• Korean Journal of Plant Resources
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• v.26 no.3
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• pp.347-354
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• 2013

Apple and pear are popular fruits consumed in Korea and are common fruit in daily diet. In order to compare the antioxidant activity of the apple and pear peels, total polyphenol contents, total flavonoid contents, $ABTS^+$ free radical scavenging activity, and DPPH free radical scavenging activity were measured from hot water, ethanol, and methanol extracts of the two fruit peels. The total polyphenol and flavonoid contents were highest in 95% methanol extracts of the apple peelsand 70% ethanol extract of the pear peels, respectively. Total polyphenol contents of the pear peels were higher than that of apple peels, and total flavonoid contents of the apple peels were higher than that of pear peels. The apple and pear peels had the highest $ABTS^{+{\cdot}}$ and DPPH free radical scavenging activity in 95% methanol extracts and 70% ethanol extracts, respectively. $ABTS^{+{\cdot}}$ and DPPH free radical scavenging activity of pear peels was higher than that of apple peels, and the DPPH free radical scavenging activity of apple and pear peels were detected in hot water, 95% methanol, and 70% ethanol extracts, respectively. Ascorbic acid, a synthetic antioxidant used as positive control, had significantly higher scavenging activity than the apple and pear peels. In conclusion, the apple and pear peelshave great potential as natural antioxidants. Therefore, above results should be considered to provide the possibility for the development of high functional antioxidants.

• Horticultural Science & Technology
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• v.30 no.2
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• pp.208-213
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• 2012

This study was performed to compare antioxidant activities of 80% EtOH extracts from young and mature fruit of three pear cultivars ('Wonhwang', 'Whangkeumbae', and 'Chuwhangbae') classified by three parts (peel, core, and flesh) of mature fruit. The total phenolics compound and flavonoid contents of 80% EtOH extracts from young fruit were 1.5-2.5 times higher than the mature fruit with great cultivar difference. In particular, the contents of those compounds were highest in 'Chuwhangbae' pear. The total phenolics compound and flavonoid contents of 80% EtOH extracts from mature fruit were the most in the peel, core, and flesh respectively. DPPH radical scavenging and $ABTS^+$ radical scavenging of 80% EtOH extracts from the young fruit were higher than the mature fruit of 'Chuwhangbae' pear. DPPH radical scavenging and ABTS+ radical scavenging of 80% EtOH extracts from mature fruit were the highest in the peel, core, and flesh respectively.

• The Journal of Natural Sciences
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• v.10 no.1
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• pp.57-61
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• 1998

Postharvest dipping of vacuum infiltration treatments of 'Chojuro' pear fruit in $CaCl_2$ resulted in increased calcium content, especially in fruit peel and outer flesh such as just below peel. As $CaCl_2$ concentrations increaced from 2% to 8% in dipping treatment, calcium content became higher. But vacuum infiltration under 200-600 mmHg did not affect and dipping and vaccum infiltration did not have any difference in fruit calcium content. Decreasing of fruit firmness determined at 4 weeks during storage was slower in fruits with $CaCl_2$ treatment than control.

• Korean Journal of Food Science and Technology
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• v.47 no.2
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• pp.170-175
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• 2015

The methanol extract of Asian pear (Pyrus pyrifolia N. cv. Chuhwangbae) fruit peel was purified using solvent fractionation, Sephadex LH-20 column chromatography, and octadecylsilane high performance liquid chromatography. Based on the electrospray ionization mass spectrometry and nuclear magnetic resonance data, the two isolated compounds were identified as quercetin 3-O-${\beta}$-D-glucopyranoside (1) and 3,5,6,7,8,3',4'-heptahydroxyflavan [(-)-dulcisflavan, 2]. Compounds 1 and 2 were isolated and identified for the first time from Asian pears and pears, respectively.

• Food Science and Biotechnology
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• v.15 no.1
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• pp.44-50
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• 2006

Contents of phenolic compounds in peel, flesh, and core of three Asian pear cultivars, Hosui, Niitaka, and Chuwhangbae, were determined at different stages of maturity. Antioxidant properties of methanol extracts of peels at various fruit maturity stages were also evaluated. Total phenolic content decreased with maturity. Arbutin, chlorogenic acid, and epicatechin were major phenolic compounds in young fruits. Catechin, 4-hydroxymethyl benzoic acid, and caffeic acid were detected in peel and core of immature and mature pears. 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activities of methanol extracts were 16.30 and $15.73\;{\mu}g$ in peel of immature Hosui and Chuwhangbae pears, respectively, and $11.59\;{\mu}g$ in mature Niitaka pears, which was significantly higher than those of other maturity stage in the same cultivar. Inhibitory activities on lipid oxidation of methanol extracts of three cultivars at all maturity stages were similar to that of ${\alpha}$-tocopherol.

• Food Science and Preservation
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• v.20 no.2
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• pp.222-226
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• 2013

This study was performed to confirm physiological activities according to parts of new pear cultivars (Gamcheonbae, Manpungbae, Chuwhangbae, Hanareum) and Niitaka pear. The total polyphenol compound contents of pear peel, flesh and core were 178~235, 95~113, 177~229 mg/100 g as tannic acid equivalent, respectively. There were differences in the contents by cultivars, Chuwhangbae and Hanareum cultivars showed high contents. The total flavonoid contents of the pear peel, flesh and core were 29.2~40.2, 24.3~34.3, 26.9~38.8 mg/100 g, respectively and those of Chuwhangbae and Gamcheonbae cultivars showed comparatively high values. The electron-donating ability was high in Chuwhangbae, Gamcheonbae and in the pear peel (29.7~57.7%), core (29.1~38.2%), flesh (7.6~17.7%), in that order. The nitrate scavenging activity was highest in that pear peel (21.0~49.8%), followed by the core (11.8~16.2%) and flesh (7.8~9.7%), but there was little difference by cultivar.

• The Journal of Natural Sciences
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• v.8 no.2
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• pp.175-179
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• 1996

The fruit soluble solids and acidity decreased during storage regardless of fruit size, fruit firmness decreased also, and the decreasing rate of the firmness in large fruit was higher than small. The ethylene production of fruit was increased during storage, and there was the peak of fruit respiration rate at 2 and 6 weeks after harvest. The calcium and magnesium content was the highest in peel, the lowest in flesh, and intermediate in core. Especially, the calcium content in the outer flesh was lower than in the inner flesh, and the magnesium content in the middle part of flesh was lower than in the other parts. The Ca/Mg ratio in the inner flesh and the K/Ca ratio in the outer flesh were higher than in the other parts.

• 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.

• 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.

• Food Science and Preservation
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• v.30 no.2
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• pp.321-333
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• 2023

The study investigated the pH, acidity, soluble solids, total sugar, polyphenol, flavonoid, anthocyanin content, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, and color of kombucha with a variety of added fruit peels during the fermentation process. Pear, grape, plum, orange, apple, and golden kiwi peels were added during fermentation. The pH showed a decrease, while an increase in acidity was observed. An increase in soluble solids, which was higher in most experimental groups than the control group, was also observed. A decrease in total sugar was observed over time. However, an increase was observed in reducing sugar. On Day 0, higher total sugar and reducing sugar were detected in the peel addition group compared with the control group. The antioxidant capacity of polyphenol, flavonoid, anthocyanins, and DPPH radicals scavenging increased with fermentation and was higher in all addition groups, except for pear, compared with the control group. Except for grapes and plums containing high levels of anthocyanins, an increase in the L-value was observed over time, and an increase in the a-value of grapes and plums was also observed (p<0.05). The possible utilization of inedible fruit peel in kombucha was shown. Applying inedible fruit peels to kombucha is proposed to increase antioxidant content and modulate color and pH.