10 research outputs found

    Lipids from Vitellaria paradoxa Gaertn Seeds by Supercritical CO2: Extraction and Optimization of Parameters by Response Surface Methodology

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    Supercritical carbon dioxide (CO2) was employed to extract lipids from Vitellaria paradoxa Gaertn seeds in semi–batch process at various operating conditions to optimize extraction process. The extraction processes were carried out at 40 – 60 oC and 20 – 40 MPa with 2 – 4 ml min–1 CO2 flow rates. Analysis of variance (ANOVA) with 33 factorial design combined with statistical was used to optimize variables in the process of Vitellaria paradoxa Gaertn seeds lipids extraction with supercritical CO2. The FT–IR spectra indicated that the Vitellaria paradoxa Gaertn seeds components were extracted by supercritical CO2. The SEM images also indicated that the physical changes in the surface of the Vitellaria paradoxa Gaertn seeds occurred after supercritical CO2 extraction treatment. The maximum of extracted lipids was 0.47 g/g–sample when the extraction was conducted at a temperature of 80 oC and pressure of 40 MPa with CO2 flow rate of 3 ml min–1. The GC–MS analysis showed that the extracted lipids mainly composed of palmitic acid (C16:0), stearic acid (C18:0), oleic acid (C18:1), and linoleic acid (C18:2). The analysis of experimental design demonstrated that pressure and temperature were the influential variables on the lipids extraction

    Seasonal Changes in the Plant Growth-Inhibitory Effects of Rosemary Leaves on Lettuce Seedlings

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    Plant biodiversity has been studied to explore allelopathic species for the sustainable management of weeds to reduce the reliance on synthetic herbicides. Rosemary (Rosmarinus officinalis L., syn Salvia rosmarinus Spenn.), was found to have plant growth-inhibitory effects, and carnosic acid was reported as an allelochemical in the plant. In this study, the effects of seasonal variation (2011–2012) on the carnosic acid concentration and phytotoxicity of rosemary leaves from two locations in Tunisia (Fahs and Matmata) were investigated. The carnosic acid concentration in rosemary leaves was determined by HPLC, and lettuce (Lactuca sativa L.) was used as the receptor plant in the phytotoxicity bioassay. The highest carnosic acid concentration was found in rosemary samples collected in June 2011, which also had the highest inhibitory activity. Furthermore, a significant inverse correlation (r = −0.529; p < 0.01) was found between the inhibitory activity on lettuce hypocotyl and the carnosic acid concentration in rosemary leaves. Both temperature and elevation had a significant positive correlation with carnosic acid concentration, while rainfall showed a negative correlation. The results showed that the inhibitory effects of rosemary leaf samples collected in summer was highest due to their high carnosic acid concentration. The phytotoxicity of rosemary needs to be studied over time to determine if it varies by season under field conditions.Peer Reviewe

    Involvement of Carnosic Acid in the Phytotoxicity of Rosmarinus officinalis Leaves

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    Weeds are rapidly developing resistance to synthetic herbicides, and this can pose a threat to the ecosystem. Exploring allelopathic species as an alternative weed control measure can help minimize the ecological threat posed by herbicide-resistant weeds. In this study, we aimed to evaluate the contribution of some polyphenols to the allelopathy of rosemary (Rosmarinus officinalis L.). The phytotoxic effects of rosemary (leaves, roots, inflorescences, and stems) crude extracts were tested on lettuce (Lactuca sativa L.). Soils incorporated with dried rosemary leaves were also tested on test plants. Reversed-phase high-performance liquid chromatography (HPLC) analysis was used to determine the content of some polyphenols (caffeic, ferulic, gallic, rosmarinic, carnosic, and chlorogenic acids) in rosemary. The specific activity and total activity of crude extracts and individual compounds were evaluated using lettuce. The crude extract of rosemary leaves showed the highest growth inhibitory effect among the rosemary organs tested. Soil amended with rosemary leaf debris reduced the dry matter and seed emergence of lettuce. Carnosic acid was the main compound detected in rosemary leaves and had a high specific activity when tested on lettuce. During the seed germination period, there was observed filter paper coloration among the test plants treated with carnosic acid (250 μg/mL). The high concentration and strong inhibitory effect of carnosic acid could explain the inhibitory activity of the rosemary leaf extract. Hence, we conclude based on the total activity estimation that carnosic acid among the other tested compounds is the major allelochemical in rosemary leaves

    Evaluation of the Effectiveness of Loose and Compressed Wood Chip Mulch in Field-Grown Blueberries—A Preliminary Study

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    Blueberry production in the field faces several challenges, including competition from weeds and soil suitability. Different mulch types are widely used in blueberry cultivation to control weeds, conserve moisture, and mitigate soil erosion. However, the comparative effects of loose and compressed wood chips on fruit quality and weed control in blueberry production systems have not been studied. Many farmers use expensive imported peat moss as soil covers, while others apply organic mulches such as chips or chaff, which can be easily washed away by runoff. This study aimed to evaluate the effects of compressed mulching boards (MB) fabricated without the use of chemical adhesives using pressurized steam and compression technologies in blueberry cultivation. During the two growing seasons, the effectiveness of compressed MB on soil moisture retention, fruit quality, and weed biomass was compared to that of wood chip (WC) and control treatments in a blueberry field. Although a significant difference was observed in the fruit fresh weight, no significant differences were observed in the other fruit growth parameters for all the treatments. Generally, the compressed MB significantly improved soil moisture retention capacity compared to WC and control during the two-year study. The compressed MB showed effective weed suppression ability by significantly reducing the weed biomass at all sampling times.Research on Agriculture and Food ScienceJST CRESTPeer Reviewe

    Influence of Soil Characteristics and Land Use Type on Existing Fractions of Radioactive 137Cs in Fukushima Soils

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    Radioactive cesium (137Cs) in distinct soil fractions provides key information to its bioavailability, and therefore determining the effect of soil characteristics and land use types on existing fractions of 137Cs in soils is important for predicting future 137Cs mobility in Fukushima. Thus, the objective of this study was to investigate the influence of soil characteristics and land use types on sequentially extracted fractions of 137Cs in Fukushima. In this study, five coniferous forest soils, eight arable soils, and eight paddy rice soils were sampled in 2012 and 2013. The 137Cs in the soils were separated into four fractions; water-soluble, exchangeable, organic matter-bound and residual fractions. More than 90% of the soil 137Cs fraction for arable and paddy rice soils was found in the residual fraction, implying significantly reduced bioavailable 137Cs with higher fixation. In contrast, forest soils measured higher exchangeable and organic matter-bound fractions of 5%–33% and 9%–44%, respectively, implying future 137Cs mobility in the forest ecosystem. Correlation analysis showed a significant negative correlation (p < 0.05) between the organic matter fraction and residual fraction in both arable and paddy rice soils. There was a significant positive correlation (p < 0.05) for both exchangeable and residual fractions with cation exchange capacity (CEC), total carbon (TC) and total nitrogen (TN) values in arable soils. Organic matter content influenced both exchangeable and residual fractions. It was not clear whether organic matter played a direct role in 137Cs fixation or mobility in the agricultural soils. In paddy rice soils, the organic matter fraction showed a significant negative correlation with TC and TN values. Soil pH was significantly negatively correlated (p < 0.05) with both water-soluble and residual fractions in forest soils but positively (p < 0.1) with the organically bound 137Cs fraction.Peer Reviewe

    Evaluation of the Effectiveness of Loose and Compressed Wood Chip Mulch in Field-Grown Blueberries—A Preliminary Study

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    Blueberry production in the field faces several challenges, including competition from weeds and soil suitability. Different mulch types are widely used in blueberry cultivation to control weeds, conserve moisture, and mitigate soil erosion. However, the comparative effects of loose and compressed wood chips on fruit quality and weed control in blueberry production systems have not been studied. Many farmers use expensive imported peat moss as soil covers, while others apply organic mulches such as chips or chaff, which can be easily washed away by runoff. This study aimed to evaluate the effects of compressed mulching boards (MB) fabricated without the use of chemical adhesives using pressurized steam and compression technologies in blueberry cultivation. During the two growing seasons, the effectiveness of compressed MB on soil moisture retention, fruit quality, and weed biomass was compared to that of wood chip (WC) and control treatments in a blueberry field. Although a significant difference was observed in the fruit fresh weight, no significant differences were observed in the other fruit growth parameters for all the treatments. Generally, the compressed MB significantly improved soil moisture retention capacity compared to WC and control during the two-year study. The compressed MB showed effective weed suppression ability by significantly reducing the weed biomass at all sampling times

    Medicinal Plants Used in the Ejisu-Juaben Municipality, Southern Ghana: An Ethnobotanical Study

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    Background: The in-depth traditional knowledge of medicinal plants is at risk of extinction due to the dependency on oral transmission, and as such, there is an urgent need to document such knowledge. This study aimed to document indigenous uses of medicinal plants among community members in the Ejisu-Juaben Municipality. Methods: Data was collected in 2016 from community members and local herbalists in the Ejisu-Juaben Municipality through a semi-structured questionnaire. Statistical tools and ethnobotanical indices, i.e., informant consensus factor (ICF), fidelity level (FL), and use value (UV) were used to analyse the data. Results: One hundred and six medicinal plants belonging to 45 families were reported to cure 68 different human diseases. The most frequently used plant part in this study was the leaves (52%). Decoction (57.5%) and oral administration (58.3%) were the most utilised herbal preparation and administration route respectively. Cleistopholis patens had the highest UV (0.54) with pain &amp; fevers and skin diseases having the highest ICF values (0.88 and 0.85 respectively). Furthermore, new medicinal uses of Hilleria latifolia and ten other species were recorded for the treatment of the traditional local disease, aseram. Conclusions: The current knowledge and uses of medicinal plants are still high in the study area based on the high degree of consensus among informants. This study could allow for the preservation of knowledge and biodiversity of medicinal plants, both of which are threatened with extinction

    International pellet watch: Global monitoring of polybrominated diphenyl ethers (PBDEs) in plastic resin pellets

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    International audiencePolybrominated diphenyl ethers (PBDEs) were measured in plastic resin pellets collected from 65 beaches across 27 countries worldwide. They were detected at 49 locations at concentrations of the sum of 49 congeners of up to 46 ng/g-pellet and a median of 2 ng/g-pellet. These values are one to two orders of magnitude lower than those of polychlorinated biphenyls (PCBs) (median, 51 ng/g-pellet). This difference can be attributed to lower production of the Penta-BDE technical mixture, which is used extensively in some countries, and lower availability of brominated flame retardants for equilibrium partitioning than PCBs. Tetra-, penta-, and hexa-brominated congeners (BDE-47, 99, 100, 153, 154) were dominant over a deca-substituted congener (BDE-209) in many samples; this was significantly detected in pellets from some locations. Results indicate that pellets reflect the pollution status of PBDEs in the dissolved phase in seawater. From the ranking of the summed concentrations of six major PBDE congeners (Σ6PBDEs), we propose five levels of pollution categorization (ng/g-pellet): no (8.5) local pollution. The USA and neighboring countries were categorized as extreme (17–36 ng/g-pellet), western Europe and Japan were categorized as high (≤8.8), and most Asian and African countries were categorized as slight (<0.8). Notably, extreme or high pollution levels were also observed in countries with no history of PBDE production, such as Ghana (Σ6PBDEs up to 16 ng/g-pellet), the Philippines (7.5), and Hong Kong (7.7). Scrapped electrical and electronic waste might explain these anomalously high values
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