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Tomato Fruits (tomato + fruit)
Selected AbstractsEFFECT OF 1-METHYLCYCLOPROPENE ON NUTRITIONAL QUALITY AND ANTIOXIDANT ACTIVITY OF TOMATO FRUIT (SOLANUM LYCOPERSICON L.) DURING STORAGEJOURNAL OF FOOD QUALITY, Issue 2 2010MENG WANG ABSTRACT The effect of 1-methylcyclopropene (1-MCP) on postharvest quality and nutritional compounds in tomato (Solanum lycopersicon Mill.) fruit during storage was determined. The green mature tomato was exposed to 1 µL/L 1-MCP for 24 h. Thereafter, the fruit were stored at 20C and 85,95% relative humidity for 20 days. The results indicated that 1-MCP treatment significantly delayed the decrease of firmness, total soluble solids, and titratable acidity, inhibited the increase of weight loss, and suppressed the rise in respiration rate and ethylene production. Moreover, 1-MCP treatment also inhibited the lycopene accumulation and chlorophyll degradation. Ascorbic acid and soluble phenolic contents in 1-MCP-treated fruit were significantly higher than those in the control fruit. 1-MCP treatment enhanced the ferric reducing antioxidant power (FRAP) values and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. These results suggested that 1-MCP can be used as a commercial technology due to its ability to improve nutritional value of tomato fruit as well as to delay fruit ripening. PRACTICAL APPLICATIONS Tomato fruit are often harvested at mature green stage to minimize damage during transport to market, and then allowed to ripen before or during presentation in retail outlets. A limitation to marketing of tomato fruit is the time that ripe fruit remain in an acceptable condition for consumers. 1-Methylcyclopropene (1-MCP) can extend the storage life and improve postharvest quality of tomato fruit. Recently, nutritional quality is of increasing interest to the consumers because of their potential health benefits in protecting against various diseases. However, the effects of 1-MCP on nutritional compounds and antioxidant activity of tomato fruit are still unclear and need to be more precisely determined. This study can provide information on the effect of 1-MCP treatment on postharvest quality and nutritional compounds in tomato fruit during storage. The results could be applicable to improve the quality and nutritional value of tomato fruit for commercial purpose. [source] QUALITY OF FRESH-CUT TOMATOESJOURNAL OF FOOD QUALITY, Issue 3 2004ABDUL HAKIM ABSTRACT Tomato fruit at pink or light-red stages of ripening were cut into slices, rinsed with water containing 50 ,L.L,1 sodium hypochlorite and drained. They were stored in perforated polyethylene package at 1C in air or controlled atmosphere for five and ten days. Weight loss, chlorophyll and lycopene contents, seed discoloration, fungal infection, total soluble solids content, titratable acidity, sugar/acid ratio, pH, flavor and taste, firmness, ascorbic acid content, rate of respiration and ethylene production, and electrolyte leakage were evaluated after each storage period. The overall quality of controlled atmosphere-stored slices was better than that of air stored slices. Slices from light-red fruit had lower weight loss, minimum seed discoloration, lower [source] EFFECT OF 1-METHYLCYCLOPROPENE ON NUTRITIONAL QUALITY AND ANTIOXIDANT ACTIVITY OF TOMATO FRUIT (SOLANUM LYCOPERSICON L.) DURING STORAGEJOURNAL OF FOOD QUALITY, Issue 2 2010MENG WANG ABSTRACT The effect of 1-methylcyclopropene (1-MCP) on postharvest quality and nutritional compounds in tomato (Solanum lycopersicon Mill.) fruit during storage was determined. The green mature tomato was exposed to 1 µL/L 1-MCP for 24 h. Thereafter, the fruit were stored at 20C and 85,95% relative humidity for 20 days. The results indicated that 1-MCP treatment significantly delayed the decrease of firmness, total soluble solids, and titratable acidity, inhibited the increase of weight loss, and suppressed the rise in respiration rate and ethylene production. Moreover, 1-MCP treatment also inhibited the lycopene accumulation and chlorophyll degradation. Ascorbic acid and soluble phenolic contents in 1-MCP-treated fruit were significantly higher than those in the control fruit. 1-MCP treatment enhanced the ferric reducing antioxidant power (FRAP) values and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. These results suggested that 1-MCP can be used as a commercial technology due to its ability to improve nutritional value of tomato fruit as well as to delay fruit ripening. PRACTICAL APPLICATIONS Tomato fruit are often harvested at mature green stage to minimize damage during transport to market, and then allowed to ripen before or during presentation in retail outlets. A limitation to marketing of tomato fruit is the time that ripe fruit remain in an acceptable condition for consumers. 1-Methylcyclopropene (1-MCP) can extend the storage life and improve postharvest quality of tomato fruit. Recently, nutritional quality is of increasing interest to the consumers because of their potential health benefits in protecting against various diseases. However, the effects of 1-MCP on nutritional compounds and antioxidant activity of tomato fruit are still unclear and need to be more precisely determined. This study can provide information on the effect of 1-MCP treatment on postharvest quality and nutritional compounds in tomato fruit during storage. The results could be applicable to improve the quality and nutritional value of tomato fruit for commercial purpose. [source] Tomato Fruit Development and Ripening Are Altered by the Silencing of LeEIN2 GeneJOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 12 2006Hong-Liang Zhu Abstract Loss-of-function ethylene insensitive 2 (EIN2) mutations showed ethylene insensitivity in Arabidopsis, which indicated an essential role of EIN2 in ethylene signaling. However, the function of EIN2 in fruit ripening has not been investigated. To gain a better understanding of EIN2, the temporal regulation of LeEIN2 expression during tomato fruit development was analyzed. The expression of LeEIN2 was constant at different stages of fruit development, and was not regulated by ethylene. Moreover, LeEIN2-silenced tomato fruits were developed using a virus-induced gene silencing fruit system to study the role of LeEIN2 in tomato fruit ripening. Silenced fruits had a delay in fruit development and ripening, related to greatly descended expression of ethylene-related and ripening-related genes in comparison with those of control fruits. These results suggested LeEIN2 positively mediated ethylene signals during tomato development. In addition, there were fewer seeds and locules in the silenced fruit than those in the control fruit, like the phenotype of parthenocarpic tomato fruit. The content of auxin and the expression of auxin-regulated gene were declined in silenced fruit, which indicated that EIN2 might be important for crosstalk between ethylene and auxin hormones. (Managing editor: Li-Hui Zhao) [source] Effects of organic fertilisers and irrigation level on physical and chemical quality of industrial tomato fruit (cv. Nautilus)JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 15 2009Ramón Madrid Abstract BACKGROUND: The objective of this work was to study the influence of irrigation and organic fertilisation on quality attributes of tomato fruit (cv. Nautilus) grown for the canning industry. The assay was carried out during two consecutive years (2006 and 2007) in agricultural soil. Nine treatments resulting from the combination of three fertilisation types (sheep manure, a mixture of sheep manure and peat and an inorganic fertiliser (control)) with three levels of drip irrigation (3.30, 5.00 and 6.70 mm day,1) under black polyethylene mulch were applied (n = 3). RESULTS: For the chromatic attributes L*, H*, C* and S* the highest values corresponded to the treatments with organic matter. However, the a*/b* ratio and colour index value were higher for the control treatment. In all cases the estimated optimal ripening time was the same, and on this date a decline in the ratios was observed. The values of the physical properties increased with increasing irrigation, higher values always being obtained in the treatments with organic fertilisers. The highest production for all irrigation levels corresponded to the treatment with mixed sheep manure and peat fertiliser. CONCLUSION: Cultivation involving fertilisation with the manure/peat mixture and an irrigation level slightly above 5.00 mm day,1 can be recommended as optimal, since it gave the most satisfactory values with respect to the quality attributes of tomato fruit grown for the canning industry. Copyright © 2009 Society of Chemical Industry [source] Keeping quality of tomato fruit by high electrostatic field pretreatment during storageJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 3 2008Yu Wang Abstract BACKGROUND: High electrostatic field, as a feasible and non-chemical technique, applied to food preservation is a new area of study. The present article intensively investigated this new preservation method, together with its effects on post-harvest physiology and quality of tomato. RESULTS: Green mature tomatoes were exposed to negative (or positive) high electrostatic field for 2 h at 20 °C and then stored for 30 days at 13 ± 1 °C, 85,90% RH. Our results indicated that negative high electrostatic field (,2 kV cm,1) could delay the decline of firmness and the change in color, total soluble sugar and titratable acidity of tomato fruit during storage. The peak of respiration and ethylene production of tomato fruit during storage were delayed by negative high electrostatic field treatment for 6 days and 3 days, respectively. Increases of malondialdehyde content and electrical conductivity in tomato fruit were inhibited significantly by negative high electrostatic field treatment during storage (P < 0.05). CONCLUSION: A high electrostatic field of , 2 kV cm,1 can be used to keep the qualities and extend the shelf-life of tomato fruit. Further research should be highly recommended to understand the mechanisms improving the storability of tomato fruit by negative high electrostatic field. Copyright © 2007 Society of Chemical Industry [source] Effect of benzyl isothiocyanate on tomato fruit infection development by Alternaria alternataJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 9 2005R Troncoso-Rojas Abstract Benzyl isothiocyanate (BITC) is known to be a strong antifungal compound in vitro against different fungi. The effectiveness of benzyl isothiocyanate to control Alternaria alternata growth in vitro and in vivo was tested. BITC in vitro activity was evaluated in A alternata growing on potato dextrose agar and exposed to 0.025, 0.05, 0.1, 0.2 or 0.4 mg ml,1. In vivo activity was evaluated by exposing A alternata -inoculated tomato fruits for either 18 or 36 h to 0.28 or 0.56 mg ml,1 BITC packed on low-density polyethylene film (LDPF) bags. Additionally, the effect of BITC on post-harvest physiology and tomato quality throughout storage at 20 °C was evaluated daily by monitoring respiration rate and ethylene production, whereas total soluble solids, pH, titratable acidity and fresh weight loss were measured every 3 days. Results showed that the minimal inhibitory concentration of BITC in vitro was 0.1 mg ml,1. A combined use of 0.56 mg ml,1 BITC with LDPF for 18 h was the optimum treatment to control Alternaria rot in packed tomato fruit. No effect of BITC on respiration rate, ethylene production, total soluble solids, pH, weight loss and titratable acidity was observed. Results suggest that BITC can be used as a post-harvest treatment to control Alternaria rot in tomato fruit without detrimental effects on the tomato post-harvest quality. Copyright © 2005 Society of Chemical Industry [source] Tomato profilin Lyc e 1: IgE cross-reactivity and allergenic potencyALLERGY, Issue 5 2004S. Westphal Background:, To date, very little data are available about the nature of tomato allergens. Immunoglobulin E (IgE) cross-reactive profilins have been suggested to account for allergic symptoms in patients suffering from tomato allergy. Methods:, The cDNA of tomato profilin was amplified by reversely transcribed polymerase chain reaction (RT-PCR) from total RNA extracted from ripe tomato fruit. The gene was cloned into the pET101D expression plasmid and the protein was produced in Escherichia coli BL21. Purification was performed via poly- l -proline (PLP) affinity chromatography. IgE reactivity of recombinant tomato profilin was investigated by immunoblot and enzyme-linked immunosorbent assay. IgE-inhibition studies were performed to analyse cross-reactivity with other profilins. To determine the allergenic activity of the recombinant protein, basophil histamine release assays using sera of patients with adverse reactions to tomato were performed. Results:, Profilin was identified as a new minor allergen in tomato fruits. The recombinant tomato profilin comprises 131 amino acids and high sequence identity to other allergenic food and pollen profilins. It was shown to be IgE-reactive with a prevalence of 22% (11/50) in tomato-allergic patients. In patients with tomato allergy and multiple sensitization to other foods and birch pollen, IgE directed against tomato profilin showed a strong cross-reactivity with profilins from plant food sources and birch pollen. The tomato profilin was able to induce mediator release from human basophils. Conclusion:, The tomato profilin is a minor allergen in tomato fruit. Thus, it shows biological activity, as confirmed by in vitro histamine release assays with human basophils and thereby has the potential to account for clinical symptoms in tomato-allergic patients. [source] Extensive solubilization and depolymerization of cell wall polysaccharides during avocado (Perseaamericana) ripening involves concerted action of polygalacturonase and pectinmethylesterasePHYSIOLOGIA PLANTARUM, Issue 4 2000Kazuyuki Wakabayashi During the ripening of avocado (Persea americana Mill.) fruit, water-soluble polyuronides increased dramatically, concomitant with marked downshifts in molecular mass. Treatment of cell walls from pre-ripe fruit with purified avocado polygalacturonase (PG, EC 3.2.1.15) promoted the release and molecular mass downshift of polyuronides. The polyuronides released by PG were similar in size distribution to water-soluble polyuronides from fruit at intermediate stages of ripening. Polyuronides released from pre-ripe fruit by PG, although of relatively high molecular mass, were not further degraded upon additional incubation with fresh enzyme. Similarly, water-soluble polyuronides prepared from fruit at intermediate stages of ripening were largely resistant to the action of purified PG in vitro. When polyuronides derived from fruit at intermediate stages of ripening were treated with weak alkali or pectinmethylesterase (PME, EC 3.1.1.11), extensive molecular mass downshifts occurred in response to incubation with PG. These results suggest that PG plays the central role in polyuronide degradation in ripening avocado fruit cell walls and that partial de-esterification is necessary for the increase in the susceptibility of polyuronides to PG. Differences in the patterns of polyuronide depolymerization in avocado fruit compared with the more thoroughly characterized tomato fruit are discussed. [source] A rapid and inexpensive microplate assay for the enzymatic determination of glucose, fructose, sucrose, L -malate and citrate in tomato (Lycopersicon esculentum) extracts and in orange juicePHYTOCHEMICAL ANALYSIS, Issue 5 2001Joyce S. Velterop Abstract Sugars and organic acids are important determinants of taste in fruits and vegetables. Based on the enzymatic analyses originally developed by Boehringer-Mannheim, rapid and reliable microplate-based assays were devised for glucose, fructose and sucrose in tomato and orange juice, and citrate and L -malate in tomato. These microplate assays were used to compare some commercially available tomato types, and to study the compartmentation of sugars and acids between pericarp and locular tissue of tomato fruit. The microplate format allows analysis of many samples per day and the only apparatus required is a microplate reader. Copyright © 2001 John Wiley & Sons, Ltd. [source] Genotype-dependent response to carbon availability in growing tomato fruitPLANT CELL & ENVIRONMENT, Issue 7 2010MARION PRUDENT ABSTRACT Tomato fruit growth and composition depend on both genotype and environment. This paper aims at studying how fruit phenotypic responses to changes in carbon availability can be influenced by genotype, and at identifying genotype-dependent and -independent changes in gene expression underlying variations in fruit growth and composition. We grew a parental line (Solanum lycopersicum) and an introgression line from Solanum chmielewskii harbouring quantitative trait loci for fresh weight and sugar content under two fruit loads (FL). Lowering FL increased fruit cell number and reduced fruit developmental period in both genotypes. In contrast, fruit cell size was increased only in the parental line. Modifications in gene expression were monitored using microarrays and RT-qPCR for a subset of genes. FL changes induced more deployments of regulation systems (transcriptional and post-transcriptional) than massive adjustments of whole primary metabolism. Interactions between genotype and FL occurred on 99 genes mainly linked to hormonal and stress responses, and on gene expression kinetics. Links between gene expression and fruit phenotype were found for aquaporin expression levels and fruit water content, and invertase expression levels and sugar content. In summary, the present data emphasized age- and genotype-dependent responses of tomato fruit to carbon availability, at phenotypic as well as gene expression level. [source] Characterization of a new xyloglucan endotransglucosylase/hydrolase (XTH) from ripening tomato fruit and implications for the diverse modes of enzymic actionTHE PLANT JOURNAL, Issue 2 2006Montserrat Saladié Summary Xyloglucan endotransglucosylase/hydrolases (XTHs) are cell wall-modifying enzymes that align within three or four distinct phylogenetic subgroups. One explanation for this grouping is association with different enzymic modes of action, as XTHs can have xyloglucan endotransglucosylase (XET) or endohydrolase (XEH) activities. While Group 1 and 2 XTHs predominantly exhibit XET activity, to date the activity of only one member of Group 3 has been reported: nasturtium TmXH1, which has a highly specialized function and hydrolyses seed-storage xyloglucan rather than modifying cell wall structure. Tomato fruit ripening was selected as a model to test the hypothesis that preferential XEH activity might be a defining characteristic of Group 3 XTHs, which would be expressed during processes where net xyloglucan depolymerization occurs. Database searches identified 25 tomato XTHs, and one gene (SlXTH5) was of particular interest as it aligned within Group 3 and was expressed abundantly during ripening. Recombinant SlXTH5 protein acted primarily as a transglucosylase in vitro and depolymerized xyloglucan more rapidly in the presence than in the absence of xyloglucan oligosaccharides (XGOs), indicative of XET activity. Thus, there is no correlation between the XTH phylogenetic grouping and the preferential enzymic activities (XET or XEH) of the proteins in those groups. Similar analyses of SlXTH2, a Group 2 tomato XTH, and nasturtium seed TmXTH1 revealed a spectrum of modes of action, suggesting that all XTHs have the capacity to function in both modes. The biomechanical properties of plant walls were unaffected by incubation with SlXTH5, with or without XGOs, suggesting that XTHs do not represent primary cell wall-loosening agents. The possible roles of SlXTH5 in vivo are discussed. [source] Folate synthesis in plants: the last step of the p -aminobenzoate branch is catalyzed by a plastidial aminodeoxychorismate lyaseTHE PLANT JOURNAL, Issue 4 2004Gilles J.C. Basset Summary In plants, the last step in the synthesis of p -aminobenzoate (PABA) moiety of folate remains to be elucidated. In Escherichia coli, this step is catalyzed by the PabC protein, a , -lyase that converts 4-amino-4-deoxychorismate (ADC) , the reaction product of the PabA and PabB enzymes , to PABA and pyruvate. So far, the only known plant enzyme involved in PABA synthesis is ADC synthase, which has fused domains homologous to E. coli PabA and PabB and is located in plastids. ADC synthase has no lyase activity, implying that plants have a separate ADC lyase. No such lyase is known in any eukaryote. Genomic and phylogenetic approaches identified Arabidopsis and tomato cDNAs encoding PabC homologs with putative chloroplast-targeting peptides. These cDNAs were shown to encode functional enzymes by complementation of an E. coli pabC mutant, and by demonstrating that the partially purified recombinant proteins convert ADC to PABA. Plant ADC lyase is active as dimer and is not feedback inhibited by physiologic concentrations of PABA, its glucose ester, or folates. The full-length Arabidopsis ADC lyase polypeptide was translocated into isolated pea chloroplasts and, when fused to green fluorescent protein, directed the passenger protein to Arabidopsis chloroplasts in transient expression experiments. These data indicate that ADC lyase, like ADC synthase, is present in plastids. As shown previously for the ADC synthase transcript, the level of ADC lyase mRNA in the pericarp of tomato fruit falls sharply as ripening advances, suggesting that the expression of these two enzymes is coregulated. [source] Life-history strategy in an oligophagous tephritid: the tomato fruit fly, Neoceratitis cyanescensECOLOGICAL ENTOMOLOGY, Issue 4 2008THIERRY BRÉVAULT Abstract 1.,In phytophagous insects, life-history traits mainly depend on host plant range. Substantial longevity, high fecundity and larval competition are the major traits of polyphagous Tephritidae while species with a restricted host range generally exhibit a lower longevity and fecundity as well as mechanisms to avoid larval competition. Our aim in this study was to investigate the life history of an oligophagous species, the tomato fruit fly, Neoceratitis cyanescens (Bezzi). 2.,We determined life tables under laboratory conditions in order to calculate the main demographic parameters of N. cyanescens and studied the influence of larval and adult diet on life-history traits. 3.,The mean longevity of N. cyanescens females was 40 days. There was a strong synchronisation of female maturity. Oviposition showed an early peak at 9,13 days after a short pre-oviposition period (6 days). The absence of proteins in the adult diet both delayed ovarian maturation and decreased female fecundity. In addition, females originating from tomato fruits produced significantly more eggs than females originating from bugweed or black nightshade, showing that even the larval host plant may strongly affect the subsequent fecundity of adult females. 4.,The traits of N. cyanescens are then discussed in the light of those documented for polyphagous and monophagous tephritids. Neoceratitis cyanescens displayed attributes intermediate between those of polyphagous and monophagous tephritids. Its smaller clutch size compared with polyphagous species and its specialisation on the Solanaceae family whose fruits contain toxic compounds may help in reducing intra- and inter-specific competition, respectively. [source] Fast determination of prominent carotenoids in tomato fruits by CEC using methacrylate ester-based monolithic columnsELECTROPHORESIS, Issue 22 2007Ana Maria Adalid Abstract In this study, the major carotenoids (,-carotene and lycopene) present in tomato fruits were analyzed by CEC with a methacrylate ester-based monolithic column. The effects of the porogenic solvent ratio, and the hydrophobicity of bulk monomer employed were examined on carotenoids separations. A fast separation of these analytes was achieved in less than 5.0,min in a mobile phase containing 35% THF, 30% ACN, 30% methanol, and 5% of a 5,mM Tris aqueous buffer, pH,8, with lauryl methacrylate-based monoliths. The CEC method was evaluated in terms of detection limit and reproducibility (retention time, area, and column preparation) with values below 1.6,,g/mL and 7.2%, respectively. The proposed procedure was successfully applied to the determination of both carotenoids in fruits of several tomato-related species and its usefulness to analyze large series of samples for nutritional quality screening trials in tomato breeding programs is demonstrated. To our knowledge, this is the first work that exploits the powerful and user-friendly monolithic technology for quality breeding and germplasm evaluation program purposes. [source] Purification and Kinetic Characterization of Peroxidase from Tomato Cultivated under Different Salinity ConditionsJOURNAL OF FOOD SCIENCE, Issue 1 2000J.N. Rodríguez-López ABSTRACT: By including hydrophobic chromatography in the purification scheme, 2 homogeneous tomato fruit peroxidase isoenzymes were obtained. The expression of these 2 peroxidases, one acid and the other basic, was determined in tomato fruits grown under different salinity conditions. Increased salinity modified the isoenzyme profile of tomato peroxidase. In tomatoes grown under highly saline conditions, there was an increase in the expression of the acid form with respect to the basic, the acid/basic ratio rising from 4.5 in tomatoes grown under normal saline conditions to 70 in those grown in highly saline conditions. Kinetic studies using 2,2,-azinobis(3-ethylbenzo-thiazolinesulfonic acid) as reducing substrate showed that increased salinity in the growth medium did not modify the kinetic parameter of tomato peroxidase over both hydrogen peroxide or reducing substrate. [source] Tomato Fruit Development and Ripening Are Altered by the Silencing of LeEIN2 GeneJOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 12 2006Hong-Liang Zhu Abstract Loss-of-function ethylene insensitive 2 (EIN2) mutations showed ethylene insensitivity in Arabidopsis, which indicated an essential role of EIN2 in ethylene signaling. However, the function of EIN2 in fruit ripening has not been investigated. To gain a better understanding of EIN2, the temporal regulation of LeEIN2 expression during tomato fruit development was analyzed. The expression of LeEIN2 was constant at different stages of fruit development, and was not regulated by ethylene. Moreover, LeEIN2-silenced tomato fruits were developed using a virus-induced gene silencing fruit system to study the role of LeEIN2 in tomato fruit ripening. Silenced fruits had a delay in fruit development and ripening, related to greatly descended expression of ethylene-related and ripening-related genes in comparison with those of control fruits. These results suggested LeEIN2 positively mediated ethylene signals during tomato development. In addition, there were fewer seeds and locules in the silenced fruit than those in the control fruit, like the phenotype of parthenocarpic tomato fruit. The content of auxin and the expression of auxin-regulated gene were declined in silenced fruit, which indicated that EIN2 might be important for crosstalk between ethylene and auxin hormones. (Managing editor: Li-Hui Zhao) [source] Impact of organic and inorganic fertilizers on yield, taste, and nutritional quality of tomatoesJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 4 2006Anuschka Heeb Abstract In a greenhouse experiment, tomato plants were grown in sand culture to test whether different fertilization regimes (mineral or organic fertilizers) at low (500 mg N plant,1 week,1) and high (750 mg N plant,1 week,1) nitrogen levels affected yield, nutritional quality, and taste of the fruits. In the mineral-fertilizer treatments, nitrate- or ammonium-dominated nutrient solutions were used. Organic fertilizer was supplied as fresh cut grass-clover mulch (a total of 2.4,kg and 3.6,kg were given per plant at low and high N level, respectively) without (orgN) and with additional sulfur fertilization (orgN+S). Yields of red tomatoes from the organically fertilized plants were significantly lower (1.3,1.8,kg plant,1) than yields from plants that received mineral fertilizer (2.2,2.8,kg plant,1). At the final harvest, yields of green tomatoes in the organic treatment with extra sulfur were similar (1.1,1.2,kg plant,1) to the NO -dominated treatments at both nutrient levels and the NH -dominated treatment at high nutrient level. Organic fertilizers released nutrients more slowly than mineral fertilizers, resulting in decreased S and P concentrations in the leaves, which limited growth and yield in the orgN treatments. Analysis of tomato fruits and plants as well as taste-test results gave no conclusive answer on the relationship between sugar or acid contents in the fruits, macronutrient content of plant leaves and fruits, and perceived taste. Sugar contents were higher in the fruits given mineral fertilizer, whereas acid contents were higher in the fruits given organic fertilizer. Preference in taste was given to the tomatoes from plants fertilized with the nitrate-dominated nutrient solution and to those given organic fertilizer with extra sulfur. Thus, a reduction in growth, which was expected to lead to a higher concentration of compounds like sugars and acids, did not result in better taste. Overall, it can be concluded that an appropriate nutrient supply is crucial to reach high yields and good taste. [source] Structural changes, chemical composition and antioxidant activity of cherry tomato fruits (cv. Micro-Tom) stored under optimal and chilling conditionsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 9 2009Perla Gómez Abstract BACKGROUND: Cherry tomato fruits cv. Micro-Tom, a model plant for tomato genetics, were analysed in order to determine the main structural and chemical changes under optimal and chilling storage conditions. The comparison of Micro-Tom to standard tomato cultivars will give an insight into suitability of this dwarf cultivar as a model for studying the influence of low-temperature conditions on tomato fruits. RESULTS: During chilling, fruit tissue was progressively destroyed due to the collapse of the deep layers of the pericarp. Chilling lowered the typical tomato kinetics of ripening in sugars (glucose, fructose, sucrose), organic acids (tartaric, malic, citric, ascorbic and succinic) and the antioxidants phenol and lycopene, while carotenoid synthesis seemed to be blocked. Glutathione level was elevated and the activity of ROS scavenging enzymes was altered. Essentially, Micro-Tom fruits showed a quality evolution that was similar to that described for standard tomato cultivars. CONCLUSION: The cherry tomato cultivar Micro-Tom could be used as a model for studying the influence of low temperature on biochemical and structural changes taking place during chilling injury conditions. Copyright © 2009 Society of Chemical Industry [source] Review of flavonoids and other phenolics from fruits of different tomato (Lycopersicon esculentum Mill.) cultivarsJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 8 2009Rune Slimestad Abstract BACKGROUND: Tomato, one of the most important vegetables worldwide, contains a range of flavonoids and phenolic acids in addition to lycopene, which are regarded as potentially useful compounds with respect to health benefits. Composition data in fresh tomatoes vary due to genetic and environmental factors and cultural practices. Breeding programs aim to produce tomatoes with enhanced levels of flavonoids and other phenolics. RESULTS: The present paper gives an overview of flavonoids, stilbenoids and other phenolics reported to occur in tomato fruits. Contents are reported for a wide range of cultivars and types. Metabolism of phenolics during fruit maturation and tissue location are described, and an overview of measured contents is given. Effects of environmental conditions and cultural practices are estimated using available literature. Recent literature on transgenic tomatoes is included, and possibilities for regulating phenolic contents in tomatoes are discussed. CONCLUSION: The literature review clearly discloses a rapidly growing interest in flavonoids and other phenolics in tomato fruits and products made thereof. This is particularly connected to the antioxidant properties of these compounds as well as other possible health effects. Choice of cultivar and effects of environment and agronomic practices are important factors with respect to phenolic qualities and quantities of tomatoes. Copyright © 2009 Society of Chemical Industry [source] Environmental conditions in relation to stress in cherry tomato fruits in two experimental Mediterranean greenhousesJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 5 2009Miguel A Rosales Abstract BACKGROUND: Considering the economic importance of tomato and its nutritional benefits to human health, a study was conducted on how different environmental factors (temperature, solar radiation and vapour pressure deficit (VPD)) influence hydrogen peroxide detoxification and several stress indicators in cherry tomato (Solanum lycopersicum cv. Naomi) fruits grown in two experimental Mediterranean greenhouses of parral (low-technology) type and multispan (high-technology) type. RESULTS: Three fruit samplings were made at the beginning, middle and end of the fruit production period. Values of temperature, solar radiation and VPD peaked at the third sampling in both greenhouses, being higher in the parral-type greenhouse, while there was a reduction in market production at the third sampling. Peroxidation (malondialdehyde content and lipoxygenase activity) increased significantly at the third sampling, indicating the presence of oxidative stress caused by the rise in temperature, solar radiation and VPD. The ascorbate content, the activities of superoxide dismutase, catalase and ascorbate peroxidase and other stress indicators (proline and sucrose degradation) also increased at the third sampling. CONCLUSION: This study showed that conditions of higher environmental stress occurred at the third sampling and in the parral-type greenhouse, leading to the accumulation of ascorbic acid in cherry tomato fruits and therefore to higher nutritional quality. Copyright © 2009 Society of Chemical Industry [source] Effect of benzyl isothiocyanate on tomato fruit infection development by Alternaria alternataJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 9 2005R Troncoso-Rojas Abstract Benzyl isothiocyanate (BITC) is known to be a strong antifungal compound in vitro against different fungi. The effectiveness of benzyl isothiocyanate to control Alternaria alternata growth in vitro and in vivo was tested. BITC in vitro activity was evaluated in A alternata growing on potato dextrose agar and exposed to 0.025, 0.05, 0.1, 0.2 or 0.4 mg ml,1. In vivo activity was evaluated by exposing A alternata -inoculated tomato fruits for either 18 or 36 h to 0.28 or 0.56 mg ml,1 BITC packed on low-density polyethylene film (LDPF) bags. Additionally, the effect of BITC on post-harvest physiology and tomato quality throughout storage at 20 °C was evaluated daily by monitoring respiration rate and ethylene production, whereas total soluble solids, pH, titratable acidity and fresh weight loss were measured every 3 days. Results showed that the minimal inhibitory concentration of BITC in vitro was 0.1 mg ml,1. A combined use of 0.56 mg ml,1 BITC with LDPF for 18 h was the optimum treatment to control Alternaria rot in packed tomato fruit. No effect of BITC on respiration rate, ethylene production, total soluble solids, pH, weight loss and titratable acidity was observed. Results suggest that BITC can be used as a post-harvest treatment to control Alternaria rot in tomato fruit without detrimental effects on the tomato post-harvest quality. Copyright © 2005 Society of Chemical Industry [source] Tomato profilin Lyc e 1: IgE cross-reactivity and allergenic potencyALLERGY, Issue 5 2004S. Westphal Background:, To date, very little data are available about the nature of tomato allergens. Immunoglobulin E (IgE) cross-reactive profilins have been suggested to account for allergic symptoms in patients suffering from tomato allergy. Methods:, The cDNA of tomato profilin was amplified by reversely transcribed polymerase chain reaction (RT-PCR) from total RNA extracted from ripe tomato fruit. The gene was cloned into the pET101D expression plasmid and the protein was produced in Escherichia coli BL21. Purification was performed via poly- l -proline (PLP) affinity chromatography. IgE reactivity of recombinant tomato profilin was investigated by immunoblot and enzyme-linked immunosorbent assay. IgE-inhibition studies were performed to analyse cross-reactivity with other profilins. To determine the allergenic activity of the recombinant protein, basophil histamine release assays using sera of patients with adverse reactions to tomato were performed. Results:, Profilin was identified as a new minor allergen in tomato fruits. The recombinant tomato profilin comprises 131 amino acids and high sequence identity to other allergenic food and pollen profilins. It was shown to be IgE-reactive with a prevalence of 22% (11/50) in tomato-allergic patients. In patients with tomato allergy and multiple sensitization to other foods and birch pollen, IgE directed against tomato profilin showed a strong cross-reactivity with profilins from plant food sources and birch pollen. The tomato profilin was able to induce mediator release from human basophils. Conclusion:, The tomato profilin is a minor allergen in tomato fruit. Thus, it shows biological activity, as confirmed by in vitro histamine release assays with human basophils and thereby has the potential to account for clinical symptoms in tomato-allergic patients. [source] Effect of Pepino mosaic virus on the yield and quality of glasshouse-grown tomatoes in the UKPLANT PATHOLOGY, Issue 5 2006N. J. Spence Two fully replicated trials were conducted with glasshouse-grown tomatoes, under conditions similar to commercial production, to define the impact of Pepino mosaic virus (PepMV). PepMV was not found to reduce bulk yields in these trials, but the quality of tomato fruits harvested was reduced significantly. Compared with uninoculated, PepMV-free control plants, 6·5% of fruits of PepMV-affected cv. Espero were downgraded from class 1 in trial 1. In trial 2, an average 38% of class 1 fruits from PepMV-affected cvs Espero and Encore were lost as a result of downgrading. Loss of quality was mainly a result of blotchy ripening, gold marbling, gold spot, and symptoms directly attributed to PepMV infection. PepMV infection also affected fruit size. The results are discussed in relation to the demands of multiple retailers in the UK for class 1 tomatoes only. [source] Proteomic analysis of tobacco mosaic virus-infected tomato (Lycopersicon esculentum M.) fruits and detection of viral coat proteinPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue S1 2006Juan Casado-Vela Abstract Tobacco mosaic virus (TMV) is a widespread plant virus from the genus Tobamovirus that affects tobacco and tomato plants causing a pathology characterised by cell breakage and disorganisation in plant leaves and fruits. In this study we undertook a proteomic approach to investigate the molecular and biochemical mechanisms potentially involved in tomato fruit defence against the viral infection. The comparison of 2-D gels from control and TMV-infected but asymptomatic tomato fruits revealed changes in several proteins. The differential expression of peptidases, endoglucanase, chitinase and proteins participating in the ascorbate-glutathione cycle in infected fruits suggests that pathogenesis-related proteins and antioxidant enzymes may play a role in the protection against TMV infection. TMV coat protein appeared as a prominent spot in 2-D gels from TMV-infected asymptomatic fruits. A Triton X-114 phase-partitioning step of tomato protein extracts favoured the solubilisation of TMV coat protein and the enrichment of two aminopeptidases not present in control fruits. PMF and MS/MS data of the 2-D gel-isolated TMV coat protein is proposed as a powerful analysis method for the simultaneous tobamovirus detection, species determination and strain differentiation in virus-infected fruit commodities. [source] Crystallization and preliminary X-ray diffraction studies of NP24-I, an isoform of a thaumatin-like protein from ripe tomato fruitsACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 8 2005Raka Ghosh NP24 is a 24,kDa (207-amino-acid) antifungal thaumatin-like protein (TLP) found in tomato fruits. An isoform of the protein, NP24-I, is reported to play a possible role in ripening of the fruit in addition to its antifungal properties. The protein has been isolated and purified and crystallized by the hanging-drop vapour-diffusion method. The crystals belong to the tetragonal space group P43, with unit-cell parameters a = b = 61.01, c = 62.90,Ĺ and one molecule per asymmetric unit. X-ray diffraction data were processed to a resolution of 2.45,Ĺ and the structure was solved by molecular replacement. [source] Two mitogen-activated protein kinase signalling cascades mediate basal resistance to antifungal plant defensins in Fusarium graminearumCELLULAR MICROBIOLOGY, Issue 6 2007Vellaisamy Ramamoorthy Summary Antifungal defensins, MsDef1 and MtDef4, from Medicago spp., inhibit the growth of Fusarium graminearum, which causes head blight disease in cereals. In order to determine the signalling cascades that are modulated by these defensins, we have isolated several insertional mutants of F. graminearum that exhibit hypersensitivity to MsDef1, but not to MtDef4. The molecular characterization of two of these mutants, designated enhanced sensitivity to defensin (esd), has revealed that the Mgv1 and Gpmk1 MAP kinase signalling cascades play a major role in regulating sensitivity of F. graminearum to MsDef1, but not to MtDef4. The Hog1 MAP kinase signalling cascade, which is responsible for adaptation of this fungus to hyperosmotic stress, does not participate in the fungal response to these defensins. Significantly, the esd mutants also exhibit hypersensitivity to other tested defensins and are highly compromised in their pathogenesis on wheat heads and tomato fruits. The studies reported here for the first time implicate two MAP kinase signalling cascades in a plant defensin-mediated alteration of fungal growth. Based on our findings, we propose that specific MAP kinase signalling cascades are essential for protection of a fungal pathogen from the antimicrobial proteins of its host plant. [source] |