Potential impact of strawberries on human health: a review of the science

Epidemiological studies have noted a consistent association between the consumption of diets rich in fruits and vegetables and a lower risk for chronic diseases including cancer and cardiovascular disease. There is accumulating evidence that much of the health-promoting potential of these plant foods may come from phytochemicals, bioactive compounds not designated as traditional nutrients. In strawberries, the most abundant of these are ellagic acid, and certain flavonoids: anthocyanin, catechin, quercetin and kaempferol. These compounds in strawberries have potent antioxidant power. Antioxidants help lower risk of cardiovascular events by inhibition of LDL-cholesterol oxidation, promotion of plaque stability, improved vascular endothelial function, and decreased tendency for thrombosis. Furthermore, strawberry extracts have been shown to inhibit COX enzymes in vitro, which would modulate the inflammatory process. Individual compounds in strawberries have demonstrated anticancer activity in several different experimental systems, blocking initiation of carcinogenesis, and suppressing progression and proliferation of tumors. Preliminary animal studies have indicated that diets rich in strawberries may also have the potential to provide benefits to the aging brain.     

Survival and growth of Listeria monocytogenes and Escherichia coli O157:H7 in ready-to-eat iceberg lettuce washed in warm chlorinated water

Cut iceberg lettuce inoculated with Escherichia coli O157:H7 and Listeria monocytogenes before and after washing for 3 min in cold (4 degrees C) and warm (47 degrees C) water containing 100 mg/liter total chlorine was stored at I and 10 degrees C in oxygen-permeable film packages (6,000 to 8,000 cc/m2/24 h). Cold chlorinated water was detrimental to the survival of E. coli O157: H7 and L. monocytogenes at both storage temperatures. In contrast, washing in warm chlorinated water favored the growth of both pathogens in lettuce stored at 10 degrees C. There was no evidence of a relationship between the magnitude of spoilage microflora and the fate of either bacterium.     

The influence of distribution and deposit of conductive coating on shielding effectiveness of textiles

This study presents the investigation of electrically conductive fabrics with low resistivity, coated with formulation containing the conjugated polymer system – poly(3,4-ethylenedioxythiophene)-polystyrene sulphonate (PEDOT-PSS). The samples of fabrics were coated with PEDOT-PSS, using a screen printing method, by different patterns or coating their surface fully with different coating deposit. Methods for measurement of electrostatic properties, reflection and transmission as well as the assessment of electromagnetic radiation (EMR) shielding effectiveness were used for the characterization of electrical properties of developed samples. EMR shielding properties were investigated within 2–12 GHz frequency bands. The highest attenuation of the electromagnetic energy among tested fabrics was obtained on the fabrics fully coated with paste and it depended on deposit considerably. The influence of distribution and deposit of conductive coating on shielding effectiveness of textiles were determined. Correlation between shielding effectiveness and electrostatic properties of developed coated fabrics was also discussed. Electrical properties of samples coated with formulation containing PEDOT-PSS were compared with these of fabrics with metalized yarns, developed by us earlier. The results of EMR shielding measurements showed that fabrics coated with the paste containing conductive polymer system compared to fabrics with in-weaved conductive metalized yarns have certain advantages as EMR shields.     

Field demonstration of successful bioaugmentation to achieve dechlorination of tetrachloroethene to ethene

A laboratory microcosm study and a pilot scale field test were conducted to evaluate biostimulation and bioaugmentation to dechlorinate tetrachloroethene (PCE) to ethene at Kelly Air Force Base. The site groundwater contained about 1 mg/L of PCE and lower amounts of trichloroethene (TCE) and cis-1,2-dichloroethene (cDCE). Laboratory microcosms inoculated with soil and groundwater from the site exhibited partial dechlorination of TCE to cDCE when amended with lactate or methanol. Following the addition of a dechlorinating enrichment culture, KB-1, the chlorinated ethenes in the microcosms were completely converted to ethene. The KB-1 culture is a natural dechlorinating microbial consortium that contains phylogenetic relatives of Dehalococcoides ethenogenes. The ability of KB-1 to stimulate biodegradation of chlorinated ethenes in situ was explored using a closed loop recirculation cell with a pore volume of approximately 64,000 L The pilot test area (PTA) groundwater was first amended with methanol and acetate to establish reducing conditions. Under these conditions, dechlorination of PCE to cDCE was observed. Thirteen liters of the KB-1 culture were then injected into the subsurface. Within 200 days, the concentrations of PCE, TCE, and cis-1,2-DCE within the PTA were all below 5 microg/L, and ethene production accounted for the observed mass loss. The maximum rates of dechlorination estimated from field date were rapid (half-lives of a few hours). Throughout the pilot test period, groundwater samples were assayed for the presence of Dehalococcoides using both a Dehalococcoides-specific PCR assay and 16S rDNA sequence information. The sequences detected in the PTA after bioaugmentation were specific to the Dehalococcoides species in the KB-1 culture. These sequences were observed to progressively increase in abundance and spread downgradient within the PTA. These results confirm that organisms in the KB-1 culture populated the PTA aquifer and contributed to the stimulation of dechlorination beyond cDCE to ethene.     

Dry fermented sausages elaborated with Lactobacillus plantarum-staphylococcus carnosus. Part II: Effect of partial replacement of NaCl with KCl on the proteolytic and insolubilization processes

The effect of partial replacement of NaCl with KCl (3% NaCl by 1.5% NaCl + 1% KCl) on the proteolytic and insolubilization processes that affect the nitrogen fractions of dry fermented sausages produced with L. plantarum-S. carnosus as starter culture was analysed. The percentage of solubility was significantly lower in the modified product, which is consistent with its significantly higher percentage of insoluble fraction observed from the beginning of the process. The myofibrillar fraction was more affected by the proposed modification than the sarcoplasmic fraction: the loss of solubility for the modified and control products were 33.6 and 27.6% for myofibrillar fraction and 9.9 and 9.3% for the sarcoplasmic fraction, respectively. Also a higher intensity of the proteolytic process was observed. The modified product was found to be slightly less hard but had a better salted taste.     

No evidence of substantial nicotine metabolism by Lasioderma serricorne (Fabricius) (Coleoptera: Anobiidae) reared on tobacco

The cigarette beetle, Lasioderma serricorne (Fabricius), is the most prevalent pest of stored tobacco and is responsible for substantial economic damage. Other than L. serricorne, few insects have been found to infest tobacco due to its low nutritional value and nicotine toxicity. Self, L.S., Guthrie, F.E., Hodgson, E. [1964a. Metabolism of nicotine by tobacco-feeding insects. Nature 204, 300-301] reported that L. serricorne metabolizes at least 70% of ingested nicotine to cotinine. This study re-examined nicotine metabolism by the L. serricorne using gas chromatography/flame ionization detection (GC/FID) and gas chromatography/thermal desorption with time-of-flight mass spectrometry (GC/TDS/ToF). Cigarette beetles reared on whole-wheat flour were compared with those reared on tobacco. Larvae, depurated larvae, frass, and both diets were analyzed to determine if nicotine was assimilated, sequestered, metabolized, and/or excreted. Contrary to previous findings, these data indicate that L. serricorne does not metabolize a significant amount of nicotine into cotinine. Nicotine is excreted unmodified. Older research involving nicotine metabolism by other insects should be reviewed in the light of these findings.     

Hydrogen sulfide oxidation by a microbial consortium in a recirculation reactor system: sulfur formation under oxygen limitation and removal of phenols

Wastewater from petroleum refining may contain a number of undesirable contaminants including sulfides, phenolic compounds, and ammonia. The concentrations of these compounds must be reduced to acceptable levels before discharge. Sulfur formation and the effect of selected phenolic compounds on the sulfide oxidation were studied in autotrophic aerobic cultures. A recirculation reactor system was implemented to improve the elemental sulfur recovery. The relation between oxygen and sulfide was determined calculating the O2/S2- loading rates (Q(O2)/Q(S)2- = Rmt), which adequately defined the operation conditions to control the sulfide oxidation. Sulfur-producing steady states were achieved at Rmt ranging from 0.5 to 1.5. The maximum sulfur formation occurred at Rmt of 0.5 where 85% of the total sulfur added to the reactor as sulfide was transformed to elemental sulfur and 90% of it was recovered from the bottom of the reactor. Sulfide was completely oxidized to sulfate (Rmt of 2) in a stirred tank reactor, even when a mixture of phenolic compounds was present in the medium. Microcosm experiments showed that carbon dioxide production increased in the presence of the phenols, suggesting that these compounds were oxidized and that they may have been used as carbon and energy source by heterotrophic microorganisms present in the consortium.     

Inulinase from Rhodotorula mucilaginosa: immobilization and application in the production of fructooligosaccharides

The crude extract containing inulinase from Rhodotorula mucilaginosa was obtained by submerged fermentation. Inulinase was immobilized on chicken eggshell by physical adsorption and covalent crosslinking, using glutaraldehyde as a crosslinking reagent, and Celite by adsorption. Fructooligosaccharides production was performed using immobilized inulinase (5%, w/v) and inulin substrate solution under experimental conditions evaluated through Doehlert experimental design. The production of inulinase was optimized for concentrations of D-glucose and yeast extract at 12.5 and 0.5 g/L, respectively, resulting in an optimal activity of 0.62 U. The optimal pH and temperature for enzyme activity were 8.0 and 75 °C, respectively, leading to an optimal activity of 3.54 U. The highest immobilization efficiency (46.27%) was obtained upon immobilization on Celite. Immobilization by adsorption to eggshell allowed for specific activity of 4.15 U/g, and adsorption to Celite resulted in specific activity of 3.70 U/g. The highest titer in fructooligosaccharides was obtained with an initial inulin concentration of 250 g/L (25%, w/v), and a reaction time of 16 h. Hence, immobilized inulinase proved to be a promising catalyst for fructooligosaccharides production since the formulation is performed through a simple, low-cost, and large-scale applicable methodology.

     

Mesoporous Silicates with Spherical Morphology Modified with Vanadium Highly Active in Oxidation of Cyclohexene with H2O2

Vanadium-containing mesoporous molecular sieves have been prepared by hydrothermal treatment at 373 K. These materials showed spherical morphology with a narrow particle size distribution between 2 and 4 μm. The techniques used for their physicochemical characterization were: XRD, AAS, N₂ physisorption, SEM, TEM and DR–UV–Vis spectroscopy. All the materials presented high specific surface area (>900 m²/g), characteristic of MCM-41 materials. A well-defined mesoporous structure was observed by TEM measures although there was no one-dimensional ordering of pores characteristic of such materials. Additionally, secondary mesoporosity domains were determined in the BJH size distribution. The sample synthesized with the highest content of V presented marked differences in their structural characteristics, which were attributed to the blockage of channels by the presence of nano-clusters and/or V_xO_y nano-oxides. From the DR–UV–Vis analysis, a successful incorporation of V ions to silica structure in tetrahedral coordination with oxygen of the network could be inferred. The catalytic activity of these materials was evaluated in the test reaction of cyclohexene oxidation using H₂O₂ as oxidizing agent, showing a high conversion of about 93% respect to the maximum, resulting dominant the radicalary mechanism over the direct oxidation mechanism. Apparently, the isolated V ions incorporated into the silica structure would be responsible for the high catalytic activity of these materials.