Characterization of some mushroom and earthy off-odors microbially induced by the development of rot on grapes

Grape rot is one of the major causes of degradation of many grape components and, thus, of deterioration in wine quality. In particular, the association of Botrytis cinerea with other, less visible, fungi frequently leads to the development of organoleptic defects in grapes and sometimes in wines. This study examines the nature of the volatile compounds responsible for mushroom, mossy, or earthy odors detected by gas chromatography-olfactometry in organic extracts of rotten grapes and musts. 2-Methylisoborneol, (-)-geosmin, 1-octen-3-one, 1-octen-3-ol, 2-octen-1-ol, and 2-heptanol were identified or tentatively identified. Their concentrations in musts were determined, and the impact of alcoholic fermentation by the yeast Saccharomyces cerevisiae was studied. The ability of fungi isolated from rotten grapes (Botrytis cinerea; Penicillium species including P. brevicompactum, P. expansum, P. miczynskii, P. pinophilum, P. purpurogenum, and P. thomii; Aspergillus section nigri; Rhizopus nigricans; and Coniothyrium sp.) to produce some of the identified compounds was evidenced.     

Cost-effective control of a quarantine disease: a quantitative exploration using "design of experiments" methodology and bio-economic modeling

ABSTRACT An integrated approach to control of quarantine diseases at the level of the plant production chain is complicated. The involved actors have different interests and the system is complex. Consequently, control policies may not be cost effective. By means of a bio-economic model for brown rot in the Dutch potato production chain, the efficacy of different control options was quantitatively analyzed. An impact analysis was performed using the methodology of "design of experiments" to quantify the effect of factors in interaction on incidence and costs of brown rot. Factors can be grouped as policy, sector, economic, and exogenous factors. Results show that brown rot incidence and economic consequences are determined predominantly by policy and sector factors and, to a lesser extent, by economic and exogenous factors. Scenario studies were performed to elucidate how the government and sector can optimize the cost-effectiveness of brown rot control. Optimal cost-effectiveness of control requires cooperation of the sector and government, in which case brown rot incidence can be reduced by 75% and the costs of control can be reduced by at least 2 million euros per year. This study demonstrates quantitatively the potential contribution of an integrated approach to cost-effective disease control at chain level.     

Genetic and molecular organization of the short arm and pericentromeric region of tomato chromsome 6

We have previously presented an integrated linkage map of tomato chromosome 6, that showed the position of restriction fragment length polymorphism (RFLP) and randomly amplified polymorphic DNA (RAPD) markers relative to a variety of classical markers. As for the short arm, map resolution has now been improved by crossing the chromosome 6 substitution line WSL6 to additional tester lines, carrying markers on the short arm. Molecular linkage analysis of the F₂ populations enabled us to produce an integrated linkage map showing the position of molecular markers relative to the classical markers Aps-1, yv, Mi, Cf-2/Cf-5, tl and pds. In order to incorporate the centromere into the integrated map, a radiation-induced deletion mapping strategy was applied, using irradiated pollen from L. pennellii LA716 in crosses to a L. esculentum line recessive for the markers yv and tl, that flank the centromere. Molecular analysis of the hemizygous yv-deletion and tl-deletion plants identified among the F₁ progeny, provided an estimate of the size of the respective deletions and, thus, of the position of the centromere relative to the molecular markers linked to yv and tl. This radiation mapping approach also provided evidence showing that, unlike published data, the root knot nematode resistance gene Mi as well as the Cladosporium fulvum resistance genes Cf-2/Cf-5 are located on the short arm.     

Identification and antioxidant potential of flavonoids and low molecular weight phenols in olive cultivar chemlali growing in Tunisia

Increasing interest in phenolic compounds in olives is due to their antioxidant and health-enhancing properties. In this study the phenolics in fruits of the Tunisian olive cultivar Chemlali were extracted by methanol-water and fractionated using Sephadex LH-20 column chromatography. The identification of phenolic monomers and flavonoids was based on separation by high-performance liquid chromatography equipped with a diode array detector followed by liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry analysis. Oleuropein, a secoiridoid glycoside esterified with a phenolic acid, was the major compound. Eight phenolic monomers and 12 flavonoids were also identified in Chemlali olives. Five flavonoids were isolated and purified using Sephadex LH-20 column chromatography and preparative paper chromatography. The antioxidant activity of the extract and the purified compounds was evaluated by measuring the radical scavenging effect on 1,1-diphenyl-2-picrylhydrazyl and by using the beta-carotene-linoleate model assay. Acid hydrolysis of the extract enhanced its antioxidant activity. Hydroxytyrosol and quercetin showed antioxidant activities similar to that of 2,6-di-tert-butyl-4-methylphenol. A hydroxyl group at the ortho position at 3' on the B ring of the flavonoid nucleus could contribute to the antioxidant activity of the flavonoids.     

Extremely potent antifeedant neo-clerodane derivatives of scutecyprol A

Two known neo-clerodane diterpenoids, scutecyprol A (1) and scutalbin C (2), have been isolated from the acetone extract of the aerial parts of Scutellaria sieberi. The antifeedant activity of scutecyprol A (1), of its 15-oxo derivative (3), and of several halohydrins (4-9), synthesized starting from compounds 1 and 3, against Spodoptera littoralis have been determined and structure-antifeedant relationships are discussed.     

Direct sequencing method for species identification of canned sardine and sardine-type products

A direct sequencing method based on a 103 bp diagnostic sequence derived from a species-specific mitochondrial DNA cytochrome b sequence of 150 bp obtained by Polymerase Chain Reaction was tested for the identification of 47 commercial canned sardine and sardine-type products from various countries. Multiple alignment of 14 analyzed reference samples belonging to Clupeomorpha species was performed versus the canned samples. Low intraspecific variability was observed for canned sardine (相似文献   

Effect of gamma-irradiation combined with washing and waxing treatment on physicochemical properties,vitamin C,and organoleptic quality of Citrus clementina Hort. Ex. Tanaka

To enhance the shelf life of a late variety of Moroccan Citrus clementina (Nour), ionizing treatments were applied at 0.3 kGy, as well as washing (cold water) and waxing treatments. It has been found that, despite the irradiation treatment, the washing and waxing treatment do not improve the quality of C. clementina, but rather result in yellower peels, peel injury, and reductions of vitamin C content, acidity, and soluble solids. However, gamma-irradiation alone enhanced significantly (p 相似文献   

Radiation safety practices among Canadian equine veterinary workers during diagnostic procedures with portable X-ray equipment

The objective of this study was to report observed radiation safety practices among equine workers using portable X-ray units at 3 veterinary practices in Canada. Practice 1 was comprised of equine field service workers from an academic institution, whereas Practices 2 and 3 were comprised of workers from private equine referral practices. Out of 2969 exposure-worker observations, protective aprons were worn for > 99% (2968/2969), thyroid shields for 87% (2584/2969), and eyeglasses for 10% (310/2969). The cassette was held by hand for 97% (1078/1114) of observations, and the X-ray unit was held by hand for 100% (1293/1293) of observations. Gloves were used for 54% (606/1114) and < 1% (5/1293) of observations involving cassette holders and X-ray tube operators, respectively. Use of gloves was more frequent among technologists than DVMs (P = 0.004), and among workers in Practices 1 and 3 than in Practice 2 (P < 0.001). In conclusion, given that workers commonly hold cassettes and X-ray tubes by hand, improvement in shielding use is needed. Consideration should be given to specific behavior recommendations in radiation regulations.     

Composting of Crucifer Wastes Using Geotextile Covers

Composting trials were undertaken in 1994 – 996 in Ste. Anne de Bellevue, Quebec, to study the feasibility of using crucifer or carrot residues with sawdust or straw for composting. Geotextile covers were tested for their influence on different parameters of the composting process. Two complete composting cycles from fall to summer were monitored. Measurements were taken for compost temperature, moisture, and leachate. Chemical analyses were performed on compost samples. Phytotoxicity tests were done with compost leachate samples. The results indicated that temperatures of covered compost (CC) decreased more slowly during late fall and early winter than non-covered compost (NC). In addition, CC did not freeze to as great a depth during the winter, and warmed earlier and faster than NC in the spring. The moisture content of CC was significantly lower than in NC at the end of both composting cycles. CC had a higher mineral content than NC in both cycles, and the levels of total N, P, K and NO₃ were significantly higher for CC in the second cycle. The carbon/nitrogen (C/N) ratio of CC decreased earlier and reached a lower level at the end of the composting cycle. The quantity of leachate from CC was significantly reduced compared to NC in the second cycle. Compost leachate in both treatments showed a high level of phytotoxicity at the beginning of the composting cycle. However, there was no evidence that compost covers influenced the phytotoxicity in leachate throughout the composting cycle. The use of covers could translate into economic or environmental benefits for most composting operations.     

Radiographic Calibration for Analysis of Bone Mineral Density of the Equine Third Metacarpal Bone

Digital radiography represents the primary diagnostic tool the veterinarian uses to diagnose skeletal injuries in the horse. Advances in digital radiography have provided the veterinarian with opportunities to make simple radiographic assessments from calibrated digital radiographs such as dimensional analyses; however, more complex variables such as radiographic opacity have yet to be standardized. Therefore, we investigated the quantification of bone mineral density (BMD) via computed radiographic absorptiometry at various radiographic exposure intensities (kV), times (sec), and milliamps (mA) in the third metacarpal in the horse. By developing a brightness/darkness index (BDI), the grayscale of radiographs, calibrated with an aluminum (Al) marker of various known thicknesses and uniform densities, can be compared to the average BMD of a region of interest at various radiographic exposures. Al BDI was a significant predictor of bone BDI (r² = 0.960, P < .001) and BMD (r² = 0.971, P < .001). This method of calibration can be used for quantitative noninvasive bone mineral analysis and allows direct comparison of radiographs taken under different exposure settings.