886 resultados para fruit-trees
Resumo:
The effect of UV radiation on fruit secondary compounds of strawberry cv ‘Elsanta’ was recorded taking chronological age and fruit position on the truss into account. When fruit of similar age post-anthesis, and truss position were compared, we found that the concentration of secondary compounds differed according to fruit position on the truss. UV radiation hastened the rate of colour development and resulted in an increase in fruit anthocyanin (14–31%), flavonoid (9–21%) and phenolic (9–20%) contents at harvesting; but it had no effect on fruit soluble solid content, pH and volatile composition. It did, however, increase leaf flavonoid (16%) and phenolic (8%) concentrations. Fruit ripened under a UV transparent film were firmer, smaller but greater in number than fruit ripened under a UV opaque film. Overall, the results indicate that UV radiation does not affect all aspects of strawberry ripening but independently alters rate of colour development and fruit firmness
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In its periodic declarations of domestic support to the WTO, the EU has progressively reduced its amber-box declarations in line with its changing system of farm support. Surprisingly, however, in 2007/08 it managed to more than halve its amber box compared with that of the previous year, easily achieving the reduction targets being touted in the Doha Round. This was largely due to a change in the calculations for fresh fruits and vegetables. These had been linked to the entry price system, which was not affected by the 2008 fruit and vegetables reform. Why the EU chose to make this change during the ongoing Doha Round negotiations remains unclear.
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The rate and magnitude of predicted climate change require that we urgently mitigate emissions or sequester carbon on a substantial scale in order to avoid runaway climate change. Geo- and bioengineering solutions are increasingly proposed as viable and practical strategies for tackling global warming. Biotechnology companies are already developing transgenic “super carbon-absorbing” trees, which are sold as a cost-effective and relatively low-risk means of sequestering carbon. The question posed in this article is, Do super carbon trees provide real benefits or are they merely a fanciful illusion? It remains unclear whether growing these trees makes sense in terms of the carbon cost of production and the actual storage of carbon. In particular, it is widely acknowledged that “carbon-eating” trees fail to sequester as much carbon as they oxidize and return to the atmosphere; moreover, there are concerns about the biodiversity impacts of large-scale monoculture plantations. The potential social and ecological risks and opportunities presented by such controversial solutions warrant a societal dialogue.
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Objective: To assess the number of portions of fruit and vegetables consumed daily by a large representative sample of older men, and to determine how blood antioxidant (vitamins E, A and carotenoids) concentrations vary with fruit and vegetable consumption. Design: Cross-sectional study of free-living men. Subjects: Men aged 55-69 y (dietary data, n=1957; blood data, n=1874) participating in Phase III (1989-1993) of the Caerphilly and Speedwell Collaborative Heart Disease Studies. Methods: Dietary data were obtained by semi-quantitative food-frequency questionnaire and blood samples were analysed for antioxidant vitamins. Men were subdivided into groups on the basis of portions per day of fruit and vegetables. Within these sub-groups, mean and 95% ranges of intakes and of blood antioxidant levels were obtained. Log transformations were performed where appropriate. Results: Only 4.3% of the men met the recommended target of five portions, while 33.3% of the men consumed one or fewer portions of fruit and vegetables per day. Those men who consumed the poorest diets with respect to fruit and vegetable intakes were more likely to be from lower socio-economic classes, drink more alcohol and be current smokers. Fruit and vegetable intake reflected plasma concentrations of antioxidants, which showed a dose-response relationship to frequency of consumption. Conclusions: Older men in the UK consume much less fruit and vegetables than current recommendations. Major difficulties are likely to be encountered in trying to meet a dietary target that is clearly much higher than the fruit and vegetable consumption of large sections of the older population in the UK.
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The aim of the work was to study the survival of Lactobacillus plantarum NCIMB 8826 in model solutions and develop a mathematical model describing its dependence on pH, citric acid and ascorbic acid. A Central Composite Design (CCD) was developed studying each of the three factors at five levels within the following ranges, i.e., pH (3.0-4.2), citric acid (6-40 g/L), and ascorbic acid (100-1000 mg/L). In total, 17 experimental runs were carried out. The initial cell concentration in the model solutions was approximately 1 × 10(8)CFU/mL; the solutions were stored at 4°C for 6 weeks. Analysis of variance (ANOVA) of the stepwise regression demonstrated that a second order polynomial model fits well the data. The results demonstrated that high pH and citric acid concentration enhanced cell survival; one the other hand, ascorbic acid did not have an effect. Cell survival during storage was also investigated in various types of juices, including orange, grapefruit, blackcurrant, pineapple, pomegranate, cranberry and lemon juice. The model predicted well the cell survival in orange, blackcurrant and pineapple, however it failed to predict cell survival in grapefruit and pomegranate, indicating the influence of additional factors, besides pH and citric acid, on cell survival. Very good cell survival (less than 0.4 log decrease) was observed after 6 weeks of storage in orange, blackcurrant and pineapple juice, all of which had a pH of about 3.8. Cell survival in cranberry and pomegranate decreased very quickly, whereas in the case of lemon juice, the cell concentration decreased approximately 1.1 logs after 6 weeks of storage, albeit the fact that lemon juice had the lowest pH (pH~2.5) among all the juices tested. Taking into account the results from the compositional analysis of the juices and the model, it was deduced that in certain juices, other compounds seemed to protect the cells during storage; these were likely to be proteins and dietary fibre In contrast, in certain juices, such as pomegranate, cell survival was much lower than expected; this could be due to the presence of antimicrobial compounds, such as phenolic compounds.
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The survival of Bifidobacterium longum NCIMB 8809 was studied during refrigerated storage for 6 weeks in model solutions, based on which a mathematical model was constructed describing cell survival as a function of pH, citric acid, protein and dietary fibre. A Central Composite Design (CCD) was developed studying the influence of four factors at three levels, i.e., pH (3.2–4), citric acid (2–15 g/l), protein (0–10 g/l), and dietary fibre (0–8 g/l). In total, 31 experimental runs were carried out. Analysis of variance (ANOVA) of the regression model demonstrated that the model fitted well the data. From the regression coefficients it was deduced that all four factors had a statistically significant (P < 0.05) negative effect on the log decrease [log10N0 week−log10N6 week], with the pH and citric acid being the most influential ones. Cell survival during storage was also investigated in various types of juices, including orange, grapefruit, blackcurrant, pineapple, pomegranate and strawberry. The highest cell survival (less than 0.4 log decrease) after 6 weeks of storage was observed in orange and pineapple, both of which had a pH of about 3.8. Although the pH of grapefruit and blackcurrant was similar (pH ∼3.2), the log decrease of the former was ∼0.5 log, whereas of the latter was ∼0.7 log. One reason for this could be the fact that grapefruit contained a high amount of citric acid (15.3 g/l). The log decrease in pomegranate and strawberry juices was extremely high (∼8 logs). The mathematical model was able to predict adequately the cell survival in orange, grapefruit, blackcurrant, and pineapple juices. However, the model failed to predict the cell survival in pomegranate and strawberry, most likely due to the very high levels of phenolic compounds in these two juices.
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The major carbohydrates of white and red-flesh pitayas (dragon fruit) were glucose, fructose and some oligosaccharides (total concentrations of 86.2 and 89.6 g/kg, respectively). The molecular weight distribution of the extract was affected by the extraction solvent. The maximum oligosaccharides content (27.40%), which included fractions with molecular weights of 273–275, 448–500 and 787–911 Da, were obtained using 80% ethanol extraction at room temperature (28 ± 2 °C). The low molecular weight fraction, including glucose and fructose, was successfully removed by yeast cultivation. The molecular weights of mixed oligosaccharides (716, 700, 490 and 474 Da) were confirmed by mass spectrometry. The mixed oligosaccharides showed that they were resistant to hydrolysis by artificial human gastric juice and human α-amylase, giving maximum hydrolysis of 4.04% and 34.88%, respectively. The mixed oligosaccharides were also found capable of stimulating the growth of lactobacilli and bifidobacteria.
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Roots, stems, branches and needles of 160 Norway spruce trees younger than 10 years were sampled in seven forest stands in central Slovakia in order to establish their biomassfunctions (BFs) and biomassexpansionfactors (BEFs). We tested three models for each biomass pool based on the stem base diameter, tree height and the two parameters combined. BEF values decreased for all spruce components with increasing height and diameter, which was most evident in very young trees under 1 m in height. In older trees, the values of BEFs did tend to stabilise at the height of 3–4 m. We subsequently used the BEFs to calculate dry biomass of the stands based on average stem base diameter and tree height. Total stand biomass grew with increasing age of the stands from about 1.0 Mg ha−1 at 1.5 years to 44.3 Mg ha−1 at 9.5 years. The proportion of stem and branch biomass was found to increase with age, while that of needles was fairly constant and the proportion of root biomass did decrease as the stands grew older.
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Forest managers in developing countries enforce extraction restrictions to limit forest degradation. In response, villagers may displace some of their extraction to other forests, which generates “leakage” of degradation. Managers also implement poverty alleviation projects to compensate for lost resource access or to induce conservation. We develop a model of spatial joint production of bees and fuelwood that is based on forest-compatible projects such as beekeeping in Thailand, Tanzania, and Mexico. We demonstrate that managers can better determine the amount and pattern of degradation by choosing the location of both enforcement and the forest-based activity.
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Scope Diets low in fruits and vegetables (FV) are responsible for 2.7 million deaths from cardiovascular diseases (CVD) and certain cancers annually. Many FV and their juices contain flavonoids, some of which increase endothelial nitric oxide synthase (eNOS) activity. A single nucleotide polymorphism in the eNOS gene, where thymine (T) replaces guanine (G) at position 894 predicting substitution of glutamate for aspartate at codon 298 (Glu298Asp), has been associated with increased CVD risk due to effects on nitric oxide synthesis and subsequently vascular reactivity. Individuals can be homozygous for guanine (GG), thymine (TT) or heterozygous (GT). Methods and results We investigated the effects of acute ingestion of a FV-puree-based-drink (FVPD) on vasodilation and antioxidant status in subjects retrospectively genotyped for this polymorphism. Healthy volunteers (n = 24; 11 GG, 11 GT, 2 TT) aged 30–70 were recruited to a randomized, controlled, crossover, acute study. We showed that acute consumption of 400 mL FVPD differentially affected individuals depending on their genotype. There was a significant genotype interaction for endothelium-dependent vasodilation measured by laser Doppler imaging with iontophoresis (P < 0.05) and ex vivo low-density lipoproteins (LDL) oxidation (P = 0.002). GG subjects had increased endothelium-dependent vasodilation 180 min (P = 0.028) and reduced ex vivo LDL oxidation (P = 0.013) after 60 min after FVPD compared with control, no differences were observed in GT subjects. Conclusion eNOS Glu298Asp genotype differentially affects vasodilation and ex vivo LDL oxidation after consumption of FV in the form of a puree-based drink.
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Background: Fruit and vegetable-rich diets are associated with a reduced cardiovascular disease (CVD) risk. This protective effect may be a result of the phytochemicals present within fruits and vegetables (F&V). However, there can be considerable variation in the content of phytochemical composition of whole F&V depending on growing location, cultivar, season and agricultural practices, etc. Therefore, the present study investigated the effects of consuming fruits and vegetables as puree-based drinks (FVPD) daily on vasodilation, phytochemical bioavailability, antioxidant status and other CVD risk factors. FVPD was chosen to provide a standardised source of F&V material that could be delivered from the same batch to all subjects during each treatment arm of the study. Methods: Thirty-nine subjects completed the randomised, controlled, cross-over dietary intervention. Subjects were randomised to consume 200 mL of FVPD (or fruit-flavoured control), daily for 6 weeks with an 8-week washout period between treatments. Dietary intake was measured using two 5-day diet records during each cross-over arm of the study. Blood and urine samples were collected before and after each intervention and vasodilation assessed in 19 subjects using laser Doppler imaging with iontophoresis. Results: FVPD significantly increased dietary vitamin C and carotenoids (P < 0.001), and concomitantly increased plasma α- and β-carotene (P < 0.001) with a near-significant increase in endothelium-dependent vasodilation (P = 0.060). Conclusions: Overall, the findings obtained in the present study showed that FVPD were a useful vehicle to increase fruit and vegetable intake, significantly increasing dietary and plasma phytochemical concentrations with a trend towards increased endothelium-dependent vasodilation.
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Epidemiological studies indicate that diets rich in fruits and vegetables (F&V) are protective against cardiovascular diseases (CVD). Pureed F&V products retain many beneficial components, including flavonoids, carotenoids, vitamin C and dietary fibres. This study aimed to establish the physiological effects of acute ingestion of F&V puree-based drink (FVPD) on vasodilation, antioxidant status, phytochemical bioavailability and other CVD risk factors. 24 Subjects, aged 30-70 years, completed the randomised, single-blind, controlled, crossover test meal study. Subjects consumed 400 ml FVPD, or fruit-flavoured sugar-matched control, after following a low-flavonoid diet for 5 days. Blood and urine samples were collected throughout the study day and vascular reactivity was assessed at 90-minute intervals using laser Doppler iontophoresis (LDI). FVPD significantly increased plasma vitamin C (P=0.002) and total nitrate/nitrite (P=0.001) concentrations. There was a near significant time by treatment effect on ex vivo LDL oxidation (P=0.068), with a longer lag phase after consuming FVPD. During the 6 hours after juice consumption the antioxidant capacity of plasma increased significantly (P=0.003) and there was a simultaneous increase in plasma and urinary phenolic metabolites (P<0.05). There were significantly lower glucose and insulin peaks after ingestion of FVPD compared with control (P=0.019 and P=0.003) and a trend towards increased endothelium-dependent vasodilation following FVPD consumption (P=0.061). Overall, FVPD consumption significantly increased plasma vitamin C and total nitrate/nitrite concentrations, with a trend towards increased endothelium-dependent vasodilation. Pureed F&V products are useful vehicles for increasing micronutrient status, plasma antioxidant capacity and in vivo NO generation, which may contribute to CVD risk reduction.
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The aim of this study was to investigate the survival of freeze dried Lactobacillus plantarum cells mixed with several freeze dried instant fruit powders (strawberry, pomegranate, blackcurrant and cranberry) during storage for 12 months as well as after reconstitution with water each month. Inulin and gum arabic were also added to the instant fruit powders at two levels (10% and 20% w/w of dry weight) to improve the cell survival and functional properties of the product. The best cell survival over the 12 months of storage was observed for the blackcurrant powder (almost no decrease) followed by strawberry (~ 0.3 log decrease), pomegranate (~ 0.9 log decrease), whereas the worst survival was obtained in cranberry powder (~ 4.5 logs). To explain these results multiple regression analysis was conducted with the log decrease [log10N0 month − log10N12 months] as the dependent variable and water activity, pH, citric acid, dietary fibre and total phenol as the independent variables. The results indicated that among all the examined factors, the [log10N0 month − log10N12 months] depended only on the water activity (P < 0.05). Inulin and gum arabic demonstrated a substantial protective effect on cell survival (1–1.5 log) in the case of cranberry, which was likely due to a physical interaction between the cells and the carbohydrates. After reconstituting the dried fruit powders at room temperature and measuring cell viability for up to 4 h, it was shown that in the case of strawberry juice there was no decrease, and very little in the case of pomegranate and blackcurrant juices (< 0.5 log). On the other hand, a significant decrease was observed for cranberry juice (P < 0.05), which increased as the storage time of the dried cranberry powder increased, indicating that the cells became more susceptible with prolonged storage. Multiple regression analysis indicated that the main factors influencing cell survival were water activity and pH, while citric acid, dietary fibre and total phenol did not have an effect. Furthermore, inulin and gum arabic addition did not have a significant (P > 0.05) effect upon reconstitution of the dried fruit powder. This study showed that instant juice powders are very good carriers of probiotic cells and constitute good alternatives to highly acidic fruit juices.
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Collaborative mining of distributed data streams in a mobile computing environment is referred to as Pocket Data Mining PDM. Hoeffding trees techniques have been experimentally and analytically validated for data stream classification. In this paper, we have proposed, developed and evaluated the adoption of distributed Hoeffding trees for classifying streaming data in PDM applications. We have identified a realistic scenario in which different users equipped with smart mobile devices run a local Hoeffding tree classifier on a subset of the attributes. Thus, we have investigated the mining of vertically partitioned datasets with possible overlap of attributes, which is the more likely case. Our experimental results have validated the efficiency of our proposed model achieving promising accuracy for real deployment.