Changes in the HPLC phenolic profile of virgin olive oil from young trees (Olea europaea L. Cv. Arbequina) grown under different deficit irrigation strategies     

Romero MP  Tovar MJ  Girona J  Motilva MJ 《Journal of agricultural and food chemistry》2002,50(19):5349-5354

The HPLC phenolic profile of virgin olive oils obtained from young olive trees (Arbequina cv.) grown under different deficit irrigation strategies was studied. Deficit irrigation (RDI) did not affect all the phenolic compounds in the same way. Lignans, vanillic acid, vanillin, and the unknown phenolic compound named P24 increased in the oils from the most irrigated treatments. The secoiridoid derivatives and the unknown phenolic compound named P19 increased in the oils from the most stressed irrigation treatments. The period of growth where a water stress significantly affects the phenolic profile of oils was between pit hardening and the first stages of fruit growth and oil accumulation, independently of the water applied during the previous period to harvest. The phenolic profile and those parameters related to phenol content, oxidative stability, and the bitter index were significantly affected only in the most severe RDI strategies. Other strategies produced important savings in irrigation requirements and an increase in the water use efficiency without noticeably affecting the phenolic profile.  相似文献   

Coffee agroecosystem performance under full sun, shade, conventional and organic management regimes in Central America   总被引：1，自引：0，他引：1  

J. Haggar  M. Barrios  M. Bola?os  M. Merlo  P. Moraga  R. Munguia  A. Ponce  S. Romero  G. Soto  C. Staver  E. de M. F. Virginio 《Agroforestry Systems》2011,82(3):285-301

Changes in coffee economics are leading producers to reduce agrochemical use and increase the use of shade. Research is needed on how to balance the competition from shade trees with the provision of ecological services to the coffee. In 2000, long-term coffee experiments were established in Costa Rica and Nicaragua to compare coffee agroecosystem performance under full sun, legume and non-legume shade types, and intensive and moderate conventional and organic inputs. Coffee yield from intensive organic production was not significantly different from intensive conventional in Nicaragua, but in Costa Rica it was lower during three of the six harvests. Full sun coffee production over 6 years was greater than shaded coffee in Costa Rica (61.8 vs. 44.7 t ha^?1, P = 0.0002). In Nicaragua, full sun coffee production over 5 years (32.1 t ha^?1) was equal to coffee with shade that included Tabebuia rosea (Bertol.) DC., (27?C30 t ha^?1) and both were more productive (P = 0.03) than coffee shaded with Inga laurina (Sw.) Willd. (21.6 t ha^?1). Moderate input organic production was significantly lower than other managements under all shade types, except in the presence of Erythrina poepiggina (Walp.) O.F. Cook. Inga and Erythrina had greater basal area and nutrient recycling from prunings than other shade species. Intensive organic production increased soil pH and P, and had higher K compared to moderate conventional. Although legume shade trees potentially provide ecological services to associated coffee, this depends on management of the competition from those same trees.  相似文献   

Antioxidant activity of olive pulp and olive oil phenolic compounds of the arbequina cultivar   总被引：3，自引：0，他引：3  

Morelló JR  Vuorela S  Romero MP  Motilva MJ  Heinonen M 《Journal of agricultural and food chemistry》2005,53(6):2002-2008

The aim of this study was to characterize antioxidant activities of phenolic compounds that appear in olive pulp and olive oils using both radical scavenging and antioxidant activity tests. Antiradical and antioxidant activities of olive pulp and olive oil phenolic compounds were due mainly to the presence of a 3,4-dihydroxy moiety linked to an aromatic ring, and the effect depended on the polarity of the phenolic compound. Glucosides and more complex phenolics exhibited higher antioxidant activities toward oxidation of liposomes, whereas in bulk lipids aglycons were more potent antioxidants with the exception of oleuropein. Lignans acted as antioxidants only in liposomes, which could partly be due to their chelating activity, because liposome oxidation was initiated by cupric acetate. The antioxidant activity of virgin olive oil is principally due to the dialdehydic form of elenolic acid linked to hydroxytyrosol (3,4-DHPEA-EDA), a secoiridoid derivative (peak RT 36, structure unidentified), and luteolin.  相似文献   

Monitoring of plant and soil pollution based on ionic impulsion     

F. Romero  C. Elejalde  G. Gomez 《Water, air, and soil pollution》1989,44(3-4):295-306

Total pollution indexes for measuring heavy metal contamination of industrialized areas may be quickly estimated from selected metal partial indexes for soil (M-SPI) or plants (M-PPI). Partial pollution indexes for plants (or soils) are calculated by the formula M-PPI (or M-SPI) = 100 (I ? I _unp)/(I _tox ?I _unp), where I = c _i ^1/ni is the ionic impulsion of the selected metal M, with oxidation number n _i, for its actual plant (or soil) concentration c _i,and I _unp and I _tox, the ionic impulsions for unpolluted and toxid levels of the M in plants (or soils). The total pollution indexes were proposed by analogous formulae containing the sums of contributions of metals accumulated in roots (Pb, Cd, Co, Cr, Ni, Cu, Zn and also Fe for plants), without participation of macroconstituents (K, Mg, Ca, Na, and also Mn), accumulated in plant tops. Partial pollution indexes may also serve to show (i) deficiency or toxicity levels of plants (or soils) and (ii) associations between pollutants, easily detected by a numerical taxonomy's dendrogram. Using correlation coefficient techniques for the Bilbao (Spain) model zone, the total soil pollution index, SPI, may be calculated from Zn-SPI, Pb-SPI, Cu-SPI or Cu-PPI. The total plant pollution index, PPI, is similarly related to Fe-PPI or Zn-PPI, though some distortion is evident when the sampling point is close to specific industrial factories. The best estimation (without distortion) for monitoring total plant pollution index is based on the sum of contributions of essential elements (Fe, Cu, and Zn). This fact suggests the existence of defense mechanisms of plants for balancing both the uptake of toxic metals and deficiencies of essential constituents. Finally total pollution indexes may be used for the estimation of the number of pollutants with toxic levels in plants or soils.  相似文献   

Influence of CaCl(2) on the foliar biomass and quality of tobacco leaves     

Ruiz JM  Romero L 《Journal of agricultural and food chemistry》2001,49(8):3600-3605

The aim of the present work was to determine the influence of different CaCl(2) dosages on foliar biomass and quality of tobacco plants (Nicotiana tabacum L. var. Tennesse 86). Plants were grown under controlled conditions and submitted to regular fertilization with macro- and micronutrients. The CaCl(2) was applied to the nutrient solution at 1.25 mM (T1), 2.5 mM (T2), and 5 mM (T3). The results indicated that, under the experimental conditions of this work, the application of 1.25 mM of CaCl(2) favored the growth and development of the leaves, this leading to improved biomass production in tobacco leaves. The increase in foliar biomass in treatment T1 could largely be a result of the stimulation of NO(3)(-) assimilation. However, this situation has negative consequences for tobacco quality, given that the T1 treatment augmented the NO(3)(-) concentration and the foliar concentration of nicotine (both effects being harmful for human consumption) and decreased the concentration of reducing sugars in leaves of tobacco plants compared with those of T2 and T3. Finally, a close and directly proportional relationship was found in our experiment between the parameters of foliar-biomass production, total N concentration, chlorophyll concentration, and decline in quality.  相似文献   

Are landscapes over-irrigated in Southwest Florida? A spatial�Ctemporal analysis of observed data     

Consuelo C. Romero  Michael D. Dukes 《Irrigation Science》2011,29(5):391-401

Monthly water billing records for eleven cities in Hillsborough County Florida were available from 2001 through 2007. Irrigation was estimated from total water use based on two different methods to estimate basic indoor water use and assumed impervious areas. Estimated irrigation use was compared with a calculated irrigation requirement by a water balance to test if homeowners were over-irrigating. Results showed that on average, the mean estimated irrigation was lower than the calculated irrigation requirements in most of the cities and years given the uncertainties in this analysis. The calculated irrigation ranged from 612 to 744 mm year⁻¹, whereas the average estimated irrigation ranged from 264 to 684 mm year⁻¹. However, there were some homeowners that greatly exceeded the calculated irrigation requirement. The estimated irrigation increased temporarily in areas under urban development, which was evidenced by built landscape expansion. Good correlation was found between the annual estimated irrigation and the annual calculated irrigation requirements, when the per capita method was used, but not between the annual estimated irrigation and the annual rainfall. Future conservation programs can use this methodology to identify users where substantial opportunity for water savings exists.  相似文献   

The after-hours mutant reveals a role for Fbxl3 in determining mammalian circadian period     

Godinho SI  Maywood ES  Shaw L  Tucci V  Barnard AR  Busino L  Pagano M  Kendall R  Quwailid MM  Romero MR  O'neill J  Chesham JE  Brooker D  Lalanne Z  Hastings MH  Nolan PM 《Science (New York, N.Y.)》2007,316(5826):897-900

  相似文献   

Atom collision-induced resistivity of carbon nanotubes     

Romero HE  Bolton K  Rosén A  Eklund PC 《Science (New York, N.Y.)》2005,307(5706):89-93

We report the observation of unusually strong and systematic changes in the electron transport in metallic single-walled carbon nanotubes that are undergoing collisions with inert gas atoms or small molecules. At fixed gas temperature and pressure, changes in the resistance and thermopower of thin films are observed that scale as roughly M(1/3), where M is the mass of the colliding gas species (He, Ar, Ne, Kr, Xe, CH4, and N2). Results of molecular dynamics simulations are also presented that show that the maximum deformation of the tube wall upon collision and the total energy transfer between the colliding atom and the nanotube also exhibit a roughly M(1/3) dependence. It appears that the transient deformation (or dent) in the tube wall may provide a previously unknown scattering mechanism needed to explain the atom collision-induced changes in the electrical transport.  相似文献   

Performance of peach and plum based rootstocks of different vigour on a late peach cultivar in replant and calcareous conditions     

Sergio Jiménez  Jorge Pinochet  Jesús Romero  Yolanda Gogorcena  María Ángeles Moreno  José Luís Espada 《Scientia Horticulturae》2011

The field performance of fifteen peach and plum based rootstocks of different vigour (Adesoto, Evrica, Garnem, GF 677, HM-2, Krymsk^® 1, PAC 9801-02, PAC 960, PAC 9907-02, PAC 9917-26, PAC-MUT, PADAC 9907-23, ROOTPAC^® 40, ROOTPAC^® 70 and Tetra) grafted with ‘Calrico’ cultivar was compared after 7 years of establishment on an Armillaria infested replant site. ‘Calrico’ is a selected clone of “Calanda” late peach cultivar. Differences in parameters such as tree survival, leaf chlorophyll content, vigour, yield, cumulative yield, yield efficiency and fruit size were analyzed among rootstocks. All PAC 9801-02 and Tetra trees survived and the mortality rate was low in Evrica, PADAC 9907-23 and ROOTPAC^® 40. The rest of genotypes showed higher mortality rates. Leaf chlorophyll concentration was higher when grafted on Adesoto and Evrica and lower when grafted on PAC 9907-02 and PAC 9917-26. Garnem and PADAC 9907-23 were the most vigorous rootstocks. The highest yield efficiency was induced by Krymsk^® 1 and PAC 9801-02 due to their lower vigour. The highest fruit weight was also induced by Krymsk^® 1 but its cumulative yield was low. Other rootstocks that showed high fruit weight and cumulative yields were ROOTPAC^® 70 and Tetra. Overall, Evrica, PAC 9801-02, ROOTPAC^® 40 and Tetra were among the best adapted to soil sickness and calcareous soil showing a good agronomic performance. The first three rootstocks (Evrica, PAC 9801-02, ROOTPAC^® 40) also exhibited a high capacity to control tree vigour associated with high yield efficiency.  相似文献   

Hydroxytyrosol 4-beta-D-glucoside,an important phenolic compound in olive fruits and derived products     

Romero C  Brenes M  García P  Garrido A 《Journal of agricultural and food chemistry》2002,50(13):3835-3839

There is increasing interest in olive polyphenols because of their biological properties as well as their contribution to the color, taste, and shelf life of olive products. However, some of these compounds remain unidentified. It has been shown that hydroxytyrosol 4-beta-D-glucoside (4-beta-D-glucosyl-3-hydroxyphenylethanol) coeluted with hydroxytyrosol [(3,4-dihydroxyphenyl)ethanol] under reversed phase conditions in the phenolic chromatograms of olive pulp, vegetation water, and pomace of olive oil processing. A method to separate this compound from hydroxytyrosol by HPLC has been developed. The concentration of this glucoside increased in olive pulp with maturation and could be the main phenolic compound in mature olives. In contrast, the presence of this compound was not detected in olive oil by using HPLC-MS. The compound must be considered both in table olives and olive oil processing because of its glucose and hydroxytyrosol contribution to these products.  相似文献