• Korean Journal of Food Science and Technology
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• v.34 no.5
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• pp.805-810
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• 2002

Development of tenderizer using domestic fruits was studied. Kiwifruit was dried using various methods, and the quality of kiwifruit powder was observed during 12 week storage. Frozen kiwifruit was prepared in paste, dice, and whole flesh. After drying, paste-type kiwifruit showed 2.0 and 1.3 times higher proteolytic activity than dice and whole flesh kiwifruits, respectively. Nine hour of hot-air drying or 46 h of freeze-drying eliminated more than 90% of water from kiwifruit, during which discoloring of kiwifruit occurred. Freeze-dried powder showed 6.6 times higher yield and proteolytic activity, and resulted in almost no discolorization than those of air-dried powder. Addition of bulking agent affected the quality of hot air-dried kiwifruit powder, except color, resulting in $3.2{\sim}3.6$ times higher proteolytic activity than that without bulking agent, which is comparable to 60% of the initial freeze-dried powder content. Moisture content of kiwifruit powder with bulking agent sustained consistently during 12 week storage, whereas proteolytic activity decreased for the first 4 weeks. Freeze-drying is a preferable method to produce kiwifruit powder for tenderizer, although hot air-drying with bulking agent treatment is more economical.

• The Plant Pathology Journal
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• v.34 no.2
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• pp.143-149
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• 2018

Flowers of kiwifruit are morphologically hermaphroditic and survivable binucleate pollen is produced by the male flowers. In this study, we investigated microbial diversity in kiwifruit pollens by analyzing amplicon sequences of 16S rRNA. Four pollen samples were collected: 'NZ' was imported from New Zealand, 'CN' from China in year of 2014, respectively. 'KR13' and 'KR14' were collected in 2013' and 2014' in South Korea. Most of the identified bacterial phyla in the four different pollens were Proteobacteria, Actinobacteria and Firmicutes. However, the imported and the domestic pollen samples showed different aspects of microbial community structures. The domestic pollens had more diverse in diversity than the imported samples. Among top 20 OTUs, Pseudomonas spp. was the most dominant specie. Interestingly, a bacterial pathogen of kiwifruit canker, Pseudomonas syringae pv. actinidiae was detected in 'NZ' by the specific PCR. This study provides insights microbial distribution and community structure information in kiwifruit pollen.

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

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.4
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• pp.481-489
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• 2017

Kiwifruit wine was prepared with the domestic new cultivars 'Jecy Sweet' and 'Jecy Gold', and quality characteristics were investigated during fermentation with Saccharomyces bayanus Lalvin and Saccharomyces cerevisiae Fermivin and aging for 120 days at $15^{\circ}C$. Total acidities were 0.94% and 1.22% for 'Jecy Sweet' and 'Jecy Gold' at the beginning, respectively, and increased gradually during fermentation; highest acidities were 1.49% and 1.26%, respectively, on the 6th day of fermentation regardless of yeast strain. Alcohol content increased greatly from the 4th day of fermentation and was highest (10.2%) in 'Jecy Sweet' fermented by S. bayanus Lalvin, followed by 9.2% in 'Jecy Sweet' fermented by S. cerevisiae Fermivin and 9.4% in 'Jecy Gold' fermented by Lalvin and Fermivin on the 12th day of fermentation. Soluble solid content was $24.8^{\circ}Brix$ at the beginning and decreased gradually during fermentation. The lowest soluble solid content was $9.7^{\circ}Brix$ on the 6th day of fermentation regardless of kiwifruit cultivar and yeast strain. Total phenols in 'Jecy Sweet' (1,127 mg/L) were 1.32-fold higher than those in 'Jecy Gold' (848 mg/L) and decreased greatly until the 6th day of fermentation, after which they increased slightly until the 12th day of fermentation. During aging, total phenols increased until the 30th day and were maintained for 120 days. Quality characteristics of kiwifruit wines were similar between the two yeast strains but were different between kiwifruit cultivars. Contents of ethanol and total phenolics were higher in 'Jecy Sweet' wine than in 'Jecy Sweet' wine.

• Journal of Plant Biotechnology
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• v.44 no.3
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• pp.303-311
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• 2017

In this study, random amplified polymorphic DNA (RAPD) and sequence-related amplified polymorphism (SRAP) analyses were used for evaluation of genetic diversity of 61 kiwifruit (Actinidia spp.) germplasms including domestic and overseas collection cultivars. Forty RAPD primers were detected in a total of 230 polymorphic bands with an average of 5.75. Thirty-two SRAP primer combinations were detected in a total of 204 polymorphic bands with an average 6.38. By unweighted pair-group method arithmetic average cluster analysis using 434 polymorphic bands, kiwifruit germplasms were classified in three groups with similarity value of 0.680. Cluster I consisted of 46 kiwifruit germplasms belonging to A. deliciosa, A. chinensis, A. deliciosa ${\times}$ A. arguta, A. chinensis ${\times}$ A. arguta, and A. chinensis ${\times}$ A. deliciosa. Cluster II consisted of seven germplasms belonging to A. arguta and 'Skinny Green', a cultivar derived from a cross between A. arguta and A. deliciosa. Cluster III consisted of seven germplasms belonging to A. rufa, A. hemsleyana, A. macrosperma, A. polygama, and A. eriantha. Genetic similarity values among tested kiwifruit germplasms ranged from 0.479-0.991, and average similarity value was 0.717. Similarity value was highest (0.991) between NHK0038 (A. deliciosa) and NHK0040 (A. deliciosa), and lowest (0.479) between 'Hayward' (A. deliciosa) and K5-1-22 (A. arguta).

• Korean journal of food and cookery science
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• v.26 no.3
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• pp.323-329
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• 2010

Studies on the tenderizing effect of fruits has been limited even though fig, kiwifruit, pear, and pineapple cultivated in Korea are utilized commonly during cooking for their proteolytic properties. Therefore, the characteristics of these fruits were investigated by treating beef with their crude protease extracts. The protease effects of crude protease extract from the fruits on casein and myofibrilar protein were in the following order : pineapple > kiwifruit > fig > pear. Electrophoretic analysis results found that pineapple, kiwifruit, and fig cleaved myosin heavy chain into smaller fragments. The myofibrilar fragmentation ratio of crude protease extracts was the highest for pineapple whileas the lowest for pear. Ground fruits (5% and 10%) increased amounts of soluble nitrogen and decreased shear force of beef. Pineapple was the most effective while pear was the least effective. Decrease in springiness and gumminess was observed by texture profile analysis of beef treated with fruits, especially pineapple and kiwifruit. Among the 5% treatments, pineapple and kiwifruit produced the highest tenderness. Additionally, 10% treatment was less preferable than the 5% treatment.

• Journal of Agricultural Extension & Community Development
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• v.23 no.2
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• pp.145-156
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• 2016

The purpose of this study is to analyze the farms growing domestic kiwi fruit 'Gold' on their management performance and efficiency in order to reduce the risks involved with introducing new kind of crops for growing, and suggest improvements. First, the result of analysis showed that domestic kiwi fruit 'Gold' growers' income were higher than the average growers due to the fruit's high unit price and productivity. Second, the analysis of management efficiency resulted in scale efficiency having greater impact on inefficiency rather than pure technical efficiency. As for the analysis of technical efficiency, the depreciation costs of agricultural facilities had the greatest influence on its inefficiency. Third, inefficient farms put in excessive inputs across the board, while labor costs(self labor cost + hired labor cost) were the largest factor of optimal inputs according to the models of technical efficiency and pure technical efficiency. Fourth, because of greater reliance on mechanical tools from rising labor costs, there's a need for individual farms to avoid buying farming equipments and instead share the equipments of nearby farms and agricultural cooperatives, or start renting agricultural machines from companies.

• Research in Plant Disease
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• v.29 no.1
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• pp.45-51
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• 2023

The study was conducted to investigate the infestation and distribution of plant-parasitic nematodes on kiwi orchards in Korea. Plant parasitic nematodes genus and densities were investigated at a total of 102 sites in Jeollanam-do, Gyeongsangnam-do, and Jeju-do, which are the main production areas of domestic kiwi orchards. Plant parasitic nematodes detected were of 9 genera, including root-knot nematodes (Meloidogyne spp.), spiral nematodes (Helicotylenchus spp.), and needle nematodes (Paratylenchus spp.), and 56% of the 102 plantations were infected with root-knot nematodes. Root-knot nematodes were found to be the most important plant parasitic nematode in domestic kiwi orchards. The average density of root-knot nematodes is 97 per 300 cm³ soil, and there is concern about the kiwi yield reduction. As a result of identifying the root-knot nematode species: M. arenaria, M. hapla, M. incognita, and M. javanica. Among them, M. arenaria is the most dominant. As the plant parasitic nematode infection route in fruit trees is often spread through the transplantation of infected seedlings, attention should be paid to the production of nematode-free plants during the production and supply of kiwifruit plants.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.2
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• pp.202-209
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• 2009

This study was conducted to gather the basic data on the spread of the domestic kiwifruits, and the development of the manufactured goods and the health functional foods produced using kiwifruits. We determined the chemical compositions of four types of kiwifruits cultivated in Korea, Daeheung, Bidan, Haegeum and Hayward. In addition, we measured the anti-microbial activities and cytotoxicities of these types of kiwifruits. The vitamin C contents of the kiwifruits increased in the order of Bidan (93.82 mg/100 g), Daeheung (85.89 mg/100 g), Haegeum (83.73 mg/100 g) and Hayward (75.28 mg/100 g). The total amino acids contents per 100 g of kiwifruit (dry weight basis) were 483.97 mg (Haegeum), 453.08 mg (Hayward), 437.27 mg (Bidan) and 369.35 mg (Daeheung). The K and Ca contents of the kiwifruits ranged from 14.56~37.12 mg/L and 1.94~8.24 mg/L, respectively; however, the Fe, Mg, Zn and Cr contents all less than 1.83 mg/L. The antimicrobial activities of methanol extracts of kiwifruits against five gram positive bacteria at concentration of 2,000 mg/L in terms of inhibition diameter ranged from 8.8~12.8mm, while raged from 9.2~13.1mm against three gram negative strains of bacteria. The hyperplasia inhibition of lung cancer cells (Calus-6) by 800 mg/L kiwifruits extracts of Bidan, Haegeum, Daeheung and Hayward kiwifruits were 21.2%, 9.5%, 6.7% and 5.0%, respectively. Consequently, it was assumed that kiwifruits was rich in vitamin C, amino acids and K, and that they would therefore be useful in processed goods.