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.     

Comparing mating designs to restore seed production of interspecific hybrids between Trifolium repens (white clover) and Trifolium uniflorum

Interspecific hybrids between Trifolium uniflorum and cultivated white clover (Trifolium repens) have highly useful characteristics for temperate pastoral systems derived from both parent species. However, the early hybrids (F₁ and BC₁) also have unacceptably poor seed production for commerce. This study analysed the basis for the poor seed production and investigated breeding strategies for overcoming the problem. The BC₁F₁ generation produced lower‐than‐expected numbers of heads per plant and seeds per floret. Backcrossing of selected hybrids to white clover corrected these deficiencies and created new variation. Seed numbers were also returned to near target levels by recurrent selection within the BC₁ generation. Thus, it was possible to retain a theoretical average of 25% of T. uniflorum genome and still achieve high seed production per plant. The BC₁F₂ and BC₂F₁ generations produced high seed numbers per plant, along with reasonable variation. Both of these second‐generation hybrid forms have high reproductive potential and should be the focus for the selection of the desired combinations of agronomic and seed production traits.     

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.     

Monitoring of atrazine treatment on soil bacterial,fungal and atrazine-degrading communities by quantitative competitive PCR

We report the development of quantitative competitive (QC) PCR assays for quantifying the 16S, 18S ribosomal and atzC genes in nucleic acids directly extracted from soil. QC-PCR assays were standardised, calibrated and evaluated with an experimental study aiming to evaluate the impact of atrazine application on soil microflora. Comparison of QC-PCR 16S and 18S results with those of soil microbial biomass showed that, following atrazine application, the microbial biomass was not affected and that the amount of 16S rDNA gene representing 'bacteria' increased transitorily, while the amount of 18S rDNA gene representing fungi decreased in soil. In addition, comparison of atzC QC-PCR results with those of atrazine mineralisation revealed that, in response to atrazine treatment, the amount of atzC gene increased transitorily in soil pre-treated with atrazine, suggesting that accelerated atrazine biodegradation in soil could be due to a transient increase in the size of the atrazine mineralising community.     

Spatial and temporal distribution of geminiviruses in leafhoppers of the genus cicadulina monitored by conventional and quantitative polymerase chain reaction

ABSTRACT Spatial and temporal distribution of Maize streak virus (MSV, family Geminiviridae, genus Mastrevirus) was monitored in the vector species Cicadulina mbila and the nonvector species C. china? using conventional and real-time quantitative polymerase chain reaction. Sustained feeding on MSV-infected plants showed that virus accumulation reaches a maximum in C. china?, but not in C. mbila. After a 3-day acquisition access feeding period (AAP), MSV was detected in the gut, the hemolymph, and the head of C. mbila, but only in the gut of C. china?. Similarly, Digitaria streak virus (genus Mastrevirus), which is not transmitted by either of the two species, was only detected in the gut. MSV was detected in the hemolymph of C. mbila 3 h after the beginning of the AAP. Although viral DNA progressively decreases in the vector and nonvector species after a 3-day AAP, MSV DNA remained stable in the salivary glands of C. mbila.     

Transient diabetes mellitus in a domestic ferret (Mustela putorius furo)

A 3.5-year-old spayed female ferret, fed a diet high in refined sugar, was referred for lethargy, polyuria, polydipsia, and polyphagia. Diabetic ketoacidosis was diagnosed. Treatment included insulin therapy and a low carbohydrate diet. Diabetes mellitus resolved 54 d later, and insulin therapy was discontinued. There has been no recurrence of the diabetes mellitus.     

Green tea polyphenol extract regulates the expression of genes involved in glucose uptake and insulin signaling in rats fed a high fructose diet

Green tea has antidiabetic, antiobesity, and anti-inflammatory activities in animal models, but the molecular mechanisms of these effects have not been fully understood. Quantitative real-time polymerase chain reaction (PCR) was used to investigate the relative expression levels and the effects of green tea (1 and 2 g solid extract/kg diet) on the expression of glucose transporter family genes (Glut1/Slc2a1, Glut2/Slc2a2, Glut3/Slc2a3, and Glut4/Slc2a4) and insulin signaling pathway genes (Ins1, Ins2, Insr, Irs1, Irs2, Akt1, Grb2, Igf1, Igf2, Igf1r, Igf2r, Gsk3b, Gys1, Pik3cb, Pik3r1, Shc1, and Sos1) in liver and muscle of rats fed a high-fructose diet known to induce insulin resistance and oxidative stress. Glut2 and Glut4 were the major Glut mRNAs in rat liver and muscle, respectively. Green tea extract (1 g) increased Glut1, Glut4, Gsk3b, and Irs2 mRNA levels by 110, 160, 30, and 60% in the liver, respectively, and increased Irs1 by 80% in the muscle. Green tea extract (2 g) increased Glut4, Gsk3b, and Pik3cb mRNA levels by 90, 30, and 30% but decreased Shc1 by 60% in the liver and increased Glut2, Glut4, Shc1, and Sos1 by 80, 40, 60, and 50% in the muscle. This study shows that green tea extract at 1 or 2 g/kg diet regulates gene expression in the glucose uptake and insulin signaling pathway in rats fed a fructose-rich diet.     

Induction of glucokinase mRNA by dietary phenolic compounds in rat liver cells in vitro

Diabetes and its complications, including oxidative stress, are major reasons for medical intervention and one of the most frequent causes of death in developed countries. Several lines of data suggest that the use of certain dietary polyphenolic compounds may alter glucose metabolism, thus decreasing the risk for type 2 diabetes. In this paper, we present the effect of phenolic acids (caffeic, chlorogenic, rosmarinic, and ferulic) and extracts from Smallanthus sonchifolius and Prunella vulgaris on glucose production in rat hepatocytes and on glucokinase, glucose-6-phosphatase, and phosphoenol-pyruvate carboxykinase mRNA expression in rat hepatoma Fao cells. The phenolics at 500 microM and after 1 h incubation lowered glucose production via both gluconeogenesis (10 mM alanine or dihydroxyacetone as precursors) and glycogenolysis compared with metformin. Most of the phenolics increased the level of glucokinase mRNA after 24 h in the same way as insulin (10(-7) M).