Luiz Antonio Mendonça Alves da Costa

Color, phenolic and flavonoid content, and antioxidant activity of honey from Roraima, Brazil

The total phenolic and flavonoid content, color, and antioxidant activity were evaluated from ten honey samples from Apis mellifera L. collected from Roraima State, Brazil. The total phenolic content was determined using the Folin-Ciocalteu reagent and ranged from 250 to 548 mg gallic acid kg –1 of honey. The total flavonoid content was obtained using two methods: total flavones/flavonols were determined with aluminum chloride, and flavonones/dihydroflavonols were determined with 2,4-dinitrophenylhydrazine. The results ranged from 9 to 48.6 mg of quercetine kg –1 of honey and 1805 to 2606 mg of pinocembrin kg –1 of honey, respectively. Antioxidant activity was measured with 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavengers, and the results of the IC 50 ranged from 3.17 to 8.79 mg/mL. Statistical analysis demonstrated positive correlations between color intensity, flavone and flavonol content, and phenolic content and negative correlations with antioxidant capacity.

Antimicrobial activities of six essential oils commonly used as condiments in Brazil against Clostridium perfringens.

Despite recent advances in food production technology, food-borne diseases (FBD) remain a challenging public health concern. In several countries, including Brazil, Clostridium perfringens is among the five main causative agents of food-borne diseases. The present study determines antimicrobial activities of essential oils of six condiments commonly used in Brazil, viz., Ocimum basilicum L. (basil), Rosmarinus officinalis L. (rosemary), Origanum majorana L. (marjoram), Mentha × piperita L. var. Piperita (peppermint), Thymus vulgaris L. (thyme) and Pimpinella anisum L. (anise) against C. perfringens strain A. Chemical compositions of the oils were determined by GC–MS (gas chromatography–mass spectrometry). The identities of the isolated compounds were established from the respective Kováts indices, and a comparison of mass spectral data was made with those reported earlier. The antibacterial activity was assessed from minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) using the microdilution method. Minimum inhibitory concentration values were 1.25 mg mL−1 for thyme, 5.0 mg mL−1 for basil and marjoram, and 10 mg mL−1 for rosemary, peppermint and anise. All oils showed bactericidal activity at their minimum inhibitory concentration, except anise oil, which was only bacteriostatic. The use of essential oils from these common spices might serve as an alternative to the use of chemical preservatives in the control and inactivation of pathogens in commercially produced food systems.

Chemical composition and antimicrobial evaluation of the essential oils of Bocageopsis pleiosperma Maas

Essential oils from the leaves, twigs and barks of Bocageopsis pleiosperma Maas were obtained by using hydrodistillation and analysed by using gas chromatography coupled to mass spectrometry. Several compounds (51) were detected and identified, being β-bisabolene the main component in all aerial parts of the plant, with higher concentration in the leaves (55.77%), followed by barks (38.53%) and twigs (34.37%). In order to increase the biological knowledge about the essential oil of Bocageopsis species, antimicrobial activities were evaluated against the microorganisms Escherichia coli, Staphylococcus epidermidis, Enterobacter aerogenes, Candida tropicalis, Candida dubliniensis, Candida glabrata and Candida albicans. The essential oil obtained from the barks exhibited a moderate effect against S. epidermidis ATCC 1228 (MIC = 250 μg/mL), while the other oils did not exhibit antimicrobial activity. These results represent the first report about the chemical composition of B. pleiosperma and the first antimicrobial evaluation with a Bocageopsis species.

Chemical composition and multivariate analysis of the volatile oil of Dalbergia frutescens (Vell.) Britton (Fabaceae)

The chemical composition of the volatile oil from the leaves of three specimens of D. frutescens, collected over a period of one year, was determined by gas chromatography-mass spectrometry (GC-MS) and gas chromatography with flame ionization detection (GC-FID). These essential oils were characterized by the presence of norisoprenoids (β-damascenone, β-ionone, and α-ionone), as well as sesquiterpenes. Multivariate analysis showed that the compounds β-damascenone and β-ionone exerted the greatest influence on spatial and temporal differences in the composition of the oils. Samples obtained from specimens located in the same city showed similar chemical compositions.

Chemical Composition and Evaluation Preliminary of Antileishmanial Activity in vitro of Essential Oil from Leaves of Eugenia pitanga, A Native Species of Southern of Brazil

Abstract Eugenia pitanga (O.Berg) Nied., Myrtaceae, popularly known as pitanga-do-campo, is a species native from Pampa biome, in southern of Brazil and is popularly used as antidiarrheal, anti-rheumatic, stimulant and febrifuge. The aim of this work was to determine the chemical composition of essential oil from fresh leaves of Eugenia pitanga (O.Berg) Nied. Preliminaries data about antileishmanial activity in vitro of essential oil against promastigotes forms of Leishmania amazonensis are presented. The method to determine the chemical composition of the essential oil from fresh leaves of E. pitanga (EoEp) was gas chromatography-mass spectrometry. EoEp was assayed in vitro for antileishmanial activity against promastigotes of Leishmania amazonensis. The EoEp comprised 57 components and was rich in oxygenated sesquiterpenes (72.97 %) with spathulenol (15.34 %), globulol (10.93 %) and (2E,6E) methyl farnesoate (7.40 %) as the major constituents. EoEp was effective against L. amazonensis promastigotes with IC50 value of 6.10 ± 1.80 μg/mL. This work reports for the first time the composition of essential oil from leaves of E. pitanga from Pampa Biome, and it suggests the importance of continuing the studies in order to explain the antileishmanial activity.

Efeitos das condições ambientais sobre o teor e variabilidade dos óleos voláteis de dalbergia frutescens (Vell.) Britton (Fabaceae)

The volatile oils of Dalbergia frutescens were obtained by hydrodistillation on a Clevenger-modified apparatus for every month of one year and assessed on GC/MS and GC/FID detectors for qualitative and quantitative analyses. The influence on content of volatile oils was directly proportional to the environmental variables, temperature and cloudiness, and inversely proportional to precipitation. Among the volatile compounds detected, linalool, β-damascenone, α-ionone, geranyl acetone and β-ionone were the main components, of which β-damascenone and β-ionone were found at the highest concentrations.

CHEMICAL COMPOSITIONS AND ANTIOXIDANT AND ANTIMICROBIAL ACTIVITIES OF PROPOLIS PRODUCED BY Frieseomelitta longipes AND Apis mellifera BEES

Edineide Cristina A. de Souzaa, Etyene Janyne G. da Silvaa, Hayron Kalil C. Cordeirob, Nauara M. Lage Filhob, Felipe M. A. da Silvac, Diany Lucy S. dos Reisd, Carla Portod, Eduardo J. Pilaud, Luiz Antonio M. A. da Costaa, Afonso D. L. de Souzac, Cristiano Menezese and Adriana Flacha,*¤ Departamento de Química, Universidade Federal de Roraima, 69310-000, Boa Vista – RR, Brasil Universidade Federal Rural da Amazônia, 66075-110 Belém – PA, Brasil Departamento de Química, Universidade Federal da Amazônia, 69077-000, Manaus – AM, Brasil Departamento de Química, Universidade Estadual de Maringá, 87020-900, Maringá – PR, Brasil Embrapa Amazônia Oriental, 66095-903 Belém – PA, Brasil

POST-ACIDIFICATION AND EVALUATION OF ANTHOCYANINS STABILITY AND ANTIOXIDAN ACTIVITY IN AÇAI FERMENTED MILK AND YOGURTS (Euterpe oleracea Mart.)

ABSTRACT – This study evaluated the post-acidification, stability of anthocyanins and antioxidant activity in acai yogurts and fermented milks for 28 days of cold storage. For the determination of post-acidification and stability of the functional properties of acai yogurt (IA) and fermented milks (LFA), products stored at 4°C were evaluated on day 0 and every 7 days for pH, titratable acidity in lactic acid, instrumental color, anthocyanins and antioxidant activity by the DPPH free radical method. Acidification of both food matrixes was more evident between days 0 and 7 of evaluation. IA presented reduction in parameter L *, while chromaticity a * and b * of IA and LFA increased as the Acai pulp content increased; however, considering the evaluation period, it was found increase in L * and b * relating to anthocyanin degradation. Anthocyanins, as well as the antioxidant activity of IA and LFA, showed an increase in their values as the pulp content increased, but their concentrations reduced at the end of the storage period. IA and LFA can be considered excellent sources of antioxidants, being alternative to individuals not used to the consumption of fruits and vegetables.