Use of Aloe vera gel coating preserves the functional properties of table grapes

Table grapes (Vitis vinifera L. cv. Crimson Seedless) were coated with Aloe vera gel according to our developed patent (SP Patent P200302937) and then stored for 35 days at 1 degrees C, and the subsequent shelf life (SL) was monitored at 20 degrees C. Uncoated clusters showed a rapid loss of functional compounds, such as total phenolics and ascorbic acid. These changes were accompanied by reduction of the total antioxidant activity (TAA) and increases in total anthocyanins, showing an accelerated ripening process. On the contrary, table grapes coated with Aloe vera gel significantly delayed the above changes, such as the retention of ascorbic acid during cold storage or SL. Consequently, Aloe vera gel coating, a simple and noncontaminating treatment, maintained the functional properties during postharvest storage of table grapes.     

Time-resolved spectral studies of blue-green fluorescence of artichoke (Cynara cardunculus L. Var. Scolymus) leaves: identification of chlorogenic acid as one of the major fluorophores and age-mediated changes

Synchrotron radiation and the time-correlated single-photon counting technique were used to investigate the spectral and time-resolved characteristics of blue-green fluorescence (BGF) of artichoke leaves. Leaves emitted BGF under ultraviolet (UV) excitation; the abaxial side was much more fluorescent than the adaxial side, and in both cases, the youngest leaves were much more fluorescent than the oldest ones. The BGF of artichoke leaves was dominated by the presence of hydroxycinnamic acids. A decrease in the percentage of BGF attributable to the very short kinetic component (from 42 to 20%), in the shape of the BGF excitation spectra, and chlorogenic acid concentrations indicate that there is a loss of hydroxycinnamic acid with leaf age. Studies on excitation, emission, and synchronized fluorescence spectra of leaves and trichomes and chlorogenic acid contents indicate that chlorogenic acid is one of the main blue-green fluorophores in artichoke leaves. Results of the present study indicate that 20-42% (i.e., the very short kinetic component) of the overall BGF is emitted by chlorogenic acid. Time-resolved BGF measurements could be a means to extract information on chlorogenic acid fluorescence from the overall leaf BGF.     

Pesticide residues in heterogeneous plant populations, a model-based approach applied to nematicides in banana (Musa spp.)

Nematicides are widely used to control plant-parasitic nematodes in intensive export banana (Musa spp.) cropping systems. Data show that the concentration of fosthiazate in banana fruits varies from zero to 0.035 g kg-1, under the maximal residue limit (MRL=0.05 mg kg-1). The fosthiazate concentration in fruit is described by a Gaussian envelope curve function of the interval between pesticide application and fruit harvest (preharvest interval). The heterogeneity of phenological stages in a banana population increases over time, and thus the preharvest interval of fruits harvested after a pesticide application varies over time. A phenological model was used to simulate the long-term harvest dynamics of banana at field scale. Simulations show that the mean fosthiazate concentration in fruits varies according to nematicide application program, climate (temperature), and planting date of the banana field. This method is used to assess the percentage of harvested bunches that exceed a residue threshold and to help farmers minimize fosthiazate residues in bananas.     

Comparative study of health properties and nutritional value of durian, mangosteen, and snake fruit: experiments in vitro and in vivo

In vitro and in vivo studies of the health and nutritional properties of durian (Durio zibethinus Murr.) were compared with snake fruit (Salacca edulis Reinw.) and mangosteen (Garcinia mangostana). Dietary fibers, minerals, and trace metals were comparable. Total polyphenols (mg of GAE/100 g of FW) and flavonoids (85.1+/-6.1) were significantly higher (p<0.05) than in snake fruit (217.1+/-13.2 (mg of CE/100 g of FW)), durian (309.7+/-19.3 and 61.2+/-4.9), and mangosteen (190.3+/-12.1 and 54.1+/-3.8). Antioxidant activity (microM TE/100 g of FW) of durian measured by DPPH and ABTS assays (228.2+/-13.4 and 2016.3+/-81.1) was significantly higher (p<0.05) than in snake fruit (110.4+/-7.9 and 1507.5+/-70.1) and mangosteen (79.1+/-5.9 and 1268.6+/-62.3). HPLC/DAD analysis of durian (microg/100 g of FW) showed that quercetin (1214.23+/-116.7) was present at levels three times that of caffeic acid, and twice as high as p-coumaric and cinnamic acids. The correlation coefficients between the bioactive compounds of fruits and their antioxidant activities were high (R2=0.99). Male Wistar rats (25) were divided into five dietary groups: the control group was fed the basal diet (BD); in addition to BD, the cholesterol (Chol) group was supplemented with 1% of Chol; the diets of the Chol/Durian, Chol/Snake, and Chol/Mangosteen groups were supplemanted with 5% of these fruits, respectively. It was found that diets supplemented with durian, and to a lesser degree with snake fruit and mangosteen, significantly hindered the rise in plasma lipids and the decrease in antioxidant activity. The nutritional values were comparably high. In conclusion, it could be suggested that inclusion of studied tropical fruits, especially durian, in known disease-preventing diets could be beneficial.     

Detection and localization of oxidized proteins in muscle cells by fluorescence microscopy

In meat, no detailed studies on the intracellular distribution of oxidized proteins during oxidative stress have been performed, to our knowledge. Therefore, we used fluorescence microscopy to detect and locate protein carbonyls, oxidation products of basic amino acids, generated in bovine M. Rectus abdominis during either exposition to a chemical free radical generating system, or refrigerated storage, or cooking. The technique consisted of an immunohistochemical detection of carbonyls by reaction with the specific probe DNPH (2,4-dinitrophenylhydrazine) followed by the sequential addition of a first antibody against DNPH-carbonylated proteins and a CY3-labeled secondary antibody. The fluorescence of the CY3 probe increased regularly with level of free radical generating system and storage time. Moreover, an important heterogeneity of carbonyl distribution was observed, with a higher oxidation level at the periphery than inside the muscle cells. Cooking induced fluorescence increase only at the periphery of cells. Specific coloration of collagen by Sirius red showed that collagen was not involved in fluorescence. We can deduce that accumulation of oxidized proteins observed in the cell periphery was linked to membrane protein oxidation and not to connective tissue oxidation. Biochemical assays were performed in parallel on membrane and myofibrillar proteins to provide complementary quantitative data on level of oxidized proteins.     

Classification of gilthead sea bream (Sparus aurata) from 1H NMR lipid profiling combined with principal component and linear discriminant analysis

The combination of (1)H NMR fingerprinting of lipids from gilthead sea bream (Sparus aurata) with nonsupervised and supervised multivariate analysis was applied to differentiate wild and farmed fish and to classify farmed specimen according to their areas of production belonging to the Mediterranean basin. Principal component analysis (PCA) applied on processed (1)H NMR profiles made a clear distinction between wild and farmed samples. Linear discriminant analysis (LDA) allowed classification of samples according to the geographic origin, as well as for the wild and farmed status using both PCA scores and NMR data as variables. Variable selection for LDA was achieved with forward selection (stepwise) with a predefined 5% error level. The methods allowed the classification of 100% of the samples according to their wild and farmed status and 85-97% to geographic origin. Probabilistic neural network (PNN) analyses provided complementary means for the successful discrimination among classes investigated.     

Carbon-14 biolabeling of (+)-catechin and proanthocyanidin oligomers in willow tree cuttings.

Proanthocyanidin polymers, oligomers, and the structurally related monomer (+)-catechin were labeled by incorporation of radioactive precursors in shoots of willow tree (Salix caprea L.). [1-(14)C]-Acetate and [U-(14)C]-phenylalanine precursors were fed through the cut stems or petioles of leaves. Optimization of several parameters such as the nature and origin of the plant material, leaf maturity, nature, and quantity of radioactive precursor applied and the duration of metabolism led to incorporation yields of 3.2% and to specific activities of 500 microCi/g. Detailed characterization of the products (polymerization degree, procyanidin/prodelphinidin ratio, specific activities) and purification by chromatography are reported. Some sugars bound to radiolabeled proanthocyanidin polymers were removed by enzymic treatment with a mixture of glycosidases. A radioactive purity close to 100% and specific activities suitable for bioavailability studies were obtained.     

1-methylcyclopropene increases storability and shelf life in climacteric and nonclimacteric plums

The effect of 1-methylcyclopropene (1-MCP) at three different doses (0.25, 0.50, and 0.75 microL L(-1)) on the ripening processes of a climacteric, cv. Santa Rosa, and a suppressed climacteric type, cv. Golden Japan, plum was studied. For both cultivars, positive effects were observed in terms of inhibition of ethylene production and delays of the physical, chemical, and biochemical changes associated with ripening. 1-MCP-treated plums were firmer with lower weight loss, reduced degrees Brix/titratable acidity ratios, and lower color changes during cold storage and subsequent shelf life at 20 degrees C than controls. For most factors, the effectiveness of 1-MCP was dose-dependent in Santa Rosa but dose-independent for Golden Japan.     

Climate change will affect the ability of forest management to reduce gaps between current and presettlement forest composition in southeastern Canada

Landscape Ecology - Forest landscapes at the boreal–temperate ecotone have been extensively altered. Reducing the gap between current and presettlement forest conditions through...     

Agriculturally productive yet biodiverse: human benefits and conservation values along a forest-agriculture gradient in Southern Ethiopia

Landscape Ecology - It remains unclear how agricultural landscapes can best serve multiple purposes such as simultaneously maintaining agricultural productivity and conserving biodiversity. Our...