Evolution of sugars in cider brandy aged in oak barrels: a contribution to its characterization

A chemometric study was carried out to typify cider brandies according to the type of wood employed in the maturation process and their aging time. Monosaccharides, previously derivatized with p-aminobenzoic ethyl ester, were analyzed using a reversed-phase high-performance liquid chromatographic method. Univariate data treatment was not sufficient to enable differentiation of the classes of cider brandies on the basis of wood type and maturation time. Two linear combinations of original variables, ascertained by principal components analysis, provided an adequate data structurization. A mathematical decision rule was established to classify cider brandies with prediction capacities of 92 and 97% using an LDA method and Bayesian analysis, respectively. The use of the PLS algorithm allowed the authors to differentiate cider brandies according to the age and type of oak used in the aging process.     

Major phenolics in apple and their contribution to the total antioxidant capacity

The contribution of each phytochemical to the total antioxidant capacity of apples was determined. Major phenolic phytochemicals of six apple cultivars were identified and quantified, and their contributions to total antioxidant activity of apples were determined using a 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging assay and expressed as vitamin C equivalent antioxidant capacity (VCEAC). Average concentrations of major phenolics and vitamin C in six apple cultivars were as follows (mg/100 g of fresh weight of apples): quercetin glycosides, 13.20; procyanidin B(2), 9.35; chlorogenic acid, 9.02; epicatechin, 8.65; phloretin glycosides, 5.59; vitamin C, 12.80. A highly linear relationship (r (2) > 0.97) was attained between concentrations and total antioxidant capacity of phenolics and vitamin C. Relative VCEAC values of these compounds were in the order quercetin (3.06) > epicatechin (2.67) > procyanidin B(2) (2.36) > phloretin (1.63) > vitamin C (1.00) > chlorogenic acid (0.97). Therefore, the estimated contribution of major phenolics and vitamin C to the total antioxidant capacity of 100 g of fresh apples is as follows: quercetin (40.39 VCEAC) > epicatechin (23.10) > procyanidin B(2) (22.07) > vitamin C (12.80) > phloretin (9.11) > chlorogenic acid (8.75). These results indicate that flavonoids such as quercetin, epicatechin, and procyanidin B(2) rather than vitamin C contribute significantly to the total antioxidant activity of apples.     

Analysis of volatile compounds and their contribution to flavor in cereals.

Recent developments in methods for isolation and measurement of volatiles from cereals are reviewed. The main types of isolation methods, namely, direct extraction, distillation, and headspace, have recently been complemented by solid phase microextraction. Direct solvent extraction provides efficient recovery of compounds with a broad range of polarities and volatilities, whereas headspace techniques provide relatively clean extracts. Supercritical fluid and solid phase microextractions have not yet been fully evaluated for cereals. GC and GC/MS remain the dominant techniques for measurement of the extracted compounds, although new electronic noses show promise. Relating these results to human perception requires careful control to ensure valid comparisons and, in this respect, aroma extract dilution analysis is a useful procedure.     

Effect of sucrose on functional properties of soy globulins: adsorption and foam characteristics

In this contribution, we have analyzed the effect of sucrose on dynamic interfacial (dynamic surface pressure and surface dilatational properties) and foaming (foam capacity and foam stability) characteristics of soy globulins (7S and 11S). The protein (at 1 x 10(-3), 1 x 10(-2), 0.1, and 1 wt %) and sucrose (at 0, 0.25, 0.5, and 1.0 M) concentrations in aqueous solution and the pH (at 5 and 7), and ionic strength (at 0.05 and 0.5 M) were analyzed as variables. The temperature was maintained constant at 20 degrees C. We have observed the following. (i) The dynamics of adsorption (presence of a lag period, diffusion, and penetration at the air-water interface) of soy globulins depend on the peculiar molecular features of proteins (7S or 11S soy globulin) and the level of association/dissociation of these proteins by varying the pH and ionic strength, as well as the effect of sucrose in the aqueous phase on the unfolding of the protein. The rate of adsorption increases with the protein concentration in solution, at pH 7 compared to pH 5, at high ionic strength, and in the absence of sucrose. (ii) The surface dilatational properties reflect the fact that soy globulin adsorbed films exhibit viscoelastic behavior. The surface dilatational modulus increases at pH 7 compared to pH 5, but decreases with the addition of sucrose into the aqueous phase. (iii) The rate of adsorption and surface dilatational properties (surface dilatational modulus and phase angle) during adsorption at the air-water interface play an important role in the formation of foams generated from aqueous solutions of soy globulins. (iv) The increased interfacial adsorption (at high surface pressures) and the combined effects of interfacial adsorption and interfacial interactions between adsorbed soy globulin molecules (at high surface dilatational modulus) can explain the higher stability of the foam, with few exceptions.     

Biodegradation kinetics of monosaccharides and their contribution to basal respiration in tropical forest soils

Low molecular weight (LMW) organic compounds in soil solution are easily biodegradable and could fuel respiration by soil microorganisms. Our main aim was to study the mineralization kinetics of monosaccharides using ¹⁴C-radiolabelled glucose. Based on these data and the soil solution concentrations of monosaccharides, we evaluated the contribution of monosaccharides to basal respiration for a variety of tropical forest soils. Further, the factors controlling the mineralization kinetics of monosaccharides were examined by comparing tropical and temperate forest soils. Monosaccharides comprised on average 5.2 to 47.7% of dissolved organic carbon in soil solution. Their kinetic parameters (V _max and K_M ), which were described by a single Michaelis-Menten equation, varied widely from 11 to 152?nmol?g^?1?h^?1 and 198 to 1294?µmol?L^?1 for tropical soils, and from 182 to 400?nmol?g^?1?h^?1 and 1277 to 3150?µmol?L^?1 for temperate soils, respectively. The values of V _max increased with increasing microbial biomass-C in tropical and temperate soils, while the K_M values had no correlations with soil biological or physicochemical properties. The positive correlation between V _max values and microbial biomass-C indicates that microbial biomass-C is an essential factor to regulate the V _max values in tropical and temperate forest soils. The biodegradation kinetics of monosaccharides indicate that the microbial capacity of monosaccharide mineralization far exceeds its rate at soil solution concentration. Monosaccharides in soil solution are rapidly mineralized, and their mean residence times in this study were very short (0.4–1.9?h) in tropical forests. The rates of monosaccharide mineralization at actual soil solution concentrations made up 22–118% of basal respiration. Probably because of the rapid and continuous production and consumption of monosaccharides, monosaccharide mineralization is shown to be a dominant fraction of basal respiration in tropical forest soils, as well as in temperate and boreal forest soils.     

Phenolic compounds in NaOH extracts of UK soils and their contribution to antioxidant capacity

Antioxidants are released during the NaOH extraction of soils, and this also releases phenolic compounds from plant and soil material. We hypothesized that phenolics would be important contributors to the antioxidant capacity (AOC) of soils. The concentrations of 12 phenolic compounds and the AOCs in 4 m ‐NaOH extracts of a range of UK soil types were measured. Samples of both surface and subsurface horizons were taken from 24 sites representing the major soil types (brown soils, gleys, podzols, peats and lithomorphic soils). The land use/vegetation varied from deciduous woodland through heather moorland to agricultural crops. The internal standards method was used to quantify the phenolics, which were detected by gas chromatography. The AOCs of the extracts and of standards of the individual phenolic compounds were measured using the TEAC (Trolox Equivalent Antioxidant Capacity) method. There were differences in the phenolic distributions extracted from soils with different land uses/plant inputs, as well as differences between surface and subsurface samples. A statistically significant linear relationship was found between the AOCs of the extracts and the sum of the phenolic compounds, as both these variables were positively correlated with the organic matter content of the soils. The AOCs of the individual phenols were used to calculate their contribution to the overall AOC of the extracts, and this was found to be small (approximately 1% of the total AOC). We concluded that the measured phenolic compounds were not important contributors to the AOCs of the soil extracts, and therefore that other unidentified antioxidant compounds were probably present.     

Trees on farms and their contribution to soil fertility parameters in Badessa, eastern Ethiopia

Surface (0–15 cm) and subsurface (30–45 cm) soil samples from under canopy, edge of canopy and away from canopy of isolated Cordia africana Lam. and Croton macrostachyus Del. trees and their leaves were examined to investigate leaf nutrient content, root biomass and the contribution of trees on farms to soil fertility parameters in Badessa area, eastern Ethiopia. Leaves of C. macrostachyus had 20% higher P and 25% lower K contents than those of C. africana. The studied species had comparable leaf N content. Both species produced shallow lateral roots that extended beyond the canopy zone. Typically, higher fine root biomass was observed in the surface soils than the subsurface soils. Both species did not affect soil organic C, pH and cation exchange capacity. Surface and subsurface soils under tree canopies had 22–26 and 12–17% higher N, respectively, than the corresponding soils away from tree canopies. Surface soil available P under tree canopies was 34–50% higher than the corresponding soil away from canopies. Available P content of subsurface soil was improved only under C. africana canopy. The available P of surface soil under C. macrostachyus canopy was more than double that for C. africana. Trees of both species increased underneath surface and subsurface exchangeable K by 18–46% compared with the corresponding controls. In conclusion, C. macrostachyus and C. africana trees on farms keep soil nutrient high via protection against leaching, translocation of nutrients from deeper to the surface layer and accumulation of litter, which create a temporary nutrient pool in the surface soils under their canopies.     

Structural identification of new curcumin dimers and their contribution to the antioxidant mechanism of curcumin

As a part of the research project on the elucidation of the chain-breaking antioxidant mechanism of natural phenolics against the oxidation of food components, curcumin, a main turmeric pigment, was investigated. A relatively high concentration of curcumin gave three dimers as radical termination products in addition to the coupling products with curcumin and the lipid hydroperoxide. The structural analysis of these dimers and quantitative analysis of their production rates revealed that radical-radical termination mainly occurred at the 2-position of curcumin. The contribution of the pathway for production of these dimers to the antioxidant mechanism of curcumin was estimated from the concentration-dependent data of the antioxidant activity and formation rates of these termination products. The A-A termination (dimer formation) was estimated to contribute at least about 40% of the entire antioxidant process against ethyl linoleate oxidation.     

Formation of natamycin:cyclodextrin inclusion complexes and their characterization

Natamycin is a broad spectrum antimycotic with very low water solubility, which is used to extend the shelf life of shredded cheese products. beta-Cyclodextrin (beta-CD), hydroxypropyl beta-cyclodextrin (HP beta-CD), and gamma-cyclodextrin (gamma-CD) were found to form inclusion complexes with natamycin in aqueous solution. The increase in solubility of natamycin with added beta-CD was observed to be linear (type A(L) phase solubility diagram). The 1:1 stability constant of natamycin:beta-CD complex was estimated from its phase solubility diagram to be 1010 M(-1). The phase solubility diagrams of both gamma-CD and HP beta-CD exhibited negative deviation from linearity (type A(N) diagram) and, therefore, did not allow the estimation of binding constants. The water solubility of natamycin was increased 16-fold, 73-fold, and 152-fold with beta-CD, gamma-CD, and HP beta-CD, respectively. The natamycin:CD inclusion complexes resulted in in vitro antifungal activity nearly equivalent to that of natamycin in its free state.     

Home gardens: an assessment of their biodiversity and potential contribution to conservation of threatened species and crop wild relatives in Benin

Despite growing literature supporting the importance of home gardens (HG) as biodiversity hotspots, knowledge of patterns of their contribution to conservation of threatened species and crop wild relatives (CWR) across climate and culture in Africa is still limited. This investigation was conducted across three climatic zones to assess the floristic diversity of home gardens and the extent to which they contribute to conservation of threatened species and CWR. Overall, 240 home gardens were sampled and their floristic diversity assessed. The ecological importance of recorded species was determined per climatic zone using the importance value index (IVI). A cluster analysis was performed to group the species according to their IVI-values and a principal component analysis helped to identify the most important species. 285 species were inventoried throughout the study area. Home garden species’ diversity globally declined from the drier to the wetter zone but was highest in the transition zone. The average number of species found per HG was 10.1 and varied weakly across zones (9.07, Guineo-Congolean zone; 10.77, Sudano-Guinean zone; and 10.53, Sudanian zone). The most important home gardens species in the Sudanian, the Sudano-Guinean and the Guineo-Congolean zones were respectively: Abelmoschus esculentus (L.) Moench and Hibiscus asper Hook.f.; Solanum lycopersicum L. and Zea mays L.; Ipomoea aquatica Forssk. and Senna occidentalis (L.) Link. They were mainly vegetables and used as food and/or medicinal plant species. Twenty CWR and twelve threatened species were recorded and were also mainly used for food and medicinal purposes. Thorough research on socioeconomic factors supporting possession of HG and choice of managed species as well as indigenous management strategies of HG and dynamic of traditional knowledge related to HG may help to deeply assess home gardens’ effectiveness in biodiversity conservation.     

Structure-antioxidant efficiency relationships of phenolic compounds and their contribution to the antioxidant activity of sea buckthorn juice

The phenolic composition of juice derived from fruits of sea buckthorn (Hippophae rhamnoides) was investigated by high-performance liquid chromatography (HPLC) with diode array and electrochemical detection. Flavonols were found to be the predominating polyphenols while phenolic acids and catechins represent minor components. Of the seven flavonols identified, isorhamnetin 3-O-glycosides were the most important representatives quantitatively. However, because of their structural properties, they were poor radical scavengers as shown by electron spin resonance spectroscopy. Phenolic compounds such as quercetin 3-O-glycosides, catechins, and hydroxybenzoic acids with a catechol structure exhibited good antioxidant capacities, but their concentration in sea buckthorn juice was small. These phenolic compounds, determined by HPLC, accounted for less than 5% of the total antioxidant activity of the filtered juice. Ascorbic acid was shown to be the major antioxidant in sea buckthorn juice. Because of its high concentration of 1.22 g/L, it contributes approximately 75% to total antioxidant activity. The remaining difference can be attributed to higher molecular weight flavan-3-ols (proanthocyanidins), which were determined photometrically after acid depolymerization to colored anthocyanidins.     

A contribution to environmental control in a glasshouse by a computer

The environmental conditions of plants grown in a glasshouse were controlled by a minicomputer (IBM-Series 1). The simulation model thus developed provides better analyses of the relationship between yield increase and control of environmental factors.The glasshouse used was in several sections, with all the necessary devices for controlling environmental conditions. Two different climatic regimes were stimulated in order to find a better agreement of simulated values with experimental data.The computer used can be applied to a system comprising several glasshouses where different crops are grown.     

Tentative assignment of the potato serine protease inhibitor group as beta-II proteins based on their spectroscopic characteristics

Potato serine protease inhibitor (PSPI) is the most abundant protease inhibitor group in potato tuber. The investigated PSPI isoforms have a highly similar structure at both the secondary and the tertiary level. From the results described, PSPI is classified as a beta-II protein based on (1) the presence in the near-UV spectra of sharp peaks, indicating a rigid and compact protein; (2) the sharp transition from the native to the unfolded state upon heating (only 6 degrees C) monitored by a circular dichroism signal at 222 nm; and (3) the similarity in secondary structure to soybean trypsin inhibitor, a known beta-II protein, as indicated by a similar far-UV CD spectrum and a similar amide I band in the IR spectrum. The conformation of PSPI was shown also to be stable at ambient temperature in the pH range 4-7.5. Upon lowering the pH to 3.0, some minor changes in the protein core occur, as observed from the increase of the intensity of the phenylalanine peak in the near-UV CD spectrum.     

Ellagitannins,flavonoids, and other phenolics in red raspberries and their contribution to antioxidant capacity and vasorelaxation properties

Analysis of extracts of Glen Ample raspberries (Rubus idaeus L.) by gradient, reverse phase HPLC with diode array and tandem mass spectrometry identified eleven anthocyanins, including cyanidin-3-sophoroside, cyanidin-3-(2(G)-glucosylrutinoside), cyanidin-3-glucoside, cyanidin-3-rutinoside, pelargonidin-3-sophoroside, pelargonidin-3-(2(G)-glucosylrutinoside), and pelargonidin-3-glucoside. Significant quantities of an ellagitannin, sanguiin H-6, with an M(r) of 1870 were detected along with lower levels of a second ellagitannin, lambertianin C, which has an M(r) of 2804. Other phenolic compounds that were detected included trace levels of ellagic acid and its sugar conjugates along with one kaempferol- and four quercetin-based flavonol conjugates. Fractionation by preparative HPLC revealed that sanguiin H-6 was a major contributor to the antioxidant capacity of raspberries together with vitamin C and the anthocyanins. Vasodilation activity was restricted to fractions containing lambertianin C and sanguiin H-6.     

Inductively coupled plasma optical emission spectrometric determination of minerals in thyme honeys and their contribution to geographical discrimination

Twenty-four Spanish thyme honey samples were analyzed using inductively coupled plasma optical emission spectrometry (ICP-OES). Twenty-four minerals were quantified for each honey. The elements Al, As, Ba, Ca, Cr, Cu, Fe, K, Li, Mg, Mn, Na, P, Pb, S, Se, Si, Sr, and Zn were detected in all samples; seven elements are very abundant (Ca, K, Mg, Na, P, S, and Si), and six are not abundant (Al, Cu, Fe, Li, Mn, and Zn). Eleven of them are trace elements (As, Ba, Cd, Co, Cr, Ni, Mo, Pb, Se, Sr, and V) at <1 mg kg(-)(1). Classification of thyme honeys according to their origin (coast, mountains) was achieved by pattern recognition techniques on the mineral data. By means of principal component analysis, a good separation by geographical origin is obtained when scores for the two first principal components are plotted. Classification functions of 11 metals (Al, As, Cr, Cu, K, Li, Mg, Na, P, S, and V) were obtained using stepwise discriminant analysis and applied to classify correctly approximately 100% of the honey samples.     

Individual contribution of grain outer layers and their cell wall structure to the mechanical properties of wheat bran

The mechanical properties of wheat bran and the contribution of each constitutive tissue on overall bran properties were determined on a hard wheat (cv. Baroudeur) and a soft wheat (cv. Scipion). Manual dissection allowed three different layers to be separated from wheat bran, according to radial and longitudinal grain orientations, which were identified by confocal laser scanning microscopy as outer pericarp, an intermediate strip (comprising inner pericarp, testa, and nucellar tissue), and aleurone layer, respectively. Tissue microstructure and cell wall composition were determined. Submitted to traction tests, whole bran, intermediate, and aleurone layers demonstrated elastoplastic behavior, whereas pericarp exhibited elastic behavior. By longitudinal orientation, pericarp governed 50% bran elasticity (elastic strength and rigidity), whereas, in the opposite orientation, bran elastic properties were mostly influenced by the other tissues. Regardless of test orientation, the linear force required to bran rupture corresponded to the sum of intermediate and aleurone layer strengths. According to radial orientation, the intermediate strip governed bran extensibility, but according to longitudinal orientation, all tissues contributed until bran disruption. Tissues from both wheat cultivars behaved similarly. A structural model of wheat bran layers illustrated the detachment of pericarp from intermediate layer within radial bran strips.     

野生大豆根系形态对局部磷供应的响应及其对磷吸收的贡献

通过土柱试验模拟局部供磷,定量评价了磷局部供应对野生大豆根系形态参数的影响以及这些根形态参数对植株磷吸收的贡献.磷局部供应明显改变了野生大豆的根形态,使总根长增加了80.5％,比根长增加了32.6％,根表面积扩大了70.7％,根直径减小了27.6％,植株对磷的吸收增加了43.2％,地上干重增加了72.0％;在所有的根形态参数中,总根长、根表面积和比根长对野生大豆植株磷吸收具有较大贡献,其中尤以比根长对植株磷吸收贡献最大,即在根长增加的同时,根直径减小能够明显提高野大豆根系对磷的吸收.结果表明,野生大豆对局部磷供应表现出高度的根系形态可塑性,通过局部养分供应优化根系空间分布和定向调控根系生长能显著提高植物对异质性土壤磷资源的获取能力.     

Soil hydrophobicity: a contribution of diuron sorption experiments

Retention processes play a major role in the fate and impact of organic contaminants in soils. The main goal of this study was to determine the influence of soil hydrophobic properties on the retention of diuron by using plots of a long‐term experiment in Versailles. We selected seven plots with pH 3.4 to 8.2 and low organic content. Sorption isotherms were obtained on soil slurries and kinetic measurements of diuron sorption were performed on undisturbed soil samples. The results showed that the Freundlich coefficient k_f decreased as pH increased and that the K_oc coefficient, k_f/TOC, was linearly related to the contact angle measured on the clay fraction over a wide range of pH. A low initial adsorption rate and low adsorption equilibrium were observed for the plot treated with NaNO₃. In this case, the structure in micro‐aggregates was assumed to limit the accessibility of adsorption sites. The CaCO₃ and CaO treated plots had similar organic matter contents, pHs, CECs and bulk densities, although their < 2 μm:C ratio differed. The higher retention of diuron in the CaCO₃ plot is attributed to the higher hydrophobicity of the < 2 μm fraction, probably masking part of the permanent clay negative charges. Thus, in addition to the different treatments, organic matter composition and distribution should also be included as specific soil properties. We conclude that the sorption properties of pesticides such as diuron can be a good tool to obtain greater understanding of soil properties and the degree of soil hydrophobicity/hydrophilicity in particular.     

Evaluation of wheat (Triticum aestivum L.) phenolic acids during grain development and their contribution to Fusarium resistance

The phenolic acid profiles of six cultivars of wheat with known tolerance to Fusarium head blight were evaluated during plant development from anthesis through maturity. Analysis by HPLC of grain at anthesis revealed that p-coumaric and ferulic acid were the two principal phenolic compounds present. The effect of these two phenolic acids on Fusarium species was evaluated in vitro. Both phenolic acids demonstrated significant reductions (p < 0.05) of Fusarium species growth at all concentrations tested. Ferulic acid is the primary phenolic acid in grain at all stages of development, and its concentration increased steadily during grain development prior to a 50% decrease during grain ripening. The accumulation of ferulic acid synthesis from anthesis until approximately 20 days after anthesis appears related with cultivar resistance to Fusarium. Concentrations of ferulic acid in the grain were similar at maturity, implying that the end-use quality would be similar for both resistant and susceptible cultivars.