• Korean Journal of Food Science and Technology
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• v.12 no.2
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• pp.122-125
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• 1980

The mechanism of cooking barlay (naked and covered barley) was investigated. Cooking properties of both naked and covered barley were similar. At higher cooking temperature of above $110^{\circ}C$, a browning reaction occurred and no terminal point of cooking was observed. The cooking rate followed the equation of a first-order reaction. The activation energies of cooking temperatures below $100^{\circ}C$ and above $100^{\circ}C$ were about 19,500 and 9,500 cal/mole, respectively. The cooking process of barley comprised two mechanisms: At temperatures below $100^{\circ}C$ the cooking rate is controlled by the reaction rate of barley constituents with water, and at temperatures above $100^{\circ}C$, it is controlled by the rate of diffusion of water through the cooked portion toward the interface of uncooked core in which the reaction is occurring.

• Horticultural Science & Technology
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• v.32 no.5
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• pp.645-654
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• 2014

This study was conducted to investigate the effect of 1-methylcyclopropene (1-MCP, $1.0{\mu}L{\cdot}L^{-1}$), a known ethylene action inhibitor, on fruit quality and incidence of physiological disorders during a simulated marketing period at $25^{\circ}C$ for 20 days in early-season Asian pear (Pyrus pyrifolia Nakai) 'Hanareum' that had been treated with 0, 0.5, 1.2 or 2.4% $GA_{4+7}$. Weight loss of stored fruits increased with $GA_{4+7}$ concentration, and the 1-MCP treatment slightly reduced the weight loss rates during the marketing period. Flesh firmness decreased abruptly in all 1-MCP-untreated fruits as the storage period extended to 10 d, whereas the firmness of 1-MCP-treated fruits remained high (> 30 N) during 15 days shelf-life. The effect of 1-MCP was significantly reduced when fruits were subjected to increased GA concentration. Higher soluble solids content and acidity during extended shelf-life were also apparent in 1-MCP-treated 'Hanareum' pears. The L-values (lightness) and hue angles of 1-MCP treated samples were higher than those of controls during 20 days shelf-life, but the a-value (redness) was lower in 1-MCP treated fruits. 1-MCP treatment did not decrease the level of ethylene evolution regardless of $GA_{4+7}$ concentration during shelf-life in early-season Asian pear 'Hanareum'. By contrast, 1-MCP treatment decreased the respiration rate significantly during shelf-life. The efficacy of 1-MCP was greatest in the GA-untreated fruit and was reduced as the $GA_{4+7}$ concentration increased. 1-MCP treatment influenced the severity of physiological disorders including core browning and mealiness: 1-MCP treatment completely blocked the incidence of core browning of during 15 days shelf-life, and reduced the severity of mealiness during 20 days shelf-life regardless of $GA_{4+7}$ concentration. Based on our results, we conclude that the use of $1{\mu}L{\cdot}L^{-1}$ 1-MCP can be of great benefit for maintaining quality and preventing physiological disorders in early-season pear cultivar 'Hanareum' pear, whereas its efficacy decreases with the concentration of $GA_{4+7}$ whereas its efficacy gradually decreases when the concentration of $GA_{4+7}$ paste increased.

• Journal of Conservation Science
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• v.30 no.1
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• pp.27-32
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• 2014

The sample book was printed in 1935. Since the books in the early twentieth century were printed using acidic paper, the color of the paper would change to brown over time due to iron corrosion. In addition to corroding iron cores, the acidity of the paper (pH 3.2) also made the paper brown and fragile, as was true in the case of the sample book. To clean the paper of the sample book and to make it strong, we replaced the iron core and performed wet cleaning on the paper to remove contaminants. Then we pressed the sample book dry, and subsequently linening every page with Minoshi($4g/m^2$). Generally, book conservator rebinding the book using wires or threads: however we have devised a new method to rebind the book using colored iron cores. To color the iron core brown, they were dipped in an aqueous coloring solution ($H_2O$, $C_2H_5OH$, $CuSO_4{\cdot}5H_2O$, $FeCl_3{\cdot}6H_2O$); subsequently, a 20% paraloid B-72 was applied to protect the colored iron cores from corrosion.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.1
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• pp.57-63
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• 2002

As an alternative to methyl bromide (MeBr) fumigation for the control of quarantine pests of pears (Pyrus pyrifolia cv. Niitaka), the effect of gamma irradiation (0.5~3 kGy) was comparatively investigated. Insects found in the pears were identified Tetranychus urticae Koch and Panonychus ulmi Koch, which were of quarantine importance. These insects were easily destroyed by MeBr even one day after fumigation. Whereas irradiation at 0.5~2 kGy was not enough to reach the mortality, even if 3 kGy showed the same mortality as MeBr after 17 days of treatment. Respiration of pears was stimulated by both increased doses of irradiation and MeBr fumigation. The rates of surface blackening and core browning were accelerated by MeBr rather than higher doses of irradiation. While the changes in flesh firmness and surface color were more apparent in irradiated samples at above 2 kGy than MeBr. There were negligible differences in the contents of titratable acidity, acetaldehyde and ethanol by the treatment conditions except for 3 kGy-irradiated group. Sensory evaluation showed that mere than 1 kGy was the threshold to induce the significant changes in quality of pears.

• Journal of Bio-Environment Control
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• v.20 no.3
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• pp.233-240
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• 2011

We evaluated the changes of fruit quality factors and the incidence of physiological disorders during the periods of high temperature environment in 'Wonhwang' and 'Whasan' pears to determine appropriate harvest time for exportation. In 'Wonhwang' pears, the fruits harvested at 130 days after full bloom (DAFB) showed 31.3 and 17.6N of flesh firmness after 5 and 10 days after simulated marketing at $30^{\circ}C$, respectively, while those of the fruits harvested at 135 DAFB lowered to 16.7 or 6.9N, respectively. Whereas, 'Whasan' pear showed higher firmness during 14 days of high marketing condition than 'Wonhwang' pears which represented 30.4, 26.5 and 21.6N in the fruits harvested 145, 150 and 155 DAFB, respectively. Higher soluble solid contents and lower acidity values observed in the late harvested fruits in both cultivar along with increased marketing period at $30^{\circ}C$. Late harvested 'Wonhwang' pears showed higher respiration rate and ethylene production than early harvested ones, while those of 'Whasan' pears showed lower values regardless of fruit maturity which represented less than 50% of 'Wonhwang' pears. The incidence of physiological disorders such as internal browning, water soaking, flesh spot decay, core breakdown and pithiness appeared more severely in the fruits of 'Wonhwang' in accordance with the progress of high temperature marketing and fruit maturity. Whereas, those symptoms were occurred only after 14 days of prolonged marketing time in 'Whasan' pears. Consequently, it was needed to pay more attention to determine the ripeness when the fruits exported to the country with high temperature environment, especially in the fruits of 'Wonhwang' pears showing rapid quality loss and severe physiological disorders.

• Journal of Bio-Environment Control
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• v.23 no.3
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• pp.212-220
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• 2014

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 simulated marketing period in Asian pears (Pyrus pyrifolia Nakai) of early-season cultivar 'Hanareum' and mid-season cultivar 'Manpungbae'. Flesh firmness was decreased abruptly at 15 days after shelf-life in untreated fruit of early-season cultivar 'Hanareum' which showed less than 19N, although those of 1-MCP-treated fruits were kept high value (>28N) during 15 days of shelf-life. However, there were no distinct firmness changes during 30 days of shelf-life in mid-season cultivar 'Manpungbae' pear. Two pear cultivars did not show any considerable differences in quality indices such as soluble solids content, titratable acidity and skin color during the shelf-life regardless of 1-MCP treatment. The reduction of ethylene production level by 1-MCP treatment did not appeared in 'Hanareum' pear. Meanwhile, 1-MCP treated 'Hanareum' pears showed significantly low respiration rate during shelf-life. On the other hand, the inhibitory effect of 1-MCP was not remarkable in mid-season 'Manpungbae' pears. 1-MCP treatment completely blocked the incidence of physiological disorders including core browning and mealiness symptom during shelf-life only in early-season 'Hanareum' pears, and reduced considerably the pithiness disorder regardless of 1-MCP concentration. Consequently, we concluded that the treatment efficacy of 1-MCP is largely cultivar-dependent and the use of $1{\mu}L{\cdot}L^{-1}$ 1-MCP was recommended for the keeping quality and the prevention of physiological disorders only in early-season Asian pear 'Hanareum'.

• Horticultural Science & Technology
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• v.34 no.1
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• pp.94-101
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• 2016

The purpose of this study was to establish postharvest management techniques including a temperature pre-conditioning protocol for maintaining fruit quality in newly developed early-season Korean pear cultivar 'Hanareum' (Pyrus pyrifolia Nakai). The fruits were treated with three different pre-conditioning temperatures (21, 25, or $29^{\circ}C$) for 4 days according to the harvest time (103 or 110 days after full bloom, DAFB). The percent weight loss was relatively low in the fruits subjected to low pre-conditioning temperature regardless of harvest time. The firmness of the fruits treated with pre-conditioning at $21^{\circ}C$ remained high during 20 days of simulated marketing at $25^{\circ}C$, although all treated fruits showed a general decline of firmness with extended time of simulated marketing. These fruits also showed higher appearance and a lower incidence of mealiness disorder symptoms. During the experimental periods, the production of ethylene was lower in the fruits pre-conditioned at $21^{\circ}C$ in comparison with those of treated at 25 and $29^{\circ}C$. High respiration rates were obvious in the fruits pre-conditioned at high temperature ($29^{\circ}C$), especially in the optimum-harvested fruits, where respiration was approximately two times higher than that of fruits exposed to $21^{\circ}C$ during pre-conditioning. However, the respiration rate was similar during simulated marketing at $25^{\circ}C$ regardless of harvest time. These results demonstrated that temperature pre-conditioning at $21^{\circ}C$ is a simple and effective postharvest technique for summer harvested Korean pear cultivars including 'Hanareum'.