EFFECTS OF RIPENING STAGES AND STORAGE DURATIONS ON RESISTANCE PARAMETERS OF BEEF TYPE TOMATOES: PART 1: SPRING PERIOD EFEITOS DE ESTÁGIOS DE MATURAÇÃO E DURAÇÕES DE ARMAZENAMENTO EM PARÂMETROS DE RESISTÊNCIA DE TOMATES CORAÇÃO DE BOI: PARTE 1: PERÍODO DE PRIMAVERA

Following the harvest, agricultural products are subjected to various negative impacts throughout the way to consumers. Mechanical damages such as color darkening, abrasion, cuts, or punctures over the fruit surface are irreversible damages and such damages ultimately end up in significant quality and economic losses. In modern production systems, only a certain portion of the products directly reach from producer to consumers. The majority of these products are subjected to mechanical damages through the crush, squeeze, vibration, and similar impacts during the harvest and postharvest processes. In this study, Tybeef tomato cultivar grown over the experimental greenhouses of Bati Akdeniz Agricultural Research Institute (BATEM) (control) and 14-193 and 14-206 coded candidate cultivars developed through breeding programs of BATEM were used as the plant material. Resistance parameters of tomato cultivars were determined at 4 different ripening stages (green, turning, pink, and red) and 4 different storage durations (4, 8, 12, and 16 days). Resistance parameters decreased with the progress of ripening and storage durations. All measurements and assessments revealed that 14-193 coded candidate cultivars were prominent for resistance parameters.


INTRODUCTION
There are intense labor and input in agricultural commodities. Therefore, pre and postharvest processes should continuously be monitored to minimize yield losses, to have products complying with certain standards, to supply high-quality products to markets, and to improve the allure of the products. Physiological and biological deteriorations during the production, harvest, and postharvest processes result in significant losses both in the quality and quantity of the products and ultimately end up with significant economic losses for both the producers and the country (KABAS, 2002). Insufficient infrastructure and organization generate about 25% losses in productions and only 7-8% of total production is exported just because of losses in the quality of the products. Since standard and desired commodities are not able to be produced, it is quite hard to compete with other exporter countries in international markets. It should always be kept in mind that "quality at the table is more significant than the quality at the branch". Thus, all the processes from the field to consumers should be performed in the uppermost appropriate manner. High-quality products should preserve quality attributes for a long time and marketed abroad on demand. Such cases will automatically improve both the producer and the country's economy.
Postharvest losses are generally generated through mechanical damages. Such damages result from crash, impact, puncture, vibration, and similar mechanical processes. About 6.1 million tons of fresh vegetables and fruits are produced in the Antalya province of Turkey. About 75% of this production (4.6 million tons) is constituted by vegetables and tomato alone constitutes about 55% of vegetable production of the province. About 62% of under-cover tomato production and 20% of openfield production of Turkey come from Antalya. About 3 million tons of fresh vegetables and fruit are exported from Turkey and, from those, 490 thousand tons are exported from Antalya alone (ANONYMOUS, 2018).
Mechanical damages may result in 30-40% losses throughout different processes from the field to consumers (PELEG; HINGA, 1986). Such damages are generally encountered through static and dynamic external forces like a crash, impact, squeeze, and vibration. Mechanical damages on agricultural products may vary with the physical and biological structure of the product and type of external forces. The damage is generally encountered as smash and fracture with the impact of crash forces and excessive deformations. Since agricultural products are living organisms, they are highly sensitive to mechanical damages. Damages during the transportation of agricultural products reduce their market values and make these products perishable and unstable for diseases and deteriorations (KARA; TURGUT, 1988). Therefore, the mechanical characteristics of agricultural products should be known to minimize such damages and losses accordingly. Several researchers have conducted studies on different agricultural products (GEZER et al., 2000) investigated dimensional attributes, mass, removal force, mass/removal force ratio, total dissolved solids, fruit flesh firmness, and modulus of elasticity of tomato, pepper, eggplant and cucumbers and reported modules elasticity value of 1006 kPa for tomato and 632 kPa for cucumber (MOHSENIN, 1986) and (SITKEI, 1986) conducted studies on external damages generated by static and dynamic forces and identified various types of external damages. Desmet et al. (2004) investigated the mechanical characteristics of tomato and pointed out that genotypes with lower punching sensitivity should be used for direct measurements of mechanical characteristics. Bentini et al. (2009) investigated the effects of potato cultivars and storage durations on the physio-mechanical characteristics and indicated that mechanical characteristics of the different cultivars were significantly different from each other. Eraltan (2005) stored Dixired and Earlyred peaches in cold storage at 0 ºC temperature and 90% relative humidity for 28 days to investigate the effects of cultivars and storage durations on mechanical attributes and reported decreasing peal tearing force, tearing energy, and firmness index with increasing storage durations. Garcia et al. (1995) investigated the effects of irrigation, moisture content, harvest time, and storage on fruit firmness peel characteristics, and damaging sensitivity of apple and pear species and put forth the relationships between fruit physical attributes and damaging. Schoorl and Holt (1983) studied the effects of storage durations and temperatures on the damaging sensitivity of Jonathan, Delicious, and Granny Smith apples.
Identification of resistance parameters of agricultural products constitutes valuable information for machine and equipment design, on one hand, aids in finding out the resistance of different agricultural products against mechanical forces and thus taking relevant measures accordingly on the other hand. In this study, the effects of 4 different fruit ripening stages (green, turning, pink, and red) and 4 different storage durations (4, 8, 12, and 16 days) on some resistance parameters of tomato were investigated.

MATERIAL AND METHOD
In this study, 3 different tomato cultivars (1 commercial cultivar -Tybeef and 2 candidate cultivars developed in tomato breeding programs of Bati Akdeniz Agricultural Research Institute  were used as the plant material ( Figure 1). Figure. 1. Tybeef, 14-193,14-206 variety Experiments were conducted at 4 different ripening stages and 4 different storage durations. The texture analysis test device was used to determine resistance parameters and a color measurement device was used to determine color parameters.
Experiments were conducted in two stages. The physical characteristics of tomatoes were determined in the first stage and resistance parameters were determined in the second stage of the study. All measurements were performed at 4 different ripening stages (green, turning, pink, and red) and 4 different storage durations (4, 8, 12, and 16 days at 12ºC temperature and 90% relative humidity).
For dimensional and shape characteristics, fruit length and diameters were measured with a digital caliper (±0.01 mm). The following equations were used to calculate the geometric mean diameter and sphericity of the fruits (MOHSENIN, 1986) and (HACISEFEROGULLARI et al., 2005).

S = Dg 2
(3) S = Surface area (mm 2 ), Dg = Geometric mean diameter (mm) A texture analysis device (probe diameter: 2 mm, probe penetration rate: 10 mm min -1 ) was used to determine puncture force, maximum puncture strain, deformation, firmness, and modules of elasticity of tomato fruits ( Figure 2). The tomato samples were placed on the base plate and pressed by the moving 2 mm diameter probe until the fruit punctured, and the forcedeformation curve was recorded in real-time for each experiment ( Figure 3). Afterward, some resistance parameters such as deformation, force, and strain were extracted from each recorded curves.
For each cultivar, 50 fruits were used in experiments. Modules of elasticity and firmness were calculated with the aid of the following equations (NELSON; MOHSENIN, 1968;MOHSENIN, 1986;KABAS et al., 2008). The Peel color of tomatoes was measured with Minolta CR-100 chronometer (Minolta CR-100, Osaka, Japan) device in accordance with L*, a*, b* color space. Measurements were performed from 6 different sections of previously numbered tomato fruits and averages of these measurements were taken. CIE L, a*, b*, chroma (C), and hue angle (ho) components of fruit color were analyzed with the aid of Minolta CR 400 (Konica Minolta) device ( Figure 4). Measurements were made under the D65 light source. The device was calibrated with a calibration plate (CR A43) before the measurements (OZDEMIR, 2001). Minolta White color standard was used in calibrations. L* indicates the changes in brightness of color. L* gets maximum values as approached to 100 and such a value indicates a 100% reflection of the light sent to the color. The a* indicates the color change from green to blue and the b* value indicates the color change from blue to yellow. Positive a* values indicate red and negative a* values indicate green color; positive b* values indicate yellow and negative b* values indicate blue color. Increasing negative or positive values indicate color darkening.

RESULTS AND DISCUSSION
Experiments were set up with 1 commercial tomato cultivar (Tybeef) and 2 candidate tomato cultivars of BATEM (14-193 and 14-206) in the spring period in a greenhouse in randomized blocks design. Fruit physical characteristics including weight, diameter, length, geometric mean diameter (GMD), sphericity, and surface area are provided in Table 1. Tybeef was the heaviest cultivar with a fruit weight of 334 g and it was followed by 14-206 (282 g) and 14-193 (248 g) cultivars. The same order of cultivars was also valid for surface area, length, and geometric mean diameter. The order of cultivars for sphericity was 14-193 > 14-206 > Tybeef. Ponjičan et al. (2012) used hybrid industrial and table tomato cultivars and reported a sphericity value of 108% for table tomatoes and 83% for industrial tomatoes. Color analyses of cultivars were performed at 4 different ripening periods (green, turning, pink, and red) ( Table 2).  (2018) reported the greatest a* value as 31.240 and the lowest a* value as -12.62. Present findings revealed that a*/b* ratio was also an important indicator for changing resistance parameters. Similar findings were also reported by Camelo and Gómez (2004).
The data were analyzed based on ripening stages. There were significant differences in the puncture force of the cultivars at a 5% level. The data on the puncture force are provided in Table 3. Variance analysis revealed that cultivars, ripening stages, and storage durations had significant effects on puncture forces at a 1% level. Cultivar*ripening stage and storage duration*ripening stage interactions had also significant effects on puncture forces (p < 0.01), but the effects of cultivar*storage duration*ripening stage triple interactions were not found to be significant. There were interactions between the cultivars and varieties in the turning phase of tomatoes. Interaction data are provided in Table 4. The greatest puncture force (24.62 N) was observed in the green ripening stage of 14-193 cultivar and the lowest puncture force (9.72 N) was observed in the red ripening stage of the Tybeef cultivar. Considering the ripening stages, the greatest puncture force was observed in green tomatoes. With regard to cultivar*ripening stage interactions, 14-193 cultivar was prominent in all ripening stages.
The greatest puncture forces were observed in green tomatoes and the lowest values were observed in red tomatoes since fruit firmness decreased with the progress of ripening. Similar findings were also reported by Sirisomboon et al. (2012) indicating decreasing firmness values from green to red tomatoes.
There were interactions between storage durations of the cultivars and the ripening stage.
Interaction data are shown in Table 5.
Considering the storage duration*ripening stage interactions, the greatest puncture force (26.76 N) was observed in the green ripening stage of 0day storage and the lowest puncture force (9.06 N) was observed in the turning ripening stage of 16-day storage. Considering the storage durations, the greatest puncture force was observed in 16-day storage. Puncture resistance decreased with the progress of ripening and storage durations. Similar findings were also reported for tomatoes by Yurtlu and Erdogan (2005) and Bui et al. (2010). Such a case indicated that fruits were more sensitive to physical damages at early ripening stages. The variance table for strain values is provided in Table 6. There were significant differences in strain values of the cultivars at a 5% level. Variance analysis revealed that cultivars, replicates, ripening stages, and storage durations had significant effects on strain values at a 1% level. Considering the interactions, cultivar*ripening stage and storage duration*ripening stage interactions were also found to be significant (p<0.01), but cultivar*storage duration and cultivar*storage duration*ripening stage triple interaction did not have significant effects on strain values.
There were interactions between the cultivars and storage durations in turning the ripening stage. Interaction data are provided in Table 7. The greatest strain value (6.15 Nmm -2 ) was observed in the green ripening stage of 14-193 cultivar and the lowest strain value (2.43 Nmm -2 ) was observed in the red ripening stage of the Tybeef cultivar (Table 7). Considering the strain values of ripening stages, the greatest value was observed in green tomatoes. Considering the cultivar*ripening stage interactions, 14-193 was prominent in all ripening stages. The greatest strain values were observed in green tomatoes and the lowest values were observed in red tomatoes since initial fruit firmness decreased with the progress of ripening. Similar findings were also reported by Sirisomboon et al. (2012). There were interactions between the ripening stage and storage durations. Interaction data are provided in Table 8  Considering the storage duration*ripening stage interactions, the greatest strain value (6.69 Nmm -2 ) was observed in the green ripening stage of 0-day storage and the lowest strain value (2.27 Nmm -2 ) was observed in the red ripening stage of 16-day storage. Considering the storage durations, the lowest puncture force was observed in 16-day storage. The resistance of tomatoes decreased with the progress of ripening stages and storage durations. Yurtlu and Erdogan (2005) also reported similar findings for tomatoes. Ciupak et al. (2012) investigated the effects of ripening on tomato cultivars and indicated that damaging strain decreased with the progress of ripening.
The variance table for deformation values is provided in Table 9. A separate analysis was performed for each ripening stage and differences in deformation values of the cultivars were not found to be significant at a 5% level. However, there were significant differences in deformation values of the storage durations at a 5% level. Interaction data are provided in Table 10. Variance analysis revealed that replicates, ripening stages, and storage durations had significant effects on deformation at a 1% level, but the effects of cultivars were not found to be significant.
Considering the interactions, cultivar*ripening stage, storage duration*ripening stage, and cultivar*storage duration*ripening stage interactions were not found to be significant, but ripening stage*storage duration interaction was found to be significant (p < 0.01).
With regard to deformation values of storage duration*ripening stage interactions, the lowest value was observed in the green ripening stage of 0-day storage (control) and the greatest value was observed in the red ripening stage of 16day storage. Considering the storage durations, the greatest deformation was observed in 16-day storage. Deformation increased with the progress of ripening stages and storage durations. Yurtlu and Erdogan (2005) also reported similar deformation values for tomatoes in their study.
The variance table for firmness values is  provided in Table 11. There were significant differences in the firmness values of the cultivars at a 5% level. Variance analysis revealed that cultivars, replicates, ripening stages, and storage durations had significant effects on firmness values at a 1% level. Considering the interactions, cultivar*ripening stage, storage duration*ripening stage, and cultivar*storage duration*ripening stage interactions were not found to be significant, but ripening stage*storage duration interaction had significant effects on firmness values (p<0.01).
There were interactions between the cultivars and the ripening stage. Interaction data are provided in Table 12. There were interactions between the ripening stage and storage durations. Interaction data are shown in Table 13. With regard to firmness values of storage duration*ripening stage interactions, the greatest value was observed in the green ripening stage of 0day storage and the lowest value was observed in the red ripening stage of 16-day storage. Considering the storage durations, the lowest deformation was observed in 16-day storage. Fruit firmness decreased with the progress of ripening. Similar results were also reported by Kaynas and Surmeli (1995). Puncture test data revealed that ripening stages had significant effects on firmness values. Olorunda and Tung (1985) reported fruit Biosci. J., Uberlândia, v. 36, n. 6, p. 2108-2119, Nov./Dec. 2020 http://dx.doi.org/10.14393/BJ-v36n6a2020-49951 firmness of tomatoes as 0.549 kg mm -1 in their research. Such a value was similar to the values for the present red ripening stage. Ince et al. (2016) indicated that the easiest harvest was performed when the tomatoes had firmness values of between 1.55 -2.00 Nmm -1 .
Data on the modulus of elasticity are provided in Table 14. There were significant differences in modulus of elasticity values of the cultivars at a 5% level. Variance analysis revealed that cultivars, replicates, ripening stages, and storage durations had significant effects on the modulus of elasticity values at a 1% level. While cultivar*ripening stage and cultivar*storage duration*ripening stage interactions were not found to be significant, ripening stage*storage duration interactions had significant effects on the modulus of elasticity (p<0.01).
There were interactions between the cultivars and the ripening stage. Interaction data are provided in Table 15. Sirisomboon et al. (2012) reported the modulus of elasticity of ripe tomatoes as 0.90 Nmm -2 and Kabas and Ozmerzi (2008) reported modules of elasticity of cherry tomatoes as between 0.16 -0.28 Nmm -2 . There were interactions between the ripening stage and storage durations. Interaction data are provided in Table 16. Considering the storage duration*ripening stage interactions, the greatest modulus of elasticity was observed in the green ripening stage of 0-day storage (control) and the lowest value was observed in the red ripening stage of 16-day storage (Table 16). Considering the storage durations, the lowest modulus of elasticity was observed in 16-day storage. Yurtlu and Erdogan (2005) reported modules of elasticity of tomatoes as between 0.18 -0.13 Nmm -2 for EF49 cultivar and as between 0.14 -0.40 Nmm -2 for the Joker cultivar. Yurtlu and Erdogan (2005) investigated the effects of ripening on tomato cultivars and reported decreasing modulus of elasticity with the progress of ripening.

CONCLUSIONS
Present experiments conducted for spring harvests revealed that cultivars, ripening stages, and storage durations had significant effects on puncture forces at a 1% level. The greatest puncture forces were observed in green tomatoes and the lowest puncture forces were observed in red tomatoes. The greatest puncture force was observed in the green ripening stage of 14-193 cultivar and the lowest value was observed in the red ripening stage of the Tybeef cultivar. Considering the storage durations, the lowest puncture force was observed in 16-day storage. The resistance decreased with the progress of ripening stages and storage durations.
Cultivars, replicates, ripening stages, and storage durations had also significant effects on strain values at a 1% level. The greatest strain value was observed in the green ripening stage of 14-193 cultivar and the lowest value was observed in the red ripening stage of the Tybeef cultivar. Considering the ripening stages, the greatest strain value was observed in green tomatoes. The greatest strain values were observed in green tomatoes and the lowest strain values were observed in red tomatoes since fruit firmness decreased with the progress of ripening. Considering the storage durations, the lowest strain values were observed in 16-day storage. Again, fruit resistance decreased with the progress of ripening and storage.
Ripening stages, replicates and storage durations had significant effects on deformation at a 1% level, but cultivars did not. The lowest deformation was observed in the green ripening stage of 0-day storage (control) and the greatest deformation was observed in the red ripening stage of 16-day storage. Considering the storage durations, the greatest deformation was observed in 16-day storage. Deformations increased with the progress of ripening and storage.
Cultivars, replicates, ripening stages, and storage durations had significant effects on firmness values at a 1% level. The greatest firmness was observed in the green ripening stage of 0-day storage (control) and the lowest firmness was observed in the red ripening stage of 16-day storage. Puncture tests revealed that ripening had significant effects on fruit firmness.