Botanical origin and chemical composition of Brazilian propolis

Brazilian propolis has been classified into 12 groups based on physicochemical characteristics: five in the southern Brazil group (group 3), one in the southeastern Brazil group (group 12), and six in the northeastern Brazil group (group 6). The plant origins of these groups were investigated using reversed-phase high-performance thin-layer chromatography (RPHPTLC), reversed-phase high-performance liquid chromatography (RPHPLC), and gas chromatography-mass spectrometry (GC-MS). It was concluded that the origins of propolis group 3, group 6, and group 12 are resins of the poplar tree, Hyptis divaricata, and Baccharis dracunculifolia, respectively.     

Model studies on the photosensitized isomerization of bixin

The photosensitized isomerization reaction of the natural cis carotenoid bixin (methyl hydrogen 9'-cis-6, 6'-diapocarotene-6, 6'-dioate) with rose bengal or methylene blue as the sensitizer in acetonitrile/methanol (1:1) solution was studied using UV-vis spectroscopy, high-performance liquid chromatography (HPLC), and time-resolved spectroscopic techniques, such as laser-flash photolysis and singlet oxygen phosphorescence detection. In both N(2)- and air-saturated solutions, the main product formed was all-trans-bixin. The observed isomerization rate constants, k(obs), decreased in the presence of air or with increase in the bixin concentration, suggesting the participation of the excited triplet state of bixin, (3)Bix, as precursor of the cis--> trans process. On the other hand, bixin solutions in the absence of sensitizer and/or light did not degrade, indicating that the ground state of bixin is stable to thermal isomerization at room temperature. Time-resolved spectroscopic experiments confirmed the formation of the excited triplet state of bixin and its deactivation by ground state bixin and molecular oxygen quenching processes. The primary isomerization products only degraded in the presence of air and under prolonged illumination conditions, probably due to the formation of oxidation products by reaction with singlet molecular oxygen. An energy-transfer mechanism was used to explain the observed results for the bixin transformations, and the consequences for food color are discussed.     

Palaeoenvironmental Reconstruction of Lago Di Albano (Central Italy) during the Late Pleistocene Using Fossil Ostracod Assemblages

A fine resolution study on fossil ostracods in late glacial sediments from Lago di Albano was performed within the framework of the European project PALICLAS. Four cores from two coring sites were analysed. At Site 1, located at 70 m depth, cores PALB94 1E and PALB94 1C were collected, while cores PALB94 6A and PALB94 6B were collected at Site 6 at 30 m depth. The autoecology of the ostracod species, cluster analysis, PCA and CA ordination numerical analyses were performed in order to identify changes in environmental conditions within the sedimentary record. Three assemblages were recognized: (a) dominated byC. neglecta representing sublittoral environments, (b) dominated byC. neglecta accompanied byPotamocypris spp. related to spring influx and (c) dominated byCyclocypris sp. associated with littoral and relatively warmer conditions. A reconstruction of lake water level, oxygen concentration near the bottom and lake productivity , based on ostracod autoecology and supported by fossil pigment data, was accomplished. Sharp fluctuations in water level and productivity seem to indicate climatic oscillations between ca 30 to ca 17 kyr BP.     

Coriander essential oil composition from two genotypes grown in different environmental conditions

The objective was to study the essential oil composition of coriander fruits in plants growing in environments differing in soil conditions and weediness level. Factorial field experiments were conducted in two locations from the Rolling Pampas, Argentina, and two coriander landraces (European and Argentinean) were tested under two levels of nitrogen fertilization and weediness. Data were evaluated with uni- and multivariate techniques. The variation in the oil composition was related to the relative proportion of the constituents and not to the presence/absence of a particular component. Weather conditions in 1997 favored linalool and camphor in both landraces. Location, fertilization, and weediness also affected the chemical profile. The European landrace showed a more stable concentration of the major components than the Argentinean landrace. These results, which show the relationships between some environmental conditions and the essential oil composition, are useful in the development of innovative strategies aimed to improve oil composition and to manage crop pests.     

Land contamination by toxic elements in abandoned mine areas in Italy

Purpose

The present paper concerns the distribution and mobility of heavy metals (Cu, Pb, Zn and Fe) in the soils of some abandoned mine sites in Italy and their transfer to wild flora.

Materials and methods

Soils and plants were sampled from mixed sulphide mine dumps in different parts of Italy, and the concentrations of heavy metals were determined.

Results and discussion

The phytoremediation ability of Salix species (Salix eleagnos, Salix purpurea and Salix caprea), Taraxacum officinale and P?lantago major for heavy metals and, in particular, zinc was estimated. The results showed that soils affected by mining activities presented total Zn, Cu, Pb and Fe concentrations above the internationally recommended permissible limits. A highly significant correlation occurred between metal concentrations in soils.

Conclusions

The obtained results confirmed the environmental effects of mine waste; exploring wild flora ability to absorb metals, besides metal exploitation, proved a useful tool for planning possible remediation projects.

     

Improvement of table grapes quality and safety by the combination of modified atmosphere packaging (MAP) and eugenol, menthol, or thymol

Table grape is a nonclimacteric fruit that shows a rapid loss of quality during storage and is very susceptible to colonization by fungi, especially Botrytis cinerea, which is considered the most important disease of this commodity. To solve this problem, synthetic fungicides have been used, although legal restrictions and consumer's concern demand the search of other safe means. In the present paper, and as an alternative of synthetic fungicides, an active packaging to improve MAP effectiveness on preserving table grape (cv. Crimson Seedless) quality and safety was developed by the addition of 0.5 mL of eugenol, thymol, or menthol inside the packages. Packages were stored at 1 degree C for 35 days. The final gas composition inside the packages was 1.4-2.0 and 10.0-14.5 kPa of CO(2) and O(2), respectively, with no significant slight differences among treatments. Results showed that the addition of eugenol, thymol, or menthol improved the beneficial effect of MAP in terms of delaying weight loss and color changes, retarding degrees Brix/acidity ratio evolution, and maintaining of firmness. Thereafter, these treatments showed additional benefit in terms of delayed rates of rachis deterioration and berry decay. Finally, the total viable counts for both mesophilic aerobics and especially yeast and molds were significantly reduced in the grapes packaged with the natural antimicrobial compounds. All of the above effects led to maintenance of table grape quality and safety for longer storage periods (3 additional weeks as compared to controls under MAP only).     

Evaluation of the antimicrobial activity of citrus essences on Saccharomyces cerevisiae

The aim of this research was to assess the antimicrobial activity of nine different industrial essences used in a soft drink factory in relation to their composition, as well as to verify the role of vapor pressure on their bioactivity. The essences were tested against a Saccharomyces cerevisiae strain isolated from spoiled soft drinks. The tests were carried out by adding the essences directly to a liquid medium or into the headspace of closed systems inoculated with the yeast. The headspace composition was evaluated through a solid phase microextraction-gas chromatography technique. The use of a mass spectrometer allowed the identification of the peaks detected. The microbial growth was indirectly monitored by measuring the metabolic CO2 released by the yeast. The results obtained indicated that the most effective essences were characterized by the highest concentration of some terpenes, such as citral, beta-pinene, and p-cymene. Moreover, all of the essences were more bioactive when added directly to the liquid medium.     

Direct HPLC analysis of quercetin and trans-resveratrol in red wine,grape, and winemaking byproducts

A simple and fast reversed-phase HPLC method using diode array detection was developed and validated for the simultaneous determination of trans-resveratrol and quercetin in Sicilian red wine from the Nero d'Avola red grape variety. Investigation was also extended to the quantitative determination of resveratrol and quercetin in grape skins and winemaking byproducts obtained from the same cultivar. Samples were eluted using a C18 narrow-bore column under isocratic conditions in less than 20 min. Quantification of trans-resveratrol and quercetin in red wine was performed without any sample pretreatment, whereas the determination of these phenolic compounds in grape skins and wine pomage required a solvent extraction procedure. Linearity was demonstrated over the 0.39-12.5 and 0.45-57.6 microg/mL range for trans-resveratrol and quercetin, respectively. Detection limits in real samples were in the low ppm level (0.07 mg/L for trans-resveratrol and 0.12 mg/L for quercetin). The HPLC-UV/DAD method was applied for the routine analyses of red wine and grape skin and winemaking byproduct extracts to evaluate their trans-resveratrol and quercetin content. In particular, a very high content of quercetin was found in wine pomace, suggesting the use of this wine byproduct as a potential source of this health-promoting phenolic compound.     

Cinosulfuron: chemical and biological degradability, adsorption and dissipation in flooded paddy field sediment

Cinosulfuron is a sulfonylurea herbicide largely used in the extensive cultures of flooded rice in North Italy. The degradation of cinosulfuron has been investigated in sterile aqueous solutions at 30 degrees C at different pH values. It was rapidly degraded at acidic pH (half-lives 3, 9 and 43 days at pH 4, 5 and 6, respectively) while the half-life was > 1 year at pH 7 and 9. Two degradation products formed by cleavage of the sulfonylurea bridge were identified by LC-MS. Degradation by selected mixed microbial cultures tested in aerobic and anaerobic conditions was very slow and attributable to chemical hydrolysis due to the acidic pH of the cultural broths. Degradation took place in freshly collected rice field water treated for two years with cinosulfuron but, in this case also, chemical hydrolysis prevailed over microbial degradation. In contrast, in flooded sediment simulating the paddy field environment, the dissipation rate of cinosulfuron was higher than expected from chemical hydrolysis according to the pH of the system, indicating the involvement of soil microflora. Although the herbicide exhibited a reduced affinity for the sediment surfaces demonstrated by the low value of the K(f) Freundlich coefficient (0.87 on a micromolar basis), the rapid dissipation observed in the simulated paddy field should prevent its leaching to ground water.     

Leaf stomatal resistance,ethylene evolution and ABA levels as influenced by (2-chloroethyl) phosphonic acid

The effect on stomatal resistance of ethylene released from ethephon sprays has been studied in 8 species of plants. Ethephon always increased stomatal resistance, but in some species only slightly. In olive and peach, increased stomatal resistance in treated plants was associated with more abscisic acid in the leaf tissues.