Removal of copper in cachaças using clays

Abstract

Increased production and cachaça consumption has stimulated research regarding its quality. It is known that copper can be harmful to human health when it is in concentrated form in the beverage and is ingested in large amounts. Thus, there is a great concern among researchers and producers about the use of adsorbent substances for the removal of excess copper. The kinetic parameters and the adsorption isotherms for copper on kaolinite were studied to evaluate the physical-chemical quality of the cachaça before and after adsorption. K01, K03 and K04 kaolinites presented a maximum adsorption capacity of 97, 95 and 90%, respectively. The kinetic rates followed the pseudo-first-order model, and the adsorption isotherm was best adjusted to the Freundlich model. All the parameters of the control samples were within the limits required by law, except for the aldehydes and copper. After adsorption with clay, the values for some of the parameters were lower and those of others were not significantly different. It was possible to describe 87% of the data with the first and second principal components of the multivariate analysis, and all the samples were different from the control for the parameters analyzed. Thus, these clays can be used for the removal of copper from cachaça, but further studies are necessary.Index terms: Beverage, kinetic parameters, isotherms, adsorption. RESUMOO aumento da produção e consumo de cachaça de alambique tem estimulado a pesquisa sobre a qualidade da bebida. Sabe-se que o cobre, quando encontrado em teor elevado na bebida e ingerido em grandes quantidades, pode causar danos à saúde humana. Assim, há uma grande preocupação por parte de pesquisadores e produtores quanto à utilização de substâncias adsorventes na remoção de seu excesso. Conduziu-se este trabalho, com os objetivos de estudar a cinética e a isoterma de adsorção de cobre em caulinitas e avaliar a qualidade físico-química da cachaça antes e após a adsorção. As caulinitas K01, K03 e K04 apresentaram capacidade máxima de adsorção do metal, 97, 95 e 90%, respectivamente. Observou-se que a cinética de adsorção segue o modelo de pseudoprimeira ordem e que os dados de isotermas se ajustaram ao modelo de Freundlich. Nos resultados das análises físico-químicas, todos os parâmetros da amostra controle estavam dentro dos limites exigidos pela legislação, exceto para os aldeídos e cobre. Após a adsorção com as argilas estudadas, a cachaça apresentou uma redução dos mesmos e para alguns parâmetros não houveram diferenças significativas. Pelos resultados da análise multivariada, com a primeira e a segunda componente principal, foi possível descrever 87% dos dados e pode-se constatar que todas as amostras diferiram-se do controle quanto aos parâmetros analisados. Assim, as argilas analisadas podem futuramente, após mais estudos, serem utilizadas na remoção do cobre da cachaça.Termos para indexação: Bebida, cinética, isotermas, adsorção.

Physicochemical profile and determination of volatile compounds in cachaça stored in new oak ( Quercus sp.), amburana ( Amburana cearensis ), jatoba ( Hymenaeae carbouril ), balsam ( Myroxylon peruiferum ) and peroba ( Paratecoma peroba ) casks by SPME‐GC–MS

“…The presence of this metal is mainly the result of the dissolution of alkaline copper carbonate [Cu 2 (OH) 2 CO 3 ] present on the inner walls of the still by the acid vapours of the beverage. Contamination can be prevented through careful cleaning of the stills during the harvests and between harvests using water and lemon juice in the first distillation or using filters with adsorbents such as activated carbon, ion exchange resins and natural clays (42)(43)(44)(45)(46)(47)(48). In the present study, the lack of contamination by copper is the result of good hygiene and good manufacturing practices exercised by the company where the experiment was conducted.…”

Determination of ethyl carbamate in cachaça stored in newly made oak, amburana, jatobá, balsa and peroba vats and in glass containers

“…The presence of this metal is mainly due to the dissolution of the basic copper carbonate [Cu 2 (OH) 2 CO 3 ], present on the inner walls of the still, by the acidic vapours of the beverage. Contamination can be avoided by cleaning the stills with water and lemon in the first distillation or by using filters with adsorbents such as activated carbon, ion exchange resins and natural clays (29)(30)(31)(32)(33)(34)(35)(36). In the present study, copper contamination occurred only in the head and heart fractions, but at concentrations within the limit required by the legislation, which is 5 mg L À1 .…”

Investigação sobre cachaças brasileiras quanto a sua padronização e qualidade

“…In cachaça or spirits, the presence of this metal is mainly due to the dissolution of the basic copper carbonate present on the inner walls of the still, which is carried over by acidic alcohol vapors during distillation. Proper sanitation for removal, as well as filling the still and coils with water to reduce copper oxidation, are measures that considerably reduce the possibility of contamination of cachaça by copper (Cardoso, 2013;Duarte et al, 2014). Santiago et al (2015) evaluated the profile of cachaça produced in copper stills in the state of Minas Gerais.…”