Acid Content In Tomato Fruits Research Articles

Improvements in the Appearance and Nutritional Quality of Tomato Fruits Resulting from Foliar Spraying with Silicon.

Research on silicon (Si), an element considered beneficial for plant growth, has focused on abiotic and biotic stress mitigation. However, the effect of Si on tomato fruit quality under normal growth conditions remains unclear. This study investigated the effects of applying different levels of Si (0 mmol·L-1 [CK], 0.6 mmol·L-1 [T1], 1.2 mmol·L-1 [T2], and 1.8 mmol·L-1 [T3]) in foliar sprays on tomato fruit quality cultivated in substrates, and the most beneficial Si level was found. Compared to CK, exogenous Si treatments had a positive influence on the appearance and nutritional quality of tomato fruits at the mature green, breaker, and red ripening stages. Of these, T2 treatment significantly increased peel firmness and single-fruit weight in tomato fruits. The contents of soluble sugars, soluble solids, soluble proteins, and vitamin C were significantly higher, and the nitrate content was significantly lower in the T2 treatment than in the CK treatment. Cluster analysis showed that T2 produced results that were significantly different from those of the CK, T1, and T3 treatments. During the red ripening stage, the a* values of fruits in the T2 treatment tomato were significantly higher than those in the other three treatments. Moreover, the lycopene and lutein contents of the T2 treatment increased by 12.90% and 17.14%, respectively, compared to CK. T2 treatment significantly upregulated the relative gene expression levels of the phytoene desaturase gene (PDS), the lycopene ε-cyclase gene (LCY-E), and the zeaxanthin cyclooxygenase gene (ZEP) in the carotenoid key genes. The total amino acid content in tomato fruits in the T2 treatment was also significantly higher than that of CK. In summary, foliar spraying of 1.2 mmol·L-1 exogenous Si was effective in improving the appearance and nutritional quality of tomato fruits under normal growth conditions. This study provides new approaches to further elucidate the application of exogenous silicon to improve tomato fruit quality under normal conditions.

Effect of Packing Materials on Shelf Life of Tomato (<i>Lycopersicon esculentum Mill</i>) Under Laboratory Condition

The experiment was done to study the effect of packing materials on the shelf life of tomatoes <i>(lycopersican esulentam</i>) under laboratory conditions of Hawassa University Agriculture College protection laboratory in 2020. To reduce post-harvest losses of tomato production the packing materials such as Nets, DPB, LTPB, and cartons were evaluated concerning their effect on the produce of shelf life of tomatoes under laboratory conditions. These studies were conducted for analysis of total weight losses, disease incidence and severity, firmness, pH value, TSS and TAA green matured tomatoes at 20°C laboratory conditions. In general, after 24 days of the storage period, the pH value of the tomato was high a significant difference within each other treatment, and the total weight losses were relatively different with the low temperature of storage condition. The disease incidence and severity closely occurred on the control with 100±2.5298%. The TSS and TAA DPB, LTPB treatment was found to be superior in retaining maximum TSS, titrable acidity, and ascorbic acid content of tomato fruits even up to the end of the storage period. The firmness measured by the newton of treatment five shows high superiority which recorded carton (743.33N ±60.590) when compared with control (130N ±60.590). The firmness values were decreased in all the samples stored in different conditions and with different packing materials.

Contribution of Piriformospora indica on improving the nutritional quality of greenhouse tomato and its resistance against cu toxicity after humic acid addition to soil.

Protected cultivation has a significant contribution in vegetable production. We investigated whether humic acid addition to soil and Piriformospora indica can improve the nutritional quality of greenhouse tomato. We conducted a pot experiment, in which the effects of P. indica inoculation, humic acid addition, and Cu spiking to soil (0, 120, 240, and 500 ppm Cu) were tested. Humic acid addition to soil spiked with 500 ppm Cu decreased the Cu concentration in the fruits of plants inoculated with P. indica from 0.65 to 0.40 mg 100 g Fw-1, which is still above the maximum allowed limits of Cu in tomato by World Health Organization (WHO). The lycopene and ascorbic acid content of tomato fruits were consistently improved by humic acid addition and P. indica inoculation. The antioxidant enzymes' activity changed in response to humic acid addition, Cu spiking to soil, and P. indica inoculation. With increasing Cu level up to 240 ppm, the activity of superoxide dismutase (SOD) and peroxidase (POD) increased significantly. However, with spiking more Cu to soil, the activity of antioxidant enzymes reduced and the MDA content increased significantly. Addition of humic acid to soil and/or presence of P. indica increased the activity of antioxidant enzymes when the soil spiked with 500 ppm Cu. This study indicated that addition of P. indica and humic acid to the soil can enhance the nutritional quality of greenhouse tomato by reduction of Cu toxicity as a common pollutant in the greenhouse media and increasing the antioxidant content of fruits.

High temperature induced changes in quality and yield parameters of tomato (Solanum lycopersicum L.) and similarity coefficients among genotypes using SSR markers

High temperature induced by climatic fluctuations are an important threat for plant growth, development and quality of agricultural produces. Adaptableness to environmental changes generally derives from a large set of genetic traits affecting physio-morphological, biochemical and agronomic parameters. Therefore, the identification of genotypes with higher yield and good quality parameters at high temperatures is becoming increasingly necessary for future breeding programs. Here, we analyzed the performance of different tomato genotypes grown under elevated temperatures in terms of yield and nutritional quality of the fruit. High temperature stress was induced from flower initiation to maturity stage by keeping the pots in a temperature controlled green house facility for 45 days. The quality and yield parameters were taken at the harvesting stage. Starch and soluble sugar concentration in the leaves of tomato genotypes showed significant reduction in its amount under heat stress. Titrable acidity (TA), total soluble solids (TSS) and ascorbic acid content of tomato fruits were highest under high temperature conditions compared to ambient condition but lycopene content decreased with rise in temperature. The yield attributes viz., number of fruits/plant, fruit set %, average fruit weight (g), yield per plant (g/plant) were significantly lower for Arka Saurabh, Arka Rakshak and Pusa Rohini when compared to other genotypes under study. Molecular characterization of selected 22 tomato genotypes were assessed using 25 simple sequence repeat (SSR) markers. Phylogenetic tree was constructed by the unweighted neighbour-joining method (UPGMA) using NTSYSpc cluster analysis software. The Jaccard's similarity matrix was constructed using the SIMQUAL method using UPGMA algorithm in NTSYSpc. Jaccard's similarity matrix among these tomato genotypes ranged from a minimum of 0.22 to a maximum of 1 with an average genetic similarity of 0.67. Hence this study has importance in identifying genotypes that could maintain good quality and higher yield under high temperature condition.

Effect on lycopene, β-carotene, ascorbic acid and phenolic content in tomato fruits infected by Alternaria alternata and its toxins (TeA, AOH and AME)

Tomato is considered as one of the most important sources of nutrients such as lycopene, β-carotene, flavonoids, ascorbic acid (vitamin C) and hydroxyl-cinnamic acid derivatives. The quality and quantity of nutrients in tomato fruits were decreased during the severe infection of Alternaria alternata. The present study deals with the estimation of lycopene, β-carotene, phenolic and ascorbic acid content in tomato fruits which were infected with A. alternata and its toxins such as tenuazonic acid (TeA), alternariol (AOH) and alternariol monomethyl ether (AME). The lycopene, β-carotene, ascorbic acid and phenolic content were found lowest in pathogen-infected fruits i.e. (0.66 ± 0.03 mg/g), (0.14 ± 0.01 mg/g), (1.89 ± 0.2 mg/g) and (0.58 ± 0.05 mg/g), respectively, followed by toxins-treated samples as compared to the control. The results concluded that A. alternata mostly affects the nutritional values of tomato fruits due to the combined effect of the toxins.

Effects of Supplemental Lighting within the Canopy at Different Developing Stages on Tomato Yield and Quality of Single-Truss Tomato Plants Grown at High Density

The single truss tomato production system (STTPS) was used to grow tomato plants at a density of 14.3 plants·m−2 for increasing the tomato yield in Japan. We applied supplemental lighting within the canopy at different tomato development stages to identify the most sensitive stage at which supplemental lighting will most effectively increase yield and quality of tomato fruits. Fluorescent lamps were used to supply intra-canopy lighting to tomato plants (5:00–21:00) during the stages of anthesis (stage 1), rapid fruit development (stage 2), fruit ripening (stage 3), and from initial anthesis to red-ripe fruit (whole stage), respectively. Supplemental lighting applied to tomato plants during stage 2 and whole stage significantly increased the yield and sugar content of tomato fruits. Moreover, the contribution of supplemental lighting to the daily increase of tomato yield was highest at stage 2. The increase of fruit fresh weight and amount of supplemental lighting showed positive linear relationship. Supplemental lighting did not affect the ascorbic acid content of tomato fruits, fruit number per plant, and plant shoot weight among all the treatments. Thus, based on economic advantage, the use of supplemental lighting during the rapid fruit development stage of tomato plants under STTPS was most efficient.

INFLUENCE OF NITROGEN AND SALINITY LEVELS ON THE FRUIT YIELD AND CHEMICAL COMPOSITION OF TOMATO IN A HYDROPONIC CULTURE

Tomato seedlings were transferred to continuously, aerated plastic containers. Treatments consisted of three nitrogen (N) levels [0, 1.5, and 3% as ammonium chloride (NH4Cl) and ammonium phosphate (NH4H2PO4) 2:1 w/w] and three salinity levels (0, 30, and 60 mM using sodium chloride (NaCl) and calcium chloride (CaCl2)]. Results indicated significant positive and negative responses in fruits fresh weight to nitrogen and salinity treatments, respectively. Number of fruits and root length decreased at high salinity level. Phosphorus (P) content was highest in fruits and lowest in roots. Fruit P uptake decreased with salinity applications in N controls. At low salinity levels, N application mitigated the salinity detrimental effects; however, such an effect was not observed at the high salinity level. Nitrogen application significantly decreased iron, zinc, copper, and manganese concentration and uptake. Application of nitrogen and salinity levels significantly increased the citric acid content of tomato fruits. Vitamin C content of fruits was neither influenced by nitrogen nor by salinity.

RNA interference of a mitochondrial APX gene improves vitamin C accumulation in tomato fruit

Reduced l-ascorbic acid can be oxidized by ascorbate peroxidase (APX) in ascorbate metabolism pathway. In present study, a mitochondrial APX (mitAPX) was cloned and suppressed by RNA interference in tomato via Agrobacterium-mediated transformation. The existence of the RNA interference T-DNA in transformed plants and their progenies were confirmed by polymerase chain reaction amplification and Southern blotting. Decreased mitAPX expression in homozygous transgenic lines was detected by semi-quantitative reverse transcriptase-polymerase chain reaction, accompanied by decreasing cytosolic APX activity by 0.4- to 0.8-fold of the untransformed control. The mitochondrial APX enzyme activity in RNAi lines decreased to 29–45% of the wild type plants. The down-regulated mitAPX expression and APX enzyme activity lead to 1.4- to 2.2-fold increase in ascorbic acid content in tomato fruits compared with wild-type control. The APX expression and APX enzyme activity were found to be correlated with increase in the amount of ascorbic acid in tomato fruits. This report demonstrates the modulation of ascorbic acid metabolic pathway by RNA interference method, and provides a feasible approach to improve ascorbic acid content in horticultural plants by suppressing genes related to ascorbic acid metabolism.

The Effect of Natural Light on Changes in Antioxidant Content and Color Parameters of Vine-ripened Tomato (Solanum lycopersicum L.) Fruits

During the vine ripening of tomato fruits (Solanum lycopersicum L.), the change in antioxidant content and color was studied under two different solar exposures. An experiment was carried out in 2008 and 2009 to determine how color evolution, surface temperature, and antioxidant content of tomato fruits were influenced by fruit position and exposure on trellised tomato plants. Trellised rows were oriented so that non-shaded fruits were subjected to full solar irradiation from 0900 hr to 1600 hr, whereas shaded fruits were completely shaded during the same time period. A significant difference (P = 0.001) between fruit surface temperatures of shaded or non-shaded fruits was observed. The more direct solar irradiation the fruits were exposed to, the higher the fruit surface temperatures increased. At 1400 hr, only the average temperature of non-shaded fruits was significantly higher (7.0 and 9.3 °C in 2008 and 2009, respectively) than the air temperature. At the end of the ripening process, color change of non-shaded fruits showed significantly higher CIELab hue compared with shaded fruits. A close negative correlation (R2 = 0.51) was detected between the hue color parameters and the cumulative fruit surface–air temperature difference of non-shaded fruits, but in the case of shaded fruits, there was only a weak (R2 = 0.29) correlation. Solar exposure had a great effect on the antioxidant content of tomato fruits. A higher fruit surface temperature resulted in significantly less lycopene and more polyphenols and ascorbic acid content in tomato fruits.

The ascorbic acid content of tomato fruits is associated with the expression of genes involved in pectin degradation

BackgroundHigh levels of ascorbic acid (AsA) in tomato fruits provide health benefits for humans and also play an important role in several aspects of plant life. Although AsA metabolism has been characterized in detail, the genetic mechanisms controlling AsA accumulation in tomatoes are poorly understood. The transcriptional control of AsA levels in fruits can be investigated by combining the advanced genetic and genomic resources currently available for tomato. A comparative transcriptomic analysis of fruit tissues was carried out on an introgression line containing a QTL promoting AsA accumulation in the fruit, using a parental cultivar with lower AsA levels as a reference.ResultsIntrogression line IL 12-4 (S. pennellii in a S. lycopersicum background) was selected for transcriptomic analysis because it maintained differences in AsA levels compared to the parental genotypes M82 and S. pennellii over three consecutive trials. Comparative microarray analysis of IL 12-4 and M82 fruits over a 2-year period allowed 253 differentially-expressed genes to be identified, suggesting that AsA accumulation in IL 12-4 may be caused by a combination of increased metabolic flux and reduced utilization of AsA. In particular, the upregulation of a pectinesterase and two polygalacturonases suggests that AsA accumulation in IL12-4 fruit is mainly achieved by increasing flux through the L-galactonic acid pathway, which is driven by pectin degradation and may be triggered by ethylene.ConclusionsBased on functional annotation, gene ontology classification and hierarchical clustering, a subset of the 253 differentially-expressed transcripts was used to develop a model to explain the higher AsA content in IL 12-4 fruits in terms of metabolic flux, precursor availability, demand for antioxidants, abundance of reactive oxygen species and ethylene signaling.

Changes in Phenolic Acid Content During Alternaria alternata Infection in Tomato Fruit

AbstractPhenolic acids are components of the plant defence system; however few studies had been done with fruits. The objective of this experiment was to elucidate the changes in phenolic acid content in tomato fruits in response to pathogenic attack. Tomato fruit ‘Pinto’ was inoculated with spores of Alternaria alternata and stored for 10 days at 25°C and 90–92% of relative humidity. Sampling of epicarp and mesocarp tissues of control and infected tomato fruits were done every 2 days. Phenolic acids were extracted from each tissue and identified by HPLC coupled to a mass spectrometer. Quantification was done based in standard curves. In vitro evaluation of the phenolic acid effect either one‐by‐one and in a mixture of phenolic acids (MPA) over A. alternata spore germination was done with 25, 50, 100, 200 and 500 mm. It was found caffeic, chlorogenic and vanillic acids in both epicarp and mesocarp tomato tissues before the beginning of the experiment. Infected tomato fruits showed significantly higher concentrations of vanillic acid in the epicarp, only. Chlorogenic acid and the MPA inhibit spore germination by 30%, whereas caffeic acid and vanillic acid inhibit 16% at 500 mm. It was concluded that chlorogenic, vanillic and caffeic acids are phytoanticipins in tomato fruit. The concentration of vanillic acid also increases in tomato fruit epicarp as part of the defence system during a pathogenic attack.

Changes in Carotenoid and Ascorbic Acid Contents in Fruits of Different Tomato Genotypes Related to the Depletion of UV-B Radiation

The aim of the present study was to investigate if the depletion of UV-B radiation affected the most representative carotenoids as well as the ascorbic acid content in tomato fruits, harvested at both breaker and firm red stages. To do this, three tomato genotypes, DRW 5981, HP 1, and Esperanza, were grown inside a greenhouse either covered with polyethylene transparent to UV-B or depleted of UV-B by a special covering film. The antioxidant properties of the fruits were evaluated on the water-insoluble fractions according to the ABTS method. UV-B effect on antioxidant activity was negligible in DRW and HP 1 genotypes, whereas it was detrimental in Esperanza at both ripening stages. This genotype seems to have a negligible capability of accumulating carotenoids and a great susceptibility to detrimental effects of UV-B; conversely, the DRW genotype shows high carotenoid levels under sunlight conditions and a further promotion by UV-B. On the other hand, the HP 1 mutant displays an intermediate behavior and represents the only genotype favored by UV-B with respect to ascorbic acid accumulation.

Influence of potassium and calcium on acid content of tomato fruits in sand culture

The effects of two levels each of potassium and calcium in factorial combination on acidity of tomato fruits and leaves were studied, using Fukuju No. 2 variety in sand culture. In the next, a study was made to investigate whether acidity of fruits was affected by the restraining of potassium supply for the different stages of growth period.1. High level of potassium in the solution induced the increase of the titratable, total and combined acidities, and potassium content in the water extract of whole fruits. On the other hand, high level of calcium decreased the titratable, total and combined acidities, and potassium content, only when combined with high level of potassium. The effect of calcium was less than that of potassium. The titratable acidity made up about 60% of total acidity, regardless of potassium or calcium treatments. In case the fruits were separated into gelatinous pulp and outer wall, acidities and potassium content in both tissues were affected similarly to those in whole fruits by these treatments.2. Period between the flowering stage of the first truss and the coloring stage of the sixth truss was divided into two parts, at the flowering stage of the sixth truss. When potassium level in the solution was lowered during the period between the flowering stage of the first truss and that of the sixth truss, reduction of the titratable, total and combined acidities was induced in the fruits on the second to the sixth trusses. In case that potassium supply was withheld after the flowering stage of the sixth truss, the acidities of fruits on the third to the sixth trusses were significantly decreased. Accordingly, the acidities of fruits were affected by the potassium level in the solution for almost all their developmental stages, except for the fruits on the first truss which had higher acidities and showed no differences of acidities by the treatments.Moreover, decreased acidities were accompanied by the lower contents of potassium in fruits. Titratable and total acidities in fruits were very closely correlated with the potassium content, with correlation coefficients +0.91 and +0.96, respectively. They were also correlated with combined acidity, correlation coefficients being +0.92 and +0.97, respectively.3. In tomato leaves, content of malic acid was 2-3 times as high as that of citric acid, contrary to fruits in which citric acid was a major organic acid. High level of potassium in the solution increased the titratable, total and combined acidities in the young leaves, while it decreased these acidities in the old leaves. High level of calcium tended to decrease the titratable, total and combined acidities in leaves of both ages, but much more in the old leaves. The changes of malic and citric acid contents induced by potassium or calcium treatments were similar to that of the total acidity. The titratable acidity made up about 16% of total acidity in the young leaves, and about 10% in the old, irrespective of the treatments.

Further Studies on the Relationship between Illumination and the Ascorbic Acid Content of Tomato Fruits

Further Studies on the Relationship between Illumination and the Ascorbic Acid Content of Tomato Fruits

The Effect of Certain Conditions Upon the Acidity of Tomato Fruits

In a recent communication the senior author (4) has referred to the possibility that the acid content of tomato fruits ripened at a temperature of 300C., or above, may be related in some way to the failure of lycopersicin development at that temperature. It was determined that the total acidity for green, ripening, and ripe fruits, grown under the same conditions, is unexpectedly uniform, amounting to .57 to .58 per cent citric acid. The fruits just referred to were of the same variety picked at the same time. The tests of acid content of incubated fruits were made later in the season, and these indicated a lower acidity than that of normally green or ripe fruits. At that time the requisite material was obtained from the Department of Horticulture, Cornell University. During the past summer several varieties of tomatoes were grown in the Missouri Botanical Garden in order to furnish material for further pigment studies, and incidentally this material has enabled us to determine with greater care the acid content of tomato fruits, especially of different varieties, and likewise the comparative acidity of fruits direct from the field and of those of the same picking incubated for various intervals. The tests included below were made by pulping thoroughly a weighed quantity of the tissue (15 gm.), diluting with 150 cc. distilled water, employing for each titration 25 cc. of this solution diluted with distilled water to 50 cc., and titrating with n/10 NaOH, using phenolphthalein as indicator. Not less than two titrations were made in any case, and these were from one or more samples of tissue. The accompanying table