bluuebunny/crossref_metadata_2025_split huggingface dataset:
Response of nutrient dynamics of decomposing pine (Pinus massoniana) needles to simulated N deposition in a disturbed and a rehabilitated forest in tropical China
Authors: Mo Jiangming , Brown Sandra , Xue Jinghua , Fang Yunting , Li Zhian , Li Dejun , Dong Shaofeng 
Published: January 2007

AbstractThe effects of simulated N deposition on changes in mass, C, N and P of decomposing pine (Pinus massoniana) needles in a disturbed and a rehabilitated forest in tropical China were studied during a 24‐month period. The objective of the study was to test the hypothesis that litter decomposition in a disturbed forest is more sensitive to N deposition rate than litter decomposition in a rehabilitated forest due to the relatively low nutrient status in the former as a result of constant human disturbance (harvesting understory and litter). The litterbag method and N treatments (control, no N addition; low‐N, 5 g N m−2year−1; medium‐N, 10 g N m−2year−1) were employed to evaluate decomposition. The results revealed that N addition increased (positive effect) mass loss rate and C release rate but suppressed (negative effect) the release rate of N and P from decomposing needles in both disturbed and rehabilitated forests. The enhanced needle decomposition rate by N addition was significantly related to the reduction in the C/N ratio in decomposing needles. However, N availability is not the sole factor limiting needle decomposition in both disturbed and rehabilitated forests. The positive effect was more sensitive to the N addition rate in the rehabilitated forest than in the disturbed forest, however the reverse was true for the negative effect. These results suggest that nutrient status could be one of the important factors in controlling the response of litter decomposition and its nutrient release to elevated N deposition in reforested ecosystems in the study region.
Identification and quantification of glycerolipids in cotton fibers: Reconciliation with metabolic pathway predictions from DNA databases
Authors: Wanjie Sylvia W. , Welti Ruth , Moreau Robert A. , Chapman Kent D. 
Published: January 2007

AbstractThe lipid profiles of cotton fiber cells were determined from total lipid extracts of elongating and maturing cotton fiber cells to see whether the membrane lipid composition changed during the phases of rapid cell elongation or secondary cell wall thickening. Total FA content was highest or increased during elongation and was lower or decreased thereafter, likely reflecting the assembly of the expanding cell membranes during elongation and the shift to membrane maintenance (and increase in secondary cell wall content) in maturing fibers. Analysis of lipid extracts by electrospray ionization and tandem MS (ESI‐MS/MS) revealed that in elongating fiber cells (7–10 d post‐anthesis), the polar lipids—PC, PE, PI, PA, phosphatidylglycerol, monogalactosyldiacylglycerol, digalactosyldiacylglycerol, and phosphatidyl‐glycerol—were most abundant. These same glycerolipids were found in similar proportions in maturing fiber cells (21 dpa). Detailed molecular species profiles were determined by ESI‐MS/MS for all glycerolipid classes, and ESI‐MS/MS results were consistent with lipid profiles determined by HPLC and ELSD. The predominant molecular species of PC, PE, PI, and PA was 34∶3 (16∶0, 18∶3), but 36∶6 (18∶3, 18∶3) also was prevalent. Total FA analysis of cotton lipids confirmed that indeed linolenic (18∶3) and palmitic (16∶0) acids were the most abundant FA in these cell types. Bioinformatics data were mined from cotton fiber expressed sequence tag databases in an attempt to reconcile expression of lipid metabolic enzymes with lipid metabolite data. Together, these data form a foundation for future studies of the functional contribution of lipid metabolism to the development of this unusual and economically important cell type.
Dietary α‐linolenic acid increases brain but not heart and liver docosahexaenoic acid levels
Authors: Barceló‐Coblijn Gwendolyn , Collison Lauren W. , Jolly Christopher A. , Murphy Eric J. 
Published: January 2007

AbstractFish oil‐enriched diets increase n−3 FA in tissue phospholipids; however, a similar effect by plant‐derived n−3 FA is poorly defined. To address this question, we determined mass changes in phospholipid FA, individual phospholipid classes, and cholesterol in the liver, heart, and brain of rats fed diets enriched in flax oil (rich in 18∶3n−3), fish oil (rich in 22∶6n−3 and 20∶5n−3), or safflower oil (rich in 18∶2n−6) for 8 wk. In the heart and liver phospholipids, 22∶6n−3 levels increased only in the fish oil group, although rats fed flax oil accumulated 20∶5n−3 and 22∶5n−3. However, in the brain, the flax and fish oil diets increased the phospholipid 22∶6n−3 mass. In all tissues, these diets decreased the 20∶4n−6 mass, although the effect was more marked in the fish oil than in the flax oil group. Although these data do not provide direct evidence for 18∶3n−3 elongation and desaturation by the brain, they demonstrate that 18∶3n−3‐enriched diets reduced tissue 20∶4n−6 levels and increased cellular n−3 levels in a tissuedependent manner. We hypothesize, based on the lack of increased 22∶6n−3 but increased 18∶3n−3 in the liver and heart, that the flax oil diet increased circulating 18∶3n−3, thereby presenting tissue with this EFA for further elongation and desaturation.
Effects of aging and dietary n−3 fatty acids on rat brain phospholipids: Focus on plasmalogens
Authors: André A. , Juanéda P. , Sébédio J. L. , Chardigny J. M. 
Published: January 2007

AbstractThe aging brain undergoes modifications in the lipid composition of cell membranes and especially in plasmalogens. These phospholipids represent between one‐half and twothirds of the ethanolamine phospholipids in the brain. They are known to facilitate membrane fusion and act as endogenous antioxidants. During normal aging and in some pathological conditions, plasmalogen and DHA levels fall. In this context, we aimed to evaluate the influence of n−3 FA intake on plasmalogens in the brain during aging. Littermates from two generations of n−3‐deficient rats were fed an n−3‐deficient diet or an equilibrated diet containing either α‐linolenic acid alone (α‐LNA) or with two doses of DHA (0.3 or 0.6% w/w). After weaning, 9 mon of diet, or 21 mon of diet, plasmalogen levels were assessed, and the sn‐2 substitutions of plasmenylethanolamines were analyzed in the cortex, striatum, and hippocampus. Our results showed that plasmalogen contents were not influenced by the diet. Plasmalogen levels were significantly decreased in aged rats compared with adults, whereas DHA levels increased in the hippocampus and remained stable in the cortex and striatum. DHA levels were significantly and similarly increased in total phospholipids and especially in plasmenylethanolamines after 9 mon of diet containing α‐LNA alone or combined with DHA. This study showed that each structure sustained specific age‐induced modifications. Dietary n−3 FA may not oppose the physiological decrease in brain plasmalogen levels during aging. Moreover, α‐LNA appears to be equally as potent as preformed DHA at replacing DHA in the brain of our rat model.
Docosahexaenoic acid supplementation in vegetarians effectively increases omega‐3 index: A randomized trial
Authors: Geppert Julia , Kraft Veronika , Demmelmair Hans , Koletzko Berthold 
Published: January 2007

AbstractLow red blood cell (RBC) membrane content of FPA+DHA (hereafter called omega‐3 index) has recently been described as an indicator for increased risk of death from coronary heart disease. The relationship between plasma and RBC FA, focusing on omega‐3 index, and the response to DHA supplementation were investigated in a double‐blind, randomized, placebo‐controlled, intervention study. Healthy vegetarians (87 f, 17 m) consumed daily a microalgae oil from Ulkenia sp. (0.94 g DHA/d) or olive oil (placebo) for 8 wk. DHA supplementation significantly increased DHA in RBC total lipids (7.9 vs. 4.4 wt%), in RBC PE (12.1 vs. 6.5 wt%), in RBC PC (3.8 vs. 1.4 wt%), and in plasma phospholipids (PL) (7.4 vs. 2.8 wt%), whereas EPA levels rose to a much lesser extent. Microalgae oil supplementation increased the omega‐3 index from 4.8 to 8.4 wt%. After intervention, 69% of DHA‐supplemented subjects (but no subject of the placebo group) reached an omega‐3 index above the desirable value of 8 wt%. Omega‐3 index and EPA+DHA levels in RBC PE, RBC PC, and plasma PL were closely correlated (r always >0.9). We conclude that an 8‐wk supplementation with 0.94 g DHA/d from microalgae oil achieves a beneficial omega‐3 index of ≥8% in most subjects with low basal EPA+DHA status. RBC total FA analyses can be used instead of RBC lipid fraction analyses for assessing essential FA status, e.g., in clinical studies.
Antioxidant activity of various teas against free radicals and LDL oxidation
Authors: Ohmori Reiko , Iwamoto Tamami , Tago Motomi , Takeo Tadakazu , Unno Tomonori , Itakura Hiroshige , Kondo Kazuo 
Published: January 2007

AbstractTea is a widely consumed beverage throughout the world. We assessed the antioxidant activity of six teas, including the aqueous extracts of green tea and oolong tea (Camellia sinensis), tochu (Eucommia ulmoides), Gymnema sylvestre, Japanese mugwort (Artemisia princeps), and barley (Hordeum vulgare), against 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) radicals and LDL oxidation, and examined the association of LDL oxidizability with the plasma catechin levels in 10 healthy volunteers with a single dose of 5 g green tea powder. In vitro, the inhibitory effects of DPPH radicals and LDL oxidation were found to be strongest in the extract of green tea and weakest in that of barley. After the ingestion of green tea powder, the lag time increased from basal 52.2±4.1 to 60.3±4.2 min at 1 h and 59.5±4.1 min at 2 h, and then returned to the baseline lag time (51.9±1.4 at 4 h and 52.1±4.7 min at 6 h). Regarding the plasma catechin levels, epigallocatechingallate and epicatechingallate significantly increased from basal 3.7±1.3 and 0.8±0.8 ng/mL to 65.7±11.6 and 54.6±12.6 ng/mL at 1 h, and 74.4±18.6 and 49.4±7.1 ng/mL at 2 h, respectively. Green tea therefore showed the strongest antioxidant activity among the six different teas, and the inhibitory effects of green tea on LDL oxidation depended on the plasma catechin levels.
Antioxidant activity of flavonoids isolated from Scutellaria rehderiana
Authors: Su Ya‐Lun , Leung Lai Kwok , Bi Yu‐Rong , Huang Yu , Chen Zhen‐Yu 
Published: January 2007

AbstractThe present study examined the antioxidant activity in heated canola oil of hexane, acetone, and methanol extracts of dry roots of gansu huangqin (Scutellaria rehderiana) as well as six flavonoids isolated from the acetone and methanol extracts. The oxidation was conducted at 95°C by monitoring oxygen consumption and decreases in both linoleic and α‐linolenic acids. The acetone extract was most effective in inhibiting oxidation of canola oil, followed by the methanol extract. The antioxidant activity of gansu huangqin acetone extract was dose‐dependent. Among the six flavonoids, baicalein and ganhuangenin were more effective than butylated hydroxytoluene (BHT) in protecting canola oil from oxidation. The present results suggest that the acetone extract of this root may be a potential source of natural antioxidants for use in processed foods.
Behavior of phenolic antioxidants in a partitioned medium: structure—Activity relationship
Authors: Cuvelier Marie‐Elisabeth , Bondet Vincent , Berset Claudette 
Published: January 2007

AbstractThe behavior of phenolic antioxidants is studied in a partitioned medium, composed of linoleic acid dispersed in an aqueous phase. Their efficiency is measured by the diene production during oxidation, induced by Fe (II)/ascorbic acid at 30°C. With a linoleic acid/Fe2+ molar ratio of 10 and a Fe2+/ascorbic acid molar ratio of 23, a steady‐state propagation rate is reached after 1 h for up to 15 h. The antioxidants cannot avoid the early dienes (30–40% of total dienes), resulting from the inducing reactions; however, they can stop all the dienes produced during propagation reactions by acting on ROO. The inhibition values reveal a great difference between the antioxidants, depending on their structure (number of hydroxyl groups or chelating sites) and on their polarity, confirming the “polar paradox”. Thus, α‐tocopherol, butylated hydroxytoluene, butylated hydroxyanisole, and isoeugenol appear to be the best antioxidants, but rosmarinic and caffeic acids, generally potent antioxidants, present a weak efficiency. Surprisingly, in such a metal‐induced system, the chelator activity seems to play a minor role.
Squalene in oils determined as squalane by gas—liquid chromatography after hydrogenation of methyl esters
Authors: Ackman R. G. , Macpherson E. J. , Timmins A. 
Published: January 2007

AbstractLow levels (≤0.1%) of squalene were anticipated in oils from the blubber of the harp seal Phoca groenlandica. The traditional roule of saponification and analytical examination of the total unsaponifiables was unattractive. A method developed for squalene in olive oil, reportedly present in the range of 0.3–0.7%, was based on total conversion of the oil to methyl ester of fatty acids by alkali transesterification, followed by hydrogenation over Adam's catalyst (PtO2). The analysis of the fully saturated methyl esters and any squalane produced concurrently was by gas—liquid chromatography. This method was satisfactory for the small amounts, 0.03% or less, of squalene in seal oil and is also illustrated for olive oil. A flame‐ionization detector excessive response of approximately 25% was observed for all levels of squalene tested. The calculated factor of 1.22 should be applied to the peak area for squalane due to the higher response of hydrocarbons relative to the methyl esters of fatty acids and the system of oil components if reporting as fatty acids.
Analysis of nonvolatile lipid oxidation products in vegetable oils by normal‐phase high‐performance liquid chromatography with mass spectrometric detection
Authors: Steenhorst‐Slikkerveer Lisette , Louter Arjan , Janssen Hans‐Gerd , Bauer‐Plank Christina 
Published: January 2007

AbstractNonvolatile triacylglyceride (TAG) oxidation products play an important role in the oxidative degradation of lipids. They serve as a reservoir of oxygen‐containing species and hence can act as off‐flavor precursors or as initiators for further oxidation reactions. Possible nonvolatile lipid oxidation products are TAG with a hydroperoxy, hydroxy, epoxy, or oxo (ketone or aldehyde) group or combination of these groups. The breakdown of TAG hydroperoxides yields nonvolatile glyceride species with two intact fatty acid chains and one short chain mostly ending in an aldehyde or hydroxy group (2 1/2 glycerides). By means of normal‐phase high‐performance liquid chromatography (HPLC) with mass spectrometric (MS) detection, non‐volatile lipid oxidation products can be separated according to polarity. This results in separation into classes of TAG oxidation products, such as epoxy‐TAG, oxo‐TAG, hydroperoxy‐TAG, hydroxy‐TAG and 2 1/2 glycerides, which can be identified using selected ion chromatograms. The retention times of TAG oxidation products on the normal‐phase HPLC system and the signal intensity of the MS detector are stable enough to enable quantitative analysis based on external calibration. The normal‐phase HPLC‐MS method is very suitable for the characterization and quantitation of nonvolatile TAG oxidation products in oxidized TAG reference compounds as well as in real oils or oil phases isolated from emulsions, spreads, or other fat‐based food products. This method can give detailed information for the study of lipid oxidation mechanisms.
Fatty acid and triacylglycerol compositions of seed oils of five Amaranthus accessions and their comparison to other oils
Authors: Jahaniaval F. , Kakuda Y. , Marcone M. F. 
Published: January 2007

AbstractThis paper reports the fatty acid and triacylglycerol (TAG) compositions of five Amaranthus accessions (RRC1011, R149, A.K343, A.K432, and A. K433) representing two species and a cross between one of these and a third species. Seed oils of these were analyzed by gas chromatography and reversed‐phase high‐performance liquid chromatography, and their compositional properties compared with buck‐wheat (Fagopyrum esculentum), corn (Zea mays), rice bran (Oryza sativa), soybean (Glycine max L. Merr.), sesame (Sesamum indicum), quinoa (Chenopodium quinoa), and cottonseed (Gossypium hirsutum) oils. All Amaranthus accessions were relatively high in palmitic (21.4–23.8%) and low in oleic (22.8–31.5%) and linolenic (0.65–0.93%) acids when compared to most of the grain and seed oils. The fatty acid composition of Amaranthus accessions K343, K433, and K432 (group I) were different from R149 and RRC1011 (group II) in mono and polyunsaturated fatty acids, but the saturate/unsaturate (S/U) ratios were very similar. All Amaranthus accessions were similar in TAG type, but showed slight differences in percentage. High similarities in UUU, UUS, and USS composition were observed among Amaranthus K343, K433 and K432, and between R149 and RRC1011. The fatty acid compositions of Amaranthus oil (group I) and cottonseed oil were similar, but their TAG compositions were different. The grain and oilseed oils were different from each other and from the Amaranthus accessions oils in terms of fatty acid composition, S/U, and TAG ratios. The UUU, UUS, and USS percentages were very diverse in grain and seed oils. The percentages of squalene in the TAG sample from the Amaranthus accessions were 8.05% in K343, 11.10% in K433, 11.19% in K432, 9.96% in R149, and 9.16% in RRC1011. Squalene was also tentatively identified in quinoa and ricebran oils at levels of 3.39 and 3.10%, respectively.
Use of chlorophyll and carotenoid pigment composition to determine authenticity of virgin olive oil
Authors: Gandul‐Rojas Beatriz , Cepero María Roca‐L. , Mínguez‐Mosquera M. Isabel 
Published: January 2007

AbstractThe chlorophyll and carotenoid pigment profile of 50 mono‐variety virgin olive oils was used to develop an index of authenticity for the product. The presence of carotenoids other than those described, or chlorophyll derivatives at another level of degradation, were found to be determing elements of this index for “virgin” olive oil quality. In addition, the ratio of chlorophyll/carotenoid should be around 1, and the ratio of minor carotenoids/lutein should be about 0.5, with a limited variability. These characteristics may be expected of virgin olive oil in general and are independent of variety. Finally, the percentage of lutein, violaxanthin, and total pigment content may be used to distinguish between mono‐variety virgin olive oils.
Demulsification of oil‐in‐water emulsion under freezing conditions: Effect of crystal structure modifier
Authors: Harada Takuya , Yokomizo Kazuhisa 
Published: January 2007

AbstractThe demulsification of oil‐in‐water (O/W) emulsions under freezing conditions is connected to fat crystallization in the oil droplet. Therefore, demulsification can be prevented by the use of oil with a low melting point, and also by lowering the O/W ratio. However, an oil with a low melting point, such as sunflower, is rather expensive, and the O/W ratio has a significant effect on the texture of emulsions. We searched for an oil that is suitable for the production of a freeze‐stable emulsion and found that soybean oil has unique characteristics. Normally, emulsions are more unstable at lower temperatures; soybean oil emulsion is unstable at −10°C and stable at −20°C. This unique characteristic results from the following two reasons. First, the solid fat content of soybean oil is almost the same at −10 and −20°C. Second, small crystals form a larger network over a period of time, and the higher temperature promotes faster restructuring. This structure formation was microscopically observed with the use of a thermostated stage. Structure formation was suppressed with the addition of a crystal structure modifier, polyglycerol fatty acid full ester, which also suppressed coalescence.
Synthesis and characterization of some long‐chain diesters with branched or bulky moieties
Authors: Knothe Gerhard , Dunn Robert O. , Shockley Michael W. , Bagby Marvin O. 
Published: January 2007

AbstractSeveral novel fatty diesters with bulky moieties were synthesized by esterification of mono‐ or bifunctional fatty acids or with mono‐ or bifunctional alcohols using p‐toluenesulfonic acid as catalyst. They were characterized by 1H and 13C nuclear magnetic resonance as well as positive chemical ionization (PCl) mass spectrometry. The PCl mass spectra of the resulting diol diesters and diacid diesters are discussed and compared. The compounds were investigated as potential additives for improving the cold flow properties of vegetable oil esters used as biodiesel.
Synthesis of cis‐12, 13‐epoxy‐cis‐9‐octadecenol and 12(13)‐hydroxy‐cis‐9‐octadecenol from vernonia oil using lithium aluminum hydride
Authors: Elhilo Eisa B. , Anderson Melissa A. , Ayorinde Folahan O. 
Published: January 2007

AbstractReduction of vernonia oil methyl esters (VOME) into epoxy fatty alcohol and diols was achieved with lithium aluminum hydride (LAH), under reflux and room temperature conditions, by using hexane and tetrahydrofuran (THF) as solvents. The reactions of VOME with LAH in hexane produced cis‐12,13‐epoxy‐cis‐9‐octadecenol as a major product with an isolated yield of 73.6%, whereas the reaction with LAH in THF gave isomers of 12(13)‐hydroxy‐cis‐9‐octadecenol as the major products with an isolated yield of 95.1%. LAH was similarly reacted with vernonia oil (VO) to give the same products in lower yields. 1H nuclear magnetic resonance (NMR), 13C NMR, gas chromatography‐mass spectrometry, and infrared were used to characterize these products.This study demonstrates the ability to control the reactivity of the epoxy functionality in VO or VOME with the choice of polar or nonpolar solvents, and extends the range of oleochemicals that can be derived from vernonia oil.
Soy protein biopolymers cross‐linked with glutaraldehyde
Authors: Park S. K. , Bae D. H. , Rhee K. C. 
Published: January 2007

AbstractBiopolymers from soy protein isolate (SPI) crosslinked with glutaraldehyde (GA) were prepared. Surface hydrophobicities of SPI‐GA biopolymers and SPI were 4.4 and 11.5, respectively. The solubility profile of SPI was slightly higher than that of SPI‐GA biopolymers. Foaming capacities of SPI‐GA biopolymers (23 mL) were higher than that of SPI (19 mL), but similar to egg white (22 mL). Foaming stabilities of SPI‐GA biopolymers (120 min) were significantly higher than those of SPI (40 min) and egg white (98 min). The emulsifying properties of SPI‐GA biopolymers were lower than those of SPI and bovine serum albumin (P>0.05). Tensile strength (TS) and elongation at break (ETB) of SPI‐GA biopolymer films were significantly higher than those of glycerol‐plasticized soy protein films. TS and ETB of SPI‐GA biopolymer films increased with increasing GA concentrations. GA treatment intensified yellowness of SPI‐GA biopolymer films. SPI‐GA biopolymers may have potential use for biodegradable packaging materials.
Preparation and characterization of rice protein isolates
Authors: Shih Frederick F. , Daigle Kim W. 
Published: January 2007

AbstractVarious enzymes were used to treat a protein‐enriched rice flour for the production of rice protein isolates. The rice flour containing 49% protein was a by‐product from the processing of brown rice for syrup production. The treatment sequence of α‐amylase followed by glucoamylase was most effective, resulting in a product with 85% protein content. The product was then treated with a mixture of cellulase and xylanase, which raised the protein content in the insoluble fraction to 91%. Inorganic impurities, such as the metal manganese in the starting rice flour, were effectively removed. The recovered rice proteins, practically intact according to electrophoretic analysis, had relatively poor solubility and emulsification properties; however, these functional properties were improved substantially by adding xanthan gum as a functionality‐enhancing agent.