Enzymatic synthesis of ascorbyl oleate and evaluation of biological activities.

Compounds that reduce or neutralize free radicals have been evaluated for use as nutraceutical or antioxidant additives in processed foods. This study aimed to enzymatically produce ascorbyl oleate and assess its biological properties. The synthesis was performed under previously maximized conditions (L-ascorbic acid/oleic acid 1:9 molar ratio, 70 °C, 1 h reaction). Immobilized commercial lipase from Candida antarctica (NS 88011) was used as biocatalyst. The reaction product was isolated, and its structure was confirmed by High-Performance Liquid Chromatography and Nuclear Magnetic Resonance. Ascorbyl oleate showed antioxidant and antimicrobial activity, besides no toxicity, did not influencing blood coagulation and also not presenting hemolytic profile. Better storage stability was achieved under refrigerated conditions, and the oxidative stability demonstrated free radicals fighting efficiency, increasing olive oil's shelf life. In vitro gastrointestinal simulation showed that ascorbyl oleate maintained antioxidant potential up to the duodenum stage during the digestive process. Therefore, the synthesized natural compound presented a high potential to be applied in the food and pharmaceutical industries.

Antibacterial and anti-biofilm activity of cinnamon essential oil and eugenol / Atividade antibacteriana e anti-biofilme de óleo essencial de canela e eugenol

ABSTRACT: Biofilms are responsible for most of the interference caused by microorganisms in food processing. The aim of this study was to evaluate the cinnamon (Cinnamomum zeylanicum) essential oil and eugenol sanitizer and anti-biofilm activity against biofilms. Concentrations used of essential oil were 0.0% (control) 0.12%; 0.48%; 0.96% and 1.92%; the amount of eugenol was 0.76%. Concentrations were determined from other published studies. Number of viable cells and quantification the bacterial biomass were determined. Anti-biofilm treatment was effective in preventing the formation of biofilms. The 1.92% concentration was the most satisfactorily with Escherichia coli reduction of 5.91log CFUcm-2 and Staphylococcus aureus reduction of 5.17log CFUcm-2 (P<0.05) biomass of the two bacteria. Sanitizing treatment was not effective in reducing biomass. Seen this, the cinnamon and eugenol essential oil may be promising alternatives for controlling biofilms.

RESUMO: Os biofilmes são responsáveis pela maior parte da interferência causada pelos micro-organismos no processamento de alimentos. O objetivo deste estudo foi avaliar a atividade anti-biofilme do óleo essencial de canela (Cinnamomum zeylanicum) e do composto majoritário eugenol. As concentrações utilizadas de óleo essencial foram de 0,0% (controle), 0,12%; 0,48%; 0,96% e 1,92%; a concentração de eugenol foi de 0,76%. As concentrações foram determinadas a partir de outros estudos publicados. Determinou-se o número de células viáveis e quantificou-se a biomassa bacteriana. O tratamento anti-biofilme foi eficaz na prevenção e formação de biofilmes. A concentração de 1,92% foi satisfatória, com redução de 5,91log CFUcm-2 de células viáveis em biofilme de Escherichia coli e redução de 5,17log CFU cm-2 de Staphylococcus aureus. A biomassa de ambas bactérias foi reduzida significativamente (P<0,05), entretanto, o tratamento sanitizante não foi eficaz na redução da biomassa. Diante dos resultados, o óleo essencial de canela e eugenol podem ser alternativas promissoras no controle de biofilmes.