CONTROLE MICROBIOLÓGICO NO PROCESSAMENTO DE ALIMENTOS

Por ano, mesmo nos países desenvolvidos, milhões de pessoas são acometidas por patologias ou infecções de origem alimentar. Devido a isso, o controle das ameaças de contaminação tornou-se uma questão de saúde pública. Alterações microbianas que acometem os alimentos resultam em danos econômicos, tanto para produtores quanto consumidores. Com isso, normas de manipulação, higienização e processamentos dos alimentos passaram a ser tema de trabalhos acadêmicos. Este estudo visa traçar um panorama sobre patentes, artigos, teses e dissertações que utilizam como tema o controle microbiológico de alimentos no período de 1985 a 2009. A metodologia empregada utiliza dados extraídos de bancos de patentes, e de dados da literatura científica, como artigos, teses e dissertações

Determination of Parameters for the Supercritical Extraction of Antioxidant Compounds from Green Propolis Using Carbon Dioxide and Ethanol as Co-Solvent.

The aim of this study was to determine the best processing conditions to extract Brazilian green propolis using a supercritical extraction technology. For this purpose, the influence of different parameters was evaluated such as S/F (solvent mass in relation to solute mass), percentage of co-solvent (1 and 2% ethanol), temperature (40 and 50°C) and pressure (250, 350 and 400 bar) using supercritical carbon dioxide. The Global Yield Isotherms (GYIs) were obtained through the evaluation of the yield, and the chemical composition of the extracts was also obtained in relation to the total phenolic compounds, flavonoids, antioxidant activity and 3,5-diprenyl-4-hydroxicinnamic acid (Artepillin C) and acid 4-hydroxycinnamic (p-coumaric acid). The best results were identified at 50°C, 350 bar, 1% ethanol (co-solvent) and S/F of 110. These conditions, a content of 8.93±0.01 and 0.40±0.05 g/100 g of Artepillin C and p-coumaric acid, respectively, were identified indicating the efficiency of the extraction process. Despite of low yield of the process, the extracts obtained had high contents of relevant compounds, proving the viability of the process to obtain green propolis extracts with important biological applications due to the extracts composition

Antioxidant, antimicrobial, antiparasitic, and cytotoxic properties of various Brazilian propolis extracts

<div><p>Propolis is known for its biological properties and its preparations have been continuously investigated in an attempt to solve the problem of their standardization, an issue that limits the use of propolis in food and pharmaceutical industries. The aim of this study was to evaluate <i>in vitro</i> antioxidant, antimicrobial, antiparasitic, and cytotoxic effects of extracts of red, green, and brown propolis from different regions of Brazil, obtained by ethanolic and supercritical extraction methods. We found that propolis extracts obtained by both these methods showed concentration-dependent antioxidant activity. The extracts obtained by ethanolic extraction showed higher antioxidant activity than that shown by the extracts obtained by supercritical extraction. Ethanolic extracts of red propolis exhibited up to 98% of the maximum antioxidant activity at the highest extract concentration. Red propolis extracts obtained by ethanolic and supercritical methods showed the highest levels of antimicrobial activity against several bacteria. Most extracts demonstrated antimicrobial activity against <i>Staphylococcus aureus</i>. None of the extracts analyzed showed activity against <i>Escherichia coli</i> or <i>Candida albicans</i>. An inhibitory effect of all tested ethanolic extracts on the growth of <i>Trypanosoma cruzi</i> Y strain epimastigotes was observed in the first 24 h. However, after 96 h, a persistent inhibitory effect was detected only for red propolis samples. Only ethanolic extracts of red propolis samples R01Et.B2 and R02Et.B2 showed a cytotoxic effect against all four cancer cell lines tested (HL-60, HCT-116, OVCAR-8, and SF-295), indicating that red propolis extracts have great cytotoxic potential. The biological effects of ethanolic extracts of red propolis revealed in the present study suggest that red propolis can be a potential alternative therapeutic treatment against Chagas disease and some types of cancer, although high activity of red propolis <i>in vitro</i> needs to be confirmed by future <i>in vivo</i> investigations.</p></div

Chemical Composition and Biological Activity of Extracts Obtained by Supercritical Extraction and Ethanolic Extraction of Brown, Green and Red Propolis Derived from Different Geographic Regions in Brazil.

The variations in the chemical composition, and consequently, on the biological activity of the propolis, are associated with its type and geographic origin. Considering this fact, this study evaluated propolis extracts obtained by supercritical extraction (SCO2) and ethanolic extraction (EtOH), in eight samples of different types of propolis (red, green and brown), collected from different regions in Brazil. The content of phenolic compounds, flavonoids, in vitro antioxidant activity (DPPH and ABTS), Artepillin C, p-coumaric acid and antimicrobial activity against two bacteria were determined for all extracts. For the EtOH extracts, the anti-proliferative activity regarding the cell lines of B16F10, were also evaluated. Amongst the samples evaluated, the red propolis from the Brazilian Northeast (states of Sergipe and Alagoas) showed the higher biological potential, as well as the larger content of antioxidant compounds. The best results were shown for the extracts obtained through the conventional extraction method (EtOH). However, the highest concentrations of Artepillin C and p-coumaric acid were identified in the extracts from SCO2, indicating a higher selectivity for the extraction of these compounds. It was verified that the composition and biological activity of the Brazilian propolis vary significantly, depending on the type of sample and geographical area of collection

Propolis sample identification by the color, region, and state of origin.

<p>Propolis sample identification by the color, region, and state of origin.</p

<i>In vitro</i> cytotoxicity of the EtOH red extracts on tumor cell lines.

<p>Experiments were performed in triplicate.</p

Determination of Minimal Inhibitory Concentration (MIC) of extracts from different samples of Brazilian propolis obtained by Ethanolic extraction (Et) and by Supercritical fluid extraction (SC).

<p>MIC is expressed as μg.mL^-1.</p

Activity of the EtOH extracts of different Brazilian propolis against <i>Trypanosoma cruzi</i> epimastigotes Y strains after 24 h (A) and 96 h (B) of incubation with both tested concentrations (75 and 300 mg.mL^-1).

<p>Activity of the EtOH extracts of different Brazilian propolis against <i>Trypanosoma cruzi</i> epimastigotes Y strains after 24 h (A) and 96 h (B) of incubation with both tested concentrations (75 and 300 mg.mL^-1).</p

Determination of antioxidant activity of the propolis extracts from different regions of Brazil by the ABTS method, using four different concentrations (100, 500and 750 μm.mL^-1), expressed as a percentage of antioxidant activity. Fig 1A –Extracts obtained by ethanolic extraction; Fig 1B –Extracts obtained by Supercritical extraction; Fig 1C –Comparison between red propolis extracts; Fig 1D—Comparison between green propolis extracts; Fig 1E—Comparison between brown propolis extracts.

<p>Values showing different letter on the same concentration for different propolis extracts show significant difference (p>0.05) through the Tukey test at 95% confidence level. Et—Extracts obtained by ethanolic extraction. SC—Extracts obtained by Supercritical extraction. Average of analysis obtained in triplicate (n = 3).</p