Nutrient uptake of pepino plants in soilless cultivation

Summary

This study addresses vegetative growth and the uptake of nutrients and their accumulation in the vegetative and reproductive tissues of pepino (Solanum muricatum Ait.). The study was conducted in soilless plastic house conditions, with a planting density equivalent to 25.000 plants ha^–1 during two seasons (1997–98 and 1998–99). The plants were sampled, fractionated into leaves, stems, fruits and roots, then dried and weighed and the macronutrient content was analysed every 30.d for 300.d after transplanting. The yield obtained was 2.kg of fruit per plant, which is 30% of the total dry weight. The relative growth rate (RGR) ranged from 0.0028 to 0.0451.d^–1. The highest N, K, Ca and Mg concentrations were recorded in the leaves, and the highest P concentration in the roots. The nutrient accumulation of this yield was 10.64, 1.12, 16.06, 10.0 and 1.58.g of N, P, K, Ca and Mg per plant respectively. The highest accumulation of all nutrients was found in the leaves. The nutrient with the highest specificuptake rate was K, which ranged from 0.0037 to 0.0838.g g^–1 d^–1.     

Improving grape phenolic content and wine chromatic characteristics through the use of two different elicitors: methyl jasmonate versus benzothiadiazole

Benzothiadiazole (BTH) and methyl jasmonate (MeJ) have been described as exogenous elicitors of some plant defense compounds, polyphenols among them. The objective of this study was to determine whether the application of BTH or MeJ to grape clusters at the beginning of the ripening process had any effect on the accumulation of the main flavonoid compounds in grapes (anthocyanins, flavonols, and flavanols) and the technological significance of these treatments in the resulting wines. The results obtained after a 2 year experiment indicated that both treatments increased the anthocyanin, flavonol, and proanthocyanidin content of grapes. The wines obtained from the treated grapes showed higher color intensity and total phenolic content than the wines made from control grapes. The exogenous application of these elicitors, as a complement to fungicide treatments, could be an interesting strategy for vine protection, increasing, at the same time, the phenolic content of the grapes and the resulting wines.     

Validation of a mass spectrometry method to quantify oak ellagitannins in wine samples

Detection and individual quantification of oak wood ellagitannins in oak barrel aged red wine samples are difficult mainly due to their low levels and the similarity between their structures. In this work, a quantification method using mass spectrometry has been developed and validated to quantify wine ellagitannins after sample fractionation with a previously reported method. The use of an internal standard is a requirement to correct mass signal variability. (-)-Gallocatechin, among the different tested compounds, was the only one that proved to be a suitable internal standard making possible the accurate and individual quantification of the main oak wood ellagitannins. The developed methodology has been used to detect and quantify these ellagitannins in different Spanish commercial wines, proving its usefulness.     

Aromatic characterization of pot distilled kiwi spirits

This study contributes fundamental knowledge that will help to develop a distillate of kiwi wine, made from kiwis of the Hayward variety grown in the southwest of Galicia (Spain). Two yeast strains, L1 (Saccharomyces cerevisiae ALB-6 from the EVEGA yeast collection) and L2 (S. cerevisiae Uvaferm BDX from Lallemand) were assessed to obtain a highly aromatic distillate. The kiwi spirits obtained were compared with other fruit spirits, in terms of higher alcohols, minor alcohols, monoterpenols, and other minor compounds, which are relevant in determining the quality and taste of the kiwi spirits. It was found that the kiwi juice fermented with yeast L1 produced a more aromatic distillate. In addition, kiwi distillates produced with both yeasts had the same ratio of trans-3-hexen-1-ol and cis-3-hexen-1-ol, which is lower than that found in other fruit distillates.     

Manufacture and properties of bifidogenic saccharides derived from wood mannan

Pinus pinaster wood samples were subjected to double hydrothermal processing. The liquors coming from the second stage, containing soluble saccharides of polymeric or oligomeric nature from hemicelluloses (POHs), were subjected to membrane processing (operating in discontinuous diafiltration) for refining and fractionation. Refined POH fractions were characterized by matrix-assisted laser desorption/ionization time of flight mass spectrometry and chromatographic techniques. The most complex POH component was made up of 14 hexoses and contained 4 acetyl groups. The fermentability of purified POHs by human fecal inocula was assessed by measuring both carbon source consumption and formation of short-chain fatty acids. The bifidogenic ability of POHs was confirmed by fluorescence in situ hybridization. The stimulatory effects on the bifidobacterial population reached by POHs were of the same order as those obtained with commercial fructooligosaccharides.     

Simultaneous determination of four biogenic and three volatile amines in anchovy by ultra-high-performance liquid chromatography coupled to tandem mass spectrometry

A new method has been developed and validated for the simultaneous determination of four biogenic (putrescine, cadaverine, histamine, and tyramine) and three volatile amines (trimethylamine, triethylamine, and tripropylamine) in anchovy. Separation and determination of the selected compounds were carried out by ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS), using an electrospray ionization source (ESI) in positive ion mode. Chromatographic separation was carried out using an aqueous solution of formic acid (0.1%) and methanol as mobile phase in gradient mode. The method was validated, and mean recoveries were evaluated at three concentration levels (75, 150, and 250 μg/kg), ranging from 70 to 110% at the three levels assayed. Intra- and interday precision, expressed as relative standard deviation (RSD), were lower than 15% and 20%, respectively. Limits of quantitation (LOQs) were 25 μg/kg for all cases, except for that of TMA, which was set at 60 μg/kg. The developed procedure was applied to determine the target compounds in anchovy samples stored during 7 days at 4 °C, observing the increasing in the concentration of these compounds at longer storage time.     

Effect of the Partial Replacement of Sodium Chloride by Other Salts on the Formation of Volatile Compounds during Ripening of Dry-Cured Ham

The effect of the partial NaCl replacement by other salts (potassium, calcium, and magnesium chloride) on the formation of volatile compounds through the processing of dry-cured ham was studied using solid-phase microextraction (SPME). Three salt formulations were considered, namely, I (100% NaCl), II (50% NaCl and 50% KCl), and III (55% NaCl, 25% KCl, 15% CaCl(2), and 5% MgCl(2)). There was an intense formation of volatile compounds throughout the processing of dry-cured hams, particularly during the "hot-cellar" stage. The differences between treatments were found to be more remarkable at the end of the curing process. Hams from formulations I and II had significantly higher amounts of lipid-derived volatiles such as hexanal than hams from formulation III, whereas the latter had significantly higher amounts of Strecker aldehydes and alcohols. Plausible mechanisms by which salt replacement may affect the generation of volatile compounds include the influence of such replacement on lipid oxidation and proteolysis phenomena. The potential influence of the volatiles profile on the aroma of the products is also addressed in the present paper.     

Food-derived peptides stimulate mucin secretion and gene expression in intestinal cells

In this study, the hypothesis that food-derived opioid peptides besides β-casomorphin 7 might modulate the production of mucin via a direct action on epithelial goblet cells was investigated in HT29-MTX cells used as a model of human colonic epithelium. Seven milk whey or casein peptides, a human milk peptide, and a wheat gluten-derived peptide with proved or probable ability to bind μ- or δ-opioid receptors were tested on the cell culture. Significantly increased secretion of mucins was found after exposure to six of the assayed peptides, besides the previously described β-casomorphin 7, as measured by an enzyme-linked lectin assay (ELLA). Human β-casomorphin 5 and α-lactorphin were selected to study the expression of mucin 5AC gene (MUC5AC), the HT29-MTX major secreted mucin gene. α-Lactorphin showed increased expression of MUC5AC from 4 to 24 h (up to 1.6-fold over basal level expression), although differences were statistically different only after 24 h of exposure. However, this increased expression of MUC5AC did not reach significance after cell treatment with human β-casomorphin 5. In conclusion, six food-derived peptides have been identifed with described or probable opioid activity that induce mucin secretion in HT29-MTX cells. Concretely, α-lactorphin is able to up-regulate the expression of the major secreted mucin gene encoded by these cells.     

Phenolic compositions of grapes and wines from cultivar cabernet sauvignon produced in chile and their relationship to commercial value

The phenolic composition of wine depends on, among other factors, the grapes used to make it. In this sense, knowledge of the chemical composition of grapes and its association with the resulting wines is an important tool to determine if there is a relationship between the phenolic composition of grapes and the price that these wines obtain in the market. For this purpose, grape skins and seeds from the cultivar Cabernet Sauvignon from the central region of Chile, in 2009 and 2010 vintages from two ripening points, were subjected to chemical and phenolic analyses, as were the wines made from these grapes. Grapes and the corresponding wines from three retail price wine categories, U.S. $6-8, U.S. $28-30, and U.S. $150-160, were evaluated. No differences were found across the price categories in the chemical analysis of grapes. Berry skins and wines from the higher price categories presented a higher concentration only of total tannins, and the differences in their concentrations were only among the different fractions of proanthocyanidins in the skins, seeds, and wines; there were no differences in their proportions. A seasonal effect influenced the concentrations of certain compounds in grapes and led to a decrease in the concentration of total phenols, total tannins, and total anthocyanins between sampling dates as harvesting moved toward the common commercial grape harvest in Chilean viticulture.     

Vermicomposts and/or Arbuscular Mycorrhizal Fungal Inoculation in Relation to Metal Availability and Biochemical Quality of a Soil Contaminated with Heavy Metals

A greenhouse pot experiment was conducted to investigate how the addition of two vermicomposts (commercial or produced from damaged greenhouse tomatoes) and/or inoculation with arbuscular mycorrhizal (AM) fungi affected availability and extractability of P, K and trace metals and biochemical quality of a soil contaminated with heavy metals. The pots were planted with Trifolium repens L., which was harvested 40?days after germination. Shoot and root dry matter of T. repens increased by the addition of both vermicomposts. P, K, Fe, Mn, Cu and Zn uptake by T. repens increased after vermicompost addition, whereas Ni, Pb and Cd concentrations were below the detection limit of the method used. After harvest, AB-DTPA-extractable Fe, Cu, Zn, Cd and Pb decreased in the organically amended soil, whereas AB-DTPA P, K and Mn increased. The addition of both vermicomposts, particularly which made from damaged tomatoes, boosted dehydrogenase, ??-glucosidase and urease activities in the postharvest soil, implying a higher microbial functional diversity and biochemical quality in this amended soil. Although phosphatase activities were greater in the postharvest soils with higher AB-DTPA-extractable metals, the other enzyme activities were negatively affected. The inoculation of the soils with AM fungi had weak effects on plant growth, as well as on the availability and extractability of metals and enzyme activities compared to non-inoculation.