their properties primarily for their ability of thickening, stabilising and gelling. The gums obtained from the endosperm of legume seeds are composed of mannose and galactose in different proportions. Using a procedure of grinding and milling, an extract rich in galactomannan (83.2%), with a mannose:galactose ratio of 2.7, was obtained from faveiro (Dimorphandra mollis), which is a Brazilian species native to the savannah and caatinga environments. The yield and composition obtained were comparable to the commercially exploited gums of guar (yield=78-82% and ratio=2) and carob (yield=88% and ratio=4). Biological assays showed that the gum from faveiro is practically atoxic. These results suggest that the gum from Dimorphandra mollis has a potential for industrial applications in the food industry. As this species is already used in Brazil for extraction of phenolic compounds and as it is of large occurrence in the savannah and caatinga ecosystems, its exploitation might be performed in a sustainable fashion with low environmental impact.A utilizacao de gomas de sementes tem trazido muitos beneficios a industria de alimentos, melhorando as propriedades dos produtos, principalmente pelo seu poder espessante, estabilizante e geleificante. Gomas obtidas a partir do endosperma de sementes de leguminosas sao compostas por manose e galactose (galactomanano). A partir da trituracao e posterior peneiramento das sementes de faveiro (Dimorphandra mollis), especie brasileira que ocorre com alta frequencia nos cerrados e caatinga, foi obtido um extrato rico em galactomanano (83,2%) com proporcao manose:galactose 2,7. Esses parâmetros sao comparaveis aos obtidos para os galactomananos de uso consagrado em formulacoes de alimentos, tais como a goma guar com 78-82% de rendimento e razao manose galactose igual a 2 e a goma locusta com 88% de rendimento e razao manose:galactose igual a 4. Ensaios biologicos demonstraram que a goma do faveiro e considerada praticamente atoxica. Esses resultados sugerem que a goma de Dimorphandra mollis apresenta potencial para ser utilizada em formulacoes de alimentos. Alem disso, como e especie ja utilizada para a extracao de rutina e tambem especie de larga ocorrencia em ecossistemas de grande importância tais como o Cerrado e a Caatinga, sua exploracao poderia ser feita de forma ecologicamente sustentavel.

Characterization of storage cell wall polysaccharides from Brazilian legume seeds and the formation of aqueous two-phase systems

Cell wall storage polysaccharides from Brazilian legume seeds of Dimorphandra mollis, Schizolobium parahybum (galactomannans), Copaifera langsdorffii, Hymenaea courbaril (xyloglucans) and the galactan from cotyledons of the Mediterranean species Lupinus angustifolius were extracted and their apparent molecular masses were determined by high-performance size exclusion chromatography analysis. They were, to a large degree, polydisperse, showing molecular masses that varied from 100,000 to 2,000,000. Polyethylene glycol (PEG, 1500, 4000, 6000 and 8000), sodium citrate and dextran (73,000, 60,000-90,000, 505,000 and 2,000,000) were used for investigating phase formation with the seed polysaccharides. Galactomannans and xyloglucans demonstrated phase formation with sodium citrate concentrations lower than 30%, as well as dextrans and polyethylene glycol, and formed gels in the presence of high concentrations of sodium citrate (above 30%). Galactan did not promote phase formation with any of the reagents used. On the basis of the results obtained, the possibility of using legume seed polysaccharides for the partitioning and purification of polysaccharide enzymes in aqueous two-phase systems is suggested.

Produção de xarope de açúcar invertido obtido por hidrólise heterogênea, através de planejamento experimental

The use of liquid sugar in the food industry constitutes a great advantage in applications where the sugar is added in solution. The invert syrup gathers the high solubility of the frutose to the difficult crystallization of the glucose, increasing its sweetness and decreasing the crystallization risks. Those properties contribute to increase the value of those syrups for use in several products, above all in the industry of soft drinks. The objective of this work was improve the stages of invert syrup production using ion exchange resins, seeking to obtain a final product of high quality that assists to the needs of the industry of soft drinks using the experimental design. The production of inverted syrup began with sucrose decolorization process employing two anionic resins columns and subsequent elution through a cationic resin column, which promoted sucrose hydrolysis until inversion level desired. The obtained product was exempted practically of any objection to the palate, scentless, low levels of color (56 ICUMSA) and HMF (11 ppm). Determination of molds, yeasts and bacteria were smaller than 1 unit/mL.

Addition of proteic nitrogen during alcoholic fermentation for the production of cachaça

Cachaca is the denomination of a typical and exclusive Brazilian spirit produced from the distillation of fermented sugarcane juice must. The objective of this study was to evaluate the effect of adding yeast extract to the sugarcane juice used for sugarcane liquor production, because for the artisanal process no studies are available on nitrogen addition nor beverage quality, involving nitrogen complementation. Results of previous studies in the laboratory scale showed that sugarcane juice complementation with proteic nitrogen can be a beneficial practice for yeast multiplication and cellular growth, and also for the improvement of fermentation yield and liquor productivity. In this pilot scale study, using recycled yeast, the addition of proteic nitrogen influenced positively the cell viability, confirmed the yeast recycling operation, and also reduced the fermentation time. The proteic nitrogen addition did not affect the sensory acceptance of the distillate, and did not change the contents of volatile compounds, indicating that assimilable forms of proteic nitrogen can be helpfull to improve the alcoholic fermentation for cachaca production.

Impurezas fibrosas da cana-de-açúcar e parâmetros tecnológicos do caldo extraído

O presente trabalho teve por objetivo verificar o efeito da presenca de folhas verdes e folhas secas nos parâmetros tecnologicos do caldo da cana-de-acucar, tendo como controle a adicao de fibra do colmo. Os ensaios foram delineados tendo por base a adicao de quantidades das fontes fibrosas - folha verde, folha seca e fibra do colmo - para formular amostras que correspondessem a acrescimos absolutos de 0,25 ; 0,50 e 0,75 pontos porcentuais sobre o teor de fibra da cana do tratamento controle. Os resultados mostraram que a presenca de folhas verdes causaram reducao no Brix, pol e pureza do caldo, e elevacao do teor de acucares redutores e cinzas do caldo. Estes resultados, estatisticamente significativos a nivel de 1% de probabilidade, foram expressos por equacoes de regressao linear e coeficiente de correlacao. A presenca de folhas secas bem como a adicao de fibra do proprio colmo, nao induziram a alteracoes no caldo.

Estudo da reciclagem de células na produção biológica de etanol

In alcohol distilleries the ethanol content in recycled yeast suspension range from 2% to 3%. Recycling yeast cells is a useful tool to inoculate another fermentation batch or to continuous fermentation. The ethanolic fermentation and yeast recovering were evaluated in laboratory. The yeast suspension recovered from the wine, by centrifugation, was treated before re-inoculation in new fermentation media, to evaluate the ethanol and other metabolites toxic effect influences in the next fermentations batch. The Saccharomyces cerevisiae IZ-1904 strain was used to inoculate molasses medium with 180g L-1 and 310g L-1 of total reducing sugars (TRS). The yeasts recovering treatment was made with double centrifugation and yeast suspension in water and wine. Eight sequential batch fermentations were done, each with three replications. The first fermentation with fresh yeast, and others with recycled cells. The high sugar content was necessary to generate elevated ethanol concentration in the wine, and to confer hard fermentation conditions so the effects of any toxic compounds were introduced and more easily detected. In fermentations with less than 6.4% ethanol (v v-1) there was no toxic effect detected. The ethanol and other metabolites inhibition on yeast were detected and the results showed that the reduction of those components from the recycled yeast suspension might optimize the fermentation process. Ethanol production and yeast death rate were affected by the recycling of ethanol.

Folhas verdes, folhas secas, fibra do colmo e a clarificação do caldo de cana-de-açúcar

A presenca de impurezas vegetais, como folhas verdes e secas, nos carregamentos de cana-de-acucar entregues nas usinas de acucar, tem preocupado os tecnicos nao somente por se tratar de um material sem qualquer valor tecnologico para processamento, como ainda por poder causar aumento na cor do caldo clarificado e consequentemente na cor do acucar produzido, com reducao de sua qualidade para o mercado; outro problema e o volume do lodo decantado nos clarificadores, cujo aumento causa maior recirculacao e maior volume do caldo filtrado, com maiores perdas de sacarose e maior utilizacao dos filtros rotativos a vacuo. O trabalho teve como objetivo avaliar a clarificacao do caldo de cana-de-acucar com a adicao de folhas verdes e folhas secas, tendo como controle a adicao de fibra do colmo. Os ensaios foram delineados tendo como base a adicao de quantidades das fontes fibrosas - folha verde, folha seca e fibra do colmo - para formular amostras que correspondessem a acrescimos absolutos de 0,25 , 0,50 e 0,75 ponto percentual sobre o teor de fibra do colmo da cana. Os efeitos sobre a clarificacao do caldo, conduzida em clarificador de bancada em laboratorio, foram avaliados pela cor do caldo clarificado e o volume de lodo decantado. Na presenca de folhas verdes ocorreu uma elevacao da cor do caldo clarificado e do volume de lodo decantado. Da folha verde sao extraidos agua e compostos que sao responsaveis por alteracoes na composicao do caldo; devido a presenca de componentes nao-sacarose o extrato foliar interfere na clarificacao do caldo. Da folha seca tambem foram extraidos compostos soluveis, todavia nao detectados atraves das analises do caldo. A fibra do colmo nao afetou a clarificacao.

SOYA PROTEIN ISOLATED IN ALCOHOLIC FERMENTATION FOR THE PRODUCTION OF CACHAÇA

SOYA PROTEIN ISOLATED IN ALCOHOLIC FERMENTATION FOR THE PRODUCTION OF CACHACA The goal of this work was to evaluate the use of soya protein isolated as a proteic nitrogen organic source for sugar cane juice complementation and the effect in the yeast cell viability maintenance and cachaca quality. Batch fermentations of sugarcane juice with yeast recycling were performed, in scale pilot. The soya protein isolated influenced positively the cellular viability maintenance, and consequently resulted in a better recycled ferment and a reduction in time of fermentation. The proteic nitrogen addition in the juice didn’t affect the sensory acceptance of cachaca, and also didn’t result in different levels of volatile compounds. KEY-WORDS: Saccharomyces cerevisiae; CELULAR VIABILITY; VOLATILE COMPOUNDS; SENSORY ANALYSIS.

Seeds of faveiro (Dimorphandra mollis) as a potential source of galactomannan for the food industry

The use of seed gums has brought a lot of benefits to the food industry, improving their properties primarily for their ability of thickening, stabilising and gelling. The gums obtained from the endosperm of legume seeds are composed of mannose and galactose in different proportions. Using a procedure of grinding and milling, an extract rich in galactomannan (83.2%), with a mannose:galactose ratio of 2.7, was obtained from faveiro (Dimorphandra mollis), which is a Brazilian species native to the savannah and caatinga environments. The yield and composition obtained were comparable to the commercially exploited gums of guar (yield=78-82% and ratio=2) and carob (yield=88% and ratio=4). Biological assays showed that the gum from faveiro is practically atoxic. These results suggest that the gum from Dimorphandra mollis has a potential for industrial applications in the food industry. As this species is already used in Brazil for extraction of phenolic compounds and as it is of large occurrence in the savannah and caatinga ecosystems, its exploitation might be performed in a sustainable fashion with low environmental impact.A utilizacao de gomas de sementes tem trazido muitos beneficios a industria de alimentos, melhorando as propriedades dos produtos, principalmente pelo seu poder espessante, estabilizante e geleificante. Gomas obtidas a partir do endosperma de sementes de leguminosas sao compostas por manose e galactose (galactomanano). A partir da trituracao e posterior peneiramento das sementes de faveiro (Dimorphandra mollis), especie brasileira que ocorre com alta frequencia nos cerrados e caatinga, foi obtido um extrato rico em galactomanano (83,2%) com proporcao manose:galactose 2,7. Esses parâmetros sao comparaveis aos obtidos para os galactomananos de uso consagrado em formulacoes de alimentos, tais como a goma guar com 78-82% de rendimento e razao manose galactose igual a 2 e a goma locusta com 88% de rendimento e razao manose:galactose igual a 4. Ensaios biologicos demonstraram que a goma do faveiro e considerada praticamente atoxica. Esses resultados sugerem que a goma de Dimorphandra mollis apresenta potencial para ser utilizada em formulacoes de alimentos. Alem disso, como e especie ja utilizada para a extracao de rutina e tambem especie de larga ocorrencia em ecossistemas de grande importância tais como o Cerrado e a Caatinga, sua exploracao poderia ser feita de forma ecologicamente sustentavel.