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Tomato (Solanum lycopersicon L.) fruit is rich in various nutrients, vitamins and health-promoting molecules. Fresh tomatoes are an important part of the Mediterranean gastronomy, and their consumption is thought to contribute substantially to the reduced incidence of some chronic diseases in the Mediterranean populations in comparison with those of other world areas. Unfortunately, tomato fruit is highly perishable, resulting in important economic losses and posing a challenge to storage, logistic and supply management. This review summarizes the current knowledge on some important health-promoting and eating quality traits of tomato fruits after harvest and highlights the existence of substantial cultivar-to-cultivar variation in the postharvest evolution of the considered traits according to maturity stage at harvest and in response to postharvest manipulations. It also suggests the need for adapting postharvest procedures to the characteristics of each particular genotype to preserve the optimal quality of the fresh product.

Introgression of spontaneous or induced mutations has been used to increase the levels and diversify the profile of antioxidants in many fruits including tomato. The high-pigment (hp) and old-gold ...

Tomato (Solanum lycopersicon L.) fruit is rich in various nutrients, vitamins and health-promoting molecules. Fresh tomatoes are an important part of the Mediterranean gastronomy, and their consumption is thought to contribute substantially to the reduced incidence of some chronic diseases in the Mediterranean populations in comparison with those of other world areas. Unfortunately, tomato fruit is highly perishable, resulting in important economic losses and posing a challenge to storage, logistic and supply management. This review summarizes the current knowledge on some important health-promoting and eating quality traits of tomato fruits after harvest and highlights the existence of substantial cultivar-to-cultivar variation in the postharvest evolution of the considered traits according to maturity stage at harvest and in response to postharvest manipulations. It also suggests the need for adapting postharvest procedures to the characteristics of each particular genotype to preserve the optimal quality of the fresh product.

In this study, the antioxidant properties of two tomato cultivars Firenze and Rio Grande grown organically in an open-field under different combinations of organic fertilizer sources were investigated, lycopene, total phenols and flavonoids contents, as well as lipophilic, hydrophilic and total antioxidant activities were determined. Significant differences were found between tomato cvs in lycopene and antioxidant activity. Firenze cv showed higher lycopene, lipophilic, hydrophilic and total antioxidant activities when compared to cv Rio Grande. On the other hand, even though antioxidant activity was affected by the different organic fertilizer treatments, tomato bioactive compounds were not affected whatever the cv. LAA ranged from 123.8 μM Trolox/100 g fresh weight (fw) in cv Rio Grande to 153.4 μM Trolox/100 g fw in cv Firenze and was significantly correlated to lycopene ( r = 0.45; p

Biofortification is the development and/or selection of micronutrient/phytonutrient rich staple crops using efficient traditional breeding techniques or modern biotechnology tools. However, even if in some cases the use of transgenic approach is crucial, consumer concerns about genetically modified organisms is increasing, which shifts most of the efforts toward the use of naturally biofortified crops. The valorization of biofortified crops is of great importance since their differences with currently and ordinary grown cultivars is clearly visible in case of high-pigment and purple tomato and colored potatoes. It has been reported that the consumption of fruit and vegetables, rich in various phytochemicals, is associated with health benefits, such as lower risk of contracting chronic diseases as well as extended shelf life and marketability compared to currently grown cultivars. In this context, the existence of genetic variability in various crops particularly, tomato (high-pigment and purple tomato) and potato (colored potato), enables the development of new crop varieties with both satisfying agronomic traits and increased functional quality. The development of such crops will contribute to satisfy the demand of (1) growers for high-income nutrient-rich crops with increased shelf life, (2) processors for high-value-added processed products with increased marketability, and (3) consumers for nutrient-rich crops and processed products as well, which will increase the intake of various phytochemicals.

Changes in bioactive compounds and antioxidant activities of three commercial selections (Crimson sweet, Dumara and Giza) and two new selections (P503 and P403) of watermelon cultivars were investigated at four different fruit ripening stages (white, white-pink, pink and red-ripe). Lipophilic and hydrophilic antioxidant activities (LAA and HAA, respectively) were determined, and their correlations with total vitamin C, phenol, flavonoid, lycopene and β-carotene contents were studied. Ripening stage significantly influenced lycopene and β-carotene contents, as well as the LAA of all investigated watermelon cultivars. Good correlations between LAA and lycopene and β-carotene contents were found using the TEAC assay. At the red-ripe stage of ripeness, P503 cultivar showed the highest amount of lycopene (64.5 mg kg−1 fw), whereas Dumara cultivar showed the highest level of β-carotene (2.1 mg kg−1 fw). Giza cultivar scored first for total phenol (260.1 mg GAE kg−1 fw), flavonoid (260.0 mg RE kg−1 fw) and total vitamin C (204.0 mg kg−1 fw) contents. Although, the HAA of the studied watermelon cultivars was significantly influenced by the ripening stages, it only correlated to the amount of total phenols and flavonoids. These data confirm the important role played by genetic background and ripening stage in determining antioxidant potential of watermelon fruits. They also give valuable insights into the synthesis and accumulation of bioactive compounds in such fruits, and furthermore move us closer to identifying the harvesting period with the highest antioxidant potential.

Changes in bioactive compounds and antioxidant activities of an ordinary (Rio Grande) and three high-lycopene (HLY 13, HLY 18 and Lyco 2) tomato cultivars (cvs) were studied at four different fruit ripening stages (green, green-orange, orange-red and red-ripe). Lipophilic and hydrophilic antioxidant activities (LAA and HAA, respectively) were determined and their correlations with ascorbic acid (AsA), dehydroascorbic acid (DHA), total vitamin C (AsA + DHA), phenolics, flavonoids, total carotenoid and lycopene contents were investigated. The stage of ripening significantly influenced the total carotenoid and lycopene contents, as well as the LAA of all investigated tomato cvs. Good correlations between LAA and both total carotenoid and lycopene contents were found using either the TEAC assay or the FRAP assay. During ripening, cvs HLY 13 and HLY 18 exhibited more than 100% higher total carotenoid and lycopene contents compared to Rio Grande. At the red-ripe stage, cv HLY 18 accumulated the highest phenolic and flavonoid contents. However, Lyco 2 showed the highest levels of DHA and total vitamin C. Although, the HAA of studied tomato cvs were also significantly influenced by the ripening stages, HAA resulted correlated only to the levels of phenolics and flavonoids when the TEAC assay was used. However, using the FRAP assay, the HAA were well correlated to the total vitamin C and DHA contents.

In this study, the antioxidant components and of six high-lycopene (Lyco 1, Lyco 2, HLY 02, HLY 13, HLY 18 and Kalvert) and one ordinary (Donald) tomato cultivars (cvs) grown simultaneously in an open-field of the Southern Italy were investigated. Lycopene, β-carotene, lutein, total phenols, flavonoids, ascorbic acid (AsA), dehydroascorbic acid (DHA) and total vitamin C (AsA + DHA) contents, as well as hydrophilic and lipophilic antioxidant activities (HAA and LAA) were determined. Significant differences were detected among tomato cvs in all studied antioxidant components, as well as in the antioxidant activity of their hydrophilic and lipophilic fractions. High-lycopene tomato cvs showed higher lycopene, β-carotene, HAA and LAA when compared to cv Donald. Cv HLY 18 showed the highest lycopene and β-carotene content with 232.9 mg/kg fresh weight (fw) and 19.4 mg/kg fw, respectively. Except for Kalvert, high-lycopene tomato cvs also obtained higher total vitamin C levels, with cv HLY 13 top ranking with an average of 352.8 mg/kg fw. LAA ranged from 133.5 μM Trolox/100 g fw in cv Donald to 540.1 μM Trolox/100 g fw in cv Lyco 2 and was significantly correlated to lycopene (r = 0.53; p

The use of adequate organic fertilization is necessary to promote organic crop production. Organic nutrient sources including compost, manure, compost extract, and authorized fertilizers could be combined and used in order to achieve a balanced nutrient supply and an improved organic tomato yield and quality. The purpose of this study was to compare the effect of different organic fertilizer treatments on fruit yield and the physico-chemical properties of two field tomato cultivars. The three treatments used were CODA: codahumus 20; COMP: 40 t ha−1 of mixed compost (50% olive husk + 30% horse manure + 20% poultry manure) + mixed compost extract + codahumus 20; and MIX: 20 t ha−1 sheep manure + 20 t ha−1 mixed compost + mixed compost extract + codahumus 20. Total and marketable yields of the two tomato cultivars were greater for the COMP and MIX treatments compared to the CODA treatment. However, tomato physico-chemical properties were not affected by the different organic fertilizer treatments. Organic to...

This study investigates the antioxidant components [lycopene, total phenolics, total flavonoids, ascorbic acid (AsA) and dehydroascorbic acid (DHA)] as well as antioxidant activities of the hydrophilic and lipophilic fractions (AAHF and AALF) of peel, pulp and seed fractions isolated from red-ripe berries of the ordinary tomato cultivar Rio Grande and the two high-lycopene tomato breeding lines HLT-F61 and HLT-F62 simultaneously grown in an open-field of Northern Tunisia. Significant differences (p < 0.05) were found among cultivars for each trait studied. All fractions isolated from the red-ripe berries of HLT lines showed higher lycopene, total phenolics and total flavonoid contents, as well as higher AAHF and AALF, than those isolated from Rio Grande. Regardless of the fraction, HLT-F61 had the highest lycopene content (893.0 mg per kg fw, 280.0 mg per kg fw, and 47.5 mg per kg fw in peel, pulp and seed fractions, respectively) and total phenolics at least 2-fold and 3-fold higher than HLT-F62 and Rio Grande, respectively. Peel and seed fractions from HLT-F61 red-ripe tomato berries had the highest AsA content (345 mg per kg fw and 115 mg per kg fw, respectively), while no significant difference was found in the seed fraction between HLT-F62 and Rio Grande. The HLT-F62 pulp fraction showed the highest content of AsA (186 mg per kg fw) and DHA (151 mg per kg fw) among all the assayed cultivars. Except for the peel fraction, where HLT-F61 had similar AAHF values to HLT-F62, the high-lycopene line HLT-F61 showed higher AAHF values than HLT-F62 and Rio Grande. Regardless of the fraction, the highest AALF values were recorded in HLT-F61 berries. Thus, both HLT tomato lines are promising for the introduction, as advanced hybrids, in either fresh market or processing industry.

In order to identify the physiological and biochemical events leading to the negative effects of the presence of sucrose in culture medium on the photosynthetic capacity of plantlets cultivated in vitro, time course in photosynthesis, metabolite pool sizes, and ribulose-1,5-bisphosphate carboxylase (EC 4.1.1.39) activity were investigated in strawberry (Fragaria x ananassa Duch. cv. Kent) plantlets following their transfer to medium with or without sucrose. When the plantlets grown in medium without sucrose were transferred to a similar medium with 30 g liter−1 sucrose, their net photosynthesis decreased and their level of phosphorylated compounds increased with time. In addition, initial catalytic turnover, total catalytic turnover, and the activation state of ribulose-1,5-bisphosphate carboxylase decreased in these plantlets. Conversely, when the plantlets grown in medium with 30 g liter−1 sucrose were transferred to a similar medium without sucrose, their net photosynthesis slowly increased with time and their level of phosphorylated compounds slowly decreased. A slow increase with time of initial catalytic turnover, total catalytic turnover, and the activation state of ribulose-1,5-bisphosphate carboxylase was also observed in these plantlets. The results of the present paper suggest that the reduced photosynthetic capacity of strawberry plantlets cultivated in vitro in the presence of sucrose is the consequence of a reduction in the efficiency of ribulose-1,5-bisphosphate carboxylase/oxygenase due to its deactivation and the possible presence of putative inhibitors of carboxylation sites.

The potential for carbon fixation was investigated in in vitro strawberry (Fragaria × ananassa Duch. Kent) shoots 5, 10 and 28 d after transfer to a rooting medium. The activities of ribulose-1,5-bisphosphate carboxylase (Rubisco) and phosphoenolpyruvate carboxylase (PEPC) and the time course of 14CO2 fixation were investigated. Five days after transfer, Rubisco activity was low but was increased two-fold after 28 d. In contrast PEPC activity was highest at 5 d and declined to about 0.4-fold by day 28. The rate of 14CO2 fixation was similar at 5, 10 and 28 d after transfer. However, a more rapid incorporation of 14CO2 into amino acids was observed at 5 than at 10 or 28 d after transfer. These results suggest that strawberry shoots undergo a progressive transition from heterotrophic to autotrophic carbon fixation during their rooting and that PEPC plays an important role in sustaining carbon fixation and amino acid synthesis during the first few days after their transfer to rooting medium. Key words: In vitro culture, phosphoenolpyruvate carboxylase, ribulose-1,5-bisphosphate carboxylase

The uptake of 15NO3 - and 15NH4 + has been examined in 5-,10- and 28-day-old micropropagated strawberry (Fragaria x ananassa Duch. cv. Kent) shoots rooted in one-half strength Murashige and Skoog (MS) liquid medium on cellulose plugs (Sorbarods). The results indicated that the plantlets absorbed both NO3 - and NH4 + during the culture with a greater uptake of NH4 + at 5 days of culture. Furthermore, a pronounced reduction in NO3 - and NH4 + uptake at 10 and 28 days of culture was observed within 6 h of the short-term uptake study. This reduction could be explained by the low CO2 concentration in test tubes during the photoperiod, since no reduction in nitrogen uptake occurred in the CO2 enriched condition. The results are interpreted as an indication of the important role for photosynthetic CO2 fixation in the process of nitrogen uptake by the plantlets during the rooting stage.

Photosynthesis and phosphoenolpyruvate carboxylase activity were investigated in 5, 10 and 28 day-old micropropagated strawberry plantlets (Fragaria x ananassa Duch. cv Kent) rooted in vitro with different levels of sucrose (0, 1, 3 and 5%) on cellulose plugs (Sorbarods). The photosynthetic capability was influenced by the level of sucrose in the culture medium with the largest rates of photosynthesis corresponding to the cultures with 0 and 1% sucrose. The apparent quantum yield and the ratio of variable fluorescence to maximum fluorescence were also reduced in plantlets cultured with 3 or 5% sucrose as compared to those with 0 or 1%. Phosphoenolpyruvate carboxylase activity was largest 5 and 10 days after the onset of culture and decreased in the absence of sucrose in the culture medium. At 28 days after the onset of culture, the activity of this carboxylating enzyme was lower than at the beginning of culture and independent of the concentration of sucrose in the culture medium. Phosphoenolpyruvate carboxylase appears to be an important carboxylating enzyme in micropropagated plantlets.

This investigation reports the variability of antioxidant components and antioxidant activities of six watermelon cultivars (cvs) (four commercial cvs Aramis, Crimson Sweet, Dumara, Giza, and two new selections P503 and P403 produced by the National Agricultural Research Institute of Tunisia) as influenced by sampling area. All cvs were simultaneously grown in an open-field and subjected to identical horticultural practices in order to minimize the effects of environmental conditions and maximize those related to genotype. Significant differences were found between watermelon cvs for lycopene, phenolics, flavonoids, ascorbic acid (AsA), dehydroascorbic acid (DHA) and total vitamin C (AsA + DHA) contents, as well as in the antioxidant activity of their hydrophilic and lipophilic fractions. P503 cv showed the highest lycopene and flavonoid contents. Crimson Sweet and Giza cvs showed the highest HAA and LAA when TEAC was used as assay method, while the highest HAA and LAA were detected in Giza and Dumara cvs and in P503 cv, respectively, when FRAP assay was used. This study demonstrates that the amount of each specific antioxidant, as well as the HAA and LAA, were both influenced by genotype and sampling area, emphasizing the need to evaluate watermelon biodiversity in order to improve its nutritional value.

Micropropagated strawberry (Fragaria × ananassa Duch. ’Kent.’) cultured for 4 wk in liquid proliferation media supported on cellulose plugs (sorbarods) developed a high rate of vitrification. This high percentage of abnormal plantlets was significantly reduced by the inclusion of two antivitrifying agents, EM1 and EM2, to the liquid medium. Virtually no vitrification occurred at 5 g L−1of EM1 or EM2. Shoots multiplied on liquid medium supplemented with 5 g L−1 of either EM1 or EM2 had significantly lower fresh weights and lower multiplication rates than on solidified agar medium (0.7%). EM2 produced better growth and proliferation than EM1 or liquid medium alone and was easier to use than EM1. Key words: Vitrification, antivitrifying agent, liquid medium

Micropropagation is one of the first biotechnologies to be extensively used by industry. This technique allows efficient and rapid multiplication of many fruit, vegetable and ornamental species and is now widely used in the trade. However, despite its extraordinary potential, it is still confronted with many problems. The stimulation of natural propagation capacity, which is desirable in terms of production efficiency, induces several anatomical, morphological and physiological changes that affect the growth of plantlets very seriously upon transfer to ex vitro conditions. A complete understanding of the conditions leading to the appearance of an aberrant morphology and physiology in vitro must be achieved in order to optimize growth of the plantlets and their survival upon transfer to acclimatization. This knowledge is necessary to increase the profitability of tissue culture laboratories and to extend the technique to industrial, agronomic and forestry crops.

To identify the physiological and biochemical events leading to the negative effects of sucrose in culture medium on the photosynthetic capacity of plantlets cultivated in vitro, time-course changes in photosynthesis, metabolize pool sizes, and ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) activity were investigated in strawberry (Fragaria × ananassa Duch. cv. Kent) plantlets following their transfer to medium with or without sucrose. When the plantlets grown in medium without sucrose were transferred to a similar medium with 30 g sucrose/liter, their net photosynthesis decreased and their level of phosphorylated compounds increased with time. In addition, initial Kcat, total Kcat, and the activation state of Rubisco decreased in these plantlets. Conversely, when the plantlets grown in medium with 30 g sucrose/liter were transferred to a similar medium without sucrose, their net photosynthesis slowly increased with time and their level of phosphorylated compounds slowly decreased. A slow increase with time of initial Kcat, total Kcat, and the activation state of Rubisco was also observed in these plantlets. The results of the present research suggest that the reduced photosynthetic capacity of strawberry plantlets cultivated in vitro in the presence of sucrose was the consequence of reduced Rubisco efficiency due to its deactivation and the possible presence of a putative tight binding inhibitor.

This study investigates the antioxidant components (total carotenoids, lycopene, β-carotene, total phenols, flavonoids, ascorbic acid and total vitamin C) as well as the hydrophilic and lipophilic antioxidant activities (HAA and LAA) of tomato genotypes consisting of one ordinary cultivar Rio Grande and the two high-lycopene breeding lines HLT-F71 and HLT-F72. The correlation of nutritional value to L∗, a∗, b∗ colour indexes and a∗/b∗ ratio was also investigated in whole and fresh cut tomato fruits. Except for β-carotene content, significant differences were found among cultivars for antioxidants. The berries of both HLT-lines recorded higher antioxidant contents, HAA and LAA (TEAC and FRAP assays) than Rio Grande. Under controlled conditions, HLT-F72 reached the highest levels of total carotenoids (165.5 mg β-ca Eq per kg fw), lycopene (150.1 mg per kg fw) and total phenolics (549.7 mg GAE per kg fw). However, HLT-F72 exhibited the highest levels of ascorbic acid (193.3 mg per kg fw), total vitamin C (271.6 mg per kg fw) and flavonoids (450.5 mg RE per kg fw). Line HLT-F71 showed the highest HAA (148.0 µM Trolox per 100 g fw and 4.2 mM FRAP per g fw) and LAA values (258.5 µM Trolox per 100 g fw and 3.2 mM FRAP per g fw respectively). Colour readings in red ripe fresh cut tomato berries particularly a∗, b∗ and the ratio a∗/b∗ could represent an indicator not only for lycopene but also for other phytochemicals and resulting antioxidant activities. HLT-Lines may serve as a starting point for the development of semi-determinate growth habit tomato cultivars with higher functional quality.