Nafion® as advanced immobilisation substrate for the voltammetric analysis of electroactive microparticles: the case of some artistic colouring agents

Voltammetry of microparticles is applied to characterise and to identify solid analytes of interest in the field of cultural heritage. Nafion® is used for the immobilisation of solid microparticles onto the surface of a glassy carbon electrode by exploiting the deposition onto the electrode surface of a micro-volume of a suspension of the microsample in polymeric solution. Cyclic voltammetry and square wave voltammetry are applied to characterise and to identify the microparticles immobilised in the Nafion® coating. The analyte studied in this work is Prussian Blue as a typical inorganic pigment, with a relatively simple electrochemical behaviour. The proposed method is applied to a sample of Venetian marmorino plaster. The performance of Nafion® for this analysis is compared with that of the polymer Paraloid B72

Traffic light labelling: traduzindo a rotulagem de alimentos Traffic light labeling: translating food labeling

OBJETIVO: Apresentar uma adaptação do Traffic Light Labelling, ou "Semáforo Nutricional", adotado no Reino Unido e outros países da Europa, às normas vigentes no Brasil e classificar produtos industrializados comercializados no país. MÉTODOS: Esta ferramenta baseia-se na utilização das cores do semáforo para valorar concentrações de gorduras total, saturada e trans, açúcar, sódio e fibra correspondente a 100g ou 100mL do produto. O sinal vermelho indica que o nutriente está presente em quantidade excessiva; o amarelo, média e o verde, adequada. Para fibras as baixas concentrações têm cor vermelha e as recomendadas, verde. A adaptação e aplicação desses conceitos para consumidores brasileiros fundamentaram-se nas normas do Regulamento Técnico Referente à Informação Nutricional Complementar da Agência Nacional de Vigilância Sanitária e da Food Standards Agency. RESULTADOS: Foram classificados cem produtos industrializados, os quais foram selecionados da página eletrônica de um hipermercado brasileiro, optando pelos primeiros cinco a oito produtos listados na página, para cada uma das 17 categorias. A análise mostra que são altas as quantidades de gordura total, saturada e sódio e baixas as quantidades de gordura trans e fibra. CONCLUSÃO: A adaptação dessa metodologia visa facilitar a escolha de alimentos saudáveis, sensibilizando os consumidores quanto às desvantagens no que se refere a qualidade nutricional dos alimentos industrializados, e estimular as indústrias a melhorar a composição nutricional de seus produtos, sob a perspectiva de receberem maior quantidade de sinais verdes e menor quantidade de sinais vermelhos; assim, contribuindo para a prevenção de erros alimentares, obesidade e doenças crônicas não-transmissíveis, principais causas de incapacidade e mortes precoces no Brasil.<br>OBJECTIVE: This study presented an adaptation of the Traffic Light Labeling or Nutrition Traffic Light adopted in the United Kingdom and other countries in Europe to the regulations in force in Brazil and classified the processed food products sold in the country. METHODS: This tool uses traffic light colors to indicate the amount of total, saturated and trans fats, sugar, sodium and fiber present in 100g or 100mL of the product. The red light indicates that the nutrient is in excess; yellow means average and green means appropriate. For fibers, low content is indicated by the red light and proper content by green light. High prices are indicated by red light and low ones by green light. The adaptation and administration of these concepts for Brazilian consumers were based on norms established by the Brazilian National Sanitary Surveillance Agency Agência Nacional de Vigilância Sanitária and by the British Food Standards Agency. RESULTS: One hundred processed foods from a Brazilian supermarket website were classified. The selected foods were the first five to eight items shown on a page of each of the 17 food categories. The analysis showed that the amount of total and saturated fats and sodium are high and the amounts of trans fats and fibers are low. CONCLUSION: The use of this method allows consumers to easily pick healthier foods, alerting consumers about the disadvantages of processed foods with respect to their nutritional quality, and incentivizes companies to improve the nutritional composition of their foods in order to receive a higher number of green lights and smaller number of red lights. This helps to prevent poor food choices, obesity and non-communicable chronic diseases, which are the main causes of early disability and death in Brazil