• Korean Journal of Agricultural Science
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• v.44 no.1
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• pp.23-29
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• 2017

This study was conducted to explore which pollen type could be an effective pollen source for self-incompatible 'Niitaka' pear (Pyrus pyrifolia Nakai), when different pollinizers were to be applied. The pollens of five different pears with similar flowering times were applied to bagged 'Niitaka' flowers grown in Cheonan city, Korea. Pollen types used were of different origins including Korean pears ('Wonhwang' and 'Chuhwangbae'), Japanese pears ('Chojuuro' and 'Okusankichi'), and Chinese pear ('Yali'). Results show that the amount of pollen produced by flowers of each cultivar was the largest in Korean pear 'Wonhwang' (234 g/100 flowers) and the smallest in Japanese pear 'Okusankichi' (126 g/100 flowers). A high proportion of large fruits (> 600 g), 71.4% of total production, was found in the fruits treated with 'Yali' pollen. However, these fruits showed an unfavorable external appearance. Based on individual fruit width differences, 'Chojuuro' treatment produced the smallest difference in fruit diameters (3.2 mm) and 'Yali' treatment' gave the largest (4.8 mm). Also, the difference in fruit length was the largest in 'Yali' (7.5 mm), which also produced the most uneven fruits among the pollinizers used. Meanwhile, the use of pollens of 'Wonhwang' and 'Chuhwangbae' improved productivity by increasing the fruit shape index and the ratio of bigger fruits in total production. Moreover, those pollens also decreased the development of lenticels on fruit skins which gave them a smoother appearance.

• Food Science and Preservation
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• v.11 no.3
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• pp.304-312
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• 2004

Early harvested Satsuma mandarin (Citrus unshiu) was treated with hot air at 45$^{\circ}C$ for 2, 4, and 6 hours and stored at 5$^{\circ}C$ for 3 weeks and additional one week at 18$^{\circ}C$ (simulated shelf-life) in order to examine the effect of mild heat treatment on the storage quality of the citrus fruits. Quality attributes of the sample fruits evaluated during storage included the respiration rate, internal gas composition, pH, titratable acidity, soluble solids content, flesh weight loss, firmness, peel color, decay ratio, and sensory properties. The initial respiration rates, just after hot air treatment, were significantly higher in the heat-treated fruits compared to the untreated. However, during storage at 5$^{\circ}C$, the respiration rates showed a similar level in all treatments. Internal gas composition exhibited no significant difference between the heat-treated and untreated samples. Hot air treatment also exerted no significant effects on the pH, titratable acidity, soluble solid contents, flesh weight loss, firmness, and peel color of the fruits during the whole storage period. The decay ratio was manifestly lower in the heat-treated fruits than the untreated. For sensory attributes including visual and organoleptic quality, no significant difference was observed among sample fruits. Results suggested that mild heat treatment with hot air at 45$^{\circ}C$ for 4-6 hours could be used as an effective preconditioning method to keep the postharvest quality of Satsuma mandarin by reducing the decay incidence remarkably during storage.

• Korean Journal of Environmental Agriculture
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• v.31 no.3
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• pp.229-234
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• 2012

BACKGROUND: The fruit quality and flowering characteristics of Kiwifruit (A. deliciosa cv. Hayward) in the following year is known to be affected by the extent and timing of defoliation of the current year. In korea, the production of kiwi, which is a perennial, straggling deciduous warm-temperate fruit, is often restricted by wind damage due to typhoons resulting to defoliation at the middle season of its growing period. In this paper, we report the effect of the different timing of defoliation and severities at the current season to the kiwifruit quality. METHODS AND RESULTS: Twenty seven-year-old 'Hayward' trees grown under polyethylene film rain-shelter were defoliated in different days from August to September at seven day-intervals. In each day, 0, 25, 50, 75 and 100% of leaves were removed from the trees. Fruits from each treatment were classified into four floating types (L: lying in bottom, S: standing on bottom, F: floating and SF: floating at the surface of water) by submerging them into tap water. Defoliation of kiwifruit trees in August and September caused air holes in locules of inner pericarp. Increased number of air hole in locules of a fruit was observed in floating types F and SF, and most of the air holes were located in stem end. The defoliation of trees in August significantly reduced the ratio of L-floating type fruits, which have the least number of locule air holes. The extent of defoliation also affected the distribution of the four types, the more leaves removed, the less L-floating type fruits harvested. The weight of fruits from trees defoliated in August was lower than that of fruits from September. Soluble solids content decreased as the number of locule air holes increased. Negative correlations were observed between the extent of defoliation and the weight and soluble solids content of fruits. CONCLUSION: Early defoliation effect on kiwifruit locule air hole occurrence and fruit quality were more severe in August than in September. And also if the defoliation severity is over 25%, severe fruit quality reduction expected to happen due to increase of fruit locule air hole in the inner pericarp.

• Food Science and Preservation
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• v.12 no.6
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• pp.511-515
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• 2005

The responses of 'Tsugaru' apple and 'Baekhyang' peach fruits treated with 1-MCP, the ethylene inhibitor, were compared. In Tsugaru apple fruits, the reduction of flesh firmness and titratable acidity were significantly retarded for 2 weeks by the treating fruits with 1 or 5 ppm of 1-MCP immediately after harvest The respiration decreased continually for 2 weeks and the onset of ethylene production were also retarded severely. However, in Baekhyang peach fruits, the effects of 1-MCP treatment on the respiration and ethylene production were only transient and the firmness reduction was retarded slightly by the repeated 1-MCP treatments. The responsiveness of the Baekhyang peach fruits on ethylene seems to be recovered rapidly after 1-MCP treatment. In case of Baekhyang fruits, the 1-MCP should be treated repeatedly for effective ethylene inhibition, and the ethylene accumulation should be avoided during the 1-MCP treatment.

• Journal of the East Asian Society of Dietary Life
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• v.17 no.1
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• pp.58-63
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• 2007

To develop a new type of surimi with added citrus fruits, we examined the colors, textural properties and sensory evaluations of surimi after production. In the folding test, all samples had good flexibility, which suggested that addition of citrus fruits did not influence the flexibility of surimi. The pH in surimi samples was, in increasing order: lemon(Citrus limon), citron(Citrus junos), tangerine(Citrus unshiu), cumquet(Fortunella japonica var. margarita), and control. The pHs of each citrus fruits and the surimi with added citrus fruits were similar. Lightness increased in the following order: lemon, cumquet, control, citron, and tangerine surimi. Redness was high in the following order: tangerine, cumquet, control, citron, and lemon surimi. Yellowness increased in the following order: tangerine, cumquet, citron, lemon, and control surimi. There were no significant differences between lemon and control surimi. The hardness of surimi was highest in lemon, followed by citron, tangerine, cumquet, and control surimi. Although control surimi was the lowest, there were no significant differences among the samples. In terms of springness, it increased in the following order: tangerine, citron, control, lemon, and cumquet, but there were no significant differences among the samples. In sensory evaluation, overall acceptability decreased in the following order: cumquet, tangerine, control, citron, and lemon. Surimi containing cumquet got the best score in colors, textural properties, and taste except flavor. All samples got positive results in sensory ova luations, except for textural properties and taste of lemon and citron. Here, we confirm that surimi can be made with added citrus fruits, although we should examine in detail the quantities of added lemon and citron in a later study.

• Korean Journal of Agricultural Science
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• v.44 no.3
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• pp.332-338
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• 2017

This study was conducted to investigate the effect of 1-methylcyclopropene (1-MCP), a known ethylene action inhibitor, on fruit quality and incidence of physiological disorders during a simulated marketing period in new mid-season Asian pear (Pyrus pyrifolia Nakai) 'Changjo'. Flesh firmness of untreated control fruits was maintained with a hardness of 20.2 N until day 14 of simulated marketing but decreased rapidly to 6.2 N at day 21 of simulated marketing; losing its commercial quality. However, the firmness of 1-MCP treated fruits remained high (> 20.7 N) during the same period. Quality indices such as soluble solids content and titratable acidity in 'Changjo' pear did not show any significant differences during simulated marketing period regardless of 1-MCP treatment. For the difference in skin color, redness ($a^*$) tended to increase as simulated marketing period became longer, and 1-MCP treatment delayed this change by 7 days compared to the untreated fruits. No decrease occurred in ethylene production level with 1-MCP treatment in 'Changjo' pear. Meanwhile, 1-MCP treated pears showed a significantly lower respiration rate compared to the untreated fruits. Also, 1-MCP treatment effectively reduced the incidence of physiological disorders including internal flesh browning and mealiness symptoms during simulated marketing periods of 21 and 14 days, respectively. Therefore, we conclude that the use of 1-MCP is recommended for quality maintenance and for prevention of physiological disorders during simulated marketing periods of ${\geq}7days$ for mid-season Asian pear 'Changjo'.

• Korean Journal of Environmental Agriculture
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• v.6 no.1
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• pp.61-66
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• 1987

1. In the vegetable crops, only MEP and Malathion showed a litte higher positive rate than other pesticides in general. On the other hand, parathion and captan were not detectable at all. 2. In the fruits, pesticides, MEP, PAP and Parathion had a little high positive rate, and Diazinon, and captan were not detectable at all. 3. However, the detected values of the pesticides in the vegetables and fruits were far below from korean tolerances and internationally recommended limits and tolerances, showing only $\frac{1}{3}{\sim}\frac{1}{66}$ and $\frac{1}{8}{\sim}\frac{1}{500}$ of Korean tolerance in vegetables and fruits, respectively.

• Horticultural Science & Technology
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• v.31 no.2
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• pp.203-210
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• 2013

This study was conducted to investigate the optimum storage temperature and the effect of 1-methylcyclopropene (1-MCP) on the postharvest physiology and quality of plumcot (Prunus salicina Lindle. ${\times}$ Prunus armeniaca L.) 'Harmony' fruits. plumcot fruits were stored at 0, 5, 10, and $20^{\circ}C$, respectively, with three different ripeness stages grouped by skin color development. Furthermore, we treated $1{\mu}L{\cdot}L^{-1}$ 1-MCP was treated at $10^{\circ}C$ for 17 hours and stored at $10^{\circ}C$ for 12 days to evaluate the effectiveness for better shelf-life. The results indicated that lower storage temperature than room temperature effectively reduced the respiration rate with delaying quality changes. While, the fruits showed worse fruit taste than the fruits stored at 10 and $20^{\circ}C$. Reversely, the fruits stored at $20^{\circ}C$ showed more respiration rate and ethylene production. 1-MCP treatment effectively reduced the skin red color development, ethylene production, $CO_2$ and softening of plumcot 'Harmony' fruits. Overall data indicated that the optimum harvest time and storage temperature could be 30-50% red color and near $10^{\circ}C$. Postharvest 1-MCP application at the level of $1.0{\mu}L{\cdot}L^{-1}$ could maintain fruit quality well in plumcot fruits.

• Horticultural Science & Technology
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• v.28 no.3
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• pp.434-441
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• 2010

'Wonhwang' pear ($Pyrus$ $pyrifolia$ Nakai) often showed physiological disorder and quality deterioration during long-term storage and shelf life although this cultivar has the advantage of a good appearance and better taste for overseas exportation. This study was conducted to investigate the effect of temperature during transportation and continuing market temperature on fruit quality, and the occurrence of physiological disorder to set up the appropriate transportation and distribution temperatures in the fruits harvested at different times. Unripe fruits harvested 120 days after full bloom maintained higher firmness until 21days of shelf life at both 18 and $25^{\circ}C$ than late harvested ones. Otherwise, ripe fruits harvested 130 days after full bloom showed high incidence of mealiness breakdown of flesh tissues in 21 days of shelf-life at $25^{\circ}C$ of market temperature, but not in the fruits stored at $18^{\circ}C$. Late harvested fruits showed much severe physiological disorders when compared with early harvested ones that showed relatively lower respiration rates. Fruit quality parameters were more highly affected by market temperature than transportation temperature. Results showed that unripe fruits harvested at 120 days after full bloom maintains high marketability until 21 days of shelf-life, while the maximum shelf-life of ripe fruits harvested 130 days after full bloom will be considered at within 7 days.

• Korean Journal of Food Science and Technology
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• v.18 no.5
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• pp.335-338
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• 1986

A simple spectrophotometric technique using sequential extraction of pigments was attempted to perform color evaluation of raw 'Taimuri' tomato (Lycopersicon esculentum Mill.) fruits. The difference between summed absorbance of 80% acetone and chloroform extract at 480 nm and 660 nm reflected the maturity of rawtomato fruits. The measurement system presented was regarded as a simple and reliable method for objective color evaluation of tomato fruits. It seems possible to predict the degree of puffiness by weight per volume w/v ratio of tomato fruits during various stages of maturity.