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Teor de açúcares em néctares de fruta e impacto na saúde do consumidor
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Resumo(s)
O consumo excessivo de açúcar tem merecido cada vez mais atenção à medida que se conhecem os impactos na saúde. Este consumo excessivo tem sido associado a diversas doenças como a obesidade, a diabetes tipo 2, as doenças cardiovasculares, alguns tipos de cancro, hipertensão e ainda doenças neurodegenerativas como a doença de Alzheimer. As bebidas açucaradas estão identificadas como uma das principais fontes de adição de açúcar na dieta, pelo que houve um comprometimento por parte da indústria no sentido de reduzir o teor de açúcar adicionado aos seus produtos. No entanto, há que ter em conta que essa redução não deve provocar alterações importantes nas características sensoriais dos produtos, para não pôr em causa a sua aceitação por parte dos consumidores. Este trabalho teve como objetivo o desenvolvimento e validação de um método de análise de teores de açúcares (sacarose, glucose e frutose) nos néctares da gama Compal clássico por cromatografia líquida de alta eficiência com deteção por índice de refração (HPLC-RI), com o objetivo de ser um método de rotina para o estudo e controlo das amostras. Foram efetuadas experiências que conduziram à otimização do método de preparação de amostra e do método analítico para a determinação dos teores em sacarose, glucose e frutose e posterior validação. No processo de validação do método analítico avaliaram-se os seguintes parâmetros: seletividade/especificidade, gama de trabalho, linearidade, precisão (repetibilidade do equipamento e do método, precisão intermédia e reprodutibilidade), exatidão, robustez e estabilidade de soluções padrão e de amostras. Analisaram-se também amostras comerciais e calculou-se o valor da incerteza associada a esta determinação. Os resultados obtidos referentes à otimização do método analítico por HPLC com deteção por índice de refração, mostraram que a amostra deveria ser previamente diluída e na análise cromatográfica o eluente mais adequado era constituído por acetonitrilo/H2O (10:90, v/v), fluxo de fase móvel de 0,6 mL/min, temperaturas do forno da coluna e do detetor de índice de refração de 30 °C e 50 °C, respetivamente. Os resultados obtidos no processo de validação mostraram que o método não é seletivo para a determinação da frutose, ocorrendo interferência de 7,6 a 17,9% para a matriz de pêssego e de 5,4 a 46,5% para a matriz de alperce. As gamas de trabalho de 100 a 1000 ppm e de 1000 a 2500 ppm estão bem ajustadas para todos os açúcares. Constatou-se que a função linear é a que melhor se aplica aos resultados. Na avaliação da precisão, concluiu-se que o equipamento é repetível bem como o método. No estudo da exatidão e da robustez determinou-se que o método é exato e robusto quando se varia a temperatura do forno da coluna. No entanto, quando se varia a composição do eluente em estudo, o método não é considerado robusto. Por último, constatou-se que as soluções padrão são estáveis e as amostras também são estáveis durante o tempo de análise estudado (72 horas). Quanto aos valores de sacarose, glucose e frutose obtidos na análise das amostras, concluiu-se que para todos os néctares, o teor total de açúcares é inferior ao valor de brix medido.
Excessive sugar consumption has received increasing attention as health impacts become known. This excessive consumption has been associated with various diseases such as obesity, type 2 of diabetes, cardiovascular diseases, some types of cancer, hypertension and even neurodegenerative diseases such as Alzheimer’s disease. Sweetened beverages are identified as one of the main sources of added sugar in the diet, so there has been a commitment by the industry to reduce the added sugar content in their products. However, it must be borne in mind that such a reduction should not cause significant changes in the sensory characteristics of products, so as not to undermine their acceptance by consumers. The objective of this work was the development of the validation of a method for analysis of sugar content (sucrose, glucose and fructose) in the classical Compal range nectars, by high performance liquid chromatography with refractive índex detection (HPLC-RI) with the objective of being a routine method for study and control. Experiments were carried out leading to the optimization of the sample preparation method and analytical method for determination of sucrose, glucose and fructose content and further validation. In the process of validation of the analytical method the following parameters were evaluated: selectivity/specificity, working range, linearity, precision (equipment and method repeatability, intermediate precision and reproducibility), accuracy, robustness and stability of standard solutions and samples. Commercial samples were also analyzed and calculated the uncertainty value associated with this determination was calculated. The results obtained regarding the optimization of the analytical method by HPLC with refractive index detection showed that the sample should be previously diluted and in the chromatographic analysis the most suitable eluent was acetonitrile/H2O (10:90, v/v), 0,6 mL/min mobile phase flow, column oven temperatures and refractive index detector temperatures of 30 °C and 50 °C, respectively. The results obtained in the validation process showed that the method is not selective in fructose determination, with interference from 7,6 to 17,9% to the peach matrix and from 5,4 to 46,5% to the apricot matrix. The working ranges from 100 to 1000 ppm and 1000 to 2500 ppm are well adjusted for all sugars. It was found that the linear function is the one that best applies to the variation of the results. In assessing of precision, it was concluded that the equipment is repeatable as well as method. In the study of accuracy and robustness it has been determined that the method is accurate and robust when varying the temperature of the column oven. However, when the composition of the eluent is varied, the method is not considered robust. Finally, it was found that the standard solutions are stable and the samples are also stable during the analysis time studied (72 hours). For sucrose, glucose and fructose values obtained in the analysis of the samples, it was concluded that for all nectars, the sugar content is lower than the measured brix values, which was expected.
Excessive sugar consumption has received increasing attention as health impacts become known. This excessive consumption has been associated with various diseases such as obesity, type 2 of diabetes, cardiovascular diseases, some types of cancer, hypertension and even neurodegenerative diseases such as Alzheimer’s disease. Sweetened beverages are identified as one of the main sources of added sugar in the diet, so there has been a commitment by the industry to reduce the added sugar content in their products. However, it must be borne in mind that such a reduction should not cause significant changes in the sensory characteristics of products, so as not to undermine their acceptance by consumers. The objective of this work was the development of the validation of a method for analysis of sugar content (sucrose, glucose and fructose) in the classical Compal range nectars, by high performance liquid chromatography with refractive índex detection (HPLC-RI) with the objective of being a routine method for study and control. Experiments were carried out leading to the optimization of the sample preparation method and analytical method for determination of sucrose, glucose and fructose content and further validation. In the process of validation of the analytical method the following parameters were evaluated: selectivity/specificity, working range, linearity, precision (equipment and method repeatability, intermediate precision and reproducibility), accuracy, robustness and stability of standard solutions and samples. Commercial samples were also analyzed and calculated the uncertainty value associated with this determination was calculated. The results obtained regarding the optimization of the analytical method by HPLC with refractive index detection showed that the sample should be previously diluted and in the chromatographic analysis the most suitable eluent was acetonitrile/H2O (10:90, v/v), 0,6 mL/min mobile phase flow, column oven temperatures and refractive index detector temperatures of 30 °C and 50 °C, respectively. The results obtained in the validation process showed that the method is not selective in fructose determination, with interference from 7,6 to 17,9% to the peach matrix and from 5,4 to 46,5% to the apricot matrix. The working ranges from 100 to 1000 ppm and 1000 to 2500 ppm are well adjusted for all sugars. It was found that the linear function is the one that best applies to the variation of the results. In assessing of precision, it was concluded that the equipment is repeatable as well as method. In the study of accuracy and robustness it has been determined that the method is accurate and robust when varying the temperature of the column oven. However, when the composition of the eluent is varied, the method is not considered robust. Finally, it was found that the standard solutions are stable and the samples are also stable during the analysis time studied (72 hours). For sucrose, glucose and fructose values obtained in the analysis of the samples, it was concluded that for all nectars, the sugar content is lower than the measured brix values, which was expected.
Descrição
Tese de Mestrado, Qualidade Alimentar e Saúde, Universidade de Lisboa, Faculdade de Farmácia, 2019
Palavras-chave
Sacarose Glucose Frutose Validação método Néctares Teses de mestrado - 2019