• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.44-44
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• 2017

The objective of this study was to evaluate firmness, and sweetness index (SI) of tomatoes (Lycopersicum esculentum) by using hyperspectral imaging (HSI) in the range of 1000-1400 nm. The mean spectra of the 95 matured tomato samples were extracted from the hyperspectral images, and the reference firmness and sweetness index of the same sample were measured and calibrated with their corresponding spectral data by partial least squares (PLS) regression with different preprocessing method. The results showed that the regression model developed by PLS regression based on Savitzky-Golay (S-G) second-derivative preprocessed spectra resulted in better performance for firmness, and SI of tomatoes compared to models developed by other preprocessing methods, with correlation coefficients (rpred) of 0.82, and 0.74 with standard error of prediction (SEP) of 0.86 N, and 0.63 respectively. Then, the feature wavelengths were identified using model-based variable selection method, i.e., variable important in projection (VIP), resulting from the PLS regression analyses and finally chemical images were derived by applying the respective regression coefficient on the spectral image in a pixel-wise manner. The resulting chemical images provided detailed information on firmness, and sweetness index (SI) of tomatoes. Therefore, these research demonstrated that HIS technique has a potential for rapid and non-destructive evaluation of the firmness and sweetness index of tomatoes.

• Korean Journal of Agricultural Science
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• v.37 no.2
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• pp.303-308
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• 2010

Surface color is the most important quality factor for the grade evaluation of cherry tomato. Color is one of the representative indicators for the maturity which is closely related to the internal quality of cherry tomato, such as firmness, sugar content, and acidity. This study was carried out to investigate the relationship between surface color and internal quality of cherry tomatoes harvested from both hydroponic and soil culture at different ripening stages. To calculate the color values of cherry tomatoes an automatic color imaging system was constructed. A specially designed image processing algorithm for the color measurement was developed. The color values of L*, a*, b* were calculated from the initial color values of RGB and then compared with the internal quality. Statistical analyses indicated that the internal quality was more highly correlated with the surface color than size of cherry tomatoes. Color image features were also investigated to detect external damage of cherry tomatoes. The value of (R value - R mean value)/R mean value was the most effective image feature for the detection of damaged areas on the surface of cherry tomatoes. The results of this study demonstrated the feasibility of color sorting process as an alternative of the conventional drum type size sorting system for cherry tomato industry.

• The Journal of the Korea Contents Association
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• v.21 no.12
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• pp.879-887
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• 2021

This study was carried out for elucidating bioacive properties of three domestic tomato cultivars. Total polyphenol and flavonoid of Rafito, Momotaro and Medison were 10.44±1.84, 11.14±1.95, 12.26±1.82 and 3.62±0.57, 3.24±0.35, 3.87±0.60 mg/g(dry weight) respectively. Domestic tomatoes showed DPPH and ABTS radical scavenging activities. All of tomatoes had no cytotoxicity for normal liver cell, but showed remarkable growth inhibitory effect against cervical cancer cell and liver cancer cell. These results suggested that domestic tomatoes can be used as a bioactive food material.

• Korean Journal of Agricultural Science
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• v.49 no.1
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• pp.129-136
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• 2022

In this study, we aimed to develop a maturity classification model for tomatoes using hyperspectral imaging in the range of 400 - 1,000 nm. Fifty-seven tomatoes harvested in August and November of 2021 were used as the sample set, and hyperspectral data was extracted from the surfaces of these tomatoes. A combined method of SNV (standard normal variate) and SG (Savitzky-Golay) methods was used for the pre-processing of the hyperspectral data. In addition, the hyperspectral data were analyzed for all maturity stages and considering bandwidths with different FWHM (full width at half maximum) values of 2, 25, and 50 nm. The PCA (principal component analysis) method was used to analyze the principal components related to maturity stages for the tomatoes. As a result, 500 - 550 nm and 650 - 700 nm bands were found to be related to the maturity stages of tomatoes. In addition, PC1 and PC2 explained approximately 97% of the variance at all FWHM conditions and thus were used as input data for classification model training based on the SVM (support vector machine). The SVM models were able to classify tomato maturity into five stages (Green, Turning, Pink, Light red, and Red) with over 95% accuracy regardless of the FWHM condition. Therefore, it was considered that hyperspectral data with 50 nm FWHM and SVM is feasible for use in the classification of tomato maturity into five stages.

• Journal of Bio-Environment Control
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• v.21 no.2
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• pp.88-94
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• 2012

This study was carried out in order to investigate the effect of temperature of treatment and storage on the longevity of 'Unicorn' tomatoes of light red maturity stage during commercial handling conditions encountered while exporting over long distances. Tomato stored at $5^{\circ}C$ and $11^{\circ}C$ temperature with 85% relative humidity by pre-treating handling temperature that was using from field to before shipment as a winter temperature $5^{\circ}C$, spring temperature $11^{\circ}C$ and summer temperature $25^{\circ}C$ for 3 days. On the final storage day, $25^{\circ}C/11^{\circ}C$ (treated/stored) tomatoes showed the highest respiration and ethylene production rate; whereas the lowest respiration and ethylene production rate was found for $5^{\circ}C/5^{\circ}C$ treated and stored tomatoes. Tomatoes treated and stored at $5^{\circ}C/5^{\circ}C$ showed higher marketability, without evidence of fungal rot, decay or spots for 23 days. The fresh weight loss under all treatment conditions increased gradually during $5^{\circ}C$ and $11^{\circ}C$ storage temperatures. The higher firmness and soluble solids were determined from $5^{\circ}C/5^{\circ}C$ and $5^{\circ}C/11^{\circ}C$ treated and stored tomatoes repectively, than from others tomatoes on the final day of storage. In addition, $5^{\circ}C/5^{\circ}C$ tomatoes showed higher vitamin C contents than tomatoes stored at other temperatures, on the final day of storage. As the ripening and storage period progressed, the titratable acidity increased, but declined (P < 0.05) thereafter, due to over ripe tomatoes under all treatment conditions. These results show that $5^{\circ}C/5^{\circ}C$ treated and stored light red maturity stages of 'Unicorn' tomatoes are optimum to export because they show the highest storability and marketability. Moreover, the marketability of light red maturity stage of 'Unicorn' tomato maintained for 2 weeks in $25^{\circ}C/11^{\circ}C$ treated and stored temperature that might be the export temperature from Korea to Japan in summer season. This research result could be useful in helping tomato growers and exporters to get optimum market value by satisfying the buyer and consumer with a fresher product.

• Journal of Bio-Environment Control
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• v.31 no.3
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• pp.194-203
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• 2022

Cultivation of tomatoes in Korea grown in soil covers 89% of the total area for tomato cultivation. Tomatoes grown in soil often encounter various environment stresses including not only salt stress and soil-borne diseases but also cold stress in the winter season. This study was conducted to comparatively analyze the performance of rootstocks with cold stress by measuring the growth, yield, and photosynthetic efficiency in tomatoes grown in soil. The rootstocks were used 'Powerguard', 'IT173773', and '20LM' for the domestic rootstock cultivars and 'B-blocking' for a control cultivar. The tomato cultivar 'Red250' was used as the scion and the non-grafted tomatoes. Stem diameter, flowering position, leaf length, and leaf width were investigated for the growth parameters. The stem diameter of the non-grafted tomatoes decreased by 15% compared to the grafted tomatoes at 80 days after transplanting when exposed to low temperatures of 9-14℃ for 14 days. The leaf length and width of the non-grafted tomatoes were the lowest with 42.4 cm and 41.8 cm at 80 days after transplanting. The total yield per plant was the highest in tomato plants grafted on 'Powerguard' with 1,615 g and lowest in non-grafted tomatoes with 1,299 g. As the result of measuring the chlorophyll fluorescence parameters, PI_ABS and DI₀/RC, which mean the performance index and dissipated energy flux, 'Powerguard' was the highest with 3.73 in PI_ABS and the lowest with 0.34 in DI₀/RC, whereas non-grafted tomatoes was the lowest with 2.62 in PI_ABS and the highest with 0.41 in DI₀/RC at 80 days after transplanting. The stem diameter has positive correlation with PI_ABS, while it has negative correlation with DI₀/RC. The results indicate that can be analyzed by chlorophyll fluorescence parameters can be used for analyzing the differences in the growth of tomato plants grafted on different rootstocks when exposed to cold stress.

• Proceedings of the IEEK Conference
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• 2003.07c
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• pp.2529-2532
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• 2003

The quality of agricultural products is represented a degree of freshness and a special qualify that has a close relation to commercial value. To grade tomatoes, it used to nondestructive equipment of a charge-coupled device(CCD) camera and near-infrared(NIR) spectrum analysis method. The NIR spectrum analysis method is used to determine internal qualities such as a brix and an acidity. The CCD camera is used to measure external qualities like color and a size of tomatoes. This paper explaines the structure and movement of the automatic grade system and applies the algorithm for deformed tomtatoes and characteristics of tomatoes through image processing to the grade system.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.1340-1345
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• 1993

Five textural characteristics , epicarp strength, deformation , firmness , toughness and penetration time were calculated from force/deformation curves obtained by pressure testing tomato fruits. The fruits were harvested at either the mature-green or red maturity stages. The effects of changing the probe diameter and cross-head speed were investigated on force/deformation characteristics of tomatoes. It was confirmed that increasing of cross-head speed and probe diameter highly significantly effect all textural of the characteristics mentioned above , except epiarp strength of red tomatoes at 200 mm minute cross-head and penetration time of red and green tomatoes after 200mm minute and 100 mm minute cross-head respectively.

• Korean Journal of Organic Agriculture
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• v.25 no.4
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• pp.679-697
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• 2017

This study analyzes an economic efficiency of environmental friendly farm and conventional farm using the data envelopment analysis (DEA). We compare the economic efficiency of Environmental Friendly farm and Conventional farm. We also analyze the effects of some explanatory variables on allocative efficiency (AE), pure technology efficiency (PTE) and scale efficiency (SE). In the case of strawberries farm, environmental friendly farm has higher overall efficiency (OE) than conventional farm. But tomatoes farm has higher overall efficiency (OE) than conventional farm. And We measure returns to scale of farms. Most strawberries and tomatoes farms showed Increasing to Scale (IRS).

• Korean Journal Plant Pathology
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• v.13 no.2
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• pp.113-117
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• 1997

Low moleuclar weight (LMW) RNAs were isolated form Korean peonies which expressed symptoms of stunt and epinasty. The LMW plant RNAs were purified by Qiagen column chromatography which could separate viroid specific nucleic acid at differential salt concentration. After the inoculation of the purified RNAs from the peonies, the inoculated tomatoes (cv. Rutgers) expressed the symptoms of stunt and epinasty. Also the same molecular weight RNAs with viroid-like RNAs were isolated from the inoculated tomatoes. Double-stranded cDNA were synthesized by the methods of reverse transcription (RT) and polymerase chain reaction (PCR) with the purified RNA and primers. The same cDNAs associated with viroid-like RNAs wre cloned from the inoculated tomatoes. The cDNA has been sequenced and its 375-nucleotides were arranged into secondary structure. The cloned cDNA showed 47~54% homology compared with other viroids. The sequence homology of the cloned cDNA were partially high with plant genomic RNAs.