| 1. |
- Cavka, Adnan, et al.
(författare)
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Identification of Small Aliphatic Aldehydes in Pretreated Lignocellulosic Feedstocks and Evaluation of Their Inhibitory Effects on Yeast
- 2015
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Ingår i: Journal of Agricultural and Food Chemistry. - : American Chemical Society (ACS). - 0021-8561 .- 1520-5118. ; 63:44, s. 9747-9754
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Tidskriftsartikel (refereegranskat)abstract
- Six lignocellulosic hydrolysates produced through acid pretreatment were analyzed for the occurrence of formaldehyde, acetaldehyde, and glycolaldehyde. Acetaldehyde was found in all six (0.3-1.6 mM) and formaldehyde in four (<= 4.4 mM), whereas glycolaldehyde was not detected. To assess the relevance of these findings, fermentations with yeast and formaldehyde or acetaldehyde were performed in the concentration interval 0.5-10 mM. Formaldehyde already inhibited at 1.0 mM, whereas 5.0 mM acetaldehyde was needed to obtain a clear inhibitory effect. After 24 h of fermentation, 1.5 mM formaldehyde reduced the glucose consumption by 85%, the balanced ethanol yield by 92%, and the volumetric productivity by 91%. The results show that formaldehyde and acetaldehyde are prevalent in pretreated lignocellulose and that formaldehyde in some cases could explain a large part of the inhibitory effects on yeast by lignocellulosic hydrolysates, as three of six hydrolysates contained >= 1.9 mM formaldehyde, which was shown to be strongly inhibitory.
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| 2. |
- Cheng, Ken, et al.
(författare)
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Impact of Reduced Dietary Levels of Eicosapentaenoic Acid and Docosahexaenoic Acid on the Composition of Skin Membrane Lipids in Atlantic Salmon (SaImo salar L.)
- 2018
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Ingår i: Journal of Agricultural and Food Chemistry. - : American Chemical Society (ACS). - 0021-8561 .- 1520-5118. ; 66, s. 8876-8884
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Tidskriftsartikel (refereegranskat)abstract
- Membrane lipids, including sphingolipids and glycerol-phospholipids, are essential in maintaining the skin's barrier function in mammals, but their composition in fish skin and their response to diets have not been evaluated. This study investigated the impacts of reducing dietary eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on membrane lipids in the skin of Atlantic salmon through a 26 week feeding regime supplying different levels (0-2.0% of dry mass) of EPA/DHA. Ceramide, glucosylceramide, sphingomyelin, sphingosine, and sphinganine in salmon skin were analyzed for the first time. Higher concentrations of glucosylceramide and sphingomyelin and higher ratios of glucosylceramide/ceramide and sphingomyelin/ceramide were detected in the deficient group, indicating interruptions in sphingolipidomics. Changes in the glycerol-phospholipid profile in fish skin caused by reducing dietary EPA and DHA were observed. There were no dietary impacts on epidermal thickness and mucus-cell density, but the changes in the phospholipid profile suggest that low dietary EPA and DHA may interrupt the barrier function of fish skin.
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| 3. |
- Cheng, Ken, et al.
(författare)
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Metabolomics Approach To Evaluate a Baltic Sea Sourced Diet for Cultured Arctic Char (Salvelinus alpinus L.)
- 2017
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Ingår i: Journal of Agricultural and Food Chemistry. - : American Chemical Society (ACS). - 0021-8561 .- 1520-5118. ; 65, s. 5083-5090
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Tidskriftsartikel (refereegranskat)abstract
- Aqua feeds traditionally rely on fishmeal as a protein source, which is costly and unsustainable. A new feed was formulated in the study with Baltic Sea sourced decontaminated fishmeal, Mytilus edulis and Saccharomyces cerevisiae, and given to Arctic char (Salvelinus alpinus) for ten months. The diet-induced changes on metabolic profile in fish plasma, liver, and muscle were studied relative to a fishmeal-based standard diet by using a H-1 NMR-based metabolomics approach. Fish fed the test diet had higher content of betaine and lower levels of trimethylamine-N-oxide and aromatic amino acids in plasma or tissues, which were mainly caused by the diet. The metabolomics results are useful to understand the mechanism of lower body mass, smaller Fulton's condition factor, and a tendency of less lipid content observed in fish fed the test diet. Thus, modifications on the dietary levels of these compounds in the feed are needed to achieve better growth performance.
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| 4. |
- Cornelis, Geert
(författare)
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Polyphosphates and Fulvates Enhance Environmental Stability of PO4-Bearing Colloidal Iron Oxyhydroxides
- 2016
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Ingår i: Journal of Agricultural and Food Chemistry. - : American Chemical Society (ACS). - 0021-8561 .- 1520-5118. ; 64, s. 8465-8473
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Tidskriftsartikel (refereegranskat)abstract
- Iron oxyhydroxide nanoparticles (Fe-NPs) are natural vectors of phosphate (PO4) in the environment. Their mobility is determined by colloidal stability, which is affected by surface composition. This might be manipulated in engineered NPs for environmental or agricultural applications. Here, the stability of PO4-Fe-NPs (HFO/goethite) was determined across contrasting environmental conditions (pH, Ca concentration) and by using fulvates (FA) and polyphosphates (poly-P's) as coatings. The PO4-Fe-NPs are unstable at Ca concentrations above 0.1 mM. Addition of FA and some poly-P's significantly improved stability. Zeta potential explained colloidal stability across treatments; surface charge was calculated with surface complexation models and explained for phytic acid (PA) and hexametaphosphate (HMP) by a partial (1-4 of the 6 PO4 units) adsorption to the surface, while the remaining PO4 units stayed in solution. This study suggests that Ca concentration mainly affects the mobility of natural or engineered PO4-Fe-NPs and that HMP is a promising agent for increasing colloidal stability.
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| 5. |
- Crowe, Jacob D., et al.
(författare)
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Relating nanoscale accessibility within plant cell walls to improved enzyme hydrolysis yields in corn stover subjected to diverse pretreatments
- 2017
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Ingår i: Journal of Agricultural and Food Chemistry. - : American Chemical Society (ACS). - 0021-8561 .- 1520-5118. ; 65:39, s. 8652-8662
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Tidskriftsartikel (refereegranskat)abstract
- Simultaneous chemical modification and physical reorganization of plant cell walls via alkaline hydrogen peroxide or liquid hot water pretreatment can alter cell wall structural properties impacting nanoscale porosity. Nanoscale porosity was characterized using solute exclusion to assess accessible pore volumes, water retention value as a proxy for accessible water-cell walls surface area, and solute-induced cell wall swelling to measure cell wall rigidity. Key findings concluded that delignification by alkaline hydrogen peroxide pretreatment decreased cell wall rigidity and that the subsequent cell wall swelling resulted increased nanoscale porosity and improved enzyme binding and hydrolysis compared to limited swelling and increased accessible surface areas observed in liquid hot water pretreated biomass. The volume accessible to a 90 Å dextran probe within the cell wall was found to be correlated to both enzyme binding and glucose hydrolysis yields, indicating cell wall porosity is a key contributor to effective hydrolysis yields.
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| 6. |
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| 7. |
- El-Sayed, Ashraf M., et al.
(författare)
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Honey Norisoprenoids Attract Bumble Bee, Bombus terrestris, in New Zealand Mountain Beech Forests
- 2018
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Ingår i: Journal of Agricultural and Food Chemistry. - : American Chemical Society (ACS). - 0021-8561 .- 1520-5118. ; 66:50, s. 13065-13072
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Tidskriftsartikel (refereegranskat)abstract
- Three varieties of honey of different dominant floral origin were found to attract social Hymenoptera, including the large earth bumble bee, Bombus terrestris, in a New Zealand mountain beech forest. This study was undertaken to identify volatile organic compounds that induce the attraction of bumble bees to honeybee (Apis mellifera) honey. We analyzed the chemical composition of the volatile organic compounds produced in three distinct varieties of honey (i.e., manuka, honeydew, and clover honey). The composition of the chemical profile of the three honey varieties differed in the quality and in the ratio of compounds in the headspace. o-Methoxyacetophenone was the main compound in the headspace of all three honey varieties. Among the 40 compounds identified in the headspace in the three varieties, only seven shared compounds (i.e., benzaldehyde, benzyl alcohol, phenylacetaldehyde, 2-phenylethanol, isophorone, 4-oxoisophorone, and o-methoxyacetophenone) were present in the headspace of the three honey varieties. The relative attractiveness of various blends of the seven common compounds found in the three honey varieties was tested for the attraction to bumble bees in a mountain beech forest. A binary blend of isophorone and 4-oxoisophorone at a ratio of 90:10 was the most attractive blend for both bumble bee workers and queens. A small number of honey bee workers were also attracted to the former binary blend. Our study represents the first identification of a honey-derived attractant for bumble bees and honey bees. The potential application of our finding for monitoring of bumble bees or to enhance crop pollination and help to tackle the current concern of a global pollination crisis is discussed.
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| 8. |
- Frank, Damian, et al.
(författare)
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Effects of Agar Gel Strength and Fat on Oral Breakdown, Volatile Release, and Sensory Perception Using in Vivo and in Vitro Systems
- 2015
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Ingår i: Journal of Agricultural and Food Chemistry. - : American Chemical Society (ACS). - 0021-8561 .- 1520-5118. ; 63:41, s. 9093-9102
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Tidskriftsartikel (refereegranskat)abstract
- The density and composition of a food matrix affect the rates of oral breakdown and in-mouth flavor release as well as the overall sensory experience. Agar gels of increasing concentration (1.0, 1.7, 2.9, and 5% agarose) with and without added fat (0, 2, 5, and 10%) were spiked with seven aroma volatiles. Differences in oral processing and sensory perception were systematically measured by a trained panel using a discrete interval time intensity method. Volatile release was measured in vivo and in vitro by proton transfer reaction mass spectrometry. Greater oral processing was required as agar gel strength increased, and the intensity of flavor-related sensory attributes decreased. Volatile release was inversely related to gel strength, showing that physicochemical phenomena were the main mechanisms underlying the perceived sensory changes. Fat addition reduced the amount of oral processing and had differential effects on release, depending on the fat solubility or lipophilicity of the volatiles.
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| 9. |
- Ganeteg, Ulrika
(författare)
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AtLHT1 Transporter Can Facilitate the Uptake and Translocation of a Glycinergic-Chlorantraniliprole Conjugate in Arabidopsis thaliana
- 2018
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Ingår i: Journal of Agricultural and Food Chemistry. - : American Chemical Society (ACS). - 0021-8561 .- 1520-5118. ; 66, s. 12527-12535
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Tidskriftsartikel (refereegranskat)abstract
- Understanding of the transporters involved in the uptake and translocation of agrochemicals in plants could provide an opportunity to guide pesticide to the site of insect feeding. The product of Arabidopsis thaliana gene AtLHT1 makes a major contribution to the uptake into the roots of free amino acids and some of their derivatives. Here, a chlorantraniliprole-glycine conjugate (CAP-Gly-1) was tested for its affinity to AtLHT1 both in planta and in vitro. Seedlings deficient in AtLHT1 exhibited a reduction with respect to both the uptake and root-to-shoot transfer of CAP-Gly-1; plants in which AtLHT1 was constitutively expressed were more effective than wild type in term of their root uptake of CAP-Gly-1. Protoplast patch clamping showed that the presence in the external medium of CAP-Gly-1 was able to induce AtLHT1 genotype-dependent inward currents. An electrophysiology-based experiment carried out in Xenopus laevis oocytes expressing AtLHT1 showed that AtLHT1 had a high in vitro affinity for CAP-Gly-1. The observations supported the possibility of exploiting AtLHT1 as a critical component of a novel delivery system for amino acid-based pesticide conjugates.
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| 10. |
- Ganeteg, Ulrika
(författare)
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Design of a New Glutamine-Fipronil Conjugate with alpha-Amino Acid Function and Its Uptake by A-thaliana Lysine Histidine Transporter 1 (AtLHT1)
- 2018
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Ingår i: Journal of Agricultural and Food Chemistry. - : American Chemical Society (ACS). - 0021-8561 .- 1520-5118. ; 66, s. 7597-7605
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Tidskriftsartikel (refereegranskat)abstract
- Creating novel pesticides with phloem mobility is essential for controlling insects in vascular tissue and root, and conjugating existing pesticides with amino acid is an effective approach. In order to obtain a highly phloem-mobile candidate for efficient pesticides, an electro-neutral L-glutamine-fipronil conjugate (L-GlnF) retaining alpha-amino acid function was designed and synthesized to fit the substrate specificity of an amino acid transporter. Cotyledon uptake and phloem loading tests with Ricinus communis have verified that L-GlnF was phloem mobile, and its phloem mobility was higher than that of its enantiomer D-GlnF and other previously reported amino acid-fipronil conjugates. Inhibition experiments then suggested that the uptake of L-GlnF was, at least partially, mediated by an active transport mechanism. This inference was further strengthened by assimilation experiments with Xenopus oocytes and genetically modified Arabidopsis thaliana, which showed a direct correlation between the uptake of L-GlnF and the expression of amino acid transporter AtLHT1. Thus, conjugation with L-Gln appears to be a potential strategy to ensure the uptake of pesticides via an endogenous amino acid transport system.
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