• Korean Journal of Food Science and Technology
• /
• v.29 no.4
• /
• pp.623-625
• /
• 1997

This study was carried out to investigate the effect of storage period on flavor components of Korean kiwifruits (Actinidia deliciosa Planch.) stored at $20^{\circ}C$. The major volatile components of Korean kiwifruits analyzed by GC and GC-MS were pentanal, methyl butanoate, ethyl pentanoate, heptanone, (E)-2-hexenal, ethyl hexanoate, 1-hexanol, cyclohexanol, butyl hexanoate, linalool oxide, linalool, butyl heptanoate, methyl benzoate, ethyl benzoate. Among them, (E)-2-hexenal was the major component in premature fruit but on further ripening ethyl butanoate began to dominate the component profile.

• The Plant Pathology Journal
• /
• v.19 no.5
• /
• pp.227-230
• /
• 2003

Ripe rot was commonly found in overripe kiwifruits (Actinidia deliciosa) during a disease survey conducted in Jeju and Jeonnam provinces in Korea in 1999. While the disease did not manifest any clear external symptoms on kiwifruits, it caused portion of the fruit surface to collapse. Watersoaked flesh tissue could be seen on the sunken part when the skin of the collapsed portion was peeled off. The milky internal symptom with dark green margin developed concentrically as the fruit ripened. A species of Botryosphaeria was consistently isolated from lesions showing typical symptoms of ripe rot on kiwifruit, and its pathogenicity was confirmed by artificial inoculation test on healthy kiwifruits. The fungus was also pathogenic to apple and pear. The mycological characteristics of the fungus were consistent with those of Botryosphaeria dothidea. This is the first report on the detailed mycological characteristics of the causal organism of post-harvest ripe rot of kiwifruit in Korea.

• Journal of Microbiology and Biotechnology
• /
• v.30 no.6
• /
• pp.912-919
• /
• 2020

Hardy kiwifruits (Actinidia arguta Planch.) have high amounts of antioxidants, including ascorbic acid (vitamin C) and phenolics. The anti-cholinesterase activity and neuroprotective effects of three different cultivars of hardy kiwifruits, cv. Mansu (A. arguta × A. deliciosa), cv. Haeyeon (A. arguta), and cv. Chiak (A. arguta), on PC-12 and SH-SY5Y cells were evaluated. Extraction of phenolics and vitamin C was carried out using 80% (v/v) aqueous ethanol and metaphosphoric acid assisted with homogenization, respectively. Hardy kiwifruit of cv. Mansu showed higher total phenolic, total flavonoid, and vitamin C contents and antioxidant capacity compared to the other two cultivars of hardy kiwifruits, cv. Haeyeon and cv. Chiak. Analysis of high-performance liquid chromatography results revealed the presence of procyanidin B2, (-)-epicatechin, neochlorogenic acid, cryptochlorogenic acid, rutin, hyperoside, isoquercitrin, and astragalin in hardy kiwifruits. The three cultivars of hardy kiwifruits had a wide range of vitamin C content of 55.2-130.0 mg/100 g fresh weight. All three cultivars of hardy kiwifruits had protective effects on neuronal PC-12 and SH-SY5Y cells exposed to hydrogen peroxide by increasing cell viability and reducing intracellular oxidative stress. Furthermore, the hardy kiwifruits inhibited acetylcholinesterase and butyrylcholinesterase. Collectively, these results suggest that hardy kiwifruits rich in antioxidants like phenolics and vitamin C have good potential as functional materials in neuroprotective applications.

• Korean Journal of Food Science and Technology
• /
• v.29 no.4
• /
• pp.618-622
• /
• 1997

This study was carried out to investigate the effect of storage temperature (0, 5, $20^{\circ}C$) on chemical components of Korean kiwifruits. Moisture content decreased in $0^{\circ}C-,\;5^{\circ}C-stored$ samples and slightly increased in $20^{\circ}C-stored$ sample. Soluble solid content increased in $0^{\circ}C-,\;5^{\circ}C-stored$ samples and decreased in $20^{\circ}C-stored$ sample ranging from 11 to $14\;^{\circ}Brix$. pH and titratable acidity remained at the level of $3{\sim}3.5$ and $1{\sim}1.5$, respectively. The content of malic and quinic acid increased during storage at $0^{\circ}C$ and $5^{\circ}C$. In case of citric acid, the content increased up to 6th week and then decreased. Kiwifruits stored at $20^{\circ}C$ showed a changing pattern of organic acids similar to those stored at 0 and $5^{\circ}C$. Glucose, fructose and sucrose increased in $0^{\circ}C-,\;5^{\circ}C-stored$ samples except fructose at $5^{\circ}C$. In case of $20^{\circ}C-stored$ sample, sucrose increased up to 2∼3th week and then decreased.

• Horticultural Science & Technology
• /
• v.33 no.2
• /
• pp.259-267
• /
• 2015

This study was conducted to comparatively evaluate antioxidant capacity (AC) of seven cultivars of kiwifruit (Actinidia spp.) and their protective effects on neuronal PC-12 cells. The contents of total phenolics (TP) and total flavonoids (TF) of kiwifruits were also examined. Five cultivars of kiwifruit, Actinidia chinensis (cv. Haehyang and cv. Haegeum), A. eriantha (cv. Bidan), A. arguta ${\times}$ A. deliciosa (cv. Mansoo), and A. arguta (cv. Chiak), were bred in Korea, while two cultivars, A. deliciosa (cv. Hayward) and A. linguiensis (accession number 041AE), originated from New Zealand and China, respectively. Skin extracts of kiwifruit showed higher TP, TF, and AC than flesh extracts. The highest levels of TP and AC were found in cv. Bidan flesh extract among cultivars studied, but the TF content of cv. Bidan flesh extract was the lowest. The kiwifruit bred in Korea had higher AC than their counterparts. AC of kiwifruit had a highly positive linear correlation with TP and TF. The flesh extracts from cv. Hayward, cv. Haehyang, and cv. Haegeum significantly (p < 0.05) prevented PC-12 cells from oxidative stress induced using $H_2O_2$ compared to a control with $H_2O_2$ only. Overall, our results suggest that kiwifruit bred in Korea may offer a good source of antioxidants and serve as functional materials.

• Korean Journal of Food Science and Technology
• /
• v.47 no.4
• /
• pp.539-543
• /
• 2015

A hardy kiwifruit is a good source of phenolics and antioxidants. This study was aimed at investigating the effects of hot air drying at three different temperatures (35, 50, and $70^{\circ}C$) for 24 h on the total phenolic and flavonoid contents and the antioxidant capacity of hardy kiwifruits of Actinidia arguta ${\times}$ A. deliciosa cv. Mansoo. Dried kiwifruit extracts were produced using 80% (v/v) aqueous ethanol under homogenization. Hot air drying lowered the total phenolic and flavonoid contents and decreased the antioxidant capacity in the dried kiwifruits compared with their fresh counterparts. The results also revealed high positive linear correlations of antioxidant capacity with total phenolic and flavonoid contents, indicating that phenolics are the major contributors to antioxidant capacity. Our results suggested that an optimal drying process must be determined for industrial application in order to obtain dried kiwifruits with increased antioxidant capacity for consumers.

• Research in Plant Disease
• /
• v.9 no.4
• /
• pp.201-204
• /
• 2003

This study was conducted to identify optimum ripening condition for kiwifruits (Actinidia deliciosa) to prevent postharvest fruit rots caused by Botryosphaeria dothidea, Diaporthe actinidiae and Botrytis cinerea. The optimum temperatures for mycelial growth of B. dothidea, D. actinidiae and B. cinerea were $26{\sim}35^{\circ}C$, $26{\sim}29^{\circ}C$ and $20{\sim}26^{\circ}C$, respectively, and the incidence was closely related with the temperature. Although kiwifruits ripened faster at higher temperatures, the rates of diseased fruits increased with the rates of ripened fruits increased. Optimum conditions for ripening of kiwifruit were 20-day at 17C.

• Research in Plant Disease
• /
• v.9 no.4
• /
• pp.196-200
• /
• 2003

Sixteen hundred fruits were randomly collected from 16 kiwifruit (Actinidia deliciosa) orchards in Jeonnam, Gyeongnam and Jejn provinces in Korea in 2000 and incidences of postharvest fruit rots were examined. The overall disease incidence was 32% and varied much with locations of orchards ranging from 5 to 68%. The percentages of kiwifruits showing internal, external, and both internal and external symptoms were 21.9%, 4.9%, and 5.2%, respectively. Several fungi were isolated from rotten fruits; Botryosphaeria dothidea, Diaporthe actinidiae and Botrytis cinerea were the major pathogens with the average isolation rates of 83.3%, 11.9% and 1.4%, respectively. Based on the symptoms on kiwifruits and the characteristics, the postharvest fruit rots caused by B. dothidea and D. actinidiae are suggested to be named as ripe rots and stem-end rots, respectively.

• Proceedings of the Korean Society of Plant Pathology Conference
• /
• 2003.10a
• /
• pp.94.1-94
• /
• 2003

Control of bacterial blossom blight of kiwifruit (Actinidia deliciosa) has been mainly depended on chemical control. Recently cultural practices such as trunk girdling of kiwifruit trees and rainproof installation over kiwifruit trees also were conducted as the alternative control practices. Each of the control methods was evaluated for the best practicing conditions for the control of bacterial blossom blight of kiwifruit. Among the various combinations of spray times and spray periods, optimum spray program of antibiotics was turned out to be 3 times with intervals of 10 days from early May during the flowering season of kiwifruits. Optimum periods of trunk girdling of kiwifruit trees were from late March to late April. Trunk girdling with 20-30 mm wide showed best control efficacies on bacterial blossom blight, irrespective of the heights of girdling on trunks of kiwifruit trees. Optimum period of rainproof installation over kiwifruit trees was from March till late April, irrespective of installation methods.

• Research in Plant Disease
• /
• v.10 no.4
• /
• pp.297-303
• /
• 2004

Bacterial blossom blight of kiwifruit (Actinidia deliciosa) has been mainly controlled by antibiotics. Among 15 candidate chemicals, streptomycin sulfate oxytetracycline WP, streptomycin copper hydroxide WP and oxolinic acid WP were selected as preventive bactericides against bacterial blossom blight of kiwfruit through in vitro and in vivo test. Spray of streptomycin sulfate oxytetracycline WP and streptomycin copper hydroxide WP at flowering period was most effective in controlling bacterial blossom blight of kiwifruit. Among the various combinations of spray times at different spray periods, optimum spray program of the preventive bactericides for the control of bacterial blossom blight of kiwifruit was turned out to be 3 times application with 10 day-interval from early May during the flowering season of kiwifruits.