Luciana Toledo - Academia.edu (original) (raw)
Papers by Luciana Toledo
Neste trabalho descrevemos a síntese de β-dicetonatos de Tb 3+ e o aumento de sua solubilidade em... more Neste trabalho descrevemos a síntese de β-dicetonatos de Tb 3+ e o aumento de sua solubilidade em água através da formação de compostos de inclusão em α-ciclodextrina (α-CD). Os complexos [Tb(ppa) 3 (H 2 O) 2 ] e [Tb(ppa) 3 (phen)] (ppa=3-fenil-2,4-pentanodiona; phen = fenantrolina) foram sintetizados, caracterizados e a seguir incluídos em α-ciclodextrina. A inclusão foi confirmada por 1 H NMR e a estequiometria de associação determinada pelo método de Job. Nos espectros de excitação, os comprimentos de onda dos máximos de intensidade dos compostos de inclusão em solução aquosa [Tb(ppa) 3 (H 2 O) 2 ]:α-CD e [Tb(ppa) 3 (phen)]:α-CD apresentaram-se deslocados em 15 e 60 nm, respectivamente, com relação aos comprimentos de onda dos máximos dos complexos não incluídos. Nos espectros de emissão, as bandas características do Tb 3+ foram observadas mesmo após a inclusão dos compostos em α-CD. In this work we describe how the inclusion of Tb 3+ β-diketonate chelates into the hydrophobic cavity of α-cyclodextrin enhances the solubility of the complexes in aqueous medium and leads to changes in their photophysical properties. To this end, the complexes [Tb(ppa) 3 (H 2 O) 2 ] and [Tb(ppa) 3 (phen)] (ppa=3-phenyl-2,4-pentanedione; phen = phenantroline) were synthesized and characterized, and they were then included into α-cyclodextrin pockets. This inclusion was confirmed by 1 H NMR spectroscopy and the stoichiometry was determined by means of the Job method. In the excitation spectra, the maximum intensity wavelength of the inclusion compounds [Tb(ppa) 3 (H 2 O) 2 ]: α-CD and [Tb(ppa) 3 (phen)]:α-CD were displaced 15 and 60 nm respectively when compared with the non-CD starting complexes. The typical Tb 3+ emission bands were maintained after inclusion of the complexes into α-CD and their subsequent solubilization in aqueous medium.
Food Science and Technology (Campinas), 2010
Grape juice contains phenolic compounds in considerable amounts, and it is fit for human consumpt... more Grape juice contains phenolic compounds in considerable amounts, and it is fit for human consumption since it can increase the intake of natural antioxidants. The objectives of this study were to investigate the sensory attributes and to evaluate the acceptance of commercial grape juices. Three types of commercial grape juices were analyzed: pasteurized juice, concentrated juice, and sugar added pasteurized juice. A modified Quantitative Descriptive Analysis and an Acceptance Test with a structured nine-point hedonic scale were used including questions about consumption and purchase intention. The results indicated that the pasteurized juice showed higher intensity of color and bitterness; the concentrated juice (reconstituted) demonstrated low intensity of all attributes; and the sugar added product showed the highest intensity in sweetness and characteristic grape juice taste. The pasteurized and the sugar added juices were the most accepted products by consumers, who indicated consumption of grape juice of four or more glasses a month. Pasteurized juices received the highest purchase intention scores, and the sugar added juice was the most consumed. Although consumers appreciated pasteurized grape juices with higher intensities of attributes, the sugar added product was the most consumed.
Food handlers play an important role in the prevention of food-borne diseases. The objectives of ... more Food handlers play an important role in the prevention of food-borne diseases. The objectives of this study were to assess the socio-educational profi le, knowledge and risk perception about food hygiene of food handlers in commercial restaurants. Forty-two commercial restaurants were randomly selected in the city of Santos / SP. As a tool for data collection, a questionnaire based on Frewer, Shepherd e Sparks (1994) and adapted to the Brazilian standards by Schattan (2006) was used. It was divided into three parts: A-demographic and educational interview; B-17 multiple choice questionnaire and C-four questions about risk perception on food hygiene. As a result, 49 food handlers, aged 17-60 years, both male and female, were interviewed. The average age was 36 years and the most prevalent level of education corresponded to those who had fi nished elementary school (35%). Amongst the food handlers, 54% received training on Good Manufacturing Practices (GMP), which had occurred during the previous year for 27% of them. The average level of knowledge corresponded to 63% correct answers and the average level of risk perception was 6.4 cm. The question about the correct procedure for disinfection of vegetables and legumes received the lower percentage of correct answers (19%), showing also the lowest level of risk perception. This study demonstrated lack of knowledge and low risk perception of food handlers about some food hygiene issues and the importance of emphasizing the concept of risk perception in the training program.
Neste trabalho descrevemos a síntese de β-dicetonatos de Tb 3+ e o aumento de sua solubilidade em... more Neste trabalho descrevemos a síntese de β-dicetonatos de Tb 3+ e o aumento de sua solubilidade em água através da formação de compostos de inclusão em α-ciclodextrina (α-CD). Os complexos [Tb(ppa) 3 (H 2 O) 2 ] e [Tb(ppa) 3 (phen)] (ppa=3-fenil-2,4-pentanodiona; phen = fenantrolina) foram sintetizados, caracterizados e a seguir incluídos em α-ciclodextrina. A inclusão foi confirmada por 1 H NMR e a estequiometria de associação determinada pelo método de Job. Nos espectros de excitação, os comprimentos de onda dos máximos de intensidade dos compostos de inclusão em solução aquosa [Tb(ppa) 3 (H 2 O) 2 ]:α-CD e [Tb(ppa) 3 (phen)]:α-CD apresentaram-se deslocados em 15 e 60 nm, respectivamente, com relação aos comprimentos de onda dos máximos dos complexos não incluídos. Nos espectros de emissão, as bandas características do Tb 3+ foram observadas mesmo após a inclusão dos compostos em α-CD. In this work we describe how the inclusion of Tb 3+ β-diketonate chelates into the hydrophobic cavity of α-cyclodextrin enhances the solubility of the complexes in aqueous medium and leads to changes in their photophysical properties. To this end, the complexes [Tb(ppa) 3 (H 2 O) 2 ] and [Tb(ppa) 3 (phen)] (ppa=3-phenyl-2,4-pentanedione; phen = phenantroline) were synthesized and characterized, and they were then included into α-cyclodextrin pockets. This inclusion was confirmed by 1 H NMR spectroscopy and the stoichiometry was determined by means of the Job method. In the excitation spectra, the maximum intensity wavelength of the inclusion compounds [Tb(ppa) 3 (H 2 O) 2 ]: α-CD and [Tb(ppa) 3 (phen)]:α-CD were displaced 15 and 60 nm respectively when compared with the non-CD starting complexes. The typical Tb 3+ emission bands were maintained after inclusion of the complexes into α-CD and their subsequent solubilization in aqueous medium.
Food Science and Technology (Campinas), 2010
Grape juice contains phenolic compounds in considerable amounts, and it is fit for human consumpt... more Grape juice contains phenolic compounds in considerable amounts, and it is fit for human consumption since it can increase the intake of natural antioxidants. The objectives of this study were to investigate the sensory attributes and to evaluate the acceptance of commercial grape juices. Three types of commercial grape juices were analyzed: pasteurized juice, concentrated juice, and sugar added pasteurized juice. A modified Quantitative Descriptive Analysis and an Acceptance Test with a structured nine-point hedonic scale were used including questions about consumption and purchase intention. The results indicated that the pasteurized juice showed higher intensity of color and bitterness; the concentrated juice (reconstituted) demonstrated low intensity of all attributes; and the sugar added product showed the highest intensity in sweetness and characteristic grape juice taste. The pasteurized and the sugar added juices were the most accepted products by consumers, who indicated consumption of grape juice of four or more glasses a month. Pasteurized juices received the highest purchase intention scores, and the sugar added juice was the most consumed. Although consumers appreciated pasteurized grape juices with higher intensities of attributes, the sugar added product was the most consumed.
Food handlers play an important role in the prevention of food-borne diseases. The objectives of ... more Food handlers play an important role in the prevention of food-borne diseases. The objectives of this study were to assess the socio-educational profi le, knowledge and risk perception about food hygiene of food handlers in commercial restaurants. Forty-two commercial restaurants were randomly selected in the city of Santos / SP. As a tool for data collection, a questionnaire based on Frewer, Shepherd e Sparks (1994) and adapted to the Brazilian standards by Schattan (2006) was used. It was divided into three parts: A-demographic and educational interview; B-17 multiple choice questionnaire and C-four questions about risk perception on food hygiene. As a result, 49 food handlers, aged 17-60 years, both male and female, were interviewed. The average age was 36 years and the most prevalent level of education corresponded to those who had fi nished elementary school (35%). Amongst the food handlers, 54% received training on Good Manufacturing Practices (GMP), which had occurred during the previous year for 27% of them. The average level of knowledge corresponded to 63% correct answers and the average level of risk perception was 6.4 cm. The question about the correct procedure for disinfection of vegetables and legumes received the lower percentage of correct answers (19%), showing also the lowest level of risk perception. This study demonstrated lack of knowledge and low risk perception of food handlers about some food hygiene issues and the importance of emphasizing the concept of risk perception in the training program.