Lipid composition of lees from Sherry wine     

Gómez ME  Igartuburu JM  Pando E  Luis FR  Mourente G 《Journal of agricultural and food chemistry》2004,52(15):4791-4794

In this paper, we describe the study and characterization of the lipids from lees of Sherry wine, one of the main byproducts from the wine-making industry in the Jerez/Xeres/Sherry denomination of the origin zone in Jerez de la Frontera, Spain. The lipid content, extractability, classification, fatty acid composition, and its main chemical characteristics have been determined in order to evaluate their potential use as a food or food additive.  相似文献   

关于开发建设项目水土保持监督管理体系的思考与建议     

高远  任明 《中国水土保持》2007,(3):31-32

把依法行政分解为法律基础和行政体系2个方面,分析了开发建设项目水土保持监督管理体系在法律基础和行政体系2个方面存在的问题。法律基础方面存在的问题:一是相关法律中提到开发建设项目水土保持监督管理的内容较少,各项职责落实不到位;二是法律中没有明确流域机构的水土保持职能。行政体系方面存在的问题有:规范化建设还不够完善,个别地方水保部门对监督管理工作内容不了解,权大于法的情况时有出现。提出了完善开发建设项目水土保持监督管理体系的建议。  相似文献   

Oxidation of methane in the rhizosphere of rice plants   总被引：14，自引：0，他引：14  

H. A. C. Denier van der Gon  H. -U. Neue 《Biology and Fertility of Soils》1996,22(4):359-366

Oxidation of CH₄ in the rhizosphere of rice plants was quantified using (1) methyl fluoride, a specific inhibitor of CH₄ oxidation, and (2) measuring changes in plant-mediated CH₄ emission after incubation under air, N₂, or 40% O₂. No significant rhizospheric CH₄ oxidation was observed from rice plants in the ripening stage. CH₄ emission from rice plants 1 week before panicle initiation increased by 40% if CH₄ oxidation in the rhizosphere was blocked. The growth stage of the rice plant is an important factor determining the rhizospheric CH₄ oxidation. Fluctuation of rhizospheric CH₄ oxidation during the growing season may help to explain the observed seasonal CH₄ emission patterns in field studies. Measurements from four rice varieties showed that one variety, Pokkali, had higher rhizospheric CH₄ oxidation. This was probably because Pokkali was in an earlier growth stage than the other three varieties. Both in the early and in the late growth stages, incubation under N₂ caused a much stronger CH₄ flux than inhibition of CH₄ oxidation alone. Apparently, N₂ incubation not only blocked CH₄ oxidation but also stimulated methanogenesis in the rhizosphere. Incubation under a higher O₂ atmosphere (40% O₂) than ambient air decreased the CH₄ flux, suggesting that increasing the oxidation of the rice rhizosphere may help in reducing CH₄ fluxes from rice agriculture. The O₂ pressure in the rhizosphere is an important factor that reduces the plant-mediated CH₄ flux. However, inhibition of methanogenesis in the rhizosphere may contribute more to CH₄ flux reduction than rhizospheric CH₄ oxidation.  相似文献   

防病促生枯萎病拮抗菌“98-Ⅰ”对4种枯萎病防治效果研究   总被引：3，自引：0，他引：3  

马利平  乔雄梧  高芬  郝变青 《中国生态农业学报》2005,(1)

经 8年系统试验研究从 330个细菌菌株中筛选出 1株防病促生枯萎病拮抗菌“98 Ⅰ” ,经鉴定属蜡质芽孢杆菌。该菌对黄瓜枯萎病、西瓜枯萎病、青椒枯萎病和番茄枯萎病 4种土传病害均有显著防治效果 ,其平皿孢子萌发抑制率分别为 79 2 %、75 1%、72 3%和 95 7% ,且该菌对多种蔬菜有促生和促进种子发芽功效。  相似文献   

Chemical composition and glycemic index of Brazilian pine (Araucaria angustifolia) seeds     

Cordenunsi BR  De Menezes Wenzel E  Genovese MI  Colli C  De Souza Gonçalves A  Lajolo FM 《Journal of agricultural and food chemistry》2004,52(11):3412-3416

The seeds of Parana pine (Araucaria brasiliensis syn. Araucaria angustifolia), named pinh?o, are consumed after cooking and posterior dehulling, or they are used to prepare a flour employed in regional dishes. Native people that live in the South of Brazil usually consume baked pinh?o. As a result of cooking, the white seeds become brown on the surface due to the migration of some tinted compounds present in the seed coat. In this work, the proximate composition, minerals, flavonoids, and glycemic index (GI) of cooked and raw pinh?o seeds were compared. No differences in moisture, lipids, soluble fiber, and total starch after boiling were found. However, the soluble sugars and P, Cu, and Mg contents decreased, probably as a consequence of leaching in the cooking water. Also, the boiling process modified the profile of the phenolic compounds in the seeds. No flavonols were detected in raw pinh?o seeds. The internal seed coat had a quercetin content five times higher than that of the external seed coat; also, quercetin migrated into the seed during cooking. The internal seed coat had a high content of total phenolics, and seeds cooked in normal conditions (with the seed coat) showed a total phenolics content five times higher than that of seeds cooked without the seed coat. Cooking was then extremely favorable to pinh?o seeds bioactive compounds content. The carbohydrate availability was evaluated in a short-term assay in humans by the GI. The GI of pinh?o seeds cooked with the coat (67%) was similar to that of the seeds cooked without a coat (62%) and lower than bread, showing that cooking does not interfere with starch availability. The low glycemic response can be partly due to its high content of resistant starch (9% of the total starch).  相似文献   

Natural and human disturbances affect natural regeneration of Swietenia macrophylla: Implications for rainforest management     

Gabriel Gutiérrez-Granados  Veronica Juárez 《Forest Ecology and Management》2011,262(2):161-169

In this paper we document how changes in forest structure mediated by natural (hurricane) and human (logging) disturbances affect natural regeneration of Swietenia macrophylla via its effects on seed predation, germination, and early recruitment. Work was carried out in two ejidos within the Mayan zone of Quintana Roo, differing with regard to their exposure to the effect of the hurricane Dean 2008 (Naranjal Poniente; high hurricane impact) and Señor (with no evidence of hurricane effects). We experimentally set S. macrophylla seeds in both hurricane conditions and contrasting logging effects, in three treatments: (1) open access, (2) rodent and insect access and (3) rodent and insect exclusion. We measured three dependent variables: (i) number of seeds predated, (ii) number of seeds germinated and (iii) number of seedlings established. We found that the three variables measured were differentially affected by logging and hurricane Dean. Seed predation was higher in areas with hurricane effects; germination showed no differences, but early recruitment was differentially affected by the two conditions, via an increasing of herbivory and sun exposition. Both types of disturbances studied occurred periodically in Yucatan Peninsula and elsewhere in tropics, so it is necessary to implement specific actions in order to face changes in mahogany natural regeneration stocks, and supporting the future management of tropical forests.  相似文献   

Variant allometric scaling relationships between bud size and secondary shoot growth in <Emphasis Type="Italic">Quercus faginea</Emphasis>: implications for the climatic modulation of canopy growth     

Arben Q. Alla  J. Julio Camarero  Pilar Rivera  Gabriel Montserrat-Martí 《Annals of Forest Science》2011,68(7):1245-1254

• Introduction and statement of the research questions  

The relationships between primary and secondary growth in tree populations of contrasting climates are poorly understood. We tested the hypotheses that bud size and stem cross-sectional area are related through allometric relationship in shoots and that their scaling slopes change in response to climatic stress.  相似文献   

Effect of coupling media on velocity and attenuation of ultrasonic waves in Brazilian wood   总被引：1，自引：0，他引：1  

Raquel?Gon?alvesEmail author  Alex?Julio?Trinca  Gisleiva?Cristina?dos?Santos Ferreira 《Journal of Wood Science》2011,57(4):282-287

Coupling media are necessary to ensure that transducers bond to wood specimens to minimize coupling losses and improve the accuracy of ultrasonic measurements. There are several types of coupling media available, and the optimal choice is not known. In this work, we analyzed the results of ultrasonic wave attenuation for 0.1-MHz longitudinal and transverse transducers with six different materials as coupling media in nine species of Brazilian wood with densities in the range 700–1170 kg/m³. Tests were performed using constant pressure on the transducer and with wave propagation in the longitudinal direction. For transverse transducers, the polarization was in the radial and tangential directions. The results were analyzed statistically and showed that, for attenuation in both longitudinal and transverse waves, the material used for coupling had significant effects, whereas the wood species had no effect. For longitudinal waves, the statistical evaluation showed that the coupling material performance was strongly dependent on the species of wood, but it was not possible to observe any tendency of behavior associated with specific anatomical properties.  相似文献   

Influence of harvest date and crop yield on the fatty acid composition of virgin olive oils from cv. Picual     

Beltrán G  Del Rio C  Sánchez S  Martínez L 《Journal of agricultural and food chemistry》2004,52(11):3434-3440

In this study was analyzed the effect of crop year and harvesting time on the fatty acid composition of cv. Picual virgin olive oil. The study was carried out during the fruit ripening period for three crop seasons. The mean fatty acid composition of Picual oils was determined. The oils contained palmitic acid (11.9%), oleic acid (79.3%), and linoleic acid (2.95%). The content of palmitic acid and saturated fatty acids decreased during fruit ripening while oleic and linoleic acids increased. The amount of stearic and linolenic acids decreased. The amount of saturated acids, palmitic and stearic, and the polyunsaturated acids linoleic and linolenic was dependent on the time of harvest, whereas the amount of oleic acid varied with the crop year. The differences observed between crop years for both palmitic and linoleic acid may be explained by the differences in the temperature during oil biosynthesis and by the amount of summer rainfall for oleic acid content. A significant relationship was observed between the MUFA/PUFA ratio and the oxidative stability measured by the Rancimat method.  相似文献   

Contribution of individual polyphenolics to total antioxidant capacity of plums   总被引：4，自引：0，他引：4  

Chun OK  Kim DO  Moon HY  Kang HG  Lee CY 《Journal of agricultural and food chemistry》2003,51(25):7240-7245

To study the effect of polyphenolics on antioxidant capacities of plums, the amounts of total phenolics, total flavonoids and individual phenolic compounds, and vitamin C equivalent antioxidant capacity (VCEAC) of eleven plum cultivars was determined. There was a good linear relationship between the amount of total phenolics and total antioxidant capacity (r2 = 0.9887). The amount of total flavonoids and total antioxidant capacity also showed a good correlation (r2 = 0.9653). Although the summation of individual antioxidant capacity was lower than the total antioxidant capacity of plum samples, there was a positive correlation (r2 = 0.9299) of total antioxidant capacity of plum samples with the sum of the VCEACs calculated from individual phenolics. Chlorogenic acids and glycosides of cyanidin, peonidin, and quercetin were major phenolics among eleven plum cultivars. The antioxidant capacity of chlorogenic acids and anthocyanins showed higher correlation (r2) of 0.7751 and 0.6616 to total VCEAC, respectively, than that of quercetin glycosides (r2 = 0.0279). Chlorogenic acids were a major source of antioxidant activity in plums, and the consumption of one serving (100 g) of plums can provide antioxidants equivalent to 144.4-889.6 mg of vitamin C.  相似文献