• Journal of Biosystems Engineering
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• v.26 no.5
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• pp.461-468
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• 2001

Impact between fruits and other materials is a major cause of product damage in harvesting and handling systems. The oriental pears are more susceptible to bruising than other fruits such as European pears and apples, and are required more careful handling. The interest in the handling of the pears for the processing systems has raised the question of the allowable drop height to which pears can be dropped without causing objectionable damage. Drop tests on pears were conducted using an impact device developed by authors to estimate the allowable drop height without bruising. The impact device was constructed to hold in a selected orientation and to release a fruit by vacuum for dropping on to a force transducer. The drop height was adjustable for zero to 60 cm to achieve the desired distance between the bottom of the fruits and the top of the impact force transducer. The transducer was secured to 150 kg$\sub$f/ concrete block. The transducer signal was sampled every 0.17 ms with a strain gage measurement board in the micro computer where it was digitaly stored for later analysis. The selected sample fruit was Niitaka cultivar of pears which is one of the most promising fruit for export in Korea. The pears were harvested during the 1998 harvest season from an orchard in Daejeon. The sample fruit was selected from two groups which were stored for 3 months and 5 months respectively by the method of current commercial practice. The pears were allowed to stabilize at environmental condition(18$^{\circ}C$, 65% rh) of the experimental room. One hundred fifty six pears were tested from the heights of 5, 7.5. 10 and 12.5 cm while measurement were made of impact peak force, contact time, time to peak force, dwell time, pear diameter and mass. The bioyield strength and modulus of elasticity were measured using UTM immediately after each drop test. The allowable drop height was estimated on the base of bioyield strength of the pears in two ways. One was assumed the peak force during impact test increasing linearly with time, and the other was based on the actual drop test results. The computer program was developed for measuring the impact characteristics of the pears and analyzing the data obtained in the study. The peak force increased while contact times decreased with increasing drop height and contact times of the sample from the hard tissue group. The allowable drop height increased with increasing bioyield strength and contact times, and also varied with Poisson\`s ratio, mass and equilibrium radius of the pears. The allowable drop height calculated by a theoretical method was in the range from 1 to 4 cm, meanwhile, the estimated drop height considering the result of the impact test was in the range from 1 to 6 cm. Since the physical properties of fruits affected significantly the allowable drop height, the physical properties of the fruits should be considered when estimating the allowable drop height.

• Journal of Biosystems Engineering
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• v.35 no.5
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• pp.316-322
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• 2010

The packaging of fruits is very important because appropriate packaging can optimize the maintenance of freshness of fruits during their distribution in low or normal temperatures until the products reach consumers. The focus of this study was on the use of functional packaging materials for the post-harvest maintenance of the freshness of fruits. Oak charcoal has excellent far infrared emission and ethylene absorption qualities, and we developed a charcoal-processing packaging linerboard to evaluate the possibility for the use of charcoal as a functional packaging material for pears. Oriental pears of the Niitaka cultivar used in this study account for about 70% of pears harvested every year, and are a very popular domestic fruit in Korea. Pears packaged in packaging materials processed with charcoal were of significantly higher quality (p<0.05) than those packaged with conventional packaging materials, suggesting that charcoal-processed packaging materials can be used as functional packaging material for extending the storability and distribution time of fruits. Charcoal-coated linerboard was shown to be the most appropriate packaging material based on its compression strength, ethylene absorption performance, and the firmness and minimal weight loss of pears.

• Horticultural Science & Technology
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• v.19 no.1
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• pp.48-53
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• 2001

The study was conducted to examine the storage potential of recently developed oriental pears, 'Kamchun' and 'Chuhwang'. The content of soluble solids of 'Kamchun' pears was above 13.2% but the acidity was below 0.082% at three harvest dates. Although skin browning disorder did not occur in 'Kamchun', about 40% of fruits were affected by core breakdown especially when harvested after middle of October. In contrast, flesh browning was also observed in early harvested fruit. Flesh firmness of 'Chuhwang' was higher than that of 'Kamchun' at harvest as well as after storage. The acidity of 'Chuhwang' was constantly higher than that of 'Kamchun'. Severe skin browning (approximately 80%) occurred in 'Chuhwang' pears regardless of harvest dates. Also, more flesh browning disorder was found in fruit harvested early in the season. Further research is required to determine the optimum harvest date of both cultivars and postharvest managements to inhibit the physiological disorders.

• Journal of Bio-Environment Control
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• v.15 no.1
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• pp.78-83
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• 2006

The objective of this study was to examine effect of ethylene removal apparatus on fruit quality of 'Niitaka' pear (Pyrus pyrifolia) in case of a double storage of apples and pears in a storage room. Ethylene and carbon dioxide concentration were efficiently decreased by the ethylene removal apparatus. Fruit weight loss was high at double storage of apples and pears (DAP) in a storage room compared with storage of pears. Fruit core browning was $5{\sim}22.5%$ at the fruits in DAP, but as setting ethylene removal apparatus it was not occurred till 90 days after storage. Soluble solids content and fruit peel hardness were not different among the treatments. Accordingly, a double storage of apples and pears in a storage room is possible as setting ethylene removal apparatus.

• Korean Journal of Agricultural Science
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• v.38 no.3
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• pp.405-411
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• 2011

In this study, we evaluated the changes of fruit quality indices during fruit development and ripening in Korean new pear cultivar 'Wonhwang' and 'Whasan' to determine appropriate harvest time and to enhance the marketability. The fruit of each cultivar harvested from 100 days after full bloom (DAFB) to 135 and 150 DAFB in 'Wonhwang' and 'Whasan', respectively. The fruit growth of both cultivars showed a typical single sigmoidal pattern. Flesh firmness of two cultivars decreased continuously with fruit development and ripening, reaching a final level of about 2.6 kgF at harvest stage. The starch content of fruit sap was much higher in the fruits of early development stage than the later stage of fruit ripening. In 'Wonhwang' pears, the starch level decreased coincide with fruit ripening (130 DAFB), while that of 'Whasan' decreased from very early stage of fruit development (120 DAFB), 30 days before full ripe. 'Whasan' pear showed much lower acidity level of about 0.13% during fruit development and ripening period compared with that of 'Wonhwang'. Therefore, the ratio of soluble solids to total acidity (TSS/acid) increased gradually with fruit development and ripening, reaching a final level of 80 and 98 in 'Wonhwang' and 'Whasan', respectively. There were no climateric rise of fruit respiration during fruit ripening periods in two oriental pear cultivar. The changes of skin color difference including hunter vale $a^*$ which means loss of green color occurred only after onset of ripening in two cultivars.

• Korean Journal of Agricultural Science
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• v.20 no.1
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• pp.1-8
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• 1993

This study was conducted to find the potential of polyethylene wrapping, ethylene scrubber, and Prolong as postharvest application in oriental pear, 'Niitaka'. Polyethylene film($30{\mu}m$) wrapping greatly reduced weight loss during storage for 80 to 110 days but the occurrence of dark skin browning became severe because of high humidity in polyethylene bags. Also, in long term storage of 110 days, parts of fruit developed uneven skin disorder or rupturing of cuticle layer. Ethylene scrubber reduced uneven skin disorder but no beneficial effect was found on the prevention of core breakdown. This indicates that the ethylene scrubber probably be effective when applied dicrectly to the storage room. The immediate application of Prolong to harverted fruit was confirmed not to be useful as postharvest treatment in 'Niitaka' pears.

• Journal of the Korean Society of Food Culture
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• v.36 no.2
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• pp.168-183
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• 2021

Using the big data analysis of the Choseonwangjosilrok, this research aimed to figure out the fruits' types, prevalence, seasonal appearances as well as the royalty's perspective on fruits during Choseon period. Choseonwangjosilrok included nineteen kinds of fruits and five kinds of nuts, totaling 1,601 cases at 72.8% and 533 cases at 24.2% respectively. The text recorded fruits being used as: tributes for kings, gifts from kings to palace officials, tomb offerings, county specialties, trade goods or gifts to the foreign ambassadors, and medicine ingredients in oriental pharmacy. Seasonally the fruits appeared demonstrating an even distribution. Periodic characteristics were observed in decreasing quantity chronologically. From fifteenth century to nineteenth century, the fruits with timely features were seen: 804 times at 36.6%, 578 times at 26.3%, 490 times at 22.3%, 248 times at 11.3%, and 78 times at 3.5% respectively. In fifteenth century: citrons, quinces, pomegranates, cherries, permissions, watermelons, Korean melons, omija, walnuts, chestnuts, and pine nuts appeared most frequently. In sixteenth century: pears, grapes, apricots, peaches, and hazelnuts appeared most frequently. In seventeenth century: tangerines and dates appeared most frequently. In eighteenth century, trifoliate orange was the most frequently mentioned fruit.

• Proceedings of the Botanical Society of Korea Conference
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• 1995.07a
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• pp.133-170
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• 1995

The major objectives of fruit breeding lie in improvement of cultivar, easy to be cultivated and of high quality, in order to produce unexpensive, delicious fruit both for fresh fruit market and processing. Recently, fruit breeding in Korea has contributed to breeding of several superior cultivars in major fruit crops, resulting in appreciable improvement in qualities such as skin color, taste and fruit-bearing habit concerned with productivity. In spite of accomplishments mentioned above, the need for both highly disease-resistant cultivars and long-keeping, physiological disorder-resistant cultivars to meet long distance transsportation in the temperate fruit crops of apples, oriental pears, stone fruits such as peaches, and grapes grown in Korea is rapidly pressing more than ever, as cultivars of today susceptible to pests and diseases and vulnerable to physiological disorders are very expensive and time-consuming in post-harvest handling and management. Thus, imporvements made in the above problems through breeding level will lead to the really enhanced productivity in fruit industry. The major impediments of tree size, the long length of juvenile period and the highly heterogeneous genetic composition to the improvement of fruit crops are responsible for the lower amount and rate of improvements of fruit crops as compared to annuals. Considering the expected limitations of the above problems to be solved through conventional breeding methods and strategy, a turning point of breeding a near perfect cultivar would be laid down if innovative breakthroughs in biological technology will be realized in applying some of the techniques of genetic manipulation at the molecular level to the cultivar improvement of fruit crops, such as the selective insertion of DNA carrying genes that govern desirable characteristics. More than anything else, those traits such as fruiting habit deciding productivity, elements of fruit qualities conditioned by monogene, and disease-and pest-resistance of vital importance for successful fruit growing are urgently desired to be improved by advancement of biotechnology for they are more than difficult and need long period to be attained through conventional breeding method.

• Journal of Korean Medical classics
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• v.31 no.1
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• pp.15-28
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• 2018

Objectives : This study first acknowledges that cough, which is a light symptom, can act as a link that leads to more serious disease. With this acknowledgement, the study ponders upon how the people of the past, before the introduction of western medicine, attempted to cure the first sign of cough and how to stop it from developing. Methods : China's Eumsunjungyo and Sikgamboncho, and Chosun's Singnyochanyo and Donguibogam are used mainly to analyze the food cure that were used in relation to sea water, and to discover what types of ingredients and preparation forms were used, how they were taken, what types of food cure there were, and how they were used. Results : There was no ingredient used commonly in all of the four literatures. Eumsunjungyo utilized ingredients related to lamb. Singnyochanyo and Donguibogam were both used in Chosun, but some similarities with the Chinese literatures were discovered in terms of food cure since they were put together with their Chinese counterparts as references. Ingredients that were used commonly in two or more of the literatures were ginger, taoren, xingren, honey, pear, liyu, and pig lung. Conclusions : Some staple folk remedies that later becamce cultural cuisines included drinking the water from boiling pear and honey and boiling and eating pears with peppers stuck in them. The eating of ginger together with korean traditional taffy have taken its own form and became saenggang jeonggwa and pyeongang. The oriental food cure method has been continuing among the folk people in the form of traditional food with the food philosophy of edible homologous as its basis.

• Horticultural Science & Technology
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• v.32 no.3
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• pp.359-365
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• 2014

Oriental pear (Pyrus communis L. cv 'Niitaka') was stored at $0^{\circ}C$ for 5 months and major metabolites involved in blackening of the peel were analyzed by untargeted GC-MS and targeted HPLC methods. In this study, peels of sound and skin-blackened pears were analyzed and compared. Skin-blackened fruit was clearly characterized by a distinctive pattern in changes which included a decrease of malic acid, succinic acid, and ascorbic acid, while an increase of fumaric acid, threonine, and gluconic acid, which indicated both reduced metabolic activity and anti-oxidative capacity of the cells. Chlorogenic acid was a major phenolic compound and the peel of sound fruit showed high levels of free phenolic compounds compared than the peel of skin-blackened fruit which are believed to be related to oxidation of phenolics in skin-blackened tissue. The changes or profiling of major metabolites by targeted or untargeted analysis method could become a useful tool for understanding physiology, disorder mechanism, and identifying metabolic networks connecting primary and secondary metabolism in postharvest research.