IntechOpen

Home > Books > Tomato Cultivation and Consumption - Innovation and Sustainability

Open access peer-reviewed chapter

The Use of Static Magnetic Field on Irrigation Water and Its Effect on Mineral and Nutrient Content in Solanum lycopersicum L.

Written By

Albys Esther Ferrer Dubois, Yilan Fung Boix, Clara Martínez Manrique, Liliana Gómez Luna, Elizabeth Isaac Aleman, Sophie Hendrix, Natalie Beenaerts and Ann Cuypers

Reviewed: 30 August 2023 Published: 23 October 2023

DOI: 10.5772/intechopen.113071

Tomato Cultivation and Consumption IntechOpen
Tomato Cultivation and Consumption Innovation and Sustainability Edited by Francesco Lops

From the Edited Volume

Tomato Cultivation and Consumption - Innovation and Sustainability

Edited by Francesco Lops

Book Details Order Print

Chapter metrics overview

52 Chapter Downloads

View Full Metrics
Advertisement

Abstract

Solanum lycopersicum L. is a nutraceutical plant. Tomato yield and morphological features have been improved by irrigation with water treated with static magnetic field (SMF). The effect of magnetically treated water with SMF (20–200 mT) on mineral and nutritional contents in Solanum lycopersicum L. was investigated. Bromatological analyses and minerals contents were determined in tomato fruits harvested after the application of two irrigation protocols (water treated with SMF between 20 and 200 mT and water without SMF treatment as control). Fruits were selected for analysis according to a completely randomized design. Although no significant differences were observed between both groups with regard to bromatological analyses (moisture, total ash, total solids, proteins), an increasing trend was determined for these components in fruits of plants irrigated with SMF-treated water. An increase was detected for potassium (K), calcium (Ca) and cupper (Cu) concentrations in these conditions as compared to fruits of control plants. The SMF treatment of irrigation water improves the nutrient uptake and the water use efficiency in tomato. The nutraceutical value of these fruits was increase and can be considered as an important strategy for future crop production to improve food quality.

Keywords

  • Solanum lycopersicum L.
  • static magnetic field
  • minerals
  • nutritional ingredients
  • fruits

1. Introduction

Tomato (Solanum lycopersicum L.) fruits are known to have some therapeutic activity in the prevention and treatment of cancer, cardiovascular and degenerative diseases [1, 2, 3, 4]. This plant is considered as a nutraceutical plant due to its antioxidant properties determined by its content in carotenoids, polyphenols, organic acids and vitamins, exerting an effective action in metabolic processes in the human diet and nutrition [5, 6, 7, 8, 9, 10]. Together with antioxidant enzymes and secondary metabolites, they participate in the defense of organisms against oxidative stress, which, when not controlled, might lead to damage. In addition, this plant has high nutritional value because of its mineral content in its fruits [11, 12].

Solanum lycopersicum L. is often used as a biological model organism in plant growth studies, since results obtained in tomato are also applicable to other horticultural species [13, 14]. As its genome is entirely sequenced, the tomato is a very useful model organism for genetic analysis of many aspects of reproductive plant development. In addition, it permits the study of growth patterns, body architecture, and fruit ripening, all of great agronomic interest [15, 16].

In previous studies, it has been shown that tomato yield and morphology are improved by irrigation with water treated with static magnetic field (SMF) [17, 18, 19, 20, 21, 22, 23, 24, 25, 26]. The irrigation protocol using SMF-treated water (20–200 mT) increased the size of the fruits and vegetative organs of tomato plants [27, 28, 29, 30]. Moreover, it has been demonstrated that the use of electromagnetic fields (EMF) can activate cellular functions and improve the yield [31, 32, 33, 34, 35, 36, 37]. The synthesis of bioactive compounds like carotenoids, lycopene, polyphenols, ascorbic acid and quercetin can be increased, as well as the antioxidant capacity in tomato juice [38, 39, 40, 41, 42].

Despite these promising results, there is currently no evidence for the effects of irrigation with SMF-treated water on the mineral content of Solanum lycopersicum L., limiting its applications. In the current study, the concentrations of macro- and micronutrients [calcium (Ca), magnesium (Mg), phosphorus (P), potassium (K), sulfur (S), copper (Cu), manganese (Mn), sodium (Na), zinc (Zn)] were determined in tomato fruits. In addition, to evaluate possible contamination via irrigation water, also the concentrations of the non-essential elements cadmium (Cd) and lead (Pb) were analyzed. Complementary to nutrient values, fruit quality parameters such as protein content, and moisture content as well as total soluble solids and ashes were compared between fruits of tomato plants irrigated with SMF-treated water and fruits of control plants.

Advertisement

2. Materials and methods

This research was conducted in the National Center of Applied Electromagnetism (CNEA, University of Oriente, Cuba), in the greenhouse “Campo Antena” (Santiago of Cuba), and Environmental Sciences Laboratory (Hasselt University, Belgium).

2.1 Plant growth, irrigation and harvest

2.1.1 Plant material and growth conditions

The tomato species used was Solanum lycopersicum L. hybrid Aegean, identify by BSC 21509, in BIOECO (Oriental Center of Ecosystems and Biodiversity, Santiago de Cuba, Cuba). The Provincial Laboratory of Seeds, which belongs to the Ministry of Agriculture (MINAG) in Santiago de Cuba, provided the certified seeds. Plants were cultivated under semi-controlled conditions in a greenhouse Type I, Model G-2 MCC during 4 months. The substrate composition used met the requirements of the Agriculture Ministry of Cuba with regard to the content of organic matter, ions, pH, conductivity and microbiological composition (Table 1). The temperature in the experimental growth area (Campo Antena, a suburban area of Santiago de Cuba) ranged from 27 to 30°C. The approximate value of precipitation was 68.04 mm and the relative humidity 70.32% during the entire period of the experiment.

IndicativePropertiesSoil
PhysicsSoil typeSour igneous rock
TextureClay with lightly wavy slope
Depth of superficial soil25–50 cm
Density1.0–1.3 g cm−3
ErosionLimited
Infiltration15–20%
Water retention capacity (saturation)Saturated, medium humidity (420 cm)
TypeBrown without carbonate
ChemicalOrganic matter3.5%
pH7.0
Electrical conductivity1.39–2.01(mS cm−1)
Phosphorus7.3 meq100 g of soil−1
Calcium38.7 meq100 g of soil−1
Potassium21.7 meq100 g of soil−1

Table 1.

Soil quality parameters for the cultivation of Solanum lycopersicum L. in the Campo Antena greenhouse.

Using the established protocols [43], soil and water quality were analyzed prior to the application of the irrigation protocol. The physical and chemical parameters of the soil quality were determined according to protocols [44, 45]. Three soil samples were randomly chosen at several places and mixed to obtain one experimental sample. Microbiological analysis was performed according to the requirements of the Ministry of Agriculture of Cuba [46].

2.1.2 Irrigation system and magnet device

For the irrigation, an air microjet device was used and the irrigation system was equipped with a pump characterized by a pump flow of 2.54–2.91 m3 h−1 and a speed ranging from 1.4 to 1.6 m s−1. The timing of irrigation was based on the cultivation phase of the plants. During the first and second cultivation phase (i.e. establishment, vegetative growth and flowering), the irrigation was performed once a day for 20 min. In the third cultivation phase, which incorporates fruit ripening, the irrigation was conducted twice a day during 20 min. The irrigation schedule was completed after 120 days.

The magnetic treatment was applied used a magnetic device composed of permanent magnets with a non-uniform SMF. This was designed, constructed and characterized in CNEA [47]. The treatment was conducted at the time of irrigation of the plants during the whole cycle of the crop growth.

2.1.3 Experimental design

For the application of the SMF treatment, a totally randomized experimental design with three replicates per experimental group (control plants or plants irrigated with SMF-treated water) was used. The experiment consisted of 25 plants per treatment making up 150 plants. After 120 days, all fruits were harvested. Ten fruits per group were chosen randomly to perform the analyses.

The experimental groups were described as follows:

  • Control plants: Solanum lycopersicum L. irrigated with water not treated withSMF.

  • SMF plants: Solanum lycopersicum L. irrigated with water treated with SMF between 20 and 200 mT.

The selection of the induction intensity was based on the recommendation provided in literature. In Solanum lycopersicum L., magnetic inductions ranging between 120 and 250 mT were used to induce seed germination, enhance the morphological features and increase the average yield per plant [16, 21, 27].

2.2 Bromatological analyses

Fruit analyses were performed on fruits harvested between the fourth (fruit ripening) and 6th stage (senescence) according to the technical protocols recommended, because a similar maturation in the majority of the fruits was obtained in this stage [48]. In the bromatological analyses, 10 mature fruits from each experimental group were randomly selected and the analyses were performed in triplicate.

2.2.1 Determination of moisture content

The determination of the moisture content was performed according to the gravimetric method described for fruits in the Official Methods of Analysis [48]. Approximately 0.5 g of ripe fruits of Solanum lycopersicum L. (fresh weight), were oven-dried at 60°C for 72 h until a constant weight (dry weight) was reached. The moisture content was calculated.

2.2.2 Determination of total ashes content

The total ashes content was determined by the gravimetric method [49]. Fruit samples (10 g) from Solanum lycopersicum L. were placed in apre-weighed silica crucible. The crucible was heated at 100°C until the material was completely charred. Thereafter, it was heated to 600°C in a muffle furnace for 3–5 h, cooled in a desiccator and weighed. In order to ensure complete incineration, the crucible was re-heated in the oven for 30 min, cooled and weighed again. This process was repeated until the ash weight is constant. The total ashes content was calculated.

2.2.3 Determination of the protein content

The determination of the total soluble proteins in alkaline medium was performed by the bicinchoninic acid (BCA) method [50]. Dried fruits (10 mg) from Solanum lycopersicum L. were placed in a centrifuge tube and 1 mL of NaOH (0.5 M) was added to each sample for alkaline digestion. The samples were placed in a water bath at 100°C for 10 min. Subsequently, they were centrifuged at room temperature (13,000 × g) for 5 min. BCA reagent (AppliChem, Germany) (1 mL) was added to 100 μL of the supernatant. The samples were mixed and after 15 min the absorbance was measured in a UV-visible spectrophotometer at 562 nm. A standard curve using bovine serum albumin (BSA) (15–125 μg mL−1) was used. The results were expressed as total protein concentration in μg protein per gram of dried weight.

2.2.4 Determination of total soluble solid content

For the determination of the total soluble solid content, a gravimetric method was used [51]. Three porcelain capsules were dried in an oven at 105°C for 60 min. The capsules were placed in a desiccator until they were completely cooled and then weighed. Aqueous extracts (50 mg mL−1) of dried fruits from Solanum lycopersicum L. were prepared in distilled water. One mL of this fruit extract was added to each capsule. The filled capsules were weighed and placed in an oven at 105°C for 60 min. After this, they were placed in a desiccator until they were completely cooled and then weighed again. The drying process was repeated until a constant weight was obtained. The percentage of total solids was calculated.

2.3 Determination of mineral elements

The concentrations of mineral elements were determined after acidic extraction of the fruits using a heating block. Five ripe fruits per experimental group were dried in an oven for 72 h at 60°C. The extraction of the elements was carried out according to the procedures of the Ministry of Public Health of Cuba. The dried fruits from Solanum lycopersicum L. were weighed, kept at 4°C and pulverized to powder in an electric mill. For an optimal extraction of the elements, this process was conducted away from moisture and light according to the requirements. The powder (50 mg) was digested using a mixture (1:1, v/v) of concentrated nitric acid (70%) and hydrochloric acid (37%). The resulting material was filtered.

The macroelements and microelements were determined in the extracts of fruits of Solanum lycopersicum L. using inductively coupled plasma emission spectroscopy (ICP-OES) (Series, Agilent Technologies, Dieghem, Belgium). The analysis was validated using Solanum lycopersicum L. certified as reference material (CRM 1573a), from the National Institute of Standards and Technology [52]. HNO3 solutions (1%) were used as blank. Calibration curves were generated to identify each mineral.

2.4 Statistical analysis

For statistical analysis, normal distribution of the data was tested by the Kolmogorov-Smirnov test. Parametric tests were applied to compare the results of the experimental groups. Either the Student t-Test or one-way Analysis of Variance (one-way ANOVA) followed by the post-hoc Tukey-Kramer test were performed. The value of statistical significance was set at 95%.

Advertisement

3. Results

3.1 Soil properties

To establish the cultivation of Solanum lycopersicum L. under semi-controlled experimental conditions, it is necessary to know the quality of the soil and irrigation water. In Table 1, the soil quality parameters are shown according to the classification of soils in Cuba for the tomato cultivation [45]. The typology of the soil is in agreement with the established quality parameters of the Ministry of Agriculture and reached the required nutritional levels. In addition, neither parasites nor nematodes were detected in the microbiological analysis.

3.2 Irrigation water properties

Water has several important basic functions in plants. It is the biggest constituent of the cytoplasm and vacuole providing turgor (85–95%). Furthermore, it is required for dissolving and transporting nutrients. Finally, it provides the electrons necessary for the redox reactions involved in photosynthesis [45]. When water is exposed to SMF with a certain induction and speed, it acquires different physicochemical characteristics (Table 2) [53, 54].

CharacteristicIrrigation water
ControlSMF-treated
Electrical conductivity (mS cm−1)0.019 ± 0.000.25 ± 0.02*
pH7.14 ± 0.027.87 ± 0.02
K (mg L−1)4.17 ± 0.845.39 ± 0.81
Ca (mg L−1)24.7 ± 0.9024.53 ± 1.27
Na (mg L−1)11.47 ± 0.9512.17 ± 0.78
Mg (mg L−1)6.02 ± 1.006.39 ± 0.91
SO4 (mg L−1)9.24 ± 0.489.25 ± 0.27
CO3 (mg L−1)17.33 ± 1.1517.33 ± 0.58
Cl (mg L−1)15.8 ± 1.817.31 ± 1.12
HCO3 (mg L−1)72.88 ± 0.9573.41 ± 0.99

Table 2.

Characteristics of the irrigation water used for the cultivation of Solanum lycopersicum L.

Indicates a significant difference between both treatment groups (p ≤ 0.05) Student’s t-test).


Notes: Values represent the mean ± SE (n = 3).

3.3 Bromatological analysis

To investigate whether alterations in irrigation water also can affect the nutritional quality of the tomato fruits, nutritionals indicators and mineral concentrations were determined in fruits of plants grown using irrigation water that was either treated with SMF in a range of 20–200 mT or where no treatment was applied. From here on, the group of plants irrigated with SMF-treated water is referred to as SMF plants, whereas the plants irrigated with water without the SMF treatment are referred to as control plants. The results of the bromatological analyses of Solanum lycopersicum L. SMF plants and control plants are shown in Table 3.

IndicatorsExperimental groups
Control plantsSMF plants
Moisture (%)93.26 ± 1.3095.23 ± 0.77
Ashes (%)0.58 ± 0.040.64 ± 0.01
Total proteins (μg mL−1)53.35 ± 17.3259.85 ± 27.93
Total solids (%)7.20 ± 1.887.63 ± 2.06

Table 3.

Analysis of nutritional indicators in Solanum lycopersicum L. fruits irrigated with water subjected to different treatments.

Notes: Control plants: Solanum lycopersicum L. irrigated with non-SMF-treated water; SMF plants: Solanum lycopersicum L. irrigated with SMF-treated water (20–200 mT). Data represent the mean ± SE (n = 3).

3.4 Mineral elements analysis

In order to further determine the nutritional value of tomato plants, the concentrations of seven different elements essential for plant growth and development were determined in the fruits of Solanum lycopersicum L. (Table 4).

Minerals
(mg kg−1 DW)		Experimental groups
Control plantsSMF plants
Potassium (K)25.02 ± 0.4228.58 ± 1.12*
Calcium (Ca)1.30 ± 0.141.77 ± 0.05*
Sodium (Na)0.37 ± 0.010.42 ± 0.02
Magnesium (Mg)1.21 ± 0.101.22 ± 0.05
Copper (Cu)0.01 ± 0.000.23 ± 0.04*
Phosphorous (P)3.03 ± 0.033.35 ± 0.01
Sulfur (S)1.45 ± 0.061.44 ± 0.06

Table 4.

Mineral content in fruits of Solanum lycopersicum L. irrigated with water subjected to different treatments.

Symbols indicate statistically significant differences between both experimental groups Student’s t-test, (p < 0.05).


Notes: Control plants: Solanum lycopersicum L. irrigated with non-SMF-treated water; SMF plants: Solanum lycopersicum L. irrigated with SMF-treated water (20–200 mT). Data represent the mean ± SE (n = 3).

Advertisement

4. Discussion

4.1 Soil properties

The water retention capacity estimates the availability of water to plants that is essential for normal growth. This parameter is among others correlated with the organic matter content. The organic matter content determined in this experiment has an average value similar to the established range between 1.65 and 2.65% [55]. According to reports, the electrical conductivity for the growth of Solanum lycopersicum L. should be between 0.75 and 2.5 mS cm−1 [12]. This coincided with the results obtained from the soil analysis of our experimental setup.

K and Ca are two primary minerals in the soil that were determined. Ca salts are predominantly present, contributing to the classification of the soil as neutral, with a pH close to 7. In this soil, no nutrients reached toxic levels according to the classification found in literature [45]. These authors considered that a neutral soil saturated with basic ions (K+, Ca2+, Mg2+, Na+) lose these minerals less than a soil with a low percentage of saturation [45]. Therefore, it can be supposed that plants easily assimilate these minerals. The chemical indicators provide knowledge on the nutritional state of the soil, associated with its fertility. The results of the soil analysis showed that the nutrient levels were adequate for the growth of Solanum lycopersicum L.

4.2 Irrigation water properties

After applying SMF, an increase in the electrical conductivity with 0.23 units was observed and therefore it has a bigger capacity to drive an electric current (Table 2). Due to its electrical conductivity and the presence of Na, the salinity of the water is classified as low to moderate according to its use for irrigation purposes [56]. The increase of the electrical conductivity could be influenced by an increase in the mobility of the ions in the water treated with SMF during irrigation of the Solanum lycopersicum L. plants. This may be due to weakening of the hydration shell around the H+ and OH− ions [57].

The effects of MF treatment on the electrical conductivity of water are controversial. The studies of Martínez et al. [58], support the results of this research, because they reported an increase of 10.75–12 mS cm−1 in the ionic conductivity for aqueous solutions of salts of sodium and chloride, to a concentration 0.1% in water treated with SMF in the range from 10 to 160 mT. These authors explained that these variations depend on the movement of the loaded ions. This are related with the changes in the distribution of the size of the polymeric species of the aqueous solutions. An increase in conductivity could be due to changes in the polarity of the water molecules, as a consequence of the changes at the dipole moment, in the electron and vibrational transition state in the molecule. All that which modifies the properties of the water and it favors the mobility of the ions for a bigger hydrate. The treatment with small magnetic inductions (smaller than 1 T), can modify the organization of the molecules of water of big to small groups, each one of them composed symmetrically by six molecules [54]. Different variations in the microscopic structures of water under the action of the MF, with an increase in their electrical conductivity have been described. Similar changes were reported with SMF of 150 mT [59]. The irrigation water through a MF with 100 mT increased the electrical conductivity [60]. In plants of Zea mays an increase of electrical conductivity after a magnetic treatment in the irrigation water of 1500 mT was obtained [61].

The soil pH of the irrigation water was in the neutral range (pH 7) (Table 2). However, an increasing trend in pH of SMF-treated irrigation water was observed. Also described differences in water treated with SMF to favors the formation of Ca(CO3)2 and other alkaline materials that slightly reduced the acidity of the water [53]. Results of the water analysis indicated that there was a slight increment in ionic concentrations of K, Na, Cl in the SMF-treated water as compared to the control water, although no significant differences were observed.

Another important aspect of the water quality to be considered is the hardness of the water. The most common minerals defining water hardness are carbonates and sulphates of Mg and Ca. Water with a total hardness in which mineral concentrations are less than 27 ppm is categorized as soft. Moderately hard water has mineral concentrations in the range of 60–120 ppm of these elements and very hard water exceeds 180 ppm [62]. Taking these values into account, under the conditions of our experiment in which Ca and Mg concentrations were 24 and 6 ppm, respectively (Table 2), we can concluded that the water used was categorized as soft water.

The main components of soluble salts of irrigation water are Ca2+, Mg2+, Na+, and K+ minerals has been demonstrated [63]. Ca2+ and Mg2+ ions cause hardness of water, in addition to dissolved metals, carbonates (CO32−), bicarbonates (HCO3−), chlorides (Cl−) and sulfates (SO42−) as dominant soluble salts. In general, magnetic treatment of water is thought to modify its structure and hence the dissolution of the minerals it contains [57]. Several studies explain about the theory of magnetization of water. According to the researches, the SMF causes physical and chemical changes in the distribution and polarization of the microscopic structure of molecules of water [64].

Experimental results have been described of infrared spectroscopy analysis of magnetically treated of water [65]. Theses confirm the variations in the physicochemical properties of the SMF-treated water in our experimental setup. In general, the surface tension was reduced and viscosity and vaporization rates were increased. These three phenomena, just as the transference of protons in the bonds by hydrogen bridges, are consequences of the modification of the molecular water structure [66]. The SMF treatment might have caused changes in the water molecule size due to the extra hydrogen bonds formation that is relative to the exposure time. The magnetic force is affecting the water molecule and disturbs dehydration phenomena by changing the orientation of the molecules. The hydrogen bonds between the molecules either changes or are released and this might release sucking energy and decrease the unity of water parts [67]. Others authors also report that MF modified the chemical structure of the water to be more clustered together [68]. The magnetically treated water can arrange its molecules in one direction. Again, the changes in the direction of these molecules might lead to changing order composing hydrogen bonds between molecules [69]. Overall, magnetic treatment of irrigation water affects the molecular structure of the water, whereas the molecular composition remains the same [53].

Water is a bipolar molecule and it allows electrostatic attraction and hydration of ions. One of its functions in plants is to act as a solvent for minerals [24]. Magnetic treatment improves the dissolving properties of water, which might result in an increased ability of nutrient assimilation by plants. Several researchers have verified that after applying MF to water, changes in the hydration of the ions occur and as a consequence, the water molecules bound more easily to soil particles, penetrating the micropores of the soil and preventing migration to greater depths [57, 66, 70]. Under conditions of this experiment, the results suggest that application of irrigation with SMF improved penetration of water in the soil and solubilization of nutrients. This is important for a better use of water by plants, which can contribute to increase growth.

4.3 Bromatological analysis

Although no statistical significant differences could be observed for the different parameters analyzed in Solanum lycopersicum L. fruits, a slight increment in total protein content (12.18%), ashes (10.34%), total solids (7.16%) and moisture (2.15%) was observed in the SMF plants as compared to the control plants. In general, this points toward an overall improvement of the nutritional value of the SMF plants.

An increase in the total protein content is considered beneficial for plants. This might be linked to the dynamic properties of the cell wall, which are modified during growth and differentiation. In the cell wall, proteins containing glycine, proline and hydroxyproline are abundant. They are related to cell wall resistance and protection against pathogens and the reactive oxygen species (ROS) production [71]. Although irrigation of Solanum lycopersicum L. plants with SMF-treated water did not significantly increased the protein content, an increasing trend could be determined (Table 3). Increased protein biosynthesis was also indicated in other studies. A significant increase in the content of total proteins and proline after irrigation of Vicia faba L. with water treated with a MF was demonstrated [72]. Similar results were obtained in Triticum sp., Linum bienne, Cicer arietinum and Lens culinaris plants irrigated with magnetically treated water [73].

Concerning the percentage of ashes found in Solanum lycopersicum L. fruits (Table 3), a slight increment was observed in fruits of SMF plants, as compared to the content of control plants. The effects of irrigation with SMF-treated water on the plants can explain this behavior. The SMF-treated water is better assimilated or absorbed by plant cells and can affect the membrane potential was suggested [74]. Therefore, the plant uptake of water and minerals was favored and it was faster than in normal conditions, due to the activation of the osmosis mechanism. Similar effects in the increased uptake of nutrients were reported [75]. They showed significant effects of non-uniform SMF of 50.6, 108.7 and 332 mT on the water absorption of Solanum lycopersicum L. seeds, possibly leading to increase moisture content in the fruits. The ashes percentage in tomato fruits in a ranged between 0.56 and 0.70% was described [76]. These are in agreement with the results obtained in this research. The ashes are the residue of the complete combustion of the organic material of the fruits and represent the mineral fraction. Therefore, the ashes content predicts the presence of minerals, especially K, Ca, S and Mg [77].

In the context of these observations, there are reports describing an increase in the absorption and assimilation of nutrients in Lens culinaris plants irrigated with magnetically treated water [78]. Positive effects were also obtained under these conditions in Vigna unguiculata a result of an increased absorption and assimilation of nutrients [79]. The moisture level is an indicator of the degree of hydration of tissues and an important determinant of fruit quality. Several studies reported that tomato fruits have high water content, ranging between 90 and 93.8% [80, 81]. These data are in agreement with those obtained in the control plants in the present research. Results show that fruits of SMF plants had slightly higher moisture content as compared to the control plants, suggesting a more efficient water absorption (Table 3).

The irrigation of some plant species with SMF-treated water activates cellular functions, thereby affecting physiological and biochemical processes, leading to increased primary metabolite levels was reported [82]. Among them are amino acids, lipids, nucleotides and proteins, which are used in combination with water and minerals in different plant processes including photosynthesis, respiration and nutrient transport and assimilation. The levels of these primary metabolites are related to the total solids levels, because they constitute the dry matter remaining after the removal of water. The total solids levels of the fruits were similar between both experimental groups and are in the established range for Solanum lycopersicum L. plants although a slight increase was observed in fruits of SMF plants (Table 3). Under normal growth conditions, the content of total solids in this plant was in a range between 3.5 and 7 0Brix was indicated [83, 84]. Whereas we did not observe a significant difference between both experimental groups, some authors explained that irrigation with water treated with a 50 Hz of EMF, can have an effect on the total solid content between 4 and 7% increase in the same variety of plant [85]. Water is essential for metabolic and physiological processes in living organisms for transporting nutrients and minerals necessary for fruit ripening. During this process, the content of total solids generally increases, which influences the biochemical quality of the fruits, together with the sugars and the total acidity, determining their flavor [83].

The results obtained in this research are also in good agreement with others researchers. The magnetically treated water had a positive effect on the nutritional qualities of Citrullus lanatus [86]. Theses authors founded a higher percentage of water content, crude protein and ashes content in plants irrigated by magnetically treated water when compared to the corresponding values of control plants. The relevance of the results obtained in the stimulation of ashes and proteins content in fruits of Solanum lycopersicum L. after magnetic treatment in irrigation water is significant. This is due to the fact that these nutritional indicators are determinant in the bromatological analyzes of the plants used for human consumption.

4.4 Mineral elements analysis

The positive effects detected in the nutrient concentrations of fruits in this research, indicate a better assimilation of nutrients and fertilizers by plants when they are irrigated with SMF-treated water during their growing cycle (Table 4). These findings are agreement with results revealed [87]. In general, it is clear that fruits of the SMF plants contained significantly higher concentrations of K, Ca and Cu as compared to the control group (p < 0.05).

The macronutrients like K, P, Ca, Mg and S have an important nutritional value in tomato fruits [45]. The higher mineral levels were found in the fruits of the SMF plants (Table 4). These results were in agreement with the increased ashes percentage obtained. Therefore, this parameter has a predictive value for nutritional value related to elemental uptake as previously indicated (Table 3).

By far, K exhibited the highest concentration of minerals determined. Similar results have been described when 85 genotypes of tomatoes were analyzed [88]. K plays an important role in the quantity of sugars that are accumulated in the fruit. It helps to increase the quantity of dry matter and vitamin C [12]. The same applies to Na, which although being a micronutrient, is considered a beneficial nutritional element. Higher levels of K, Ca, Fe and Zn in the leaves of Solanum lycopersicum L. of plants irrigated with magnetically treated water at 250 mT was obtained [89]. Since it exists in an ionized state in plant organs, K is water-soluble and easily dissociable. This explains its mobility and high concentrations in plants. Interestingly, K is considered the main cation in vegetable juices [45]. The K concentration in Solanum lycopersicum L. fruits of the SMF plants can be linked to the total protein levels obtained in this group (Table 3). The high concentrations of K ions are required for the synthesis of proteins, as well as sugars and starch. Furthermore, K is known to affect the activation of several plant enzymes during the reproductive phase. It is known to be involved in the phase of fruit ripening, in which their demand depends on the needs of fruits that contain plenty of water, such as in Solanum lycopersicum L. [12, 90].

In addition, that irrigation of plants of Phaseolus vulgaris L. with magnetically treated water increased significantly of levels of K [91]. Also in plants of Capsicum annuum L. the irrigation with magnetically treated water with 500 mT, enhance the uptake of K [67]. This mineral is the third most abundant mineral in the human body. This important element for food should have a high concentration with respect to Na. The Na/K ratio measured in this analysis was 0.014 for both experimental groups, which is in agreement with data available in literature [92]. This ratio contributes to the balance of the cellular membrane potential. At the same time, to the validation of these fruits as protective agents against cardiovascular diseases and it have important functions in the muscular and nervous system [92]. Consequently, a diet rich in K is advised, as this nutrient helps to counteract the hypertensive effects of Na. An imbalance in the Na/K ratio cannot only cause hypertension, but can also lead to other diseases [93].

As indicated before, the Ca concentration was significantly increased in fruits of Solanum lycopersicum L. irrigated with SMF-treated water (Table 4). Ca is the second most abundant chemical element in plants and is a structural component of the cell wall and cell membranes. Furthermore, it is a cofactor of several enzymes involved in metabolic reactions, including ATPases, phosphatases and phospholipases [45]. It regulates the uptake of nitrogen and affects the translocation of carbohydrates and proteins. The exposure of seeds to a MF with an interval of 100 nT to 0.5 mT, had influence in the Ca channels in the cell membrane of Pisum sativum [94]. The increased Ca level after irrigation of Solanum lycopersicum L. plants with SMF-treated water, suggests that these ions have a sensitive response to the MF. The involvement of Ca in magneto sensitivity and the consequent signal transduction have been a topic of discussion [94]. In this respect, that irrigation with magnetically treated water (3.5–136 mT) increased the Ca concentration in shoots of Apium graveolens L. and in the pods of Lathyrus odoratus, which is in agreement with the results obtained in this study [95].

In addition, in fruits of Capsicum chinense the concentration of Ca, Mg, S, Mn and Zn was increased after the irrigation with MF-treated water in a range between 0 and 156 mT [96]. Ca and K are involved in all stages of plant growth and development, also in responses to environmental changes [90]. On the other hand, the strong antagonism between K with Ca and Mg was described [45]. When the concentration of K increases, Ca and Mg levels decrease as a consequence of a reduced absorption of these minerals [45]. However, the results of the present research do not confirm these data, as both K and Ca concentrations increased in tomato fruits after irrigation with SMF-treated water. In connection to this, Petroselinum crispum (Mill) irrigated with magnetically treated water exhibit an increase in K and Ca as compared with plants irrigated with tap water (control) [97]. SMF plants had a K/Ca ratio, which was higher (26.81) than the ratio obtained in the control plants (23.72). Others studies confirmed these effects: an increase of the intracellular Ca, K and Na concentrations were detected in shoots of Pisum sativum and Cicer arietinum after irrigation with magnetically treated water (3.5 and 136 mT) [98]. In the previous study using the irrigation with magnetically treated water, the K and Ca contents were also increased in Vicia faba L. [72].

Concerning P, it plays an important role in photosynthesis, respiration and metabolism. It has an important function in several molecules and cellular structures, such as the diester bonds of nucleic acids and phospholipids [99]. In previous reports, an increase in the concentration of K and P in Solanum tuberosum plants was detected when they were irrigated with water treated with an EMF. In contrast to, in the present research no significant effect on the P concentration in tomato fruits was observed. These results coincide with those obtained by others researchers [100]. The concentrations of these minerals remained unchanged in Solanum lycopersicum L. plants irrigated with SMF-treated water were reported. The action of the external MF was beneficial to the formation of mineral crystals in the soil pressure contents of N, P, and other effective nutrients in the soil, thereby further improving soil quality was revealed [101].

With a magnetic funnel (Magnetic Technologies L.L.C. Model No. MFLa, Dubai, U.A.E.) used for water treatment in the cultivation of Beta vulgaris, an increase in some chemical elements (N, K, P and Ca) was obtained [102]. In this plant species, the macronutrients (N, P, K, Mg) were increased by irrigation under magnetic water treatments of 0.75 and 1.75 mT [103].

Regarding the Mg concentrations, they were not affected by irrigation with SMF-treated water in Solanum lycopersicum L. plants. For the concentrations of micronutrients, only Cu levels were significantly higher in fruits of plants irrigated with SMF-treated water as compared to fruits of control plants (Table 4). Cu is essential for growth, involved in many physiological processes, and is part of the active centre of antioxidant enzymes, like superoxide dismutases [104]. Even though it is a micronutrient, it is considered a phytotoxic element in concentrations exceeding 14.7 mgkg−1 [90, 105]. However, the Cu concentrations measured in this analysis, did not reach these toxic levels. In Beta vulgaris plants irrigated with magnetically treated water with 0.75 and 1.75 mT, an increase in Cu and Zn elements was detected [103].

Other non-essential toxic trace elements such as Cd and Pb were not detected in the fruits of Solanum lycopersicum L. The finding of Yusuf et al. [106], supports the results of this research who explained that the magnetic treatment in the irrigation water did not add heavy metals in Solanum lycopersicum L. In addition, also other trace elements (Mn, Zn) were analyzed, but fell below the detection limit.

In general, an increased the uptake of nutrients, an enhanced higher crop yield and improved the qualities of fruits were detected. The plants irrigated with SMF-treated water between 20 and 200 mT improved the solubility and absorption of essential minerals, besides their nutritional status. These results confirm that water is probably the primary receptor of the MF in biological systems [107]. It means that different changes in properties of water underexposure to the MF may change the metabolic activity of plants. In this research, it was demonstrated that the chemical and physiological variations caused by MF treatment, increases water absorption, and consequently a higher mineral and nutrient uptake by Solanum lycopersicum L. plants. The significance of these results is novel because it can contribute to an increase in the development and growth of plants of this plant species. All of which can lead to an increase crop yields.

There are some hypotheses about the effects of MF on plant growth and development [35, 108, 109]. Although of all the researches, the knowledge of the complex mechanisms involved is of great interest in the novelty of this topic.

Advertisement

5. Conclusions

Based in the results, the irrigation with SMF-treated water (20–200 mT) enhances the accumulation of nutritional elements, especially the content of several essential nutrients in the fruits of Solanum lycopersicum L. under greenhouse conditions. An overall increase in the moisture, ashes percentage and total soluble solid levels were obtained. Taken together, these results indicate that irrigation with SMF-treated water improves the nutritional quality of this tomato fruits. The use of MF technology is therefore a useful strategy to improve the nutraceutical value of Solanum lycopersicum L., possibly resulting in a positive impact on its antioxidant properties, which should be further investigated in future experiments.

Advertisement

Acknowledgments

The VLIR-IUC UO Project from Belgium and Cuba funded this study. Thanks to the National Center for Applied Electromagnetism (CNEA) of the Universidad of Oriente, in Cuba and the Centre for Environmental Sciences of Hasselt University, in Belgium.

Advertisement

Conflict of interest

The authors declare that they have no conflict of interest.

References

  1. 1. Khan I, Ahmad S. The impact of natural antioxidants on human health. In: Ahmad S, Al-Shabib NA, editors. Functional Food Products and Sustainable Health. Singapore: Springer; 2020. pp. 11-24. DOI: 10.1007/978-981-15-4716-4_2
  2. 2. Rehman MU, Abdullah KF, Niaz K. Introduction to natural products analysis. In: Sanches Silva A, Nabavi SF, Saeedi M, editors. Recent Advances in Natural Products Analysis. Holland: Elsevier; 2020. pp. 3-15. DOI: 10.1016/B978-0-12-816455-6.00001-9
  3. 3. Salehi B, Sharifi-Rad R, Sharopov F, Namiesnik J, Roointan A, Kamle M, et al. Beneficial effects and potential risks of tomatoes consumption for human health: An overview. Nutrition. 2019;62:201-208. DOI: 10.1016/j.nut.2019.01.012
  4. 4. Shrinet K, Singh RK, Chaurasia AK, Tripathi A, Kumar A. Bioactive compounds and their future therapeutic applications. In: Rp S, Häder D-P, editors. Natural Bioactive Compounds: Technological Advancements. Holland: Academic Press Elsevier; 2021. pp. 337-362. DOI: 10.1016/B978-0-12-820655-3.00017-3
  5. 5. Navarro-González I, Periago MJ. El tomate, ¿alimentos aludable y/o funcional? Revista Española de Nutrición Humana y Dietética. 2016;20:323-335. DOI: 10.14306/renhyd.20.4.208
  6. 6. Pathak SS, Akhade OP, Bhojane KG, Sadar MD, Folane P, Biyani K. A review on recent techniques of extraction and isolation of lycopene from tomato. International Journal of Research and Review. 2020;7(4):487-490. DOI: 10.4444/ijrr.1002/1927
  7. 7. Pimentel-Moral S, MdlL C-G, Rodríguez-Pérez C, Segura-Carretero A. Recent advances in extraction technologies of phytochemicals applied for the revaluation of agri-food by-products. In: Prakash B, editor. Functional and Preservative Properties of Phytochemicals. Holland: Academic Press Elsevier; 2020. pp. 209-239. DOI: 10.1016/B978-0-12-818593-3.00007-5
  8. 8. Pinto T, Aires A, Cosme F, Bacelar E, Morais MC, Oliveira I, et al. Bioactive (poly) phenols, volatile compounds from vegetables, medicinal and aromatic plants. Food. 2021;10:106. DOI: 10.3390/foods10010106
  9. 9. Sariñana-Aldaco O, Sanchez-Chavez E, Fortis-Hernández M, González-Fuentes JA, Moreno-Resendez A, Rojas-Duarte A, et al. Improvement of the nutraceutical quality and yield of tomato by application of salicylic acid. Notulae Botanica e Horti Agrobotanici Cluj-Napoca. 2020;48:882-892. DOI: 10.15835/nbha48211914
  10. 10. Tan S, Ke Z, Chai D, Miao Y, Luo K, Li W. Lycopene, polyphenols and antioxidant activities of three characteristic tomato cultivars subjected to two drying methods. Food Chemistry. 2021;338:128062. DOI: 10.1016/j.foodchem.2020.128062
  11. 11. Ahmad N. Nutraceutical and bioactive healthy compounds in vegetable crops. IJCS. 2020;8:3078-3086. DOI: 10.22271/chemi.2020.v8.i4ak.10120
  12. 12. Larín, M., Díaz, L., y Serrano, R. Cultivo de tomate (Lycopersicon esculentum). Salvador. CENTA. 2018. Available from: http://centa.gob.sv/docs/guias/hortalizas/Guia%20Centa_Tomate%202019.pdf
  13. 13. Anwar R, Fatima T, Mattoo A. Tomatoes: A model crop of solanaceous plants. In: Oxford Research Encyclopedia of Environmental Science. New York, United States: Oxford University Press; 2019. pp. 1-50. DOI: 10.1093/acrefore/9780199389414.013.223
  14. 14. Hiwasa-Tanase K. Fruit ripening in tomato and its modification by molecular breeding techniques. In: Ezura H, Ariizumi T, Garcia-Mas J, Rose J, editors. Functional Genomics and Biotechnology in Solanaceae and Cucurbitaceae Crops. Biotechnology in Agriculture and Forestry. Vol. 70. Berlin, Heidelberg: Springer; 2016. DOI: 10.1007/978-3-662-48535-4_10
  15. 15. Umhsapiens. El gusto por la genética en una fruta de tomate. UMH SAPIENS. Universidad Miguel Hernández (UMH). Elche. España.[Internet]. 2014. Available from: https://umhsapiens.com/el-gusto-por-la-genetica-en-un-fruto-de-tomate/
  16. 16. Wang A, Chen D, Ma Q , Rose JKC, Fei Z, Liu Y, et al. The tomato high pigment1/damaged DNA binding protein 1 gene contributes to regulation of fruit ripening. Horticulture Research. 2019;6:1-10. DOI: 10.1038/s41438-018-0093-3
  17. 17. Aguilera JG, Martín RM. Água tratada magneticamente estimula a germinação e desenvolvimento de mudas de Solanum lycopersicum L. Revista Brasileira de Agropecuária Sustentável. 2016;6:47-53. DOI: 10.21206/rbas.v6il.320
  18. 18. Almeida RC, Deus FP, Diotto AV, Teixeira ALP, Lemos LTO, Pizetta SC, et al. Desenvolvimento vegetativo do tomateiro sweetheaven irrigado com água tratada magneticamente. Brazilian Journal of Development. 2020;6:5428-5434. DOI: 10.34117/bjdv6n2-007
  19. 19. De Souza A, Sueiro L, García D, Porras E. Extremely low frequency non-uniform magnetic fields improve tomato seed germination and early seedling growth. Seed Science and Technology. 2010;38:61-72. DOI: 10.15258/sst.2010.38.1.06
  20. 20. Dubois AF, Lamezon Y, Fung Y, Isaac E. Aplicación de campo magnético para mejorar la calidad en plantas de tomate (Lycopersicon esculentum). Revista Tecnología Química Edición Especial. 2007:-85. DOI: 81. Available from: https://magnetismocnea.files.wordpress.com/2010/08/agricultura.pdf
  21. 21. El-Shafik El-Zawily A, Meleha M, El-Sawy M, El-Attar E-H, Bayoumi Y, Alshaal T. Application of magnetic field improves growth, yield and fruit quality of tomato irrigated alternatively by fresh and agricultural drainage water. Ecotoxicology and Environmental Safety. 2019;181:248-254. DOI: 10.1016/j.ecoenv.2019.06.018
  22. 22. Fakhri N, Mehdaoui HY, Elloumi N, Kallel M. Magnetic Treatment Effects on Salt Water and Tomato Plants rowth. New York, United States: Springer International Publishing; 2018. DOI: 10.1007/978-3-319-70548-4_316
  23. 23. Jedlička J, Paulen O, Ailer Š. Influence of magnetic field on germination, growth and production of tomato. Potravinarstvo Slovak Journal of Food Sciences. 2014;8:150-154. DOI: 10.5219/349
  24. 24. Ogunlela A, Yusuf K. Effects of water stress on growth and yield of tomato irrigated with magnetically treated water. Nigerian Journal of Pure and Applied Sciences. 2016;29:2834-2835. DOI: 10.19240/njpas.2016.A21
  25. 25. Torres C, Díaz JE, Cabal PA. Efecto de campos magnéticos en la germinación de semillas de arroz (Oryza sativa L.) y tomate (Solanum lycopersicum L.), Agronomía Colombiana. 2008;26:177-185. ISSN 0120-9965. Available from: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0120-99652008000200002&lng=en&nrm=iso
  26. 26. Yusuf KO, Adeleye AA. Effect of magnetic treatment of irrigation water on growth and yield of maize under different water deficit conditions. FUOYE. Journal of Engineering and Technology. 2018;3:83-87. DOI: 10.46792/fuoyejet.v3i2.193
  27. 27. Dubois AEF, Aguilera JG, Boix YF, Alemán EI, Zuffo AM. Use of GREMAG® technology to improve seed germination and seedling survival. In: Zuffo AM, Aguilera JG de Oliveira BR, editors. Ciência em Foco. Pantanal, Brasil. 2019. p. 138-149. DOI: 10.22533/at.ed.567181510
  28. 28. Fadil K, Merza TK. Physiological study of irrigation with treated magnetic water on some of vegetative characteristics and yield of three wheat cultivars in Najaf. Kufa Journal for Agriculture Sciences. 2014;6:140-169. Available from: https://www.iasj.net/iasj/article/110820
  29. 29. Oduardo DZ, Fernández PR, Dubois AF, Boix YF, Aleman EI, Kindelan GA. Producción de tomate (Solanum lycopersicum L.) bajo riego con agua magnetizada en casa de cultivo protegido. Ciencia en su PC. 2020;1:60-74. Available from: https://www.redalyc.org/journal/1813/181363107005/html/
  30. 30. De Souza-Torres A, Sueiro-Pelegrın L, Zambrano-Reyes M, Macias-Socarras I, Gonzalez-Posada M, Garcıa-Fernandez D. Extremely low frequency non-uniform magnetic fields induce changes in water relations, photosynthesis and tomato plant growth. International Journal of Radiation Biology. 2020;96:951-957. DOI: 10.1080/09553002.2020.1748912
  31. 31. Dhawi F. Why magnetic fields are used to enhance a plant's growth and productivity? Annual Research & Review in Biology. 2014;4:886. DOI: 10.9734/ARRB/2014/5983
  32. 32. Duarte CE, Sarmiento O. Influencia de tratamiento alternativo del agua de riego en los requerimientos hídricos de algunas hortalizas para condiciones de deficiencias hídricas. Ingeniería de Recursos Naturales y del Ambiente. 2013;1:91-99. Available from: https://www.redalyc.org/articulo.oa?id=231130851009
  33. 33. Guruprasad K, Shine M, Joshi J. Impact of Magnetic Field on Crop Plants. Breeding and Genetic Engineering. The Biology and Biotechnology Research. 2016. Available from: https://www.researchgate.net/publication/322277518
  34. 34. Maffei ME. Plant responses to electromagnetic fields. In: Biological and Medical Aspects of Electromagnetic Fields. 4th ed. Boca Raton, Florida, United States: CRC Press; 2018. pp. 89-110. eBook ISBN 9781315186641. Available from: https://www.crcpress.com/Biological-and-Medical-Aspects-of-Electromagnetic-Fields-Fourth-Edition/Greenebaum-Barnes/p/book/9781138735262
  35. 35. Sarraf M, Kataria S, Taimourya H, Santos LO, Menegatti RD, Jain M, et al. Magnetic field applications in plants: An overview. Plants. 2020;9(9):1139. DOI: 10.3390/plants9091139
  36. 36. Teixeira J, Dobránszki J. Magnetic fields: How is plant growth and development impacted? Protoplasma. 2016;253:1-18. DOI: 10.1007/s00709-015-0820-7
  37. 37. Vian A, Davies E, Gendraud M, Bonnet P. Plant responses to high frequency electromagnetic fields. BioMed Research International. 2016;2016:1-14. DOI: 10.1155/2016/1830262
  38. 38. Dubois AEF, Leite GO, Rocha JBT. Irrigation of Solanum lycopersicum L. with magnetically treated water increases antioxidant properties of its tomato fruits. Electromagnetic Biology and Medicine. 2013;32:355-362. DOI: 10.3109/15368378.2012.721847
  39. 39. Dubois AF, Boix YF, Leite GO, Luna LG, Boligon AA, Athayde ML, et al. Evaluación de la irrigación con el uso de campos magnéticos estáticos sobre la síntesis de metabolitos secundarios en Solanum lycopersicum L. (tomate). Investigación y Saberes. 2012;1:54-61. Available from: http://revistasdigitales.utelvt.edu.ec/revista/index.php/investigacion_y_saberes/article/view/19
  40. 40. González-Casado S, Martín-Belloso O, Elez-Martínez P, Soliva-Fortuny R. Enhancing the carotenoid content of tomato fruit with pulsed electric field treatments: Effects on respiratory activity and quality attributes. Postharvest Biology and Technology. 2018;137:113-118. DOI: 10.1016/j.postharvbio.2017.11.017
  41. 41. Luengo E, Álvarez I, Raso J. Improving carotenoid extraction from tomato waste by pulsed electric fields. Frontiers in Nutrition. 2014;1:12. DOI: 10.3389/fnut.2014.00012
  42. 42. Vallverdú A, Oms G, Odriozola I, Lamuela R, Martín O, Elez P. Effects of pulsed electric fields on the bioactive compound content and antioxidant capacity of tomato fruit. Journal of Agricultural and Food Chemistry. 2012;60:3126-3134. DOI: 10.1021/jf205216m
  43. 43. Ferreira S, Freitas R, Lazzari E. Padrão de identidade e qualidade do tomate (Lycopersicon esculentum Mill.) de mesa. Ciência Rural. 2004;34:329-335. DOI: 10.1590/S0103-84782004000100054
  44. 44. Casanova A, Gómez O, Depestre T, Igarza A, Leon M, Santos R, Chailloux M. Manual para la producción protegida de hortalizas. 2da. Ed. Inst. Inv. Hortícolas “Liliana Dimitrova” . MINAG. 2007. La Habana, Cuba. 138 p. ISBN: 9597111373, 9789597111375
  45. 45. Navarro G, Navarro S. Química Agrícola. Química del Suelo y de los nutrientes esenciales para las plantas. 3ra ed. España: Ed. Mundi-Prensa; 2013. 508 p. ISBN: 9788484766568, 848476656X
  46. 46. Mayea S. Microbiología Agropecuaria. 2d ed. La Habana, Cuba: Editorial Félix Varela; 2004
  47. 47. Gilart F, Deas D, Ferrer D, López P, Ribeaux G, Castillo J. High flow capacity devices for anti-scale magnetic treatment of water. Chemical Engineering and Processing: Process Intensification. 2013;70:211-216. DOI: 10.1016/j.cep.2013.04.001
  48. 48. AOAC. Official Methods of Analysis. 15th ed. Washington, D.C.: Association of Official Analytical Chemists; 1990
  49. 49. Park YW. Determination of moisture and ash contents of food. In: Nollet LML, editor. Handbook of Food Analysis. New York, USA: Marcel Dekker Inc; 2004. pp. 55-82
  50. 50. AOAC. Official Methods of Analysis. 14th ed. Washington, D.C.: Assoc. Offic. Anal. Chem.; 1984
  51. 51. Miranda M, Cuellar A. In: Varela F, editor. Manual de prácticas de laboratorio Farmacognosia y Productos Naturales. Cuba: La Habana; 2000. 34-49 p. ISBN: 978-959-07-1795-6
  52. 52. Linstrom PJ, Mallard WG. NIST Chemistry Webbook, NIST Standard Reference 69. NGaithersburg: National Institute of Standards and Technology; 2005
  53. 53. Hasaani AS, Hadi ZL, Hasaani AS, Rasheed KA. Experimental study of the interaction of magnetic fields with flowing water. International Journal of Basic and Applied Sciences. 2015;3(3):1-8. Available from: https://www.academia.edu/32188601/Experimental_Study_of_the_Interaction_of_Magnetic_Fields_with_Flowing_Water:
  54. 54. Yadollahpour A, Rashidi S, Fatatemeh K. Applications of magnetic water technology in farming and agriculture development: A review of recent advances. Current World Environment: An International Research Journal of Environmental Sciences. 2014;9:695-703. DOI: 10.12944/CWE.9.3.56
  55. 55. Julca-Otiniano A, Meneses-Florián L, Blas-Sevillano R, Bello-Amez S. La materia orgánica, importancia y experiencia de su uso en la agricultura. Idesia (Arica). 2006;24:49-61. DOI: 10.4067/S0718-34292006000100009
  56. 56. Esmaeilnezhad E, Choi HJ, Schaffie M, Gholizadeh M, Ranjbar M. Characteristics and applications of magnetized water as a green technology. Journal of Cleaner Production. 2017;161:908-921. DOI: 10.1016/j.jclepro.2017.05.166
  57. 57. Holysz L, Szczes A, Chibowski E. Effects of a static magnetic field on water and electrolyte solutions. Journal of Colloid and Interface Science. 2007;316:996-1002. DOI: 10.1016/j.jcis.2007.08.026
  58. 58. Martínez CM, Machado R, Casals M. Evaluación de los efectos del tratamiento magnético a la solución CM-95 por medidas de conductividad eléctrica. Revista Cubana de Química. 2011;23:76-79. ISSN: 0258-5995. Available from: https://www.redalyc.org/pdf/4435/443543722010.pdf
  59. 59. Pang XF, Shen G-F. The changes of physical properties of water arising from the magnetic field and its mechanism. Modern Physics Letters B. 2013;27:1-9. DOI: 10.1142/S021798491350228X
  60. 60. Mohamed AI, Ebead BM. Effect of magnetic treated irrigation water on salt removal from a sandy soil and on the availability of certain nutrients. International Journal of Engineering. 2013;2:36-44. ISSN 2305-8269. Available from: http://magtech.com.pk/pdf/agriculture-7.pdf
  61. 61. Abedinpour M, Rohani E. Effects of magnetized water application on soil and maize growth indices under different amounts of salt in the water. Journal of Water Reuse and Desalination. 2017;7:319-325. DOI: 10.2166/wrd.2016.216
  62. 62. El-Dayeim DE-TB. Evaluation of magnetic technology for vegetable production under drip irrigation system [doctoral dissertation]. Sudan: University of Khartoum; 2015. Available from: http://www.secheresse.info/spip.php?article53125
  63. 63. Shahin MM, Mashhour AMA, Abd-Elhady ESE. Effect of magnetized irrigation water and seeds on some water properties, growth parameter and yield productivity of cucumber plant. Current Science International. 2016;5:152-164. ISSN: 2077-4435. Available from: https://www.doa.go.th/seed/wp-content/uploads/2021/08/vegetable12.pdf
  64. 64. Pang XF, Zhong LS. The suspension of water using a superconductive magnetic-field and its features. IEEE Transactions on Applied Superconductivity. 2016;26(7):1-4. DOI: 10.1109/TASC.2016.2603598
  65. 65. Pang XF. The experimental evidences of the magnetism of water by magnetic-field treatment applied superconductivity. IEEE Transactions on Applied Superconductivity. 2014;24(5):1-6. DOI: 10.1109/TASC.2014.2340455
  66. 66. Pang X-F, Deng B. The changes of macroscopic features and microscopic structures of water under influence of magnetic field. Physica B: Condensed Matter. 2008;403:3571-3577. DOI: 10.1016/j.physb.2008.05.032
  67. 67. Rawabdeh H, Shiyab S, Shibli R. The effect of irrigation by magnetically water on chlorophyll and macroelements uptake of pepper (Capsicum annuum L.) Jordan. The Journal of Agricultural Science. 2014;10:205-214. Available from: https://journals.ju.edu.jo/JJAS/article/viewFile/6757/3897
  68. 68. Mghaiouini R, Elaouad A, Taimoury H, Sabir I, Chibi F, Hozayn M, et al. Influence of the electromagnetic device aqua 4d on water quality and germination of lettuce (Lactuca sativa L.). International Journal of Current Engineering and Technology. 2020;10:19-24. DOI: 10.14741/ijcet/v.10.1.4
  69. 69. Aly MA, Thanaa ME, Os M, Maze AAA. Effect of magnetic irrigation water and some anti-salinity substances on the growth and production of Valencia orange. Middle East Journal of Agriculture Research. 2015;4:88-89. ISSN: 2077-4605. Available from: https://www.curresweb.com/mejar/mejar/2015/88-98.pdf
  70. 70. Pang X-F, Deng B, Tang B. Influences of magnetic field on macroscopic properties of water. Modern Physics Letters B. 2012;26:1-13. DOI: 10.1142/S0217984912500698
  71. 71. Berni R, Luyckx M, Xu X, Legay S, Sergeant K, Hausman JF, et al. Reactive oxygen species and heavy metal stress in plants: Impact on the cell wall and secondary metabolism. Environmental and Experimental Botany. 2019;161:98-106. DOI: 10.1016/j.envexpbot.2018.10.017
  72. 72. El Sayed HESA. Impact of magnetic water irrigation for improve the growth, chemical composition and yield production of broad bean (Vicia faba L.) plant. American Journal of Experimental Agriculture. 2014;4:476-496. DOI: 10.9734/AJEA/2014/7468
  73. 73. Hozayn M, Abdel-Monem AA, Qados AMSA. Irrigation with magnetized water: A novel tool for improving crop production in Egypt. In: Fifteenth International Water Technology Conference, IWTC-15; 2011; Alexandria, Egypt. pp. 4206-4222. Available from: http://www.magtech.com.pk/pdf/agriculture-13.pdf
  74. 74. Socorro A, García F. Simulation of magnetic field effect on a seed embryo cell. International Agrophysics. 2012;26:167-173. DOI: 10.2478/v10247-012-0024-8
  75. 75. Poinapen D, Brown DCW, Beeharry GK. Seed orientation and magnetic field strength have more influence on tomato seed performance than relative humidity and duration of exposure to non-uniform static magnetic fields. Journal of Plant Physiology. 2013;170:1251-1258. DOI: 10.1016/j.jplph.2013.04.016
  76. 76. Shahzad T, Ahmad I, Choudhry S, Saeed M, Khan M. DPPH free radical scavenging activity of tomato, cherry tomato and watermelon: Lycopene extraction, purification and quantification. International Journal of Pharmacy and Pharmaceutical Sciences. 2014;6:223-228. ISSN: 2656-0097. EISSN: 0975-1491. Available from: https://hero.epa.gov/hero/index.cfm/reference/details/reference_id/8222123
  77. 77. Canti MG. Aspects of the chemical and microscopic characteristics of plant ashes found in archaeological soils. Catena. 2003;54:339-361. DOI: 10.1016/S0341-8162 (03)00127-9
  78. 78. Abdul Qados A, Hozayn M. Magnetic water technology, a novel tool to increase growth, yield and chemical constituents of lentil under greenhouse condition. American-Eurasian Journal of Agricultural & Environmental Sciences. 2010;7:457-462. Available from: http://www.idosi.org/aejaes/jaes7(4)/13.pdf
  79. 79. Sadeghipour O, Aghaei P. Improving the growth of cowpea (Vigna unguiculata L. Walp.) by magnetized water. Journal of Biodiversity and Environmental Sciences. 2013;3:37-43. ISSN: 2220-6663. Available from: http://www.innspub.net/wp-content/uploads/file/JBES-V3No1-p37-43.pdf
  80. 80. Guil J, Guerrero L, Rebolloso M, Fuentes M. Nutrient composition and antioxidant activity of eight tomato (Lycopersicon esculentum) varieties. Journal of Food Composition and Analysis. 2009;22:123-129. DOI: 0.1016/j.jfca.2008.10.012
  81. 81. Pinela J, Barros L, Carvalho A, Ferreira I. Nutritional composition and antioxidant activity of four tomato (Lycopersicon esculentum L.) farmer’ varieties in Northeastern Portugal homegardens. Food and Chemical Toxicology. 2012;50:829-834. DOI: 10.1016/j.fct.2011.11.045
  82. 82. Albuquerque W, Costa M, Fernandes T, Porto A. Evidences of the static magnetic field influence on cellular systems. Progress in Biophysics and Molecular Biology. 2016;121:16-28. DOI: 10.1016/j.pbiomolbio.2016.03.003
  83. 83. Hernández-Yépez J-N, De La Haba M-J, Sánchez M-T. Effect of different prepackaging treatments on the physical/chemical quality of margariteño tomatoes during postharvest storage at room temperature. Journal of Food Quality. 2013;36:113-120. DOI: 10.1111/jfq.12022
  84. 84. Panjai L. The role of post-harvest supplementary light exposure for ripening and quality development of tomato fruit [dissertation]. Online-Ausgabe: Rheinische Friedrich-Wilhelms-Universität Bonn; 2020. Available from: https://nbn-resolving.org/urn:nbn:de:hbz:5-60488
  85. 85. Križaj D, Valenčič V. The effect of ELF magnetic fields and temperature on differential plant growth. Journal of Bioelectricity. 1989;8:159-165. DOI: 10.3109/15368378909020954
  86. 86. Yusuf KO, Ogunbamowo TR, Obalowu RO. Effect of magnetized water on water use efficiency, yield and nutritional qualities of watermelon under deficit irrigation. Agricultural Engineering International. CIGR Journal. 2020;22:51-60. Available from: https://cigrjournal.org/index.php/Ejounral/article/view/5833/3363
  87. 87. Dhawi F. Why magnetic fields are used to enhance a plant's growth and productivity? Annual Research & Review in Biology. 2014;4:886-896. DOI: 10.9734/ARRB/2014/5983
  88. 88. Anjum S, Hamid A, Ghafoor A, Tahira R, Shah SZA, Awan SI, et al. Evaluation of biochemical potential in tomato (Solanum lycopersicum) germplasms. Pakistan Journal of Agricultural Sciences. 2020;57:177-187. DOI: 10.21162/PAKJAS/20.8140
  89. 89. El Shokali AA, Abdelbagi AM, Abdallah M. Enhancing on the mineral elements of exposure to magnetic field in plants leaves. Journal of Basic and Applied Sciences. 2015;11:440-444. ISSN: 1814-8085. Available from: http://www.lifescienceglobal.con/inde
  90. 90. Barker AV, Pilbeam DJ. Handbook of Plant Nutrition. 2nd ed. Boca Raton, Florida, USA: CRC Press.Taylor and Francis Group; 2015. 773 p. DOI: 10.1201/b18458
  91. 91. Khattab E, Mona M, Hegazi A, Arafa A. Magnetic treatment of irrigation water for improving vegetative growth, fresh and dry yield of bean (Phaseolus vulgaris L.) grown under plastic house. Egyptian Journal of Agricultural Research. 2014;92:1395-1411. DOI: 10.21608/ejar.2014.156788
  92. 92. Elbadrawy E, Sello A. Evaluation of nutritional value and antioxidant activity of tomato peel extracts. Arabian Journal of Chemistry. 2011;11:1-9. DOI: 10.1016/j.arabjc.2011.11.011
  93. 93. Houston MC. Treatment of hypertension with nutrition and nutraceutical supplements: Part 1. Alternative and Complementary Therapies. 2018;24:260-275. DOI: 10.1089/act.2018.29191.mho
  94. 94. Belyavskaya NA. Biological effects due to weak magnetic field on plants. Advances in Space Research. 2004;34:1566-1574. DOI: 10.1016/j.asr.2004.01.021
  95. 95. Maheshwari B, Grewal H. Magnetic treatment of irrigation water: Its effects on vegetable crop yield and water productivity. Agricultural Water Management. 2009;96:1229-1236. DOI: 10.1016/j.agwat.2009.03.016
  96. 96. Ospina-Salazar DI, Benavides-Bolaños JA, Zuñiga-Escobar O, Muñoz-Perea CG. Photosynthesis and biomass yield an in tabasco pepper, radish and maize subjected to magnetically treated water. Corpoca Cienc. Tecnol. Agrepecuaria. 2018;19:201-305. DOI: 10.21930/rcta.vol19_num2_art:537
  97. 97. Mohamed HH, Elnasri M. The impact of magnetized water on some physiological characters of parsley Petroselinum crispum (Mill). International Journal of Innovative Science and Research Technology. 2019;4:725-729. ISSN No:-2456-2165. Available: https://ijisrt.com/wp-content/uploads/2019/05/IJISRT19MA205.pdf
  98. 98. Grewal HS, Maheshwari BL. Magnetic treatment of irrigation water and snow pea and chickpea seeds enhances early growth and nutrient contents of seedlings. Bioelectromagnetics. 2011;32:58-65. DOI: 10.1002/bem.20615
  99. 99. Azcón-Bieto J, Talón M. Fundamentos de Fisiología Vegetal. España: McGraw Hill Interamericana; 2008. 134 p
  100. 100. García G. Revisión ingesta de nutrientes: Conceptos y recomendaciones internacionales (1ª Parte). Nutrición Hospitalaria. 2006;21:291-299 Available from: https://scielo.isciii.es/pdf/nh/v21n3/revision.pdf
  101. 101. Cui H, Liu X, Jing R, Zhang M, Wang L, Zheng L, et al. Irrigation with magnetized water affects the soil microenvironment and fruit quality of eggplants in a covered vegetable production system in Shouguang City, China. Journal of Soil Science and Plant Nutrition. 2020;20:2684-2697. DOI: 10.1007/s42729-020-00334-7
  102. 102. Ibrahim MO, Mutwali EM, Salih EA, Ismail WH. Effect of magnetized water on the germination and some yield components of swiss chard (Beta vulgaris var. cicla). International Journal of Innovative Science and Research Technology. 2018;3:410-415. ISSN:-2456-2165. Available from: https://ijisrt.com/wp-content/uploads/2018/10/IJISRT18SP217.pdf
  103. 103. Hozayn M, El-Dahshouri M, Salama AM, Abdelraouf R, Ahmed A. Influence of magnetic brackish-water treatments on growth, anatomical structure, yield and quality of sugar beet (Beta vulgaris L.). Plant Archives. 2020;20:8271-8278. e-ISSN:2581-6063 (online), ISSN:0972-5210. Available from: http://www.plantarchives.org/20-2/8271-8278%20(7091).pdf
  104. 104. Muñoz VO, Casas CP, Vázquez SM, Espinal MJM. Los procesos redox y su relevancia en la vida. In: Muñoz Ocotero V, editor. Lecturas de apoyo para comprender mejor la Química. México: Facultad de Ciencias, UNAM; 2015. pp. 105-114. Available from: http://librosoa.unam.mx/bitstream/handle/123456789/267/30.pdf?sequence=2&isAllowed=y#page=103
  105. 105. Bressy FC, Geysa BB, Barbosa IS, Teixeira LSG, Korn MGA. Determination of trace element concentrations in tomato samples at different stages of maturation by ICP OES and ICP-MS following microwave-assisted digestion. Microchemical Journal. 2013;109:145-149. DOI: 10.1016/j.microc.2012.03.010
  106. 106. Yusuf KO, Baiyeri MR, Sakariyah SA. Effects of magnetically-treated water on tomato yield and uptake of heavy metals under water deficit conditions. In: 8th International Conference on Agricultural, Environment, Biology and Medical Sciences of International Institute of Chemical, Biological and Environmental Engineering (IICBEE); 2017; Dubai. 2017. pp. 11-20. ISBN 978-93-86878-07-6. Available from: http://heaig.org/images/proceedings_pdf/C1217203.pdf
  107. 107. Shalatonin V. Effect of unipolar magnetic field on macroscopic properties of distilled water international. Journal of Pharma Medicine and Biological Sciences. 2017;6:89-93. DOI: 10.18178/ijpmbs.6.3.89-93
  108. 108. Zhang X, Yarema K, Xu A. Impact of static magnetic field (SMF) on microorganisms, plants and animals. In: Biological Effects of Static Magnetic Fields. Singapore: Springer; 2017. pp. 133-172. DOI: 10.1007/978-981-10-3579-1_5
  109. 109. Rifna EJ, Ratish Ramanan K, Mahendran R. Emerging technology applications for improving seed germination. Trends in Food Science & Technology. 2019;86:95-108. DOI: 10.1016/j.tifs.2019.02.029

Written By

Albys Esther Ferrer Dubois, Yilan Fung Boix, Clara Martínez Manrique, Liliana Gómez Luna, Elizabeth Isaac Aleman, Sophie Hendrix, Natalie Beenaerts and Ann Cuypers

Reviewed: 30 August 2023 Published: 23 October 2023

© 2023 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution 3.0 License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Continue reading from the same book

View All
Chapter 1 Management of Phytopathogens by Antagonistic Bacil...

By Owais Iqbal, Chengyun Li, Nasir Ahmed Rajput and A...

82 downloads

Chapter 2 Impacting of Root-Knot Nematodes on Tomato: Curren...

By Mohamed Youssef Banora

93 downloads

Chapter 3 Biological Seed Coating Innovations for Sustainabl...

By Patta Sujatha, Madagoni Madhavi, Mandalapu Pallavi...

143 downloads