• The Korean Journal of Pesticide Science
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• v.6 no.2
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• pp.64-71
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• 2002

Plant growth promoting activity of quinolinone metabolites, 2-(2-hepteny)-3-methyl-4-quinolinone (1), 2-heptyl-3-methyl-4-quinolinone, and 2-nonyl-3-methyl-4-quinolinone, produced by Pseudomonas cepacia and ethyl 2-methyl-3-alkyl-4-quinolinone carboxylates chemically synthesized were tested by using seed-germination assay, growth increments in plant height after foliar applications. Plant height increment, fresh weight, and the number of fruits were measured after seed-soaking and drench treatment. Compound 1 among the natural products showed a consistent growth promoting effect in seed-germination and plant height after a foliar application. After a seed-soaking and drench treatment, compound 1 and synthetic ethyl 2-methyl-4-quinolinone-3-carboxylate (5) showed a significant enhancement in fresh weight and the number of fruits after harvest. Compound 1 and 5 increased the number of fruits per plant by 44% and 84% over the control, respectively.

• The Korean Journal of Food And Nutrition
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• v.30 no.3
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• pp.568-577
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• 2017

Vegetables and fruits contain a great deal of vitamins, minerals, dietary fiber and phytochemicals. Therefore, healthconcious consumer prefer beverage made from fresh fruits and vegetables due to their health benefits. This study was conducted to investigate differences in nutritional composition and sensory characteristics of juices depending on the apparatus used: either a low-speed juicer or high-speed blender. All ingredients could be made into juice without addition of water using the low speed juicer. However, addition of water was necessary to produce juice with the high-speed blender. Phenol and flavonoid content, were higher in juice made with the low-speed juicer than that produced with the high-speed blender and were correlated with DPPH radical scavenging ability. Protease activity of pineapples juices was not significantly different for the two methods, but protease activity of kiwi juice was about 8 times higher in juice made with low-speed juicer than that made with the high-speed blender. SOD activity also tended to be higher in the juice made with low-speed juicer. The concentration of dissolved oxygen in the juice made with high-speed blender was higher than that of juice made with a low-speed juicer and was correlated with color change. In addition, the high-speed blender caused an increase juice temperature, but temperature was not changed during use of the low-speed juicer. The noise level of the low-speed juicer was low, but the high-speed blender had high noise intensity comparable to that of railway or aircraft noise. In the sensory evaluation of juice, juice made with the low-speed juicer was preferred over juice made with the high-speed blender. As a result, the overall quality of the juice produced using the low-speed juicer was superior.

• Korean Journal of Food Science and Technology
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• v.21 no.3
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• pp.387-390
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• 1989

Citrus fruit (Citrus unshiu Marc) were stored in the facillity controlled with a microprocessor-based storage controller, and the respiration rate and weight loss of fruits were measured with the infrared gas analyzer and the strain gauge load cell. The storage conditions and measuring intervals were set by the keyboard of personal computer. The interfacing cicuitry between the computer and Z-80 microprocerssor was built with peripheral Interfacing It chips 6821 and 8255. The data measured were saved to a data file for recording and further analysis. When the fresh and bruised fruits were subjected to the storage condition for 4 days at 20 C, the respiration rate of the fresh one showed a stable value of 3-5ml $CO_2/kg$ h throughout the storage period while the bruised one exihibited an abruptly increased rate after 50 hours. And the weight loss recorded about 5% during the storage.

• The Korean Journal of Food And Nutrition
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• v.21 no.2
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• pp.176-183
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• 2008

This study examined the anti-microbiological effects of chlorine treatment on the surface of fresh fruits, in order to improve microbiological safety in school foodservice operations. Non-peeled fruit(strawberries) and peeled fruit(bananas) were treated with different concentrations of chlorinated water and rinsing numbers, followed by microbiological testing. The fruits were immersed at different concentrations of chlorinated water(0 ppm, 50 ppm, and 100 ppm) and durations(3 min and 5 min), and were then rinsed with tap water(one time, two times, or three times). The total viable cell counts of both the strawberries and bananas ranged from $10^3$ CFU/g to $10^4$ CFU/g, and coliform levels ranged from $10^2$ CFU/g to $10^3$ CFU/g. As the chlorine concentration, immersion time, and rinsing number increased, anti-microbiological activity increased. The largest microbial reduction was shown with immersion for 5 min in 100 ppm chlorinated water and three rinsings. In the strawberries, this treatment reduced the initial population of total viable cells and coliforms by 3.29 log CFU/g and to an undetectable level, respectively, no total viable cells or coliforms were detected on the banana surface following this treatment. However, after a sterilization treatment with immersion for 5 min in 50 ppm chlorinated water and three rinsings, the total viable cell counts and coliform counts of the strawberries and bananas decreased to acceptable levels, based on the microbiological standards for ready-to-eat foods. Overall, it was shown that the sterilization treatment of 50 ppm chlorinated water, soaking for 5 min, and three rinsings provided an effective reduction in surface microbes, and enhanced the microbiological safety of the fruit.

• Food Science and Preservation
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• v.11 no.2
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• pp.135-141
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• 2004

To examine the quality changes of tomato and plum fruits during storage under various storage conditions, the rate of weight loss, pH change, titratable acidity, Hunter a value, firmness, and anthocyanin content were determined during storage. Tomato and plum fruits were stored at 4$^{\circ}C$ and 25$^{\circ}C$. Tomato fruits were packaged with high density polyethylene film (HDPE) and polyvinylidene chloride film (PVDC), and plum fruits were packaged with HDPE. Tomato fruits packaged with PVDC and plum fruits packaged with HDPE at 4$^{\circ}C$ were the most desirable in terms of weight loss. Titratable acidity of tomato fruits decreased with increasing storage time regardless of temperature and packaging method. Hunter a value of tomato fruits stored at 25$^{\circ}C$ increased regardless of packaging method, while it was not changed for tomato fruits stored at 4$^{\circ}C$. Firmness of plum fruits stored at 25$^{\circ}C$ significantly decreased during storage and anthocyanin content increased. Microbial numbers of tomato fruits increased during storage, but its rate was retarded during storage when tomato fruits were packaged with HDPE and stored at 4$^{\circ}C$. These results suggest that cold chain system and appropriate packaging could maintain the quality and prolong the shelf life of fresh produce.

• Applied Biological Chemistry
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• v.41 no.2
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• pp.141-146
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• 1998

In order to determine the optimmum harvest time of Citrus unshiu Marc. var. miyagawa and C. unshiu Marc. var. okitsu produced in Cheju, citrus fruits sampled at packing houses or harvested directly on citrus tree in south and north area of Cheju were analyzed. The fruits were grown in size till middle of October, and soluble solids were increased continuously after that. The fruits size were different by positional directions on the tree, the quality of citrus fruits in central southern positions on the tree was good for fresh fruit consumptions. Compared with only the quality of citrus fruits as a factor of soluble solids, total sugar, pH, and color index, the optimum harvest time were supposed to be reasonable at late of November for C. unshiu Marc. var. okitsu, and at early of December for C. unshiu Marc. var. miyagawa. The results obtained from citrus fruits sampled at packing houses were supposed to be not suitable for determing the optimum harvest time, because of storage after harvest at ordinary harvesting time.

• Applied Biological Chemistry
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• v.16 no.2
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• pp.94-98
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• 1973

1. Tomato variety used was Bogsu No. 2 and it was grown in field. Experiments were conducted in 1971 and 1972 to examine the changes of $CO_2$ product on in each growth-period and the contents of acid, sugar and vitamine C during storage. 2. By controlled atmospheric pressure the effects of respirationreduction in tomato fruits were the most effective at 660 Torr. part. 3. $CO_2$ production of tomato fruits harvested at each growth-period was differently changed at each growth-period and $CO_2$ production in tomato fruit at the same maturity from the plant showed Sigmoid type. 4. $CO_2$ production of tomato fruits harvested at the same ripeness score was in influenced by controlled atmospheric pressure during growth period and $CO_2$ production was reduced at SAP part compared with NAP part during the full growth-period. 5. The change of weight in tomato fruits was decreased in NAP part than in SAP part during storage and contents of acid, sugar, and vitamine C showed the same tendency.

• Korean Journal of Agricultural Science
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• v.43 no.3
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• pp.340-345
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• 2016

The kiwi fruit (Actinidia deliciosa cv. 'Hayward') should be ripened at any step during postharvest handling before consumer consumption. This is essential for freshly harvested kiwi fruit. But, this requires correct temperatures and ethylene concentrations. More testing of a newly developed ethylene generator using charcoal for commercial purposes is needed. This study was conducted to investigate the optimum storage temperatures and the effect of ethylene on the postharvest quality of kiwi fruit. Three different ethylene concentrations of 10, 50, and $100{\mu}L{\cdot}L^{-1}$ were used on fresh kiwi fruit stored at different temperatures of 10, 15, and $20^{\circ}C$. The quality changes of the fruits were assessed by sensory evaluation and by measuring firmness, soluble solids content, titratable acidity, and ethylene production. Higher storage temperatures and ethylene concentrations softened the kiwi fruit quickly and led to the rapid loss of acidity while soluble solid contents of fruit increased to a significant extent during the same storage period. Similarly, the firmness of ethylene-treated fruits stored at 20 and $15^{\circ}C$ dramatically decreased in the experiment while treated fruits stored at $10^{\circ}C$ decreased only slightly. Quality characteristics of kiwi fruits stored at 15 and $20^{\circ}C$ were better than those of fruits at $10^{\circ}C$. With regards to the effect of temperature, fruits stored at lower temperatures took a longer time to ripen and retained their quality longer. The newly developed ethylene generator maintained the ethylene concentration in the 5 kg box at $40-400{\mu}L{\cdot}L^{-1}$. The ethylene generator could also be used to soften persimmons.

• Journal of Biosystems Engineering
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• v.30 no.5 s.112
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• pp.274-279
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• 2005

Impact is one of the major cause of damage to fruits druing varios processes from the production on the farm to the consumer. The tissue of fruits are ruptured in a very short period time less than 10ms by impact loading. Mechanical behavior of fruits under impact loading can be analyzed better with high speed sampling data acquisition system and one of them is a digital storage oscilloscope. A impact test system was developed to test the physical properties of fruits including apple, pear, and peach which may lead to a better understanding of the physical laws. The test system consisted of a digital storage oscilloscope and simple mechanism which can apply impact force to fresh produce. Rupture force, energy, and deffrmation were measured at the five levels of drop heights from 4 to 24cm fur each internal and external tissues. Rupture forces for apple and pear were in the range of 72.9 to 87.7 N and 70.8 to 84.1 N for external and internal tissues, respectively. Rupture forces far peach external tissues were in the range of 43.4 to 65.0 N.

• Microbiology and Biotechnology Letters
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• v.47 no.2
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• pp.183-194
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• 2019

The consumption of fresh vegetables has been related to recurrent outbreaks of foodborne diseases (FBD) worldwide. Therefore, the development of effective alternative technologies is necessary to improve the safety of these products. This study aimed to isolate and identify epiphytic lactic acid bacteria (LAB) from fresh fruits and leafy vegetables and characterize their antagonistic capacity due to their ability to produce bacteriocins or antibacterial compounds. For this, 92 LAB isolates from fruits and leafy vegetables were screened for antagonistic activity. Two strains with the highest and broadest antagonistic activities were selected for further characterization; one from cantaloupe melon (strain CM175) and one from cilantro leaves (strain C15). The cell-free supernatants (CFS) of CM175 and C15 were found to exhibit antagonistic activity against FBD-causing pathogens. The CM175 and C15 strains were identified as Pediococcus pentosaceus and Lactobacillus graminis, respectively. Notably, the P. pentosaceus CM175 CFS stopped the growth of Salmonella Typhimurium, Salmonella Saintpaul, Staphylococcus aureus, and Listeria monocytogenes, and delayed Escherichia coli O157:H7 growth. Moreover, L. graminis C15 CFS delayed the growth of all indicator pathogens, but did not completely stop it. Organic acids and bacteriocin-like molecules were determined to be possibly exerting the observed antagonistic activity of the identified LAB strains. Thus, application of the antagonistic compounds produced by Pediococcus pentosaceus and Lactobacillus graminis could be a novel and ecological strategy in developing antimicrobial biopreservatives for the food industry and mitigating FBD by reducing the biological contamination in fruit and vegetable orchards, mainly via their potential in controlling both gram-negative and gram-positive pathogenic bacteria.