Bovine Blood Constituents as Fat Replacers in Ham Pâté

Some tests were carried out in this work with the aim of evaluating a partial replacement of fat in the raw batter of ham pâté by using bovine blood constituents, such as globin (GL), plasma (PL) or 1:1 globin and plasma (GP). Plasma was separated from red cells by blood centrifugation, and globin was extracted by the carboxymethylcellulose method. The salt-soluble protein content (SSP) and the binding properties including water holding capacity (WHC) and raw batter stability (RBS) were estimated. The results indicated that among the 3 treatments studied, the use of globin showed to be a little more advantageous for the quality of the raw batter of ham pâté, since its incorporation as fat replacer led to an increase in RBS but no change of SSP was observed

Methylxantines by capillary electrophoresis : method development, optimization and validadion. Application to decaffeinated coffee and other beverages

Orientador: Helena Teixeira GodoyTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de AlimentosResumo: A otimização simultânea de múltiplas respostas foi utilizada no desenvolvimento de um método por eletroforese capilar (EC) para a determinação de cafeína em café descafeinado. O método foi desenvolvido utilizando o planejamento composto central para otimizar a concentração de dodecilsulfato de sódio (SDS), a concentração de carbonato de sódio e a voltagem. Os experimentos foram conduzidos com uma amostra de café descafeínado, onde o resíduo de cafeína foi extraído com clorofórmio, ressuspenso em água e filtrado. As condições otimizadas foram encontradas pela avaliação dos efeitos de seis respostas: separação de interferentes, área, ruído, variação na linha de base, corrente e tempo de análise. Modelos de regressão lineares e quadráticos foram gerados para cada conjunto de respostas. Os modelos de regressão, coeficientes de correlação e a análise de componentes principais (PCA) foram usados na determinação das condições experimentais ótimas. Os melhores resultados foram obtidos usando-se um capilar de 50 mm x 48 cm, tampão contendo 10 mmol. L-1 de carbonato de sódio e 50 mmol. L-1 de SDS (pH 11,0), 15 kV, 25,0 ºC e detecção a 206 nm. Sob as condições otimizadas, a cafeína foi separada dos interferentes. O tempo de análise foi de 5,5 min. O método desenvolvido foi validado e comparado a um método por CLAE quanto à eficiência de separação, tempo de análise, custo por análise e volume de resíduos gerados. O método por EC foi então aplicado a amostras de café descafeinado torrado moído e instantâneo e amostras de bebida enérgética. A quantidade total de xantinas presentes nas bebidas chimarrão e tererê, a base de erva-mate (Ilex paraguariensis), também foi avaliada. Estas bebidas foram preparadas como são tradicionalmente consumidas. Os valores de cafeína das amostras analisadas tanto por EC quanto por CLAE não foram estatisticamente diferentes a 95% de confiança. A sensibilidade do método por CLAE foi 42 vezes maior que a do método por EC, porém este apresentou um tempo total de análise 30,4% menor. O volume de resíduos gerados foi 33 vezes maior no método por CLAE, e o custo em reagentes foi 76,5 vezes menor por EC. A vantagem mais importante do método por EC foi o uso de tampão aquoso econômico e ecológico no processo de separação. Com relação às amostras analisadas, sete amostras de café de quatro diferentes marcas apresentaram teor de cafeína acima do permitido pela legislação brasileira, e 76% das bebidas energéticas possuíam menos cafeína do que o valor informado no rótulo do produto. O teor de cafeína e teobromina variou nos diferentes tipos comerciais de erva-mate empregados no preparo das bebidas. Além disso, o tererê apresentou níveis de xantinas 2,5 vezes maior que o chimarrãoAbstract: Multiple response simultaneous optimization was used to develop a micellar electrokinetic chromatography (MECK) method for caffeine determination in decaffeinated coffee samples. The method was developed using a central composite design to optimize the concentration of sodium dodecylsulfate (SDS), sodium carbonate and voltage (V). The experiments were carried out using a sample of Brazilian decaffeinated coffee extracted with chloroform, which was subsequently recovered with water and then filtered. Optimized conditions were found by evaluating the effects of six responses: interferent separation, area, noise, baseline variation, current e analysis time. Each set of response values was regressed on the factor levels of the experimental design using linear and quadratic models. The regression models, correlation coefficients involving both factor levels and response values, and a principal component analysis (PCA) were used to determine the optimum experimental conditions. Successful results were obtained using a fused-silica capillary of 50 mm x 48 cm total length, buffer containing 10 mmol. L-1 of sodium carbonate and 50 mmol. L-1 of SDS (pH 11.0), voltage of 15 kV, temperature of 25.0 ºC, with detection at 206 nm. Under optimized conditions, caffeine was separated from the interferents. The analysis time was of 5.5 min. After validation, the capillary electrophoresis (CE) method was compared to a HPLC method regarding separation performance, quantification of caffeine in twenty samples, analysis time, costs per analysis and volume of generated residue. CE method was applied to decaffeinated instant and groundroasted coffee, and energy drinks. The total amount of xanthines in mate (Ilex paraguariensis) beverages, ¿chimarrao¿ and ¿terere¿ obtained in the same way as they are traditionally consumed, was also estimated using the CE method. Caffeine content of the samples analyzed with both CE and HPLC methods did not differ statistically at 95% confidence level. HPLC method sensitivity was 42 times greater than by CE method. In another hand, CE presents total analysis time 30.4% lower than HPLC. The volume of generated residues was 33 times greater in HPLC and the cost in reagents for CE was 76.5 times lower than for HPLC. The most important advantage of CE is the use of economical and ecological aqueous buffer in the separation process. Regarding samples analyzed, seven decaffeinated coffee samples of four different brands showed higher levels than the limit specified by Brazilian legislation and 76% of the energy drinks samples had caffeine content lower than the value informed to the consumer. Caffeine and theobromine levels varied in different commercial types of mate employed for the beverages preparation. Besides, ¿terere¿ presented quantities 2.5 times higher than the ¿chimarrao¿ beverageDoutoradoDoutor em Ciência de Alimento

Comparison of capillary electrophoresis and high performance liquid chromatography methods for caffeine determination in decaffeinated coffee

Decaffeinated coffee accounts for 10 percent of coffee sales in the world; it is preferred by consumers that do not wish or are sensitive to caffeine effects. This article presents an analytical comparison of capillary electrophoresis (CE) and high performance liquid chromatography (HPLC) methods for residual caffeine quantification in decaffeinated coffee in terms of validation parameters, costs, analysis time, composition and treatment of the residues generated, and caffeine quantification in 20 commercial samples. Both methods showed suitable validation parameters. Caffeine content did not differ statistically in the two different methods of analysis. The main advantage of the high performance liquid chromatography (HPLC) method was the 42-fold lower detection limit. Nevertheless, the capillary electrophoresis (CE) detection limit was 115-fold lower than the allowable limit by the Brazilian law. The capillary electrophoresis (CE) analyses were 30% faster, the reagent costs were 76.5-fold, and the volume of the residues generated was 33-fold lower. Therefore, the capillary electrophoresis (CE) method proved to be a valuable analytical tool for this type of analysis

Comparison of capillary electrophoresis and high performance liquid chromatography methods for caffeine determination in decaffeinated coffee Comparação de métodos por eletroforese capilar e cromatografia líquida de alta eficiência para a determinação de cafeína em café descafeinado

Decaffeinated coffee accounts for 10 percent of coffee sales in the world; it is preferred by consumers that do not wish or are sensitive to caffeine effects. This article presents an analytical comparison of capillary electrophoresis (CE) and high performance liquid chromatography (HPLC) methods for residual caffeine quantification in decaffeinated coffee in terms of validation parameters, costs, analysis time, composition and treatment of the residues generated, and caffeine quantification in 20 commercial samples. Both methods showed suitable validation parameters. Caffeine content did not differ statistically in the two different methods of analysis. The main advantage of the high performance liquid chromatography (HPLC) method was the 42-fold lower detection limit. Nevertheless, the capillary electrophoresis (CE) detection limit was 115-fold lower than the allowable limit by the Brazilian law. The capillary electrophoresis (CE) analyses were 30% faster, the reagent costs were 76.5-fold, and the volume of the residues generated was 33-fold lower. Therefore, the capillary electrophoresis (CE) method proved to be a valuable analytical tool for this type of analysis.<br>O comércio de café descafeinado constitui 10% das vendas mundiais de café, sendo preferido pelos consumidores que não desejam ou são sensíveis aos efeitos da cafeína. Este artigo apresenta uma comparação analítica de métodos por eletroforese capilar (CE) e cromatografia líquida de alta eficiência (HPLC) para a quantificação de cafeína residual em café descafeinado, quanto aos parâmetros de validação, custos, tempo de análise, composição e tratamento dos resíduos gerados, bem como quantificação de cafeína em 20 amostras comerciais. Ambos os métodos apresentaram parâmetros de validação adequados. O teor de cafeína não diferiu estatisticamente pelos dois métodos. A vantagem do método por HPLC foi o limite de detecção 42 vezes mais baixo. Não obstante, o limite de detecção da CE foi 115 vezes menor do que o permitido pela legislação brasileira. A análise por CE foi 30% mais rápida, os custos com reagentes foram 76,5 vezes mais baixos e o volume de resíduos gerados foi 33 vezes menor. Portanto, o método por CE mostrou-se uma valiosa ferramenta analítica para este tipo de análise

A fast and efficient method for the study of caffeine levels in energy drinks using micellar electrokinetic chromatography (MEKC)

Energy drinks are becoming popular in Brazil and in the world due to their stimulant properties. Caffeine is present in energy drinks with the aim of stimulating the central nervous system and intensifying brain activity. On the other hand, the ingestion of high doses of caffeine can cause undesirable symptoms such as anxiety and tachycardia. Therefore, it is necessary to monitor the caffeine content added to energy drinks to guarantee that the levels in the final product are in accordance with the labeling and within the legislation limits. The goal of this work was to validate a fast, efficient, and low-cost method for the determination of caffeine in energy drinks by micellar electrokinetic chromatography (MEKC). A total of seven brands were analyzed, each in three lots. The electrolyte was prepared with 50 mmol.L-1 of sodium dodecyl sulfate (SDS) and 10 mmol.L-1 of sodium carbonate (pH 11.0). The mean concentration of caffeine ranged from 122.8 to 318.6 mg.L-1. None of the brands had caffeine levels above the maximum limit. Considering the interval of confidence (95%), 72% of the samples had less caffeine than the amount informed on the product label

Bovine Blood Constituents as Fat Replacers in Ham Pâté

Some tests were carried out in this work with the aim of evaluating a partial replacement of fat in the raw batter of ham pâté by using bovine blood constituents, such as globin (GL), plasma (PL) or 1:1 globin and plasma (GP). Plasma was separated from red cells by blood centrifugation, and globin was extracted by the carboxymethylcellulose method. The salt-soluble protein content (SSP) and the binding properties including water holding capacity (WHC) and raw batter stability (RBS) were estimated. The results indicated that among the 3 treatments studied, the use of globin showed to be a little more advantageous for the quality of the raw batter of ham pâté, since its incorporation as fat replacer led to an increase in RBS but no change of SSP was observed