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  • Author or Editor: L. Helyes x
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In the present study the concentration of soluble solids (Brix°), total carbohydrate, total organic acid, lycopene, total polyphenol, hydroxymethylfurfural, and antioxidant capacity were investigated in tomato fruits at six ripening stages from mature green to fully red. In case of Brix o  and carbohydrate, the highest values were observed at the last stage of ripening. Carbohydrate content constitutes nearly 50% of the soluble solids. In mature green stage the lowest acid content was detected but in subsequent stages it did not change significantly. Polyphenol content remained almost the same during ripening, thus there were not significant differences found among ripening stages. In case of lycopene content, there were great differences among maturity stages. Lycopene accumulated mainly during deep red stage. The antioxidant characteristic of tomato fruit expressed as total antioxidant status (TAS) showed significant linear correlation with lycopene, polyphenol and hydroxymethylfurfural content and increased continuously during ripening period. Marked correlation was observed between lycopene content and formation of hydroxymethylfurfural, as well.

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Carrot is an important source of sugars. The objective of this study was to investigate the effects of water supply (precipitation + irrigation) on the concentration and ratio of fructose, glucose, and sucrose in carrot. Irrigation did not decrease the dry matter content and the summed concentration of the three measured sugars. Glucose accumulation was not influenced either by irrigation or by year. Low amount of precipitation during the early growing period was detrimental for fructose accumulation. Irrigation enhanced sucrose concentration, presumably by ensuring better photosynthetic activity. However, dry and hot weather during the irrigation cut-off period in 2011 also resulted in increased sucrose accumulation, presumably as a stress effect. It was found that irrigation did not influence the ratio of the three investigated saccharides at all, and even the growing year had just a slight effect on that.

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The objective of this study was to investigate the influence of irrigation on the composition and content of phenolic compounds and carotenoids in different tomato cultivars using HPLC/DAD-UV technique and reverse-phase (RP) chromatographic columns for analysis. Among phenols, the quercetin derivatives and hydroxycinnamic acids and their derivatives were the major compounds, while lycopene was the dominant carotenoid in the extract of tomato. It was found that the response of tomatos to shortage of water is affected by genetic factors and seasonal environmental variations. In general, 100% irrigation yielded tomatoes with the lowest level of carotenoids and polyphenols. In 2012, when the temperature and number of sunny hours were at record levels, the non-irrigated plants of cultivar Strombolino yielded tomatoes with significantly higher levels of carotenoids and phenols than that of the other cultivars.

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Tomato quality factors such as size, firmness, colour, taste and nutritional content are important criteria for marketing of tomato fruit. The aim of present study was to evaluate the effects of different types of varieties and cultivation technologies (forcing, open-field with supporting system, open-field with processing varieties) on the ingredient content of tomato fruit. The soluble solids (°Brix), carbohydrate, organic acid, lycopene and ascorbic acid contents were measured. Average soluble solids content ranged from 5.2 to 8.7%. The highest °Brix was observed in the fruits of a cherry type tomato, namely Favorita (8.7%). Carbohydrate content constitutes nearly 50% of the °Brix. The highest carbohydrate content was observed for Favorita and Cheresita (both cherry type tomatoes), whereas the lowest was detected in Falcorosso, a processing variety. Low acid content was found in Nívó and Delphine F 1 cultivars (processing and eating variety, respectively). The sugar-acid ratio was 40% higher in the case of cherry type tomatoes than in the other varieties. Average lycopene content of examined tomato varieties turned out to be extremely diverse (48–134 mg kg −1 ). Ascorbic acid levels did not differ so much, ranging from 226 to 381 mg kg −1 . In case of open-field cultivation with supporting system, cherry type varieties showed significantly higher °Brix and carbohydrate content than those of round tomato type with average fruit weight of 100∓130 g. All varieties examined produced significantly higher organic acid content in forcing as compared to the values of round tomato varieties cultivated in open-field with supporting system and processing varieties. Lycopene content of tomato fruits from greenhouse was higher than that of fruits from field. Processing varieties yielded significantly higher lycopene content than the others.

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The extractable (ASTA) colour retention of four different milled spice paprikas was evaluated at 10, 20, 35, 50, and 60 °C storage temperature. The ASTA colour stability during long-term storage period strongly depended on the temperature, primary handling and drying of the fresh crop, and the applied production technology. The cooled (10 °C) or temperature-controlled (20 °C) conditions appeared to be a reasonable solution to preserve the quality of paprika powder. The kinetics study on the temperature dependence of ASTA colour loss estimated the apparent reaction order, rate constants, predicted half-life times and activation energy. The Q10 approach and shelf life-plot resulted in useful data, which can be suitable for quick and economical evaluation of further spice paprika products.

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The snap bean is a significant food crop. Under the Hungarian climate conditions, the supply of raw material of good quality and appropriate quantity to canning factories can be ensured only with irrigation. The present paper evaluates the result of irrigation experiments carried out on snap beans sown in spring and summer and grown with and without irrigation. The experiments were run over the course of 12 years. In the average of 12 years, the yield was 2.8 t ha-1 for spring-sown and 1.9 t ha-1 in summer-sown plants without irrigation. The lowest level of profitable production, the 5.5 t ha-1 was reached twice in the case of spring-sowing and only once in the case of summer-sowing. Profitable yield production can be ensured only with regular irrigation and thus the yield may be increased by 4-5 times. In four of the twelve years we determined the canopy surface temperature of snap bean stands with and without irrigation. A Raynger II infrared remote thermometer determined the canopy surface temperature each day at 13.00 hours. The canopy temperature can well characterise the water supply of plant stands. This parameter may be used for describing the degree of drought and the water turnover of plant stands with different water supply. The positive values of foliage-air temperature differences (SDD) numerically express the degree of drought and the water supply of the crops. The results indicated that a 1 °C higher SDD value might cause 90-130 kg ha-1 yield loss. The method can be useful for investigation of drought affected natural vegetation responses also.

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Quantification of red pigment content of fruits using destructive techniques is expensive and it enables only the analysis of batches but not of individual items. This study examined the feasibility of using non-destructive, spectrophotometric method to predict one of the most valuable internal quality indices, lycopene, in individual tomato fruits. An open field experiment was conducted to study the effect of irrigation and potassium supplementation on the yield and lycopene content of processed tomato fruit. Three different treatments (regularly irrigated RI, irrigation cut-off 30 days before harvest CO, and rainfed RF unirrigated control) and two different potassium fertilisations (P) were applied. Regular irrigation significantly decreased the lycopene content of tomato fruits. The CO treatment resulted in the highest total lycopene without potassium supplementation. Potassium supplementation, given at the time before fruit maturity, significantly increased the lycopene concentration of cultivar Brigade F1, independently of irrigation. The closest correlation was at 700 nm R2=0.38 and R2=0.45, between reflectance and the (all-E)-lycopene and the (9Z)+(13Z)-lycopene isomers, respectively.

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Soil-born diseases often cause problems in vegetable forcing; this is because growers use greenhouses for the longest time possible. During the years several solutions have been found to displace chemical control. Grafting is a possible chemical free solution that shows several changes in plants thanks to the vigorous rootstock. In this study we examined the effect of grafting on the yield and fruit characteristics in tomato cultivar. Lemance F1was used as scion and Beaufort as rootstock. Earliness, total yield, fruit weight and number of each graft combination were recorded. Moreover, the main fruit components such as Brix°, carbohydrate, acid and the carbohydrate/acid ratio were analysed. We harvested more yield from the grafted plants. The increase of yield was mainly caused by higher average fruit weight. Brix° and carbohydrate content were lower in the fruits on grafted plants than on ungrafted ones but there was no significant difference in acid content.

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Recently several studies have focused on the antioxidant activity of lycopene such as quenching of singlet oxygen and scavenging of peroxyl radicals. These properties may play a role in the prevention of different cancer and heart diseases. Tomato is one of the most important sources of lycopene. The main information on the effect of environmental parameters on quality and health-retaining constituents of tomato fruit is mostly related to temperature (air- and fruit canopy temperature) and light effects that might provide a stress to the fruit. Nowadays little is know about the direct effect of elevated CO2.The aim of the present work was to evaluate the effects of elevated CO2 in Perspex open top chambers (OTC) on the lycopene content of tomato fruit.Experiments on the effects of elevated CO2 concentrations showed mixed results. In this work it was found that concentrations of lycopene in a fruit decreased significantly when elevated CO2 was used. Elevated nitrogen sources generated only slight, but not significant difference in the lycopene concentration of tomato fruit.

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A two-year open field experiment was carried out to study the effect of elevated carbon dioxide (CO2) and nitrogensupply on fruit components of tomato. Korall determinate growth type processing tomato cultivar plants were planted and cultivated for the entire growing season in open top chambers (OTC) in years 2007 and 2008. Compared with the control (350 ppm) CO2 enrichment (700 ppm) significantly decreased the lycopene content at all three harvest dates in both years, but higher supply of nitrogen and 700 ppm CO2 resulted in significantly higher lycopene values in second year. Elevated nitrogen concentration combined with 700 ppm CO2 significantly increased the Brix, sugar content, total phenolics, and total antioxidant status (TAS) of tomato fruits.

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