RESUMO
ABSTRACT Recent research on Vitamin K has shown its importance in maintaining vascular and bone health. Brazilian food composition tables do not show phylloquinone content in national foods. These data are needed to obtain more reliable results in nutritional status assessment studies of individuals in relation to this vitamin as studies have shown a geographical influence in food phylloquinone content. This study aims to determine phylloquinone (Vitamin K1) levels in its most important source: dark green leaved vegetables. Several varieties of vegetables were purchased directly from CEAGESP (General Warehouse Company of São Paulo) at different times. Phylloquinone was extracted using organic solvents and quantified by High Performance Liquid Chromatography - HPLC. Results show the concentrations of phylloquinone in commonly consumed foodstuffs. In general, results showed variations with data from literature on the amount of Vitamin K in the plants analysed.
Assuntos
Vitamina K 1/farmacologia , Vitamina K/análise , Alimentos/estatística & dados numéricos , Brasil , Cromatografia Líquida de Alta Pressão/instrumentação , Composição de Alimentos , Produtos Vegetais/classificaçãoRESUMO
Estudos sobre a vitamina K têm evidenciado seu papel na manutenção da saúde óssea e vascular. A atuação desta vitamina em tecidos extra-hepáticos não é considerada na recomendação dietética da DRI de 2001, sendo reconhecidas necessidades maiores para função óssea em pessoas acima dos 60 anos e em indivíduos que fazem uso de medicamentos antivitamina K. Visando colaborar com pesquisas futuras, onde o conhecimento do teor de vitamina K1 é relevante, além de contribuir com dados para Tabela Brasileira de Composição de Alimentos - TBCA-USP, o presente trabalho foi conduzido para determinação do teor de filoquinona (vitamina K1) de hortaliças consumidas na cidade de São Paulo. As hortaliças analisadas foram escolhidas após a conclusão de um inquérito alimentar realizado, com adultos e idosos, num projeto de pesquisa desenvolvido junto ao Departamento de Alimentos e Nutrição Experimental da FCF/USP visando a análise da ingestão diária de vitamina K. Desta forma, foram analisadas as hortaliças mais consumidas por esses grupos, submetidas ou não ao processo de cocção. Estas amostras foram adquiridas diretamente na CEAGESP - Companhia de Entrepostos e Armazéns Gerais de São Paulo. As metodologias empregadas na determinação da filoquinona (vitamina K1) foram extração e purificação pelo método líquido-líquido utilizando solventes orgânicos e quantificação através da Cromatografia Líquida de Alta Eficiência (CLAE). Os resultados mostraram que as amostras de hortaliças de colorações verdes mais escuras apresentaram os maiores teores da vitamina como: salsa 491,05 µg/100g; espinafre 375,01 µg/100g, quando comparados com as amostras de colorações verdes mais claras as quais como é o caso da alface americana 113,42 µg/100g e a couve-flor 32,55 µg/100g. A maioria das hortaliças analisadas apresentaram variações entre as diferentes épocas do ano e quando comparadas com dados da literatura
Studies on vitamin K have shown its role in maintaining bone and vascular health. The role of this vitamin in extrahepatic tissues is not considered in the dietary recommendation of DRI 2001. Increased need for vitamin K intake is recognized for the bone function in people over age 60 and individuals who use anti-vitamin K drugs. Aiming at supporting future research, where knowledge of vitamin K1 is relevant, and contribute data to the Brazilian Table of Food Composition - TBCA-USP, this study was conducted to determine the level of phylloquinone (vitamin K1) of vegetables consumed in the city of São Paulo. The vegetables studied were chosen after completion of a nutrition survey carried out with adults and elderly people, a research project developed by the Department of Food and Experimental Nutrition FCF / USP aimed at analyzing the daily intake of vitamin K. Therefore, we analyzed the most consumed vegetables by these groups submitted or not to the cooking process. These samples were acquired directly at CEAGESP - General Warehouses Company of São Paulo. The methodologies employed in the determination of phylloquinone (vitamin K1) were extraction and purification method using liquid-liquid organic solvents followed by High Performance Liquid Chromatography (HPLC). The results showed that the samples of darker green vegetables showed the highest levels of vitamin such as parsley (491.05 µg/100g) and spinach (375.01 µg/100g), when compared with samples of lighter coloration (e.g. 113.42 µg/100g lettuce, and 32.55 µg/100g cauliflower). Most vegetables analyzed showed variation in results when compared to the different seasons and the literature data
Assuntos
Idoso , Verduras/metabolismo , Vitamina K/análise , Vitamina K 1/análise , Análise de Alimentos/estatística & dados numéricosRESUMO
Vitamin K is a cofactor for the synthesis of blood coagulation Factors II, VII, IX and X, and inhibitors such as Protein C and S and bone matrix protein. Its active form is a coenzyme in the glutamic acid carboxylation. Vitamin K-dependent factors form enzymatic complexes with calcium and membrane phospholipids. The insufficiency of gamma glutamic carboxylation impairs the hemostatic function. Hereditary deficiencies, antibiotics and oral anticoagulants, decrease the capacity of complex formation giving way to hemorrhage or thrombosis, or bone mass disturbances which are easily treated with administration of Vitamin K. The main causes of Vitamin K deficiency are lack of hepatic storage in newborns, liver insufficiency, malabsorption, dietetic deficiency, therapy with the antibiotics and coumarin administration. For the study of Vitamin K there are methods to measure the Vit K dependent proteins and as well methods to measure specifically the quinonas.