Estudo da adsorção do corante azul de metileno em caulinita rosa

This work aimed to study the adsorption of blue methylene dye using as adsorbent a kind of kaolinite called(named) pink kaolinite. The adsorbent was characterized from its chemical composition, by X-ray diffraction method and surface area by BET method. The variable parameters for the study in question were: the equilibrium time and the ratio of adsorbent mass per volume of adsorbate. It was found that the equilibrium time is less than 20 minutes and the highest adsorption occurred at 1:200 ratio, with a removal of 97%. The isotherm adsorption was constructed from the optimized kinetics adsorption parameters. The data were linearized for the models of Langmuir and Freundlich, and Langmuir model was that better explained the results.Este trabalho teve como objetivo estudar a adsorção do corante azul de metileno usando como adsorvente uma espécie de caulinita chamada caulinita rosa. A caulinita foi caracterizada a partir da sua composição química, pelo método de difratometria de raio-X e área superficial, pelo método de BET.Os parâmetros variáveis ​​para o estudo em questão foram: o tempo de equilíbrio e a relação entre massa de adsorvente por volume de adsorvato. Verificou-se que o tempo de equilíbrio é menor do que 20 minutos e o máximo de adsorção ocorreu na razão de 1:200, com uma remoção de 97%. A isoterma de adsorção foi construída a partir de parâmetros otimizados da cinética de adsorção. Os dados foram linearizados para os modelos de Langmuir e Freundlich, e modelo de Langmuir foi que melhor explicou os resultados

Teores de carbamato de etila e outros componentes secundários em diferentes cachaças produzidas em três regiões do estado de Minas Gerais: Zona da mata, sul de minas e vale do jequitinhonha

Minas Gerais is the highest producer of handmade spirits. Research has been carried out aiming to contribute to progress. Thus, the goal of this work is to evaluate the quality of spirits in three different regions of Minas Gerais state. We analyzed ethyl carbamate, alcoholic grade, volatile acidity, higher alcohols, aldehyde, esters, methanol, furfural and copper. The values obtained for ethyl carbamate varied from undetectable to 643.5 µg L-1, with only one region not following the legislation (150 µg L-1). Most of the compounds in the spirits were present within the limits estabilished by the legislation

Stingless bee propolis: composition, biological activities and its applications in the food industry

Abstract The breeding of stingless bees, known as meliponiculture, can be found throughout the world, and is closely linked to the history of the first human communities in the Americas. This activity provides products of industrial interest (food, cosmetics, pharmaceuticals), and among them propolis stands out. This matrix is a resinous material but being difficult to classify and conceptualize due to its variability according to the environment and producing species. The propolis produced by these bees is a source of compounds with nutritional and functional potential, but the main interest is focused on the phenolic compounds. This potential makes propolis a product that can be used in the prospection of new molecules with antimicrobial and antioxidant activity. Thus, the scientific literature describes propolis activity (generally extracts) against bacteria and fungi, but with a higher microbicidal activity against gram-positive bacteria. The high antioxidant activity of this bee product is a consequence of the presence of several phenolic compounds. The use of propolis from SBP (Stingless bee propolis) is still quite limited, generally restricted to its antioxidant potential, but studies with application in other sectors can benefit this productive sector, as with the propolis produced by the bee Apis mellifera. This work presents and discusses the composition of stingless bee propolis and its consequent biological activities, as well as its potential applications in the food industry. Graphical Abstrac

Determination of acrolein, ethanol, volatile acidity, and copper in different samples of sugarcane spirits

Seventy-one samples of sugarcane spirits from small and average size stills produced in the northern and southern Minas Gerais (Brazil) were analyzed for acrolein using HPLC (High Performance Liquid Chromatography). Ethanol and copper concentrations and volatile acidity were also determined according to methods established by the Ministry of Agriculture, Livestock and Supply (MAPA). A total of 9.85% of the samples tested showed levels of acrolein above the legal limits, while the copper concentrations of 21.00% of the samples and the volatile acidity of 8.85% of the samples were higher than the limits established by the Brazilian legislation. The concentration of acrolein varied from 0 to 21.97 mg.100 mL-1 of ethanol. However, no significant difference at 5% of significance was observed between the samples produced in the northern and southern Minas Gerais. The method used for determination of acrolein in sugarcane spirits involved the formation of a derivative with 2,4-dinitrophenylhydrazine (2,4-DNPH) and subsequent analysis by HPLC