Structural changes,chemical composition and antioxidant activity of cherry tomato fruits (cv. Micro‐Tom) stored under optimal and chilling conditions

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     

Variations in tomato (Lycopersicon esculentum) cultivars grown under heat stress

Tomato (Lycopersicon esculentum Mill) is considered as important and economic agricultural crop all over the world. For improving the yield and yield attributes, varieties are often produced and evaluated under different growth condition. In the study presented morphological (growth and yield parameters), biochemical (oil, moisture content and radical scavenging activity) and molecular diversity (RAPD and ISSR) of eleven freshmarket tomato (L. esculentum) cultivars (Aledo VF, Carmeuco 201M, Castle-rock, Falkon, Money Maker, Peto 86, Red Star, Super Marmande, Super Queen, Super Strain B, and UC97–3) were analyzed under heat stress in Egypt to assist breeders in selecting heat tolerant cultivars and nutritional quality. Cultivars Aledo, Peto86 and Red Star were found to have the most vigorous growth habit, while cv. Super Queen has the most significant average fruit weight, yield/plant and total yield/m² under heat stress. For nutritional quality cv. Super marmande and cv. Aledo showed the highest oil content while cv. Aledo and cv. Money Maker showed the highest radical scavenging activities (RSA). Molecular polymorphism among cultivars was detected using two molecular markers systems, RAPD (random amplified polymorphic DNA) and ISSR (inter-simple sequence repeat), providing further facilities for molecular comparison.     

Grafting to improve nitrogen‐use efficiency traits in tobacco plants

Nitrate plays a major role in the yield and quality of tobacco plants. This work explored the nitrogen‐use efficiency (NUE) and how it can be affected by grafting. Two experiments were designed: in the first, using six commercial tobacco cultivars, the best cultivar for the NUE was selected and analysed for foliar NO₃^? content, total N, nicotine and nitrate reductase (NR) activity. The results showed the cultivar H‐20 to have the best performance on NUE. It was further featured by the highest NR activity and total N and by the lowest NO₃^? and nicotine content, resulting in the highest foliar leaf biomass production and quality. In the second experiment it was tested whether the cultivar H‐20 could be used as rootstock to improve the NUE of the other cultivars under study. The results showed that the grafted plants had improved the NO₃^? assimilation with respect to non‐grafted plants. Hence grafting tobacco plants can be used as a quick and effective method to improve NUE, which has beneficial implications for human health and for a reduction in environmental pollution. Copyright © 2006 Society of Chemical Industry     

Biosynthesis of flavour compounds in Muscat Gordo Blanco grape berries

Inflorescences of the floral grapevine cv Muscat Gordo Blanco (syn. Muscat of Alexandria) were grown on their own shoots until maturity or, after approach-grafting before flowering, on the shoots of the non-floral cv Shiraz (in the glasshouse) or Sultana (in the field). The flavour compounds of their berries were compared with those in the berries of the non-floral cultivars, grown either on their own shoots or, by grafting, on the shoots of the Muscat cultivar. For this, monoterpene glycosides were isolated from the fruits, enzymatically hydrolysed and the released monoterpene aglycons were liquid-liquid extracted and analysed by GC-MS. The Muscat Gordo Blanco berries of ungrafted bunches and of bunches grafted onto Shiraz or Sultana vines yielded fruit with monoterpenes at levels and types typical of this floral grape variety. The berries of Shiraz and Sultana bunches contained only low levels of monoterpene glycosides both on their own shoots or grafted onto Muscat shoots. The lack of difference between flavour compounds in grafted and non-grafted fruit indicate that aroma compounds are synthesised in the berries and that their presence is determined by the genotype of the grape bunch rather than by the genotype of the vine.     

Difference in volatile composition between the pericarp tissue and inner tissue of tomato (Solanum lycopersicum) fruit

Numerous studies have reported the volatile profiles in the whole fruit or pericarp tissue of tomato (Solanum lycopersicum) fruit; however, information is limited on the volatile composition in the inner tissue and its contribution to tomato aroma. For this, the pericarps and inner tissues of “Moneymaker,” “UglyRipe,” and “FL 47” fruits were separated before volatile analysis. Result showed that the volatile profiles were quite similar between the pericarp and inner tissue, suggesting the inner tissues also have a contribution to overall aroma quality. Besides the difference in volatile profile among cultivars, a higher concentration of alcohols was observed in the inner tissues of tomato fruit in comparison with that in the pericarp, which was associated with higher levels of 3‐methylbutanal, 2‐methylbutanal, 3‐methylbutanol, and 2‐methylbutanol in the inner tissue. These results also imply that different sampling methods might impact tomato aroma quality, which needs further verification via sensory penal.

Practical applications

The information on the volatile profile in the inner tissue and its contribution to tomato aroma is still rudimentary. In this study, the pericarp and inner tissue were separated from three tomato cultivars of different genetic background, and the volatile compositions were analyzed with HS‐SPME‐GC‐MS. Result showed that the volatile compositions were quite similar between the pericarp and inner tissue, suggesting that the inner tissues also have a contribution to overall aroma quality. Besides, a higher concentration of alcohols was observed in the inner tissues of tomato fruit in comparison with that in the pericarp, which was associated with higher levels of 3‐methylbutanal, 2‐methylbutanal, 3‐methylbutanol, and 2‐methylbutanol in the inner tissue. This study will provide the researchers and consumers some useful information on volatile composition in the inner tissue, its contribution to tomato aroma, and the impact of different sampling methods on the volatile profile.     

植物生长调节剂对番茄产量和品质的影响及膳食摄入风险评估

目的 明确不同植物生长调节剂赤霉酸、2,4-滴和噻苯隆对番茄产量和品质的影响, 掌握它们在番茄中的残留情况以及对不同人群的膳食摄入风险。方法 在番茄花期施用植物生长调节剂赤霉酸、2,4滴和噻苯隆各1次, 正常成熟期采摘, 分析不同植物生长调节剂处理对番茄产量和品质的影响及残留情况, 整合两年的番茄市场监测数据, 利用农药残留专家联席会议农药急性膳食风险摄入量计算法和@risk定量风险评估软件, 对番茄中3种植物生长调节剂残留在我国不同人群中的膳食摄入风险进行评估。结果 3种植物生长调节剂均可显著提高番茄的产量和品质(P<0.05), 其中噻苯隆效果最显著, 且产品中相应植物生长调节剂残留量较低, 平均值0.0042~0.0058 mg/kg; 3种植物生长调节剂在市场监测的300个样品中均有检出, 总检出率9.33%, 检出平均值0.034~0.069 mg/kg; 番茄中赤霉酸、2,4-滴和噻苯隆残留的短期膳食摄入量在0.00104~ 0.00658 mg/kg bw/d, 仅占相应每日急性参考剂量的0.60%~7.24%, 急性风险较低。结论 在番茄花期施用赤霉酸、2,4-滴或噻苯隆可显著提高番茄的产量和品质, 且产品中残留量低, 番茄中3种植调剂残留在不同人群中的膳食摄入风险均很低, 在可接受范围内。     

Optimisation of biological and physical parameters for lycopene supercritical CO2 extraction from ordinary and high‐pigment tomato cultivars

BACKGROUND: Lycopene is used for several industrial applications. Supercritical CO₂ (SC‐CO₂) extraction from red‐ripe tomato fruits is an excellent technique to replace the use of harmful solvents. In this study, starting from red‐ripe tomatoes of ordinary and high‐lycopene cultivars, the effect of different agronomical and technical aspects on lycopene content, stability and yield was evaluated throughout the production process from fresh tomatoes to the final SC‐CO₂‐extracted oleoresin containing lycopene. RESULTS: Red‐ripe tomato cultivars differed in their lycopene content. Irrigation excess or deficit caused an increase in the amount of lycopene in the fruits. Fresh tomatoes were processed into a lyophilised matrix suitable for SC‐CO₂ extraction, which could be stored for more than 6 months at ? 20 °C without lycopene loss. Under the optimal extraction conditions, efficiencies of up to 80% were achieved, but the recovery of lycopene in the extracted oleoresin was very low (～24%). Co‐extraction of the tomato matrix mixed with a lipid co‐matrix allowed the recovery of ～90% of lycopene in the oleoresin. Using the high‐lycopene cultivars, the yield of total extracted lycopene increased by ～60% with respect to the ordinary cultivars. Lipids and other biologically active molecules were present in the oleoresin. CONCLUSION: A method for extracting, from a tomato matrix, a natural and solvent‐free oleoresin containing lycopene dissolved in a highly unsaturated vegetable oil has been described. The oleoresin represents an excellent product for testing on cancer and cardiovascular disease prevention. Copyright © 2010 Society of Chemical Industry     

LeMAPK4 participated in cold‐induced ethylene production in tomato fruit

BACKGROUND: Mitogen‐activated protein kinase (MAPK, EC 2.7.11.24) cascade from several plant species has been shown to be activated during response to abiotic stress. Ethylene plays an important role in fruit tolerance to environmental stress. However, the mechanisms by which MAPK regulates defence systems in fruit and the relationship between MAPK and ethylene remain to be determined. RESULTS: MAPK inhibitor significantly decreased the chilling tolerance of tomato (Lycopersicon esculentum cv. Lichun) fruit during cold storage. Moreover, decreases in ethylene content, LeACS2 expression and activities of 1‐aminocyclopropane‐1‐carboxylic acid (ACC) synthase (ACS, EC 4.4.1.14) and ACC oxidase (ACO, EC 1.14.17.4) due to MAPK inhibitor occurred within 24 h after cold treatment. Upon treatment with cold and ethephon, the ethylene content, activities of ACS and ACO and expression of LeACS2, LeACO1 and LeMAPK4 increased. CONCLUSION: The results showed the regulation of MAPK in ethylene biosynthesis to protect tomato fruit from cold stress. In addition, the participation of LeMAPK4 in cold‐induced ethylene biosynthesis in tomato fruit was indicated. © 2013 Society of Chemical Industry     

PHYSICOCHEMICAL PROPERTIES OF FOUR TOMATO CULTIVARS GROWN IN NIGERIA

The physicochemical characteristics of tomato fruits from three commercial cultivars available in the local market were compared with a Wild cultivar. The results showed that the Ibadan‐Local and Wild cultivars had a higher fruit yield than Ife‐1 and Roma‐VF cultivars. The Wild cultivar has a high skin and seed content. The shape of the fruits varied from spherical to pear‐like. Physicochemical properties such as specific gravity, pH, titratable acidity, ash and refractive index did not vary significantly while total solids, longitudinal (stem→blossom end) and cross‐sectional diameters (transverse diameter), vitamin C and reducing sugars were significantly different (P > 0.05) among the cultivars investigated. The results showed that the Wild cultivar has attributes (i.e., physicochemical characteristics) comparable to commercial cultivars to recommend it to breeders for cultivation.     

Environmental conditions in relation to stress in cherry tomato fruits in two experimental Mediterranean greenhouses

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     

Effect of sea water on biochemical properties of fruit of tomato (Lycopersicon esculentum Mill.) genotypes differing for ethylene production

BACKGROUND: Three near‐isogenic lines of cv. Gimar differing in ethylene production were used to evaluate the influence of salinity on fruit quality. Plants were grown in rockwool culture and were irrigated with nutrient solution with electrical conductivities (ECs) of 3 and 8 mS cm^?1, which corresponded to 0 and 10% of sea water. For fruits picked at ‘red‐turning’ and ‘red‐ripe’ stages physico‐chemical parameters, ethylene, ascorbate and organic acid content, and cell reductive power were analysed. RESULTS: The same response was observed in all genotypes: the higher salinity growth solution increased dry matter content, total soluble solids (TSS) and titratable acidity but reduced crop yield. Ascorbic acid and also organic acid contents showed a greater accumulation with ripening in the mutant genotypes: this might be due to a slowing of ripening. Our data confirm the lack of any relationship between the larger accumulation of TSS and ethylene production in the fruits of salt‐treated plants. CONCLUSION: These findings suggest that although salinity (10% sea water) reduces fruit yield, it does not have a negative effect on quality. So, it seems possible that controlled use of diluted sea water, combined with suitable tomato genotypes might represent a valid alternative to fresh irrigation water. Copyright © 2007 Society of Chemical Industry     

基于烟茄嫁接的低烟碱烟草烟叶化学成分变化

为探索通过嫁接技术有效降低烟叶烟碱含量的技术,以茄子为砧木,云烟87为接穗,采用盆栽试验研究了烟茄嫁接生产低烟碱烟叶的可行性和烟叶化学成分的变化。试验共设烟/烟、烟/茄不培土、烟/茄培土等3个处理。结果表明:烟茄嫁接,烟株植物学特征和农艺性状未显著改变,烟叶烟碱含量降至极低水平,鲜烟叶中烟碱含量低至0.08%,烤后烟烟叶烟碱含量低至0.10%,比对照降低95%,假木贼碱和降烟碱含量也有所降低,但假木贼碱的下降比例较小,表明假木贼碱在叶片中有一定的合成能力,新烟草碱在鲜烟叶和烤后烟中均未检测到。在接穗底部培土诱发了不定根产生,能够促进生物碱的合成,导致烟/茄培土的烟碱含量比烟/茄不培土明显升高;烟茄嫁接的烟叶叶绿素含量显著高于对照,成熟较慢,蛋白质、淀粉、总氮含量较高,总糖、还原糖含量降低。本研究为通过农业措施选择性降低和调节烟叶烟碱含量提供了新的途径。      

Antioxidant content and ascorbate metabolism in cherry tomato exocarp in relation to temperature and solar radiation

Considering the economic importance of the tomato and its nutritional benefits to human health, a study was made of how two different environmental factors (temperature and overall solar radiation) influence the nutritional quality of cherry tomatoes during the plant full production cycle. Solanum lycopersicum L. cv. Naomi plants were grown in an experimental greenhouse. Three fruit samples were taken over the full production period: first sampling at the beginning of harvest (7 January 2004), second at mid‐harvest (22 March 2004) and third at harvest end (30 May 2004). Values for temperature and overall accumulated solar radiation peaked at a maximum in the third sampling, without lowering the yield with respect to previous samplings. Regarding the antioxidant activity in the exocarp fraction of the cherry tomato fruits, the results showed that the increase in temperature and solar radiation diminished the lycopene and β‐carotene contents in the third sampling, inducing defective pigmentation (sunscald). This occurred simultaneously with an increase in lipid peroxidation during the third sampling, quantified as lipoxygenase activity and malondialdehyde content. Finally, in relation to ascorbate metabolism, the higher temperatures and stronger solar radiation at the third sampling increased the oxidation of reduced ascorbate (AsA) due to intensified ascorbate peroxidase (APX) and ascorbate oxidase (AO) activities and a depression of the enzyme dehydroascorbate reductase (DHAR). In conclusion, the results indicate that despite the oxidation of AsA by APX and AO, the minimal regeneration of the latter, together with the greater lipid peroxidation with increasing temperature and solar radiation in the greenhouse, explained the lower content of antioxidants in the exocarp and therefore the loss of nutritional quality of the cherry tomato fruits grown under these conditions. Copyright © 2006 Society of Chemical Industry     

The effects of 1-methylcyclopropene treatment on the shelf life and quality of cherry tomato (Lycopersicon esculentum var. cerasiforme) fruit

The use of 1‐methylcyclopropene (1‐MCP) to extend the shelf life of cherry tomato (Lycopersicon esculentum var. cerasiforme) was investigated. Higher concentrations of 1‐MCP delayed the ethylene induced climacteric peaks in mature green (MG) and breaker (BR) fruits. Thirteen days after treatment, control fruits were 55% as firm as fruit treated with 0.11 μL L^?1 1‐MCP. The initiation of fruit softening, chlorophyll degradation and accumulation of lycopene and carotenoids was delayed in treated fruits. Higher 1‐MCP concentrations inhibited the accumulation of lycopene and carotene such that the colour of the fruit did not reach that of control fruit. Treatment of MG cherry tomatoes with 1‐MCP enhanced shelf life optimally, while treatment of BR fruits was beneficial where full colour and high content of lycopene and carotenoids is important. Differentiation of the different stages of ripening before application of 1‐MCP is needed in order to succeed in accomplishing different postharvest objectives.     

Protein and enzyme changes in tomato fruit in relation to blotchy ripening and potassium nutrition.

The effects of potasium deficiency and blotchy ripening in tomato fruit on some nitrogenous constituents, especially the proteins, have been investigated. The distribution of nitrogen in normal and potassium-deficient fruit of the cherry tomato Lycopersicon pimpinellifolium was examined and compared with that from potassiumdeficient and blotchy ripened fruit of a cultivated variety (L. esculentum, cv. Moneymaker). The protein fraction from cv. Amberley Cross was analysed in detail using disc gel electrophoresis. Changes induced by potassium deficiency in the general protein pattern and on a wide range of enzymes active in ripening were compared with the effects brought about by blotchy ripening. The distribution of protein components and isoenzymes in low potassium fruit was to a large extent similar to that of normal tissue at an earlier stage of development, whereas the alterations in blotchy tissue appeared to be of a random nature.     

嫁接对烤烟烟碱和钾含量的影响

为研究嫁接对烤烟烟碱和钾含量的影响,选用烟碱和钾积累效率不同的基因型进行嫁接,并对烤后烟叶的烟碱和钾含量进行测定。试验结果表明,不同烤烟基因型烟碱和钾积累效率差异显著;自身嫁接对烟碱和钾积累的影响不显著;采用烟碱和钾积累效率不同的烤烟基因型进行嫁接,以烟碱和钾积累效率高的基因型为砧木可以提高烟碱和钾积累效率低的接穗烟叶的烟碱和钾含量,使用烟碱和钾积累效率低的基因型为砧木可以降低烟碱和钾积累效率高的接穗烟叶的烟碱和钾含量;多数嫁接组合烤后烟叶的烟碱和钾含量处于砧木和接穗之间,呈现趋中性,部分嫁接组合表现出超亲性状。嫁接技术可以用于调节烤烟叶片中烟碱和钾的含量。      

Effect of conventional and organic production systems on the yield and quality of field tomato cultivars grown in Tunisia

BACKGROUND: The agricultural production system and cultivation practices are critical factors in determining yield and food nutritional quality. Controversy remains regarding whether or not organic foods have a nutritional advantage when compared with their conventionally produced counterparts. In this study the effect of conventional and organic production systems on yield, physicochemical and nutritional properties of four field tomato cultivars (Perfectpeel, Rio Grande, Hypeel 108 and Firenze) was determined. In the organic system, different fertiliser combination treatments were used. RESULTS: When production system data were combined, marketable yield was not affected by cultivar. When averaged across cultivars, organic yield was about 63% of conventional yield. The production system affected fruit soluble solids, pH, titratable acidity and firmness only in some cultivars. However, no effect was found on lycopene and total phenolics in all cultivars. In the organic system, fertiliser combination treatments affected tomato yield of Rio Grande and fruit quality of Firenze and Hypeel 108. A general trend of higher quality data was obtained by using mixed compost C2 combined with its extract and codahumus 20. CONCLUSION: The production system affects tomato yield and some fruit quality attributes. The effect on fruit quality varies among cultivars, thus highlighting the need to use a range of varieties in this kind of study. Copyright © 2009 Society of Chemical Industry     

PURIFICATION AND KINETIC CHARACTERIZATION OF POLYPHENOL OXIDASE FROM TOMATO FRUITS (LYCOPERSICON ESCULENTUM CV. MUCHAMIEL)

Two different polyphenol oxidase (PPO) fractions, soluble and particulate, were purified from unripe tomato fruits (Lycopersicon esculentum M. cv. Muchamiel). The PPO present in the soluble fraction was purified fivefold with a 43.5% yield after ammonium sulfate fractionation. PPO in the particulate was purified 4.56‐fold with a 23% yield using the nonionic detergent Triton X‐114. A strong correlation between tomato fruit PPO activity and the physiological disorder blossom‐end rot (BER) was found, with a large increase of the PPO activity in the particulate fraction. Kinetic characterization, including kinetic parameters, pH and temperature profiles, substrate specificity and inhibitors showed similarities in both the soluble and the particulate enzyme(s). However, thermal stability of the particulate enzyme was significantly higher than stability of the soluble PPO, thus indicating possible structural differences. Cupric ions were activators, probably because of their ability to reactivate PPO partly denatured during purification.     

Investigation of UV-A light irradiation on tomato fruit injury during storage

We investigated the effect of UV-A light (wavelength 315 to 400 nm) irradiation during storage on tomato fruit injury. Mature green tomato fruit (cv. House Momotaro) were exposed to UV-A at doses of 0.02, 0.5, and 2 mW x cm(-2) throughout storage at 25 degrees C. The physiological disorders, fruit ripening, superoxide dismutase (SOD) activity, and increases in fruit temperature were evaluated. All UV-A-irradiated and nonirradiated tomatoes developed a full red color at the same time (2 weeks). Irradiated fruit ripened normally, and exposure of tomato fruits to UV-A did not lead to the discoloration of ripe tomato fruit at any dosage. The fruit temperature did not increase in response to various UV-A light doses and exposure times, and none of the UV-irradiated fruits showed physiological disorders (dull skin blemish, pitting). The SOD activity of UV-A-irradiated fruit exposed to the various UV-A doses did not significantly (P = 0.05) differ from that of fruit stored in dark conditions. The SOD results imply that UV-A light might not induce reactive oxygen species in UV-A-irradiated fruit.