Dry Bark Research Articles

Nutritional and bioactive potentials of a powder and a decoction made from Ceylon cinnamon bark, Laurus nobilis leaves, and Curcuma longa Linn rhizome

The blends of Ceylon cinnamon bark (F1), Laurus nobilis leave (F2), and Curcuma longa rhizome (F3) powders are recommended by therapists, as are their decoction, for fighting chronic diseases. This study aimed to assess the nutritional and bioactive potential of a powder blend made from those three plant food matrices and the form of consumption with the most beneficial antioxidant potential. Ceylon cinnamon dry bark, Laurus nobilis fresh leaves, and Curcuma longa fresh rhizome were purchased and processed directly into powders. A substitution plan of Cinnamon powder involving three powder blends (F4, F5, F6) and a decoction marketed had been retained. The proximate composition, nutrient density, bioactive compounds, and antioxidant activity of the powder blends and decoction (bioactive compounds and antioxidant activity) were determined. F1 powder, presents the best characteristics in terms of protein content, nutrient density, and bioactive compounds. The powder blend F6, composed of 50 % Ceylon cinnamon bark, 30 % Laurus nobilis leaves and 20 % Curcuma longa rhizome, had higher contents of total protein (14.85 ± 0.37 g/100 g DM), crude fiber (32. 49 ± 0.90 g/100 g DM), total polyphenols (268.50 ± 2.00 mg GAE/g DM), total flavonoids (55.09 ± 1.01 mg QE/g DM), and a higher nutrient density in iron (1.03 mg/100 Kcal) and zinc (1.61 mg/100 Kcal). The decoction obtained from the F6 powder blend after 5 min of boiling, had high soluble bioactive compounds contents: polyphenol (24.5 ± 1.07 mg GAE/g DM), flavonoids (0.25 ± 0.01 mg QE/g DM), and condensed tannins (0.09 ± 0.00 mg CE/g DM). An antioxidant activity whose main basic mechanism is the reduction of Fe3+ to Fe2+, higher (74.94 % close to vitamin C) than that of the blend itself (65.20 % close to vitamin C). The decoction derived from the boiling of the F6 powder blend represents its most advantageous form of consumption.

Using dietary exposure to determine sub-lethal effects from imidacloprid in two springtail (Collembola) species

Standard toxicity tests expose springtails (Collembola) through soil, while dietary exposure tests with animals visible on a surface are less commonly applied. We refined a method for dietary chemical exposure for two widely distributed and abundant Collembola species: Folsomia quadrioculata and Hypogastrura viatica as existing methods were sub-optimal. Newly hatched Collembola were offered bark with a natural layer of Cyanobacteria that was either moistened with a solution of the neonicotinoid insecticide imidacloprid using a micropipette or soaked in the solution overnight. The first method was superior in producing a measured concentration close to the nominal (0.21 and 0.13 mg/kg dry bark, respectively), and resulting in sub-lethal effects as expected. The adult body size was reduced by 8% for both species, but egg production only in H. viatica. Contrastingly, soaked bark resulted in a measured concentration of 8 mg/kg dry bark, causing high mortality and no egg production in either species. Next, we identified the sub-lethal concentration-range by moistening the bark to expose H. viatica to 0, 0.01, 0.04, 0.13, 0.43 and 1.2 mg imidacloprid/kg dry bark. Only the highest concentration affected survival, causing a mortality of 77%. Imidacloprid reduced moulting rate and the body size at first reproduction. The age at first reproduction appeared delayed as some replicates did not reproduce within the experiment duration. The method of moistened bark for dietary exposure proved optimal to continuously study life history traits, such as growth and reproductive outcomes, which are important to understand effects on key events crucial for population viability and growth.

Extraction of (+)-catechin from oak (Quercus spp.) bark: Optimization of pretreatment and extraction conditions

Oaks (Quercus L., Fagaceae) are a widespread tree species worldwide, and in Hungary they account for nearly 30 % of the forests. Their wood is valuable, but their bark is considered as a by-product. Oak bark, available in large quantities but with no dedicated use, contains a significant amount of valuable extractives. Its (+)-catechin content is around 1 %. (+)-Catechin is mostly used for food industry, medicine and many other industrial purposes, representing a significant financial value. The aim of the present research was to compare the (+)-catechin concentrations in the bark of the most important oak species found in Hungary and to optimize sample pretreatment (conservation) and extraction methods in order to achieve fast and efficient extraction. From these species the highest concentrations were measured in Q. robur and Q. robur ssp. slavonica (8–12 mg (+)-catechin/g dry bark). The combination of microwave sample pretreatment and microwave assisted extraction proved to be the most time- and cost-effective method. The utilization of the extracted bark powder for energetic purposes requires further investigations.

Quantitative proteomics reveals the therapeutic effects of RFAP against depression via pathway regulation of long-term depression and potentiation

Ethnopharmacological relevanceRFAP is a compound extraction complex of four Traditional Chinese Medicine (TCM), including the dry bark of Paeonia lactiflora Pall. (Radix Paeoniae Alba), Gardenia jasminoides J. Ellis (Fructus Gardeniae), Albizia julibrissin Durazz. (Albizia julibrissin Durazz), and Paeonia × suffruticosa Andrews (Peony bark). Not only RFAP but also the individual ingredients have been commonly used for the treatment of depression in the clinic. However, the underlying mechanism of pharmacology is difficult to interpret since its holistic and multidrug nature. Aim of the studyThis study aimed to elucidate the potential antidepressant mechanism of RFAP in the treatment of chronic unpredictable mild stress (CUMS) rats' model via the quantitative proteomics approach. Materials and methodsWe established the CUMS rats' model and evaluated the efficacy of RFAP using multiple behavior assays, including the sugar preference test, open field test, and forced swimming test. Then label-free quantitative proteomics analyses were performed to evaluate the integrated changes of proteome profiling in control, CUMS, RFAP low dose, and RFAP high dose groups. Finally, we validated the critical changed proteins in the pathways of long-term depression and potentiation via RT-PCR and Western blotting assays. ResultsWe successfully established the CUMS rats' model. The behavior assays indicated that the rats demonstrated a tendency to behavioral despair after four weeks. Label-free quantitative proteomics showed that 107 proteins were significantly upregulated and 163 proteins were downregulated in the CUMS group compared to the control group. These differentially expressed proteins were involved in long-term potentiation, long-term depression, nervous system development, neuronal synaptic structural constituent of ribosome, ATP metabolic process, learning or memory, and cellular lipid metabolic process. RFAP treatment partially restored the differentially expressed protein profile. The protective effect of RFAP on behavioral assessment were consistent with the results of proteomics. ConclusionsThe results indicated that RFAP exerted a synergistic effect on CUMS by regulating long-term inhibition and potentiation-related proteins.

EFEITO DO DESBASTE SOBRE OS VOLUMES DE BIOMASSA E O TEOR DE TANINOS CONDENSADOS DA CASCA DE Mimosa caesalpiniifolia BENTH.

ABSTRACT This research aimed to evaluate the effect of thinning on the wood volumes per hectare on the tannin content in the bark of Mimosa caesalpiniifolia. The planting was subdivided into two plots, one thinned at 12 and 55 months of age (T1), while the other plot was kept intact (T2). The dendrometric variables were measured, and ten trees were felled, five in each plot. Subsequently, wood and bark’s volume, mass, and moisture content were determined. Then, the total solids content (TST), the Stiasny index (I), and the condensed tannin content (TTC) were quantified. Dry wood productivity was statistically different between the two treatments, with values of 26.7 and 22.8 t ha-1 for T1 and T2, respectively. The percentage of dry bark corresponded to 16% of the total biomass for both treatments. The only variable that showed a significant difference was I, with values with and without thinning, 59.83 and 79.31%, respectively. Therefore, it was verified that the way the thinning was used changed the I and how they were conducted, favoring the emission of boles and increasing the frequency in the lower diametric classes instead of favoring the increase in DBH. It is concluded that thinning interferes with the biomass volumes and the Stiasny index of M. caesalpiniifolia. However, it does not alter the concentration of tannins present in the species’ bark.

Study of the Subacute Toxicity of Dry Bark of Albizia ferruginea (Mimosaceae) (Guill. &Perr.) Berth. in Wistar Albino Rats

This present work aimed to assess the subacute toxicity of the total aqueous extract of the dry bark of Albizia ferruginea in rats. Subacute toxicity was done in accordance with 2008 OECD Guideline 407, for oral toxicity at a daily dose for 28 days in rodents. The animals were divided into six groups of 10 rats each (5 males and 5 females). One control group received 10 mL/kg of distilled water, three groups received 200, 400 and 800 mg/kg of extract respectively, one satellite control group and one satellite treated group received 10 mL/kg of distilled water and 800 mg/kg extract respectively. After 28 days of treatment, the satellite groups were left under observation without treatment for an additional 14 days. Behavior, body weight and death rate were monitored during the experimental period. The relative weight of some organs, hematological and biochemical parameters and the histopathological study of the liver, kidneys and lungs were evaluated at the end of the experiment. There were no significant effects on body weight gain and the relative weight of organs investigated. At the 800 mg/kg dose, there was a significant increase in the level of monocytes by 26.53%; the mean corpuscular hemoglobin content (MCHT) of 18.18%; and in the corpuscular hemoglobin concentration (MCHC) of 20.70 %, only in male rats. ALT and ASAT activity were increased significantly in both male and female rats. These increases were not seen in satellite treated rats. The histology of the organs investigated showed no difference when comparing the treated rats to the control rats. The subacute toxicity study of total aqueous extract of the dry bark of Albizia ferruginea did not show any signs of significant toxicity for parameters studied in rats.

Accessing the ephemeral using multiscale 3D microscopy of bone microwear

Ancient people used perishable resources much as people do today. Such materials do not preserve well in the archaeological record, and so there are types of items that would have been made from animal skins or vegetal matter like clothing, footwear, and containers that are not present in many assemblages. Direct evidence for such items is often lacking, but indirect evidence in the form of microwear traces can be found on more durable materials, such as bone tools, that interacted with these less permanent items prior to deposition. In this study, 3D microscopic methods are applied to quantitatively evaluate traces from three perishable materials (semi-fresh animal skin, processed split leather, and dry bark) on experimental bone tools. Bones were scanned on two objectives (20x and 100x) with a confocal disc-scanning microscope and evaluated using 3D surface texture parameters. Quantitative measurements of the bone surfaces varied at the different scales, but material wear patterns were evident and indicative of the differences in properties of the three materials. This study indicates that the use of 3D microscopic methods on bone tools at multiple scales is useful for understanding how contact with perishable materials affects bone surfaces. This method has the potential to indirectly evaluate ephemeral resources that once came into contact with ancient bone artifacts and reconstruct some of the less tangible aspects of ancient human behavior.

PHARMACOGNOSTIC AND PRELIMINARY PHYTOCHEMICAL STANDARDIZATION OF BARK EXTRACT OF SALACIA RETICULATA WIGHT.

Salacia reticulata Wight belongs to the family Celastraceae are renowned species of plant having hypoglycemic action. It is standardized based on preliminary phytochemical and pharmacognostic properties. Pharmacognostic studies have shown that S. reticulata dry bark has a yellowish outer surface while brown to dark brown color internally. It has a bitter taste with a characteristic odor. Under microscopic evaluation S. reticulata stem cross-section showed xylem, cambial zone with cells arranges in rows after the xylem, phloem driver, and other structures. Phytochemical standardization has revealed the presence of chemical components including Sterols, Tannins, Terpenoids, Saponins, Phenols, Flavonoids, and Carbohydrates, normal fluorescence behavior at normal, 254nm, and 366nm. In the TLC test two solvent systems, Chloroform-Methanol-Water (80:20:2) and Ethyl acetate-Methanol-Water (100:16.5:13.5) showed the presence of 11 chemical constituents that need to be further explored.

Valorization of birch bark using a low transition temperature mixture composed of choline chloride and lactic acid

Abstract This article presents the results obtained in the extraction of birch bark with a green solvent. A low transition temperature mixture (LTTM) consisting of choline chloride (ChCl) and lactic acid in a molar ratio of 1:1 was used as the solvent. Extraction was performed at 60°C and 80°C. At both temperatures, the effect of extraction time on the yield of the extracted substances was monitored. The yields reached were compared with those obtained in studies using common solvents such as ethanol, methanol, d-limonene, ethyl acetate, and others. The extract was quantitatively analyzed by HPLC-UV to determine betulin and betulinic acid (0.491–1.788 mg/g dry bark and 0.106–0.316 mg/g dry bark, respectively). Total phenolic content was determined spectrometrically using Folin–Ciocalteu reagent and expressed as Gallic acid equivalents (GAE; 18.6–56.8 mg GAE/g dry bark). This study has shown that extraction with a green solvent composed of ChCl and lactic acid can be an effective method for extracting polyphenolic compounds from birch bark. The process for extracting triterpenes (betulin and betulinic acid) is less suitable compared to conventional methods using the mentioned organic extractants.

Influence of Extracts from Bark of Deciduous Trees on the Activity of the Amylolytic Enzyme - Alpha Amylase

The effect of water extracts obtained from bark of growing in Latvia and widely spread in Europe grey alder (Alnusincana), black alder (Alnusglutinosa) and aspen tree (Populustremula), on the amylase activity in human saliva was evaluated. The extracts were obtained using advanced ACE equipment and distilled hot water as a solvent. The total yields of extractives from bark were rather similar and varied from 16 % to 21 % based on dry bark. However, the content of proantocianidine and salicine derivatives used as diagnostic characteristic for evaluation of effect of extracts on activity of amylase – a glucose-polymers cleavage enzyme - differed significantly. The results of in-vitro tests realized using the model of human gastrointestinal pass have shown that the abovementioned extracts in micro dosages are able to increase significantly activity of amylase. However, this effect is dose dependent and when the dose is exceeded the opposite effect – inhibition of amylase activity - is observed. This effect is explained by increasing of proantocianidins component in the volume of the tested extract dose, because pure proantocianidins, isolated from grey alder bark significantly inhibited activity of amylase. The further investigation is necessary in order to estimate effective and safe dosages for application of extracts providing a guaranteed unambiguous effect of activation or inhibition of amylase activity.

The effect of thermal drying on the contents of condensed tannins and stilbenes in Norway spruce (Picea abies [L.] Karst.) sawmill bark

Norway spruce (Picea abies (L.) Karst.) bark contains marked amounts of polyphenolic compounds. Condensed tannins (CTs) and stilbenes show commercial potential as antioxidants, antimicrobials, preservatives in food and cosmetic applications, technochemical products, and pharmaceuticals. Storing of bark before the conversion process leads to substantial losses of extractives compounds. In the present study, the potential of thermal drying for maintaining extractives content was assessed based on an experiment in which bark samples were dried in convection kilns at 40, 50, 60, and 70 °C temperatures. The development of CTs and stilbene contents and CT degradation were followed for 28–34 h. CTs were analysed from bark samples with thiolysis. Quantities of stilbene glycosides and stilbene aglycones in water-acetone extracts were analysed applying gas chromatography with flame-ionization detection (GC-FID). Multilevel regression analysis was used to analyse the statistical differences in moisture content and extractives composition between the drying schemes.The initial CT content of 35–36 mg g−1 in dry bark material declined to 25–31 mg g-1 in 28–34 h. The average degree of polymerisation (DP) decreased slightly, and the relative proportion of prodelphinidins in CTs increased significantly in the 60 and 70 °C schemes. The proportion of A-type linkages slightly increased with the increase in drying temperature. The initial mean stilbene contents varied from 19 mg g−1 to 22 mg g−1 in dry bark mass. Isorhapontin was the major stilbene constituent, with a proportion of 45–49 % of the total stilbenes. Stilbene losses of up to 60 % were detected during the drying processes. In 10 h, for example, 36–43 % of total stilbenes were lost. Degradation activities by enzymes released from the bark and oxidative reactions after crushing at the debarking phase were concluded to be the primary mode of degradation. The results indicate that bark CT content can be preserved at a moderate temperature not exceeding 50 °C, but the degradation of CTs may affect their suitability for various applications. Sufficient stilbene content for industrial processes is unlikely to be maintainable through thermal drying. The permanence of the post-drying extractives content should be assessed based on a practical-scale storage experiment using bark dried to varying moisture contents.

Application of Myrcia splendens tannins in the composition of urea-formaldehyde adhesive for sustainable wood bonding

Tannins from Myrcia splendens from the Amazon rainforest were used for the first time in the formulation of a urea-tannin-formaldehyde (UTF) resin. The objective was to evaluate the effect of different tannin proportions on the glue line performance in Pinus sp. woods, glued with UTF adhesive. The tannins were extracted in a water bath, using 1500 mL of water and 100g of dry bark (liquor/bark 15:1), with addition of 3% Na2SO3, at a temperature of 70 °C for three hours. The adhesives formulations were based on the gradual replacement of mass of the urea-formaldehyde (UF) adhesive by tannin powder, totalizing four compositions and one control treatment. UTF adhesives were evaluated for their physicochemical properties, shear bond strength (wet and dry) and wood failure. The addition of M. splendens tannins to the urea formaldehyde adhesive promoted an increase in glue line strength. The proportion of 5.0% of tannins proved to be ideal in the formulation of the UTF adhesive, considering all the parameters evaluated. Thus, this study proves the potential use of Amazonian tannins from Myrcia splendens in the partial composition of more sustainable UTF adhesives.

Effect of Seasonal Storage on Single-Stem Bark Extractives of Norway Spruce (Picea abies)

Increasing the net value of forestry side-streams has both ecological as well as economic benefits for emerging biorefining industries. Spruce bark represents one of the nature’s abundant sources of valuable extractives. In this study, the impact of storage on the quality and quantity of Norway spruce (Picea abies) extractives was examined as a function of storage time, environmental conditions and season (i.e., winter or summer). The bark from stored spruce saw logs was extracted with an accelerated solvent extractor (ASE) at 120 °C with hexane and water. The produced extracts were analysed qualitatively and quantitatively by gas chromatography with a flame ionisation detector (GC-FID) and high-performance liquid chromatography (HPLC) methods. The total amount of phenolics in the water extracts was evaluated by the Folin–Ciocalteu method, while the carbohydrate and lignin content of the extractive-free bark was estimated by acidic hydrolysis and acidic methanolysis. According to the results, storage season and temperature dramatically influenced both the chemical composition and degradation rate of bark extractives. After a storage period of 24 weeks, the winter-stored saw log bark retained 22% more hydrophilic extractives than the summer-stored bark. Lipophilic extractives, however, were 14% higher during the summer. Notably, the average amount of monomeric stilbenoids was 61% higher during the winter storage period. The initial total phenolic content in the water extracts was significantly higher during winter, but the degradation rate was about equal during winter and summer. The amount of cellulose in dry bark decreased from 17% to 11% and from 13% to 6% during winter and summer, respectively. By contrast, hemicelluloses increased from 17% to 26% and 15% to 30% during winter and summer, respectively. Overall, it was demonstrated that the seasonal factors of storage greatly affected the degradation rate of valuable spruce bark extractives, which should be considered in the planning stages of the raw materials procurement chain.

Libidibia ferrea extract as a promising antidiabetic agent: characterization, pre-clinical analysis and development of pharmaceutical dosage forms / Extrato de Libidibia ferrea como um promissor agente antidiabético: caracterização, análise pré-clínica e desenvolvimento de formas de dosagem farmacêutica

The present work aimed at developing pharmaceutical dosage forms based on the dry bark extract of Libidibia ferrea for the treatment of diabetes mellitus . The physicochemical characterization of the plant raw material, extractive solution and dry extract obtained by freeze drying were carried out. Effervescent granules, oral solution and tablets from the dry extract were developed and subjected to the recommended quality control tests. All materials presented standardized values after physical-chemical characterization. The presence of several secondary compounds was confirmed, and the content of the tannins was determined. The extract did not present acute toxicity in the in vivo experiment and provided an increase in glucose uptake in the in vitro study. The developed formulations complied with previously established values for quality control. The results show the safety and efficacy of the developed products, may being promising options in the treatment of diabetes mellitus .

OPTIMIZATION OF THE PROCESS OF BIOLOGICALLY – ACTIVE BETULIN DIPROPIONATE PRODUCTION FROM OUTER BIRCH BARK

The aim of this work was the mathematical modeling and selection of optimal regimes for the process of biologically active betulin dipropionate production based on the treatment of birch bark by propionic acid. In order to achieve this aim, two variable factors of the process were varied: X1 – the average size of bark particles (3.5 and 15.0 mm); X2 – the duration of the process. The output parameters were: Y1 – product yield (as a percentage by mass of the absolutely dry bark); Y2 – mass fraction of betulin dipropionate in the product (in percent); Y3 – the yield of betulin dipropionate as a percentage by mass of the absolutely dry bark. For mathematical processing of the results, the Statgraphics Centurion XVI package, the DOE block, the Multi-Factor Categorical procedure were used.
 It was established by experimental and computational methods that the optimal conditions for obtaining the product with the highest content of betulin dipropionate are as follows: a ratio liquid/solid of 20, an average size of bark particles of 3.5 mm, a time of 8–12 hours.
 The structure of betulin dipropionate, obtained under optimal conditions, was confirmed by physicochemical methods, the purity of the product was 95%. Due to its low toxicity and valuable pharmacological properties the betulin dipropionate has prospects for use in medicine.

Herbal textual research on Cortex Erythrinae

There are many records about the plant origin of Cortex Erythrinae in the past dynasties, but the descriptions were simple and there are many varieties used in different places, which leads to the confusion of Cortex Erythrinae commodities.It is necessary to make a thorough textual research on this herb to get the accurate origin and standardize the use of Cortex Erythrinae. In this paper, according to the plant morphological characteristics, producing areas, habitat, attached drawings of medicinal materials and efficacy, we have made a detailed research on Cortex Erythrinae recorded in the past dynasties. It is concluded that the authentic Cortex Erythrinae contained in the past dynasties should be the dry bark of Bombax malabaricum, which also named as Guanghaitongpi collected in the current local standards of Guangdong province and it is still in use today.The dry bark of Erythrina varlegata var. orientalis and E. arborescens recorded in Chinese Pharmacopoeia in 1977 should be "Citong" in ancient times. In this paper, based on the systematic and detailed summary of the origin changes, producing area changes and quality evaluation of Cortex Erythrinae, the basis for the correct use of Cortex Erythrinae and the further development and utilization of resources was provided.

O uso da fumaça para o controle do comportamento defensivo de abelhas Tiúba

The aim of the study was to evaluate the effect of smoke from different plant products on the defensive behavior of tiuba bees (Melipona compressipes fasciculata Smith, 1854). The experiment was carried out in a meliponary with 12 colonies with equity regarding the biological development. The following treatments were applied to the colonies weekly: smokeless, sawdust (100% of the smoker), eucalyptus (50%) + sawdust (50%) and sawdust with 2 suber fragments, the dry bark of Amburana cearensis (Allemao) A.C.Sm.. Regarding the development of the colonies, it was observed that the use of smoke did not change the number of brood cells nor the number of pollen and honey storage cells in the colonies. Regarding the number of bees adhering to gloves and headband, it was observed that colonies managed without smoke were more defensive compared to the other ones (p ≤ 0,05). It was concluded that the use of smoke (100% sawdust in the smoker) decreased the defensive behavior of tiuba bees, being an alternative in the meliponiculture management since it does not interfere negatively in the colonies development of the colonies.

Investigation of Total Phenolic Content and Antioxidant Activities of Spruce Bark Extracts Isolated by Deep Eutectic Solvents

Extracts from spruce bark obtained using different deep eutectic solvents were screened for their total phenolic content (TPC) and antioxidant activities. Water containing choline chloride-based deep eutectic solvents (DESs) with lactic acid and 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and 1,5-pentanediol, with different molar ratios, were used as extractants. Basic characteristics of the DESs (density, viscosity, conductivity, and refractive index) were determined. All the DESs used behave as Newtonian liquids. The extractions were performed for 2 h at 60 °C under continuous stirring. TPC was determined spectrophotometrically, using the Folin-Ciocalteu reagent, and expressed as gallic acid equivalent (GAE). The antioxidant activity was determined spectrophotometrically by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. The TPC varied from 233.6 to 596.2 mg GAE/100 g dry bark; radical scavenging activity (RSA) ranged between 81.4% and 95%. This study demonstrated that deep eutectic solvents are suitable solvents for extracting phenolic compounds from spruce bark.

Inhibitory Effects of Pinus Pinaster Aiton Subsp. Atlantica Bark Extracts Against Known Food Pathogens

Pine bark extracts are a rich source of natural polyphenols that besides their known antioxidant activity may also exhibit significant antimicrobial properties. In the current study, the antimicrobial activity of Pinus pinaster Aiton subsp. atlantica extracts was screened against gram-positive bacteria (Bacillus cereus, Clostridium perfringens, Listeria monocytogenes, Staphylococcus aureus), gram-negative bacteria (Pseudomonas aeruginosa, Escherichia coli, Salmonella enterica serovar Enteritidis) and the fungus Aspergillus brasiliensis ATCC 16404, using the disk diffusion assay. The hydroethanolic extracts obtained by Microwave assisted extraction (MAE) at 1600 W and 110 oC for 30 minutes, were compared to the Soxhlet extracts. The pine bark was dried to reach equilibrium humidity at 40 °C for 72 hours and milled to a particle’s size of 200-850 µm. The extraction yield was determined by the amount of extract recovered in mass compared to the initial amount of dry bark and the total phenolic content was determined by the Folin Ciocalteu colorimetric method at 725 nm. Hydroethanolic pine bark extracts were prepared at 0.25, 0.50 and 80.00 mg/mL concentrations.MAE attained higher extraction yield and higher total phenolic content (20.4±0.7% w/w and 71.1±3.4 mg of gallic acid equivalent (GAE) per g of sample, respectively) than Soxhlet extracts (17.6±0.2% w/w and 54.9±2.6 mg GAE/g sample, respectively).The pine bark extracts presented inhibition halos ranging from 7 to 17 mm against the gram positive bacteria, namely C. perfringens ATCC 13124 and B. cereus NCTC 11143. The MAE extracts presented higher inhibition halos than the Soxhlet ones. Regarding the tested concentrations, only C. perfringens ATCC 13124 and B. cereus NCTC 11143 were sensitive to the 0.25 and 0.50 mg/mL concentrations. At 80 mg/mL all the gram-positive bacteria were sensitive to the pine bark extracts obtained by both extraction methods. On the other hand, the extracts did not show inhibitory effect against the tested gram-negative bacteria and A. brasiliensis.This study reveals that MAE is a fast and efficient method for obtaining Pinus pinaster Aiton subsp. atlantica extracts with antimicrobial activities against Gram-positive bacteria.

Emission characteristics of particulate matters from a 30 MW biomass-fired power plant in China

The emission characteristics of particulate matters from a full-scale biomass-fired power plant equipped with bag filters were investigated. Results show that particle size distribution at the inlet of bag filter from the combustion of blended feedstocks is bimodal, while that of dry bark feedstocks is essentially unimodal with negligible emission of coarse particles with diameter in the range of 1.0–10 μm. The combustion of blended fuels generates higher yields of submicro particles than that of dry bark feedstocks. Elemental analysis shows that submicro particles in all cases mainly consist of potassium, chlorine, and sulfur. Higher chlorine but lower sulfur contents are observed in submicro particles from blended fuels compared with that from dry bark feedstocks. The vibrating operation of grate furnace reduces submicro particles emission as well as the sulfur content in all particles. Ion chromatography results show that sulfate ion and chloridion are the two most abundant water-soluble anions in particulate matters, while water-soluble cations are richest in potassium with considerable content of calcium, magnesium, sodium and ammonia. The contribution of organic and element carbon in particulate matters is in the range of 1–3%, indicating high combustion efficiencies and low organic and element carbon emissions of biomass-fired grate furnaces.