Tomato Quality from Organic and Conventional Production in the Selected Area of Dharan , Sunsari , Nepal

From the selected area of Dharan, Sunsari, Nepal, conventional and organic tomatoes were grown and tested with different parameters. Conventional tomatoes contained less value of Mg, Ca, K, Cu and Mn, but more value of Fe than organic tomatoes, where as Pb and Ni were not detected.The Zn was found to be same in both tomatoes sample. The sizes of conventional tomatoes were reportedly bigger than organic tomatoes. The viscosity and surface tension of organic tomatoes juice were reported to be higher than in conventional tomatoes juice. The refractive index value was found to be lower in conventional tomatoes juice than in organic tomatoes juice. The vitamin C value was found to be higher in conventional tomatoes juice than in organic tomatoes juice. The comparative study of color, juice containing capacity, storage capacity and firmness of organic and conventional tomatoes of Dharan,Sunsari,Nepal has also been included.


Introduction
Nowadays organic farming is very famous than conventional farming in our Country.Atmospheric conditions, soil environment and farming process influences the tomato farming.After potato, the tomato is used widely (Lugasi et al., 2003).
From the tomatoes, many foods are possible such as sauces, catsup (ketchup), puree, pastes, soups, juices and juice blends etc (Preedy and Watson, 2008).Tomato is an important source of micronutrients, certain minerals and carboxylic acids (Caputo et al., 2004;Hernandez-Suarez et al., 2007).Tomatoes and tomato products are antioxidant and carotenoids (George et al., 2004;Sahlin et al., 2004;Ilahy et al., 2011;Pinela et al., 2012).The consumption of tomatoes has been shown to reduce the risks of cardiovascular disease and certain types of cancer, such as cancers of prostate, lung and stomach (Canene-Adams et al., 2005).
It was reported, lycopene plays a role in the prevention of different health issues, cardiovascular disorders, digestive tract tumors and in inhibiting prostate carcinoma cell proliferation in humans (Levy and Sharoni, 2004).
It was noticed that the higher levels of bioactive compounds in organically produced tomato fruits compared to conventional ones, but not all studies have been consistent in this respect (Rembiałkowska, 2004;Ordonez-Santos et al., 2011;Chassy et al., 2006).Organic tomatoes give good prices compared to conventional tomatoes (Kapoulas et al., 2011).
The differences between organic and conventional production tomatoes are observed by the use of the fertilizer as: organic-manure; conventional-mineral fertilizer ( Kapaulas, 2012 ).Some studies report better taste, higher Vitamin C contents and higher levels of other quality related compounds for organically grown products (Mitchell et al., 2007, Caris-Veyrat et al., 2004), whereas several other studies have found the opposite characteristics between organically and conventionally grown vegetables (Caris-Veyrat et al., 2004).
In the United States in 2003 originated from California farms, ninety three percent of the organic tomatoes sold (Economic Research Service, 2005).
It was studied by (Barrett et al., 2007) organically grown products experienced a doubling in percent penetration of

Research Article
The quality of tomato fruit was studied by Pilipavicius (2014) during 2008-2010 also.The study was located in the Sapes, North eastern Greece, using two different growing systems: organic and conventional and found organic tomatoes contained more carotenoids, more minerals (P, K, Mg, Ca, Zn, Cu, Ni), far less heavy metals (Zn, Cu, Ni, Fe), less nitrates, about 30-40% less and any pesticide residues.
The levels of some phenolic compounds were known to be higher in organic fruit (Petkovsek et al., 2010).Plants create phenolic compounds for many reasons, but a major reason is to make plant tissues less attractive to herbivores, insects and other predators.Accordingly, it is important to sort out if higher levels of phenolic compounds affect the taste of organic fruits and vegetables when compared to conventionally grown (Kapoulas et al., 2011).
Vitamin C of tomato fruits accounts for up to 40% of the recommended dietary allowance for human beings.Farm management skills combined with site-specific effects contribute to high Vitamin C levels, and the choice of variety significantly influences the content of ascorbic acid (Ilahy et al., 2011).
Ascorbic acid content in organically fertilized tomatoes ranges between 29% and 31% (Verma et al., 2015), which is higher than the results obtained from tomatoes that were fertilized with mineral solutions.
The objective of this study is to compare the quality value of processing tomatoes grown on matched commercial grower fields in selected area of Dharan, sunsari.Several tomato quality components, including color, size, viscosity, surface tension, refractive index, juice contents, metal ions, firmness, vitamin C and storage capacity contents are to be compared in processing tomatoes grown by conventional production systems and organic production systems.

Materials
The F1 hybrid of tomatoes seeds was bought from Dharan, Sunsari which were produced and marketed by Syngenta India Ltd. to grow in Dharan-16, near Samichowk of Dharan Sub-metropolitan city,Sunsari.The seeding was done.The plants were transplanted after one month.The farming was done by taking five plants in two ways: Organic tomatoes farming and conventional tomatoes farming.For conventional farming, the seeds of tomatoes were planted by using urea whereas for organic farming, the seeds of tomatoes were planted by using goat manure and plant leaves as shown in Fig. 1.The samples were ready for analysis after 5 months of plantation.The taste of organic edible fruits were sour where as that of conventional were sweet & sour.These edible fruit of tomatoes were the samples for analysis of different parameters.The samples were tested in different laboratories (Chemistry Lab. in Sunsari Technical College, Dharan-4, Nepal, Nepal Environmental Service Centre, Biratnagar, Nepal, and Department of Food Technology and Quality Control, Babarmahal, Kathmandu Nepal).In order to measure different parameters like surface tension, viscosity and refractive index, amount of metals like P, Mg, K, Ca and heavy metals like Zn, Mn, Ni , Pb, and Fe as well as the size of tomatoes, color, juice contents etc. for both conventional and organic tomatoes.It was taken equal amount of organic and conventional tomatoes.Both organic and conventional tomatoes were cut with small pieces and kept separately in the oven for drying up to temperature 80ºC.Drying was continued up to 50 hrs.After then temperature was increased up to 300ºC for approx one hour.The samples were dried till black, grinded and made powder.The equal amount of powder was kept in separate dry clean beaker and added equal amount of distilled water in both beaker.The tomato juice was filtered with filter paper in separate beaker.The residue was removed and filtrate was used for measuring the surface tension and viscosity of both tomatoes juice.
For density calculation of tomatoes juice, the equation (1) was used. = The surface tension and viscosity were calculated at 32℃ temperature.
The viscosity of a liquid is determined with respect to that of distilled water.This is called relative viscosity.Let t1 and t2 be the times of flow of fixed volume v of the two liquids through the same capillary.
The equation used for the calculation of viscosity is given below Thus by determining the densities and the times of flow of the two liquids, the coefficient of viscosity of one of them can be easily calculated, provided the coefficient of viscosity of the other liquid.
The relative viscosity coefficient is calculated from the expression: Knowing the value of viscosity coefficient of water (ηw) at the temperature of the experiment, the absolute viscosity coefficient (η) of the given liquid can be found.
The drop weight method for determination of surface tension is based on the principle that the weight of a liquid falling from a capillary tube held vertical is approximately proportional to the surface tension of the liquid.If the surface tension of two liquids be γ1 and γ2 and w1 and w2 be the mean weight of their drops falling from the same capillary tube.
Let us suppose the number of drops of the two liquids be n1 and n2 for the same volume V of the liquids.Then Where d1 and d2 are the respective densities of the liquids. Hence, If the surface tension of one of the liquids is known then that of the other can be easily calculated from equation ( 5).

Procedure for operating Atomic absorption spectroscopy in determination of metals:
1. 10 g ground sample was transferred into ashing vessel.2. The sample was charred in muffle, then ashed at 500℃ overnight.3. The ash was redissolved in 20 ml 2N HCl. 4. The ash was filtered through fast paper into 100 ml volumetric flask, washing paper and residue thoroughly with water.It was diluted into 100 ml. 5.The absorption of solution was measured directly.
At least 4 standard solutions was read within analytical range before and after each group of 6 to 12 samples.6.The calibration curve was done from average of each standard before and after sample group.

Results and Discussion
From the experiment, the following data has been obtained and are as follows: The weight of conventional tomatoes juice = 50.69g.
The weight of organic tomatoes juice = 50.613g.The nature of juice of organic tomatoes has found to be more surface tension than conventional tomatoes juice.
The size of the organic tomatoes was smaller than conventional tomatoes as shown in Fig. 2. Organic tomatoes were dark red colour than conventional tomatoes.It was observed that colour in conventional tomatoes were faint red Refractive index in conventional tomatoes: 2.5 Brix Refractive index in organic tomatoes: 2.9 Brix The result of total suspended solid (TSS) by using refractometer is given below: Total suspended solid (TSS) in conventional tomato: 5.3% Total suspended solid (TSS) in organic tomato: 5.3% It was obtained by the experiment for acidity measurement, P H in conventional tomatoes juice: 4.7 P H in organic tomatoes juice: 5.1 The Table 1 shows the comparative studies of organic and conventional tomatoes farming in the parameters as TSS, refractive index, surface tension, viscosity, pH , Vitamin C, color , size, juice contents, storage capacity and firmness.
The calibration curve for the determination of heavy metals of both tomatoes (conventional and organic) by using Atomic absorption spectroscopy are given in Figs. 3 to 6.According to test of AAS in Environmental Service Centre Lab., Biratnagar, Morang, Nepal the metals like Potassium, Calcium and Magnesium were present maximum amount in organic tomatoes than conventional tomatoes juice.Also, the heavy metals like Copper was present higher amount in organic tomatoes than conventional tomatoes whereas the heavy metal like Iron was present lower amount in organic tomatoes than conventional tomatoes.The Zinc was found to be same amount in both organic and conventional production tomatoes.Lead and Nickel could not be detected in both organic and conventional tomatoes (Table 2).Our organic tomatoes achieved significantly greater concentrations of minerals.Such greater concentrations of minerals were found in the literature for organic tomatoes (Kelly and Bateman, 2010).
We have found significantly greater concentrations of K, Ca, Cu and Mg in organic tomatoes and greater concentrations of Fe in conventionally grown tomatoes.Our findings matched with the literature (Ilić et al., 2013).
The calcium content in the organic tomatoes (377.53 mg/100 g) in our research found to be higher than in conventional tomatoes (181.60 mg/100 gm).But the calcium concentrations for organic tomatoes (15.97-23.13mg/100 g) were higher in the reported literature (Ordonez-Santos et al., 2011).
The lead content of tomato fruit, in general, was very low and ranges depending on the hybrid and the methods of production from 0.07 to 0.19 mg/ 100g (Kapoulas et al., 2011).But we found nil result of Lead in both tomatoes.
Vitamin C from organic tomatoes farming has been found to be low (26 mg/100g) in comparison with conventional tomatoes (28mg/100g).Such high Vitamin C in organic tomatoes trends have been found in the literature (Lundegardh and Martensson, 2003;Borguini and Torres, 2006).It was also found that fertilizer that was rich in soluble nitrogen (N) could cause a decrease in the ascorbic acid content.
We can say that organic tomatoes were dark red color than conventional tomatoes due to presence of more carotene in organic production tomatoes than conventional production tomatoes.The juice of organic tomatoes has found to be more surface tension than conventional tomatoes juice due to more force of interaction between metals or other particles present in the organic tomatoes juice.So, number of drops of organic tomatoes is minimum than conventional production tomatoes juice and the nature of juice of organic tomatoes has found to be more viscous than conventional tomatoes juice due to presence of more amount of minerals, vitamins and some other constituent particles.The organic production tomatoes juice was more concentrated than conventional production tomatoes juice.So, it moves slowly due to more retarding force present in organic production juice.
Refractive index of organic tomatoes juice has greater value than conventional tomatoes juice.
Organic and inorganic fertilizer also influences the element present in the tomatoes.Organic production increases yields and builds soil quality.The organically farmed soils exhibited higher potential denitrification rates, greater denitrification efficiency, higher levels of organic matter, and greater microbial activity than the conventionally farmed soils.

Conclusions
The following conclusions have been drawn from the above results and discussion.Potassium, calcium and magnesium were present in high quantity in organic production tomatoes than in conventional production tomatoes.The Iron present was low in organic production tomatoes than in conventional production tomatoes.Copper present was high amount in organic production tomatoes than in conventional production tomatoes.Vitamin C present was low in organic production tomatoes than in conventional production tomatoes.Lead was not detected in both samples of tomatoes.The size of organic tomatoes was found to be smaller than conventional tomatoes.The surface tension and viscosity value of organic tomatoes juice was found to be of higher value than conventional tomatoes juice.The refractive index value was higher in organic tomatoes juice than in conventional tomatoes juice.Therefore, it can be concluded that organic tomatoes contain more nutritional value than conventional tomatoes.

Fig. 1 :
Fig. 1: Tomatoes farming (A.Conventional farming, B. Organic farming) Methods 10 Tomato samples were collected.Determination of refractive index was carried out by a refractometer.The determination of metals in tomato was measured by Atomic absorption spectroscopy (AAS).The viscosity and surface tension was also determined.
The weight of distilled water = 50.61g.It was obtained by the experiment for viscosity measurement, Time flow for organic tomatoes juice: 19 sec Time flow for conventional tomatoes juice: 18 sec Time flow for distilled water: 20 sec Viscosity in organic tomatoes: 7.609x10 -3 poise Viscosity in conventional tomatoes: 7.220x10 -3 poise The nature of juice of organic tomatoes has found to be more viscous than conventional tomatoes juice.It was obtained by the experiment for surface tension measurement, No of drops for conventional tomatoes juice: 130 No of drops for organic tomatoes juice: 124 No. of drops for distilled water: 128 Surface tension in conventional tomatoes: 70.353 dyne/cm Surface tension in organic tomatoes: 73.645 dyne/cm

Fig. 2 :
Fig. 2: Variation in size of tomatoes; A. Conventional; B. Organic It was obtained by the experiment for refractive index measurement.

Table 1 :
Comparison among TSS, refractive index, surface tension, viscosity, pH, Vitamin C, colour, size, juice contents, storage capacity and firmness for organic and conventional tomatoes.

Table 2 :
The data obtained from farming