No abstract

Extracts rich in bioactive compounds added to edible films have allowed the development of active packaging that increases the shelf life of food. However, it is necessary to search for solvents that are nontoxic and not harmful to the environment, with natural deep eutectic solvents (NADES) being an attractive and easily synthesized alternative. This research aimed to design NADES by lyophilization to be used in the extraction of anthocyanins from the Chilean Luma chequen (Molina) A. Gray berry, and subsequently adding them to the matrix of edible ƙ-carrageenan films. For this purpose, ultrasound-assisted extraction (UAE) was used and the anthocyanin content was evaluated with the pH differential method. The antioxidant capacity of extracts was determined by DPPH assay and the antibacterial capacity by diffusion agar tests. The results obtained indicate that the designed NADES are efficient at extracting anthocyanins, reaching concentrations between 81.1 and 327.6 mg eq cyanidin 3-glucoside/100 g dw of L. chequen (Molina) A. Gray. The extracts reached inhibition diameters between 5 and 34 mm against Escherichia coli, Staphylococcus aureus, and Salmonella typhi strains. Once the extracts were incorporated into ƙ-carrageenan films, active edible films with antioxidant and antibacterial capacities were obtained.

No abstract

Monofloral Ulmo honey is a very appreciated product in the international market but more information is needed in order to support their health properties. Total phenolic and flavonoid contents, antioxidant capacity and antibacterial activity of monofloral Ulmo (Eucryphia cordifolia) honey samples were determined. The samples contained between 176 and 208 mg gallic acid eq (GAE)/100 g for total phenolic content (TPC) and 43-90 mg Quercetin eq/100 g for total flavonoid content (TFC). The antioxidant activity ranged between 91 and 152 mM eq Trolox/g and 28-49 mM eq Trolox/g for DPPH and ABTS assays, respectively. All phenolic extracts from honey samples inhibited Staphylococcus aureus, Streptococcus pyogenes, Pseudomonas aeruginosa and Escherichia coli by plate assays. The chromatographic profile showed that Ulmo honey contained the polyphenolic gallic, caffeic, and coumaric acids, the flavonoids pinocembrin, chrysin, quercetin, luteolin and apigenin, and abscisic acid. Compuestos bioactivos y propiedades antibacterianas de la miel monofloral de Ulmo RESUMEN La miel monofloral de Ulmo es un producto muy apreciado en el mercado internacional, pero se necesita más información para respaldar sus propiedades saludables. Se determinaron los contenidos fenólicos y flavonoides totales, la capacidad antioxidante y la actividad antibacteriana de muestras de miel monofloral de Ulmo (Eucryphia cordifolia). Las muestras contenían entre 176-208 mg eq de ácido gálico (GAE)/100 g para el contenido fenólico total (TPC) y 43-90 mg eq de quercetina/100 g para el contenido total de flavonoides (TFC). La capacidad antioxidante osciló entre 91-152 mM eq Trolox/g y 28-49 mM eq Trolox/g, para los ensayos de DPPH y ABTS, respectivamente. Todos los extractos fenólicos de muestras de miel de ulmo inhibieron Staphylococcus aureus, Streptococcus pyogenes, Pseudomonas aeruginosa y Escherichia coli mediante ensayos en placa. El perfil cromatográfico mostró que la miel de ulmo contenía como compuestos bioactivos los ácidos, gálico, cafeico y cumárico, los flavonoides pinocembrina, crisina, quercetina, luteolina y apigenina, y ácido abscísico.

Objectives: To investigate the prevalence of Streptococcus pneumoniae (pneumococci) in the nasopharynx of healthy children enrolled in public day-care centers of the municipality of Umuarama, state of Paraná, Brazil. The susceptibility of the pneumococcal strains to antimicrobial agents was also studied.Methods: Nasopharyngeal specimens from 212 children were collected from April to October 2008. After the specimens were seeded in blood agar and incubated at 37 °C for 24-48 hours, the colonies suspected of belonging to S. pneumoniae were identified using α-hemolysis, optochin sensitivity, and bile solubility test. Penicillin susceptibility was investigated using the disk diffusion and dilution tests. Susceptibility to the other antimicrobial agents indicated for the treatment of pneumococcal infections was investigated using the disk diffusion test. Results:The prevalence of nasopharyngeal pneumococci was 43.4% (92/212), with higher rates in children between 2 and 5 years old (p = 0.0005). There was no significant difference between sexes. Intermediate and full resistance to penicillin were found in 34.8 (32/92) and 22.8% (21/92) isolates, respectively. Sixty-seven strains (72.8%) were resistant to sulfamethoxazole-trimethoprim, eight (8.7%) were resistant to erythromycin, and six (6.5%) to tetracycline. One strain was resistant to clindamycin (1.1%) and another was resistant to chloramphenicol (1.1%). All strains were sensitive to levofloxacin, ofloxacin, rifampicin, telithromycin, linezolid, and vancomycin. Nine strains were considered multiresistant because they were resistant to three or more classes of antimicrobial agents. Conclusions:The present study detected a high prevalence of healthy children colonized with penicillin-resistant S. pneumoniae strains who may be important reservoirs of this pathogen in the community.J Pediatr (Rio J). 2009;85(6): 516-522: Streptococcus pneumoniae, nasopharynx, healthy carriers, penicillin resistance. ResumoObjetivos: Investigar a prevalência de Streptococcus pneumoniae (pneumococos) na nasofaringe de crianças sadias atendidas em creches municipais da cidade de Umuarama (PR). Avaliar a susceptibilidade aos antimicrobianos dos pneumococos isolados.Métodos: Secreção da nasofaringe de 212 crianças foi coletada no período de abril a outubro de 2008. Após semeadura dos espécimes em ágar sangue e incubação a 37 °C por 24-48 horas, as colônias suspeitas de pertencerem a S. pneumoniae foram identificadas pela α-hemóli-se, sensibilidade à optoquina e bile solubilidade. A susceptibilidade à penicilina foi investigada pelos testes de disco-difusão e de diluição. A susceptibilidade aos demais antimicrobianos indicados no tratamento das infecções pneumocócicas foi realizada por disco-difusão.Resultados: A prevalência de pneumococos na nasofaringe foi de 43,4% (92/212), sendo maior em crianças com idade entre 2 e 5 anos (p = 0,0005). Não houve diferença significativa entre os sexos. Resistência intermediária e resistência plena à penicilina foram encontradas respectivamente e...

It is known that polyphenolic extracts have antibacterial activity, but usually with not very broad spectrum of action. To enhance its individual antibacterial effect, to combine different extracts has been proposed. In this work, the combined antibacterial effect of 3 extracts and their mixtures (Ulmo and Quillay honeys, multifloral pollen) was evaluated. Their polyphenol content was quantified by HPLC-DAD analysis. E. coli, S. aureus, Salmonella spp, Pseudomonas spp, L. acidophilus, and B. thermosphacta were used as foodborne pathogenic-spoilage strains in the antibacterial assays. Polyphenol-target bacteria relationships were established. Results showed that all extracts and their combinations have activity against all strains. Relationships were established between all pathogenic strains with 4 phenolic acids and 2 flavonoids, and 2 spoilage strains with 3 phenolic acids and 3 flavonoids. These findings will contribute to the rapid assessment of mixtures of outstandingly antibacterial extracts to be applied in the food industry.Bioactividad de mezclas de extractos fenólicos obtenidos de mieles y polen de abeja chilenos RESUMEN Se sabe que los extractos polifenólicos tienen actividad antibacteriana con un espectro de acción generalmente no muy amplio. Para potenciar su efecto antibacteriano individual, se ha propuesto la combinación de extractos. En este trabajo se evaluaron los efectos antibacterianos combinados en 3 extractos y sus mezclas (miel de ulmo y quillay, y polen multifloral). El contenido de polifenoles se cuantificó mediante análisis por HPLC-DAD. E. coli, S. aureus, Salmonella spp y Pseudomonas spp, L. acidophilus, B. thermosphacta se usaron como cepas patógenas de deterioro transmitidas por los alimentos en los ensayos antibacterianos. También se establecieron relaciones polifenol-bacteria. Los resultados mostraron que todos los extractos y sus combinaciones tienen actividad contra todas las cepas. Se establecieron relaciones entre todas las cepas patógenas con 4 ácidos fenólicos y 2 flavonoides, y entre 2 cepas de deterioro con 3 ácidos fenólicos y 3 flavonoides. Estos hallazgos contribuyen a la evaluación rápida de mezclas de extractos antibacterianos para usar en la industria alimentaria. ARTICLE HISTORY

Surface free energy (SFE; γ SV ) of 16 fruit epicarps present on the Chilean market was calculated by two approaches: the acid-base and Zisman. The results show that the fruit epicarps were low surface energy since the magnitude of γ SV falls within a narrow range, between 37 and 44 mJ m −2 . Zisman approach gave a critical surface tension values, γ cr lower than the SFE calculated by the acid-base approach. Significant differences in SFE between the fruits may be explained by the variation in the chemical composition of epicuticular waxes. The polar (γ AB SV ) and apolar (γ LW SV ) components of the SFE were also calculated and a mathematical relation was between both values was found. Values of γ AB SV and γ LW SV could also be associated with the fruit family and the tissue origins in the ovary region. Finally, it has been shown that fruit epicarps exhibited predominantly electron-donator behaviour since γ − SV > γ + SV . We believe that the results reported here can potentially impact in food engineering because the compatibility of coatings and fruit epicarps depends on the interaction of their respective chemical and physical properties.

No abstract