Vacuum Drying for Extending Litchi Shelf-Life: Vitamin C,Total Phenolics,Texture and Shelf-Life Assessment

In an attempt to obtain shelf-stable litchi fruit with preserved nutritional quality and good sensory features, quarters of peeled and pitted fruits were vacuum dried at 50, 60 and 70 °C at a constant pressure of 8.0 kPa. The product was assessed for its vitamin C, total phenolics and texture (hardness). In addition, the product with the best texture was assessed for its shelf-life by means of accelerated testing. Results suggest that vacuum dried litchi retained almost 70% of the vitamin C and total phenolics when compared to frozen fruits (control). Vitamin C and phenolic compounds content significantly decreased with drying, while no difference was found between different drying temperatures. Hardness increased with drying temperature. The sample dried at 70 °C presented crispness, which is a desired quality feature in dried fruit products. This sample was subjected to shelf-life evaluation, whose result suggests a shelf-life of eight months at 23 °C. Total color change (CIE ΔE₀₀) was the expiry criterion. Vacuum drying was a suitable technique for producing shelf-stable litchi fruit with good texture while preserving its desirable original nutrients. Consumption of vacuum dried litchi may be beneficial to health due to its remarkable content of phenolic compounds and vitamin C.     

Nitrogen Fertilizer Management Practices to Reduce N<Subscript>2</Subscript>O Emissions from Irrigated Processing Potato in Manitoba

Nitrogen fertilizer practices affect nitrous oxide (N₂O) emissions from agricultural soils. The “4R” nutrient stewardship framework of using N fertilizer at the right rate, right source, right placement and right time can reduce N₂O emissions while maintaining or improving yield of field crops, but understanding of how the various factors affect N₂O emissions from irrigated processing potato is lacking. We examined the effects of selected 4R practices on emissions, using results from two irrigated processing potato studies each conducted in 2011 and 2012 in Manitoba, Canada. Experiment 1 examined combinations of source (urea, ESN), placement (pre-plant incorporation [PPI], banding), and rate (100 and 200 kg N ha^-1) on a clay loam soil. Experiment 2 examined timing and source treatment combinations (urea PPI, ESN PPI, urea split, urea split/fertigation) on a loamy fine sandy soil. For Experiment 1, use of ESN at 200 kg ha^-1 did not reduce area-, yield- and applied fertilizer N- based N₂O emissions compared to urea at 200 kg ha^-1, irrespective of placement. Emissions from pre-plant banding ESN at 200 kg ha^?1, however, were 32% lower than from PPI ESN. For Experiment 2, compared to single pre-plant urea application, fertigation simulated by in-season application of urea ammonium nitrate (UAN) gave lower area-, yield- and applied fertilizer N- based emissions. Split urea ( \( \raisebox{1ex}{$2$}\!\left/ \!\raisebox{-1ex}{$3$}\right. \) pre-plant, \( \raisebox{1ex}{$1$}\!\left/ \!\raisebox{-1ex}{$3$}\right. \) hilling) also reduced area- and yield- based N₂O emissions compared to single pre-plant urea application. Emissions were generally lower at the site with loamy fine sandy soil than the site with clay loam soil. These results demonstrate that combinations of “4R” practices rather than source alone are best to achieve reductions in N₂O emissions from irrigated potato production.     

From shallow to deep waters: habitats used by larval lampreys (genus Petromyzon and Lampetra) over a western European basin

Abstract –  Habitat requirements of lamprey ammocoetes (Petromyzon marinus and Lampetra genus) were investigated, for the first time, from shallow to deep waters, at different spatial scales across the Gironde‐Dordogne continuum, thanks to a water suction dredge. Fish‐habitat relationships were assessed through two complementary statistical analyses: habitat‐use curves and habitat suitability models using the Boosted Regression Trees (BRT) technique. Analyses were performed on a small‐size data set that was characterised by the low prevalence of lamprey. The sea lamprey larvae occurred in deeper areas than their Lampetra genus counterparts. ‘Pools’ of 2 m’ depth and more were optimal habitats for the former species. Among the environmental variables retained to model lamprey occurrences, the mesohabitat (a categorical variable) was demonstrated to be highly influential, in terms of fine grain‐size substratum and vegetation cover. These preliminary results suggest that monitoring using the water suction dredge method may contribute to sea lamprey conservation.     

Synthesis and in-vitro antifungal activity of 6-trifluoromethyipyrazolo[3,4-6d]pyrimidin-4(5H)-thiones

Twelve 6-trifluoromethylpyrazolo[3,4-d]pyrimidin-4(5H)-thiones were prepared by the reaction between 4-thiocarbamoyl-5-aminopyrazoles and trifluoroacetic anhydride. They were tested in vitro for antifungal activity against a series of phytopathogenic fungi of different taxonomic classes. The EC50 and MIC values of four compounds were comparable or inferior to those of reference commercial fungicides in controlling Sclerotinia minor, Corticium solani and Phytium ultimum.     

Fungitoxicity of 5-aminoisoxazole-4-thiocyanate derivatives

3-Methyl-5-(acyl/alkyl)aminoisoxazole-4-thiocyanates were prepared by rhodanation of N-acyl/alkyl-3-methyl-5-isoxazolamines. These products were tested for antifungal activity against a series of phytopathogenic fungi of different taxonomic classes. Some of the compounds showed interesting in-vitro activity. The more active compound in the in-vitro test displayed a moderate preventive activity against Plasmopara viticola, Alternaria solani and Pyricularia recondita.     

Methyl bromide in natural fresh waters: Hydrolysis and volatilisation

The effect of some physical factors on the processes (hydrolysis, volatilisation) regulating the persistence of methyl bromide in fresh surface waters was investigated to complement previous research. It has been confirmed that electromagnetic radiation in the visible field has no influence on the hydrolysis kinetics of the fumigant. The removal of methyl bromide by volatilisation from stirred and ventilated solutions appears to be of greater importance in practice. It has been shown that under these conditions the half-life is directly proportional to the liquid depth. Without stirring volatilisation is greatly reduced, due to the low diffusivity of methyl bromide in the aqueous phase.     

Field evaluation of the single intradermal cervical tuberculin test and the interferon-gamma assay for detection and eradication of bovine tuberculosis in Spain

A field comparison of the interferon-gamma (IFN-gamma) assay and the single intradermal cervical tuberculin (SICT) test for the diagnosis of bovine tuberculosis was conducted. A total of 1136 cattle belonging to 85 herds placed in 'Castilla y León' (northwestern Spain) were chosen, and 21 of these herds were subjected to the diagnostic assays two or three times at intervals of at least 4 months. All the animals positive to any of the tests were slaughtered and tuberculosis was confirmed by culture isolation method (CIM) and further identification by means of PCR. Only 10.6% of cattle reacted with the bovine PPD in the SICT test, a percentage that increased to 12.8% in the IFN-gamma assay. The sensitivity of the IFN-gamma assay compared to CIM was shown to be higher (84.9%) than that of the SICT test (80.2%), but the combination of both tests offered the highest sensitivity (92.9%). The number of false positive reactors (those animals in which CIM was negative) was considerably higher for the IFN-gamma assay than for the SICT test and, conversely, the number of false negative animals (M. bovis isolation but negative immunological result) was higher for the skin test than for the interferon assay. In the herds tested twice, tuberculosis was eradicated after the second cycle of testing in 50%, and in 75% after the third cycle in herds tested three times. The combination of these two techniques instead of separately seems, therefore, to be useful in eradication programmes against bovine tuberculosis.     

Effect of temperature on the incubation period and leaf colonization in bacterial blight of anthurium

ABSTRACT Effect of temperature on leaf colonization in anthurium blight was studied using a bioluminescent strain of Xanthomonas campestris pv. dieffenbachiae. In a susceptible cultivar, colonization of leaf tissues (monitored by detection of bioluminescence) and symptom development (assessed visually) advanced rapidly at higher temperatures. For a susceptible cultivar, there was a linear relationship between degree-days and percent leaf area colonized by the pathogen, indicating that leaf colonization in a susceptible cultivar was a direct function of the cumulative effect of temperature. The degree-day intercept of the regression line represented the time from inoculation to detection of bioluminescence, and the slope indicated the increase of leaf colonization per degree-day. There also was a linear relationship between the logarithm of degree-days and the logarithm of percent leaf area showing visible symptoms in a susceptible cultivar. The degree-day intercept of this relationship represented the incubation period (about 500 degree-days). The degree-days required to detect bioluminescence was not considerably different between susceptible and resistant cultivars. However, the subsequent rates of leaf colonization were significantly lower for a resistant cultivar than for a susceptible cultivar in all temperature regimes. The results suggest that multiplication of the pathogen in the leaf tissues is optimized in the susceptible cultivar. In contrast, in the resistant cultivar, the defense mechanisms overshadow the temperature effect. The differential response to temperatures may be an additional indicator of cultivar susceptibility.     

Incidence of salmonellae in captive and wild free-living raptorial birds in central Spain

A total of 595 faecal samples from raptorial birds, either captive or free-living, residing in GREFA Wildlife Hospital were bacteriologically examined using various selective media and an Automated Diagnostic Assay System for Salmonella detection. Serotype and phage type of the strains identified as Salmonella was determined. In the captive group, of the 285 samples examined, 21 (7.36%) were positive for Salmonella. Serotyping revealed that most of the individuals were infected by Salmonella serotype Havana. This result suggested that there could be a source of contamination in the Hospital although it could not be established. In the wild free-living group, over 310 samples examined (4.19%) were positive for Salmonella. The Salmonella isolates showed a major variety of serotypes: Enteritidis, Adelaide, Brandenburg, Newport, Typhimurium, Hadar, Saintpaul and Virchow. Most of them are similar to those commonly described in isolates from human and domestic animals. These results indicate that wild birds could be involved in the dissemination of Salmonella in humans or domestic animals or vice versa.