Abstract This study evaluated the effect of water temperature (65 °C, 75 °C, 85 °C, 95 °C) on the concentration of caffeic acid, 5-caffeoylquinic acid, 3,4-dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid, 4,5-dicaffeoylquinc acid and rutin in chimarrão aqueous extracts prepared from two commercial types of yerba mate: traditional and coarse ground. The chimarrão preparation simulated the homemade process. Regardless of the temperature, aqueous extracts from the coarse ground had 60% more phenolic compounds than the traditional ones. In the extracts of coarse ground yerba mate the temperature of 95 °C favored the extraction of the compounds in relation to the other temperatures. For the traditional yerba mate extracts there was no difference regarding the temperature. The chlorogenic acids content in the chimarrão extracts is significantly higher than in other foods and beverages and represent an excellent contribution for chlorogenic acids intake.

Abstract Rutin has shown promising results in reducing various human diseases. However, many plants consumed in Brazil do not have their rutin content reported in the literature yet. More than eighty plants were analyzed using aqueous (popularly known as tea) and ethanolic extraction (employed in commercial rutin purification) by liquid chromatography. Rutin was found in 47 samples when ethanol extraction was used. Echinodorus grandiflorus had the highest content (14,878.7 mg 1000 g-1), followed by Sambucus nigra, Drimys winteri and Taraxacum officinale. In aqueous infusion, Echinodorus grandiflorus, Sambucus nigra, Drimys winteri and Ruta graveolens presented the highest levels of rutin, ranging from 15.5 to 29.7 mg of rutin in 300 mL of infusion from 2 g of the plant. Echinodorus grandiflorus, Sambucus nigra, Drimys winteri, Taraxacum officinale and Ruta graveolens presented a high amount of flavonoid and might be good alternatives as ingredients in food and pharmaceuticals in order to obtain health benefits.

Abstract The objective of this study was to develop, optimize and validate a fast and reliable method for the simultaneous determination of caffeine and taurine contents by micellar electrokinetic chromatography with diode array detector, using direct and indirect detection concomitantly. Multivariate statistical techniques were used as a central composite design and the simultaneous optimization method of responses of Derringer and Suich were used for optimization. The method was applied in the analysis of 73 samples of energy drinks commercialized in Brazil. The optimized method employed a capillary tube with an extended bulb of 50 µm i.d. x 72 cm total length, an electrolyte containing 16.20 mmol.L-1 of benzoic acid and 39.90 mmol.L-1 of SDS, a pH value of 7.26, + 30 kV voltage, direct detection of caffeine at 274 nm and indirect detection of taurine at 230 nm. Validation parameters have demonstrated the reliability and applicability of this method. It was found that more than 50% of the samples were out of the legal limits determined by the Brazilian government regarding the taurine content and 68 % contained caffeine below the value declared on the label. Therefore, the need for greater control concerning the composition of these drinks exists.

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.

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.

As bebidas energéticas tornaram-se populares no Brasil e no mundo devido às suas propriedades estimulantes. A cafeína está presente na bebida energética com a finalidade de estimular o sistema nervoso central e intensificar a atividade cerebral. Por outro lado, a ingestão de altas doses pode causar sintomas indesejáveis como ansiedade e taquicardia. Por isso, é necessário monitorar a quantidade de cafeína adicionada às bebidas energéticas a fim de comprovar se os níveis no produto final estão de acordo com a rotulagem e dentro dos limites legais. O objetivo deste trabalho foi validar um método rápido, eficiente e econômico para determinação de cafeína nessas bebidas por cromatografia eletrocinética micelar (MEKC). Foram analisadas sete marcas, cada uma em três lotes. O eletrólito foi preparado com 50 mmol.L-1 de dodecil sulfato de sódio (SDS) e 10 mmol.L-1 de carbonato de sódio (pH 11,0). A concentração média de cafeína variou entre 122,8 e 318,6 mg.L-1. Nenhuma das marcas apresentou níveis de cafeína acima do limite máximo permitido. Considerando-se os intervalos de confiança (95%), verificou-se que 72% das amostras possuíam teor de cafeína menor que o informado aos consumidores através dos rótulos.

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.