2-Furoylmethyl amino acids and hydroxymethylfurfural as indicators of honey quality

Determination of changes in 2-furoylmethyl amino acids and hydroxymethylfurfural during the storage of four honey samples at 25 and 35 degrees C during 12 months was achieved to assess the potential use of both parameters, singly or in combination, as quality indicators. 2-Furoylmethyl amino acids increased during storage at both temperatures, whereas hydroxymethylfurfural only presented slight variations during storage at 25 degrees C but increased noticeably at 35 degrees C. The study of 2-furoylmethyl amino acids in 49 commercial honeys revealed that 2-furoylmethyl lysine (furosine) was present in all samples, whereas 2-furoylmethyl derivatives of arginine, GABA, and proline were only present in seven samples. Hydroxymethylfurfural can be considered as a good indicator of heat treatments applied to honey samples, whereas 2-furoylmethyl amino acids can be used as suitable markers of the storage period. The use of both parameters can be useful to detect adulteration with invert syrups, excessive heat treatments, or prolonged storage of honey samples.     

Analysis of volatiles in porcine liver pâtés with added sage and rosemary essential oils by using SPME-GC-MS

The effect of the addition of two natural antioxidant extracts (sage and rosemary essential oils) and one synthetic (BHT) on the generation of volatile compounds in liver patés from Iberian and white pigs was analyzed using SPME-GC-MS. Lipid-derived volatiles such as aldehydes [hexanal, octanal, nonanal, hept-(Z)-4-enal, oct-(E)-2-enal, non-(Z)-2-enal, dec-(E)-2-enal, deca-(E,Z)-2,4-dienal] and alcohols (pentan-1-ol, hexan-1-ol, oct-1-en-3-ol) were the most abundant compounds in the headspace of porcine liver patés. Patés from different pig breeds presented different volatiles profiles due to their different oxidation susceptibilities as a probable result of their fatty acid profiles and vitamin E content. Regardless of the origin of the patés, the addition of BHT successfully reduced the amount of volatiles derived from PUFA oxidation. Added essential oils showed a different effect on the generation of volatiles whether they were added in patés from Iberian or white pigs because they inhibited lipid oxidation in the former and enhanced oxidative instability in the latter. SPME successfully allowed the isolation and analysis of 41 volatile terpenes from patés with added sage and rosemary essential oils including alpha-pinene, beta-myrcene, 1-limonene, (E)-caryophyllene, linalool, camphor, and 1,8-cineole, which might contribute to the aroma characteristics of liver patés.     

Effect of cooking temperatures on chemical changes in species of organic arsenic in seafood

The concentrations of arsenobetaine (AB), tetramethylarsonium ion (TMA(+)), and trimethylarsine oxide (TMAO) were determined in samples of sole, dory, hake, and sardine, raw and after being subjected to cooking processes--baking, frying, and grilling--at various temperatures. In all cases, the temperature attained inside the product during the cooking process was measured. The arsenic species extracted from the samples with methanol/water were separated by means of a column switching technique between a PRP-X100 column and a PRP-X200 column. AB was detected by hydride generation atomic absorption spectrometry, whereas TMA(+) and TMAO were detected by hydride generation atomic fluorescence spectrometry. The results obtained showed that, in all of the types of seafood studied, TMA(+) appeared after cooking, possibly because heating facilitates decarboxylation of AB to TMA(+).     

Relationships between Acid Ions and Carbonaceous Fly-Ash Particles in Deposition at European Mountain Lakes

The concentrations of major ions and spheroidal carbonaceous fly-ash particles (SCPs) in bulk deposition were determined in weekly samples from six European mountain lakes during 1997/98. SCPs are produced only from high temperature combustion of fossil-fuels and therefore provide an unambiguous indicator of atmospheric deposition from this source. Positive correlations were observed between SCPs and SO₄ ^2?, NO₃ ^? and NH₄ ⁺ at all sites except for some determinands at Jorisee (Switzerland) and Starolesnienske (Slovakia). Correlations between SCPs and SO₄ ^2? + NO₃ ^? were always more positive than for SCPs with 'total acid ions' (SO₄ ^2? + NO₃ ^? + NH₄ ⁺). This is in agreement with the expectation that the contribution to NH₄ ⁺ deposition made by fossil-fuels is negligible. Good positive correlations between SCPs and all acid anions were observed at Estany Redo (Pyrenees); lower but still positive correlations were observed for all acid ions with SCPs at Gossenköllesee (Austria), Lochnagar and Kårvatn (central Norway), whilst little trend in correlation was observed for Jorisee and Starolesnienske. It is suggested that this gradient reflects the influence of fossil-fuels on acid deposition in these areas. A high positive correlation was observed between SCP and Cl^? at Gossenkollesee possibly as a result of HCl from coal combustion.     

Effect of the addition of sewage sludge as a fertilizer on a sandy vineyard soil

Purpose

The application of sludge from wastewater in agriculture has increased in recent years, and it is therefore important to assess the effect that such treatment has on both the soil and the plant. The aim of the study described here was to ascertain whether there is a variation in the properties of the soil and to determine if this addition has an impact on the plant.

Materials and methods

The area of investigation was close to the municipality of Villarrubia de los Ojos (Ciudad Real). In this work, six samples were taken from the surface horizon in the studied plot at a depth of 35 cm. A further three samples were taken: (i) a surface horizon of a soil close to the area under investigation but without treatment (control sample), (ii) a sample of sludge from the wastewater treatment plant and (iii) a sample of the mixture used by farmers as fertilizer. Laboratory tests were conducted in accordance with the SCS-USDA (1972) guidelines. Trace element samples were analysed by X-ray fluorescence spectrophotometry (Philips PW 2404).

Results and discussion

The parcel of land studied is dominated by a sandy texture (88.3 % sand), and a decrease in pH was observed in areas in which the mixture (manure + sludge) was added (pH?=?8.0) compared to areas in which fertilizer was not applied (pH?=?8.5). It was observed that the addition of the compound led to an increase in the electrical conductivity of the soil. The trace elements can be organized into two groups based on the results obtained in this study. One group contains the trace elements that were only present in the rows that were treated with the fertilizer. The other group of trace elements was mobilized throughout the whole plot.

Conclusions

The application of sewage sludge on agricultural soils can be very useful as an organic amendment because it produces an increase in soil organic matter. However, sewage sludge must be applied with caution due to the changes in soil chemical properties (for example, pH and E.C.). The use of this type of waste for prolonged periods of time can cause problems of contamination in the soil.

     

Arsenic,lead, and uranium concentrations on sediments deposited in reservoirs in the Rio Grande Basin,USA–Mexico border

Purpose

The El Granero reservoir is the last reservoir of the Rio Conchos before it joins the Rio Grande at the Mexico–USA border. This reservoir, together with the San Marcos reservoir, is located in the arid region of Chihuahua, Mexico. High, naturally occurring radioactivity levels, as well as high arsenic (As) concentrations, have been found in both reservoirs. The main goal of this research was to establish the spatial and temporal distribution of trace and radioactive elements in surface sediments and cores collected from these reservoirs.

Materials and methods

Sediment cores were dated using ²¹⁰Pb and ¹³⁷Cs measurements and applying the constant rate of supply (CRS) model. Major, trace, and radioactive elements were determined in surface samples and three sediment cores. Radioactive elements were determined by both alpha and gamma spectrometry. Major and trace elements were determined by inductively coupled plasma optical emission spectrometry (ICP-OES) using the EPA 3051a method. Enrichment factors (EF), contamination factors (CF), and pollution load indexes (PLI) were calculated in order to identify the human impact in both reservoirs, whereas the chemical index weathering (CIW) was used to assess differences in the degree of weathering.

Results and discussion

High uranium (U) enrichment (EFs?=?24.9–54.7) was observed in core layers at the San Marcos reservoir, while in surface sediments, this enrichment was lower. The high variability of lead (Pb) and As in sediment cores from the Granero reservoir was attributed to human influence. Arsenic and Pb enrichment differences between entry and exit sediment cores were explained by the filtering capabilities of the elongated shape, the topography, and the presence of plants on the reservoir’s bed. The highest PLI was found at the entrance core of the Granero reservoir.

Conclusions

The natural element concentration levels of As, Pb, and U were established at the Granero reservoir. High EFs for As and Pb suggest an anthropogenic origin of these pollutants at specific time intervals. High U concentrations in the San Marcos area are explained as naturally occurring. The concentrations of As in most of the studied sediments could pose a risk to human health by As ingestion, since they are above the probable effect level (PEL).

     

1,2,4-Trichlorobenzene Flow Characteristics in Saturated Homogeneous and Stratified Porous Media

Aerosol samples were continuously collected at Rishiri Island, Japan and concentrations of trace metals and water-soluble ionic constituents in the aerosol samples were measured in this study. Trace metal concentrations were analyzed by using inductively coupled plasma mass spectrometry equipped with a laser ablation sample introduction (LA/ICP-MS), which is a rapid and simultaneous method for multi-element analysis. The average concentrations of trace metals and water-soluble ionic constituents in TSP at Rishiri Island from March 2001 to October 2003 were: Al: 251 ± 371 (n= 359), Ti: 27 ± 38 (n= 342), V: 1.3 ± 1.6 (n= 327), Cr: 2.0 ± 2.2 (n= 202), Mn: 8.6 ± 12.0 (n= 353), Fe: 356 ± 645 (n= 349), Co: 0.18 ± 0.25 (n= 250), Ni: 1.9 ± 3.4 (n= 232), Cu: 7.4 ± 10.2 (n= 123), Zn: 16 ± 20 (n= 242), As: 1.2 ± 2.1 (n= 312), Se: 0.49 ± 0.65 (n= 133), Cd: 0.19 ± 0.33 (n= 285), Sb: 0.46 ± 0.62 (n= 265), Pb: 16 ± 30 (n= 314), Na⁺: 1153 ± 1384 (n= 306), NH₄ ⁺: 247 ± 257 (n= 254), K⁺: 74 ± 63 (n= 284), Ca²⁺: 144 ± 174 (n= 294), Mg²⁺: 150 ± 161 (n= 293), Cl^?: 2703 ± 3151 (n= 180), NO₃ ^?: 339 ± 415 (n= 332), SO₄ ^2?: 1648 ± 1398 (n= 362) (unit: ng m^?3). The obtained trace metal concentration levels in the aerosol were 1/10–1/70 of those obtained at Beijing, China and 1/2–1/40 of those obtained at Tokyo, Japan. The correlation between Al, Ti, Mn, and Fe, which were derived mainly from soil dust, was high at Rishiri Island. High-concentration events (when the measured value exceeds the average +3σ for the entire observation period) for each chemical constituent were observed several times per year, although the chemical concentration levels in TSP at Rishiri Island were almost constant throughout the year. The high-concentration phenomenon, which occurred in only 2% of the measurement days, raised the average concentration of the atmospheric chemical constituents at Rishiri Island by about 10%. The average value of the Pb/Zn ratio at Rishiri Island during the entire period was 1.8 ± 2.9, which is higher than 1. This suggests that the atmosphere at Rishiri Island has constantly been receiving contaminants from the Asian Continent. We conclude that the chemical constituents in the aerosol at Rishiri Island have been regularly transported from a wide area across the Asian Continent.     

Remediation of As-Contaminated Soils in the Guadiamar River Basin (SW, Spain)

In 1998, the pond containing the ore wastes from a pyrite mine in Aznalcóllar (SW, Spain) broke open, spilling some 36×10⁵ m³ of acidic waters and 9?×?10⁵ m³ of tailings containing high concentrations of As and heavy metals. The affected area was around 55 km² of predominantly agricultural soils. After the clean-up of the tailings, many remediation actions were undertaken and the use of blocking agents to immobilize the As was one of the most extended measure. The first experiment performed was to determine the most important soil components in As adsorption under acidic conditions. A second experiment was conducted to neutralize the acidity caused by the solution coming from the tailings undergoing oxidation; an adequate liming material (sugar-refinery scum) was selected and the application rates were established. After the remediation measures, the zone was monitored for three years. A detailed study in four experimental plots located in the most polluted sector was carried out to test the influence of iron oxides in the As immobilization. The use of red soils of the area (rich in free-iron oxides Fe_d) was established as an appropriate material in the remediation of the area.     

Browning evaluation of ready-to-eat apples as affected by modified atmosphere packaging

The color and polyphenol oxidase (PPO) activity of fresh-cut Golden delicious apples were evaluated throughout cold storage under modified atmospheres. The shelf life of cut apples was extended to several weeks, especially when an initial atmosphere of 90.5% N(2) + 7% CO(2) + 2.5% O(2) and plastic pouches of 30 cm(3)/cm(2) x bar x 24 h were used. Under these conditions, a maximum 62% PPO activity depletion was observed. In all cases, the faster the initial PPO activity decays, the less the color changes. A fractional conversion first-order model was proposed for predicting color changes in minimally processed apples. Browning was better described through lightness (L) (k(L) = 0.017 - 0.07 day(-1)) and color difference (Delta E*) values (k(Delta E) = 0.015 - 0.073 day(-1)), which fitted the model with enough accuracy.     

Fermentation of white wines in the presence of wood chips of American and French oak

Must obtained from Airén grapes was fermented in the presence of wood chips (4 and 7 g/L) of either French oak (from Vosges, central France, and Allier zones) or American oak. Fermentation yields were higher than in the control fermentations carried out in the absence of wood, and production of volatile substances during fermentation (alcohols, esters, and acetates) was also higher. The volatile substances that leached out of the wood were analyzed by GC-MS-SIR. The results showed that their concentrations depended on the type and amount of the oak; some of these substances were consumed in part by the yeasts during fermentation. A taste panel favorably assessed the wines produced by fermentation in the presence of oak chips, which retained part of the must original fruity aroma.