Quantificação de carbamato de etila em vinhos

The ethyl carbamate is a compound present in most foods yeast-distillates; due to its carcinogenic potential, national legislation has established a limit of 0.150 µg / mL for spirits, so the values above the same, pose a threat to both public health as well for the economic sector by preventing the export of these products. The aim of this work is to provide the optimization of an analytical method employing the technique of gas chromatography equipped with flame ionization detector (FID) to determine the concentration levels of ethyl carbamate in some samples of wine. The use of ethyl acetate as solvent employed in the extraction, the ethyl carbamate present in wine samples proved to be suitable, where Recoveries were between 97.6 to 103.3% (m / m), with a standard deviation for between 0.56 to 3.50%. The concentrations of ethyl carbamate in particular wine samples vary between 3.22 µg / ml and 3.80 µg / mL, with a mean of 3.48 µg / mL. These valuesare all above the limit set by law. Thus, the results indicate the need for changes in the process of wine production, in order to control the levels of the substance

Caracterização físico-química e sensorial de vinhos brancos da região noroeste de São Paulo

Brazilian wines are appreciated by consumers for having fruity odor and taste which are typical from Vitis labrusca cultivars. The rusticity of these cultivars, the winemaking and the physicochemical properties are some of the key factors to obtain a quality beverage. In this context, the aim of this article was to analyze the quality of three white wines from wineries located in northwest region of São Paulo state by determining physicochemical properties and sensory profile. Data were analyzed by statistical tests and by Principal Component Analysis (PCA). It was possible to observe statistical differences (P<0,05) in most physicochemical properties. Furthermore, the PCA showed that the attributes body and color significantly explained the variance of the first and second component, respectively, higlighting the Vitis vinifera wine. Thus the connection between the physicochemical and sensory properties of white wines was important for characterization of these beverages produced in the northwest of São Paulo.

Porta-enxertos na produção e nas características físico-químicas da uva e do vinho de diferentes cultivares em Jundiaí, SP

Pós-graduação em Agronomia (Horticultura) - FCA

Influência do desponte de panículas de sorgo sacarino sobre a qualidade da matéria-prima e produção de bioetanol

Pós-graduação em Microbiologia Agropecuária - FCAV

Efeito da escovação dentária no manchamento de braquetes estéticos cerâmicos

Objective: this study aimed to analyze the in vitro effect of brushing on the color stability of ceramic brackets immersed in dye solutions. Materials and Methods: seven ceramic brackets of four commercial brands were tested: two monocrystalline and two polycrystalline. The parameters of color were obtained by spectrophotometer before and after 21 days of immersion of the brackets in coffee, red wine, Coca-Cola, black tea and artificial saliva. Another group of brackets of each brand were also immersed in the same solutions and for an equal time to the previous group, but with intervals of daily brushing performed by a toothbrushing machine (Mavtec). The data were evaluated by analysis of variance, multiple comparison tests for means and Student's t-test. Results: the mean color change of the brackets without brushing ranged from 0.46 to 7.61, while in the group with brushing these means ranged from 0.36 to 2.50. The staining still remained noticeable (change of color greater than 3.7) for all brackets when immersed in black tea. Conclusion: daily brushing helped significantly in the color stability of ceramic brackets, maintaining the color change to levels considered not visible to the human eye, except for the solution of black tea in which the staining remained relevant.

Effect of staining agents on color change of composites

Composite resins are materials that can present color changing when exposed to pigments. Objective: The aim of this study was to evaluate, in vitro, the color changing of composites after immersion in different substances for different periods. Material and methods: Two microhybrid composite resins: Charisma (Heraeus – Kulzer) and Opallis (FGM) were used. Red wine and acai pulp were also used as immersion medium. For this study, 32 specimens with 10 mm of diameter and 2 mm of thickness were used, divided into 4 groups: Group 1 – Opallis composite immersed in red wine solution; Group 2 – Opallis composite immersed in acai berry pulp solution; Group 3 – Charisma composite immersed in red wine solution; Group 4 – Charisma composite immersed in acai berry pulp solution. The specimens were evaluated in the following time periods: T0 – baseline, T1 – 24 hours, T2 – 48 hours, T3 – 72 hours and T4 – 96 hours. For the assessment of staining, a spectrophotometer for colorimetry was used (Color Guide 45 / 0, PCB 6807 BYK-Gardner Gerestsried GmBH, Germany), and the values obtained were transferred to a computer and recorded according to CIELAB system. Results: The data were evaluated using Kruskal- Wallis non-parametric tests with the following mean values for the immersion periods of 24, 48, 72 and 96 hours, respectively: G1 – 7.35, 7.84, 9.04,10.48; G2 – 2.92, 4.15, 4.30, 4.64; G3 – 3.14, 7.35, 8.13, 8.43, G4 – 4.49, 5.99, 6.92, 6.76. Conclusion: Red wine showed a higher tendency toward altering the composite color than acai berry pulp. In addition, no significant difference was found concerning to the behavior of the two composite resins. Concerning to the immersion time periods, significant differences were only observed among the groups in the 24 hour time period.

In vitro study of staining agents effects on optical properties of esthetic restorative materials

The authors have studied the effect of four staining agents on the optical properties of esthetic restorative materials through translucency tests. Two commercial brands of composite resins were used: Point 4 (Kerr) and Charisma (Heraeus-Kulzer). The liquids tested were: wine, cola, chlorhexidine solution and nicotine solution. The translucency was measured at different periods of time: P0 – before immersion (baseline), P1 - 1 h after immersion, P2 - 2 h after immersion and successively, P3 – 24 h after immersion up to a period of 7 weeks. ANOVA statistical analysis was applied to the data (p < 0.05). The results lead to the following conclusions: (1) Composite resins submitted to the tested immersion mediums were stained, (2) the lower percentage of translucency was observed for nicotine containing solution, (3) The percentage of translucency decreased with the period of immersion.

Colour stability of acrylic resin denture teeth after immersion in different beverages

The colour stability of acrylic resin denture teeth in beverages was investigated. A spectrophotometer measured the colour (CIE-L*a*b* system) of all specimens after storage in distilled water for 24 h at 37°C (T0). Specimens were then immersed in various beverages. After 15 days (T1) and 30 days (T2), for each material, the mean ∆E values were calculated and compared by two-way ANOVA and Tukey intervals (α=0.05). In the ∆T0T1 period, specimens stored in red wine were significantly discoloured, compared to distilled water (P=0.003). There was no difference between immersion solutions in ∆ET0T2 (P=0.772) and in ∆ET1T2 (P=0.058), and no difference between materials in all immersion periods.

In vitro study of color stability of polycrystalline and monocrystalline ceramic brackets

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Green and brown propolis: efficient natural biocides for the control of bacterial contamination of alcoholic fermentation of distilled beverage

This study aimed to evaluate the efficiency of natural biocides, brown and green propolis, for the control of bacterial contamination in the production of sugarcane spirit. The treatments consisted of brown and green propolis extracts, ampicillin, and a control and were assessed at the beginning and end of harvest season in ten fermentation cycles. In the microbiological analyses, the lactic acid bacteria were quantified in the inoculum before and after the treatment with biocides, and the viability of yeast cells during fermentation was evaluated. The levels of acids, glycerol, total residual reducing sugars, and ethanol were analyzed for the wine resulting from each fermentation cycle. A reduction in the number of bacterial contaminants in the inoculum in the treatments with the natural biocides was observed, but it did not affect the viability of yeast cells. The control of the contaminants led to the production of higher levels of ethanol and reduced acidity in the wine produced. The results of the use of brown and green propolis to control the growth microorganisms in the fermentation of sugarcane spirit can be of great importance for using alternative strategies to synthetic antibacterials in fermentation processes including other distilled beverage or spirits.

Produção de bioetanol a partir da fermentação de caldo de sorgo sacarino e cana-de-açúcar

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Produção de bioetanol de segunda geração pelo consórcio Zymomonas mobilis CCT4494 e Candida tropicallis em resíduos de uvas Isabel e Bordô

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Seleção, avaliação e utilização de uma levedura personalizada para a produção de etanol

Pós-graduação em Microbiologia - IBILCE

Produção de etanol a partir de sorgo sacarino com tratamento enzimático

Pós-graduação em Microbiologia Agropecuária - FCAV