Supercritical Extraction of Red Propolis: Operational Conditions and Chemical Characterization.

The objective of this study was to determine the best operational conditions for obtaining red propolis extract with high antioxidant potential through supercritical fluid extraction (SFE) technology, using carbon dioxide (CO2) as the supercritical fluid and ethanol as the cosolvent. The following parameters were studied: overall extraction curve, S/F (mass of CO2/mass of sample), cosolvent percentage (0, 1, 2 and 4%) and global yield isotherms as a function of different pressures (250, 350 and 450 bar) and temperatures (31.7, 40 and 50 °C). Within the investigated parameters, the best conditions found were an S/F of 131 and the use of ethanol at the highest concentration (4% w/w), which resulted in higher extract yields and higher content of antioxidant compounds. Formononetin, the main biomarker of red propolis, was the compound found at the highest amounts in the extracts. As expected, the temperature and pressure conditions also influenced the process yield, with 350 bar and 40 °C being the best conditions for obtaining bioactive compounds from a sample of red propolis. The novel results for red propolis found in this study show that it is possible to obtain extracts with high antioxidant potential using a clean technology under the defined conditions.

Effect of Experimental Parameters on the Extraction of Grape Seed Oil Obtained by Low Pressure and Supercritical Fluid Extraction.

Grape seeds are an important byproduct from the grape process. The objective of this work was to evaluate the effect of experimental parameters (temperature and time of pretreatment with ultrasound) to obtain grape seed oil using low pressure (Soxhlet-Sox and Bligh Dyer-BD) and high pressure (supercritical carbon dioxide-SFE) methods. The best condition for pretreatment of samples was 30 min of sonication at 30 °C before extraction by Sox or BD. Ultrasound pretreatment was efficient to increase oil extraction yield by 32.10 (Sox), 20.31 (BD) and 12.54% (SFE), depending on the extraction method used as well as, and certainly influenced the total phenolic concentration in 311 (Sox), 234 (BD), and 184 (SFE)%. Ten fatty acids were identified in the oils, the major ones being 18:2ω-6cis (linoleic 52.39%-63.12%), 16:0 (palmitic 20.22%-26.80%) and 18:0 (stearic 8.52%-13.68%). The highest epicatechin concentration was identified in the BD sample: 30-30 (150.49 ± 5.98mg/kg), which presented a concentration of ≥3 times compared to the control (56.68 ± 1.81mg/kg). Ultrasound pretreatment also contributed positively (56% and 99% increase) in the α-tocopherol content of the SFE: 30-30 and BD: 30-30 samples, respectively. The results indicate that the ultrasound pretreatment is a suitable technology to improve the quality of the oil from the grape seed.

Evaluation of the antioxidant profile and cytotoxic activity of red propolis extracts from different regions of northeastern Brazil obtained by conventional and ultrasound-assisted extraction.

Propolis is a complex mixture of resinous and balsamic material collected from the exudates of plants, shoots, and leaves by bees. This study evaluated red propolis extracts obtained by conventional (ethanolic) extraction and ultrasound-assisted extraction of six samples from different regions of northeastern Brazil. The total phenolic compounds and flavonoids, in vitro antioxidant activity, concentration of formononetin and kaempferol and the cytotoxicity against four human tumor cell lines were determined for all twelve obtained extracts. Significant variations in the levels of the investigated compounds were identified in the red propolis extracts, confirming that the chemical composition varied according to the sampling region. The extraction method used also influenced the resulting propolis compounds. The highest concentration of the compounds of interest and the highest in vitro antioxidant activity were exhibited by the extracts obtained from samples from state of Alagoas. Formononetin and kaempferol were identified in all samples. The highest formononetin concentrations were identified in extracts obtained by ultrasound, thus indicating a greater selectivity for the extraction of this compound by this method. Regarding cytotoxic activity, for the HCT-116 line, all of the extracts showed an inhibition of greater than 90%, whereas for the HL-60 and PC3 lines, the minimum identified was 80%. In general, there was no significant difference (p>0.05) in the antiproliferative potential when comparing the extraction methods. The results showed that the composition of Brazilian red propolis varies significantly depending on the geographical origin and that the method used influences the resulting compounds that are present in propolis. However, regardless of the geographical origin and the extraction method used, all the red propolis samples studied presented great biological potential and high antioxidant activity. Furthermore, the ultrasound-assisted method can be efficiently applied to obtain extracts of red propolis more quickly and with high concentration of biomarkers of interest.

Avaliação e remoção de cobre em aguardentes de cana pela utilização dos aluminossilicatos: zeólita e bentonita / Evaluation and removal of sugar cane brandy using aluminossilicates: zeolite and bentonite

A cachaça, bebida genuinamente nacional, é um produto de grande aceitação nos mercados interno e externo. Durante o processo de produção há alguns pontos críticos, ocorrendo a formação de contaminantes que podem afetar a qualidade da bebida, sendo necessário o conhecimento de sua composição química. Com este trabalho, objetivou-se comparar o comportamento do cobre, quando presente em solução alcoólica 40 por cento e uma aguardente comercial (utilizando sulfato de cobre pentaidratado como fonte desse mesmo metal), além de avaliar a remoção de cobre na bebida, utilizando dois aluminossilicatos (zeólita e bentonita) comumente empregados na adsorção de metais. A zeólita e bentonita adsorveram mais cobre quando estiveram presentes em solução alcoólica do que em aguardente. Esses resultados sugerem que o cobre em aguardente deva estar ligado a moléculas volumosas, dificultando sua entrada nos pequenos poros da argila bentonita e da zeólita ZSM-5. Quando os aluminossilicatos estiveram presentes na aguardente impregnada com cobre em alambique, a bentonita foi mais eficiente na remoção do cobre do que a zeólita; no entanto a zeólita é mais recomendada na remoção do cobre, pois a redução das concentrações dos componentes secundários foi menor, não descaracterizando a bebida.

The "cachaça", a genuinely national drink, is a product of great acceptance in the domestic and international markets. Therefore, we need to know its chemical composition, as in the production process a few critical points due to the presence of contaminants that can affect the quality of the drink. This work is aimed to compare the behaviour of copper, when present in a 40 percent alcohol solution and a "cachaça" trade (using copper sulfate pentahydrate as a source of the same metal), in addition to evaluating the removal of copper in the spirit, using two aluminosilikate (zeolite and bentonite) commonly employed in the adsorption of metals. The zeolite and bentonite adsorbed more copper when were present in alcoholic solution than in spirits. These results suggest that copper in spirits should be linked to large molecules, hampering its entry in the small pores of the bentonite clay and zeolite ZSM-5. When the aluminosilikate were present in spirit impregnated with copper still in the bentonite was more efficient in the removal of copper than zeolite, although the zeolite is recommended in the removal of copper in the spirit, because the reduction of concentrations of the components side was lower, not losing its peculiar feature.

Parâmetros físico-químicos e cromatográficos em aguardentes de cana queimada e não queimada / Physicochemical and chromatographic parameters in sugar cane brandies from burnt and non-burnt cane

Este trabalho teve por objetivo avaliar as concentrações de furfural, álcoois superiores, ésteres, aldeídos, cobre, acidez volátil, metanol e grau alcoólico de aguardentes obtidas de cana, com e sem queima prévia. Foram utilizadas amostras de aguardente artesanal de cana queimada e não queimada, fermentadas com a mesma levedura e destiladas no mesmo destilador; amostras de produtor de aguardente industrial de cana queimada e amostras obtidas de outro produtor artesanal de cana não queimada. As análises físico-químicas e cromatográficas (CG) foram realizadas no Laboratório de Análise Físico-Química de Aguardente - LAFQA/DQI na Universidade Federal de Lavras. As concentrações de furfural apresentaram diferença significativa (P<0,01), entre os grupos de aguardentes artesanais, obtidas de cana-de-açúcar com e sem queima prévia, oriundas de um mesmo processo de produção, com médias de 1,48 mg.100mL-¹ etanol e 0,63 mg.100mL-¹ etanol, respectivamente, embora tenham estado abaixo do limite máximo (5,0 mg.100mL-¹ etanol) permitido. Os demais componentes das aguardentes estudadas não foram afetados significativamente pela queima prévia da cana-de-açúcar.

This work was intended to evaluate the concentrations of furfural, higher alcohols, esters, aldehydes, copper, volatile acidity methanol and alcoholic degree of sugar cane brandies obtained from sugar cane both with and without previous burning. Samples of artisanal brandies from burnt and non-burnt cane, fermented with the same yeast and distilled in the same still, samples of burnt cane from an industrial brandy producer and samples of non-burnt cane obtained from another artisanal producer were utilized. The physicochemical and chromatographic (CG) analyses were accomplished in the Sugar Cane Brandy Physicochemical Analysis Laboratory at the Federal University of Lavras. The concentrations of furfural showed significant differences (P<0.01) among the groups of artisanal brandies obtained from sugar cane with and without previous burning, coming from the same manufacturing process with means of 1.48 mg.100mL-1 ethanol and 0.63mg.100mL-1 ethanol, respectively, although they have been bellow the maximum limit (5.0 mg.100mL-1 ethanol) allowed. The other components of the brandies studied were not affected significantly by the previous burning of sugar cane.

Determinação das composições físico-químicas de cachaças do sul de minas gerais e de suas misturas / Determination of the physical-chemical composition of homemade cachaças produced in the South of Minas Gerais and their mixtures

Este trabalho teve por objetivo a determinação da composição físico-química de cachaças artesanais produzidas no sul do Estado de Minas Gerais e suas misturas. Foram analisados os teores de etanol, acidez volátil, aldeídos, cobre, ésteres, álcoois superiores totais e metanol, além dos álcoois propanol-1, isobutanol e 3-metil-butanol-1. Os resultados apresentam o perfil peculiar desta bebida, que apresentou teores satisfatórios de álcoois superiores, ésteres e aldeídos. O teor de cobre apresenta-se como preocupante já que algumas amostras excederam o limite de 5 mg.L-1. A produção de misturas foi estudada e esta apresenta-se como uma alternativa viável ao produtor e cooperativas.

The present study sought the physical-chemical composition of homemade cachaças produced in the south of the state Minas Gerais and of mixtures of the same cachaça samples. The ethanol, aldehyde, copper, higher alcohol, volatile acid and methanol concentrations were determined, in addition to the individual propanol, 2-methyl-1-propanol and 3-methyl-1-butanol concentrations. The results demonstrated the characteristic profile of this beverage, which presented satisfactory concentrations of higher alcohols, esters, and aldehydes. The copper concentrations of some samples exceeded the limit of 5 mg. L-1. The mixtures produced from some of the cachaça samples presented a viable alternative for the producers and cooperatives because the concentrations of the components were more adequate for exportation.