Storage and Packaging Dependent Physical Properties of Tomatoes

The study was conducted to see the effect of packaging material and storage condition on the physical properties of tomatoes (Lycopersicon esculentum Mill) varieties (Himshikhar and NS – 524). These varietal tomatoes were packaged in High Density Poly Ethylene (HDPE) and stored under refrigerator, BOD incubator and ambient temperatures. Tomato variety Himshikhar packed in HDPE showed minimum shrinkage at ambient temperature followed by refrigerator and BOD condition.

Tomato (Lycopersicon esculentum Mill) is the world's most commercially produced vegetable (Gaware et al., 2010).The first known record of tomato is in the year 1554 in South America, after 200 years it gradually spread to other parts of the world (Kumar et al., 2012).Tomato is rich source of vitamins A, C, potassium, minerals and fibers.Lycopene is a phytochemical nutrient element found in many fruits and vegetables, but excessively found in tomato that imparts natural red colour (Holden et al., 1999).Use of tomatoes is increasing day by day and a variety of products like puree, syrup, paste, ketchup, juice etc. are made.To design and optimization a machine for handling, cleaning, conveying, separation and storing, the physical attributes and their relationships must be known (Mirzaee et al., 2008).Designing such equipment without consideration of these properties may yield poor results.
Therefore the determination and consideration of these properties have an important role (Taheri-Garavand et al., 2009).Among these physical properties, length, width, thickness, mass, volume, projected areas and center of gravity are the most important factors in sizing systems (Mohsenin, 1986).Viswanathan et al., (1997) concluded that properties viz., size, density, moisture and force varied with the variety of the tomato fruits.The per cent seed, pulp and skin content in the fruit also varied with the variety.Varshney et al., (2007) studies the physical and mechanical properties of tomato and revealed that moisture content and weight density of fruits decreased while loss and volume shrinkage increased with storage period.Kaymak et al., (2010) determined the color and several physical characteristics of two common tomato cultivars (Alida F1 and H2274) grown in Erzincan region in Turkey.Taheri-Garavand et al., (2011) studied on some morphological and physical characteristics of tomato used in mass models to characterize best post harvesting options.Li et al., (2011) studied the structural and geometrical properties; Atallah, (2012) conducted study on three different varieties of tomato, Onifade et al., (2013) investigate some physical properties of local variety of tomatoes that are relevant in the handling and processing of the fruits.HDPE (High Density Poly Ethylene) used as storage materials, since packaging of fruits in polyethylene films results in modified atmosphere which reduced the fruit decay, softening and loss soluble solids during storage.Keeping of fruits in the polyethylene package help in extension of storage life and retention of quality (Salunkhe and Wu, 1973).According to Vidigal et al., (1979) packing in polyethylene bags decreased weight loss and controlled atmosphere storage improves keeping quality in fruits.Kumar et al., (1999) and Sammi and Masud, (2007) also used polyethylene packaging in their investigation to improve the shelf life of tomatoes.To our knowledge, detailed investigations concerning physical properties of tomato in relation with storage conditions and storage material have not been published.Therefore, the aim of this research was to see the effect on physical attributes of tomato due to HDPE as storage material and three different storage conditions.This information provides useful insights into design of processing, packing equipments and transportations for tomato.

MATERIALS AND METHODS
The experiment was conducted at Food Analysis Laboratory of Sardar Vallabhbhai Patel University of Agriculture and Technology, Meerut (India).Fresh, ripe, red in colour tomatoes, free from disease and insects were procured directly from the farmers of village Dhanju and Lawad.Two varieties of tomatoes namely Himshikhar and NS-524 were used for the present investigation.
Measurement of dimensions: Three linear dimensions namely polar diameter (D 1 ), major diameter (D 2 ) and minor diameter (D 3 ) for all tomatoes were measured using a Vernier Caliper (least count 0.01mm).Polar diameter is defined as the distance between tomato apex and the stem end.Major and minor diameters of the tomatoes are defined as maximum and minimum width respectively in a plane perpendicular to a polar axis (Mohsenin, 1986).
Mass, volume and density: Mass of fresh tomatoes was determined using high accuracy electronic balance.As the tomatoes were numbered the weight of individual tomatoes were recorded every day.The volume of tomato was determined individually by water displacement method using a cylinder of 1 liter capacity.The mass and volume were expressed in 'g' and 'ml' respectively (1 ml=1cm 3 ).Densities for tomatoes were calculated using the following equation: ... (1) Geometrical and morphological properties: Arithmetic mean diameters (AMD), geometric mean diameter (GMD), surface area and sphericity for tomatoes were calculated by using the following equations as suggested by Mohsenin (1986) ... (6) Where, Where, V= volume S= surface area TSS: Total soluble solids of tomatoes were measured using a hand hold refractrometer.

Packaging and storage
High density poly ethylene (HDPE) as packaging material was used and then samples were stored under three different storage condition viz.ambient temperature, BOD incubator and refrigerator condition.

Statistical analysis
The data obtained from various experiments were recorded during the course of study and subjected to statistical analysis as per the method of "Analysis of variance".The significance and non significance of data obtained from various experiments was judge with the help of F (Variance ratio) table.OPSTAT software and spreadsheet software (Microsoft Office excel-2007) were used to analyze the recorded data.

CONCLUSION
On the basis of the experimental finding it may be conclude that tomato variety Himshikhar packed in HDPE shows minimum shrinkage at ambient temperature then refrigerator and BOD incubator storage condition.Tomato variety NS -

(
For sphericity D 1 = largest diameter) Shape factor ( : Shape factor based on volume & surface area of tomatoes was determined (McCabe and Smith, 1984) as;

Table 1 .
Effect of packaging material (HDPE) and storage condition (ambient temperature) on the physical properties of tomato (variety: Himshikhar)

Table 2 .
Effect of packaging material (HDPE) and storage condition (refrigerator) on the physical properties of tomato (variety: Himshikhar).

Table 3 .
Effect of packaging material (HDPE) and storage condition (BOD incubator) on the physical properties of tomato (variety: Himshikhar)

Table 4 .
Effect of packaging material (HDPE) and storage condition (ambient temperature) on the physical properties of tomato (variety: NS-524)