• Korean Journal of Agricultural Science
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• v.41 no.4
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• pp.265-274
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• 2014

Physiological characteristics of two Korean golden kiwifruit cultivars, 'Halla Gold' and 'Haehyang', were compared to determine the storage potential of fruit. The soluble solid levels of the fruit were 8.9 and 6.9 oBrix in 'Halla Gold' and 'Haehyang' at harvest, respectively but increased up to 15.4 in 'Halla Gold' and 17.5 oBrix in 'Haehyang' after 2 months of storage. Major sugars were fructose and glucose, and sucrose content was relatively low regardless of cultivar. The edible quality of 'Haehyang' was better than 'Halla Gold' because of higher amount of sugars. Firmness of the fruits gradually decreased as the increase of storage period in 'Halla Gold' in both flesh and core tissue. Th firmness loss of 'Haehyang' fruit was faster in the first 2 months and then became slow. After 75 days of storage, the firmness of 'Haehyang' fruit was only 5.2% at harvest. Core tissue was soften enough to eat at ripe stage. Wall modifying enzyme activities including xylanase, ${\alpha}$-L-arabinofuranosi-dase and ${\beta}$-galactosidase were consistently higher in 'Haehyang' and the activity of pectate lyase was more increased than 'Halla Gold' after 2 months of storage. Respiration rate of 'Haehyang' was higher than 'Halla Gold' and further increased after 2 months of storage. Weight loss was much higher in 'Haehyang' which showed higher rate of the firmness loss. The storage potential of golden kiwifruit was estimated to be about 2 months for 'Haehyang' and 3 months for 'Halla Gold' when determined on the basis of the fruit firmness.

• Horticultural Science & Technology
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• v.18 no.6
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• pp.808-810
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• 2000

The chemical components of xylem sap collected from kiwifruit (Actinidia chinensis Planch cv. Hayward) trees were analyzed and processing of xylem sap drink were accomplished to increase utilization of xylem sap as a drink. Water content, soluble solids, viscosity, and pH of the xylem sap were 99.60%, 0.90%, 1.01, and 6.50, respectively. In the xylem sap, fructose was the highest among free sugars followed by glucose, sucrose, galactose, and mannitol. The major inorganic components in the sap were calcium, potassium, and magnesium, and calcium was the dominant among them. Ten kinds of amino acids in the xylem sap were detected by amino acid analyzer, and the major amino acids were glutamic acid, lysine, and isoleucine. Glutamic acid was the most dominant amino acid in the xylem sap. Major compositions of xylem sap drink were 74.5% xylem sap, 15% kiwifruit puree and 10% high fructose. Nutritional facts in drink (252 mL) processed by using the xylem sap were 21.8 g sugar, 23.1 mg calcium, 14.1 mg potassium, 554.5 mg amino acid, and 15.6 mg ascorbic acid.

• Horticultural Science & Technology
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• v.17 no.1
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• pp.11-14
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• 1999

This experiment was conducted to estimate seasonal changes in the properties and chemical components of xylem sap from 'Hayward' (Actinidia chinensis Planch) and wild kiwifruit species (Actinidia aguta Sieb. et Zucc. Planch) in 1996 and 1997. Amount of bleeding sap from kiwifruit vines considerably decreased with collection time in both species. There was no difference in water content, soluble solid content, viscosity, and pH of the sap between 'Hayward' and wild species, while turbidity and organic acid contents were much higher in 'Hayward'. Fructose content was highest among free sugars, followed by glucose, sucrose, galactose and manitol in 'Hayward', but only low concentration of fructose and glucose was detected in wild species. The major inorganic components in the sap were calcium, potassium, and magnesium, and calcium was dominant among them. The saps of 'Hayward' and wild species were composed of 17 kinds of amino acids respectively, and major amino acids were glutamic acid, lysine, and isoleucine. Glutamic acid content was highest in both species and except histidine, contents of methionine and tyrosine were much higher in 'Hayward' than wild species. Concentrations of inorganic elements and amino acids were slightly increased with delaying collection time, but sugar contents decreased.

• Journal of Plant Biotechnology
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• v.42 no.4
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• pp.342-349
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• 2015

Kiwifruit is a new fruit crop that was commercialized in the late 1970s. Recently, its cultivation and consumption have increased rapidly worldwide. Kiwifruit is a dioecious, deciduous, and climbing plant having fruit with hairs and various flesh colors and a variation in ploidy level; however, the industry consists of very simple cultivars or genotypes. The need for efficient cultivar improvement together with the evolutional and biological perspectives based on unique plant characteristics, have recently encouraged genome analysis and bioinformatics application. The draft genome sequence and chloroplast genome sequence of kiwifruit were released in 2013 and 2015, respectively; and gene annotation has been in progress. Recently, transcriptome analysis has shifted from previous ESTs analysis to the RNA-seq platform for intensive exploration of controlled genetic expression and gene discovery involved in fruit ascorbic acid biosynthesis, flesh coloration, maturation, and vine bacterial canker tolerance. For improving conventional breeding efficiency, molecular marker development and genetic linkage map construction have advanced from basic approaches using RFLP, RAPD, and AFLP to the development of NGS-based SSR and SNP markers linked to agronomically important traits and the construction of highly saturated linkage maps. However, genome and transcriptome studies have been limited in Korea. In the near future, kiwifruit genome and transcriptome studies are expected to translate to the practical application of molecular breeding.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.256-261
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• 2017

The effects of temperature and length of cold storage on the quality maintenance of fresh "Gold" kiwifruit were investigated. Physio-chemical properties were analyzed in kiwifruit held at $2^{\circ}C$ and $6^{\circ}C$ temperatures compared to fruit at room temperature ($20{\sim}28^{\circ}C$) during 8 weeks of storage. Low temperatures ($2^{\circ}C$ and $6^{\circ}C$) significantly delayed softening and soluble solids content (SSC) accumulation compared to higher temperature ($20{\sim}28^{\circ}C$). Physico-chemical properties of fruits, including weight losses, firmness, SSC, titratable acidity (TA), SSC/TA ratio, and flesh color properties were monitored during storage. Fast firmness loss was detected in fruit stored at higher temperatures compared to low temperature ($2^{\circ}C$). Similar results were observed for acidity according to storage temperature and length of cold storage, whereas SSC increased to the limited values (%Brix) during storage. The soluble solids content (SSC) increased markedly during the first 60 days of storage and remained almost constant thereafter for all treatments. SSC accumulation rates decreased from 5 weeks after storage probably due to differences between initial and ripe kiwifruits, and SSC decreased with each passing week due to natural starch conversion over time. The SSC/acid ratio increased from 18 to 27 until 5 weeks after storage and then slowly declined in all kiwifruit stored at different low temperatures. Sensory evaluation results showed no differences in kiwifruit flesh color stored at two storage temperatures of $2^{\circ}C$ and $6^{\circ}C$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.3
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• pp.343-349
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• 2011

The chemical composition and antioxidative activity of kiwifruit varieties in Jeju, such as Jecy Gold (Actinidia chinensis var. 'Jecy Gold'), Halla Gold (A. chinensis var. 'Halla Gold'), Jecy Sweet (A. deliciosa var. 'Jecy Sweet') and Hwabuk 94 (A. deliciosa var. 'Hwabuk 94') were investigated. The crude protein, crude lipid, and pH showed no differences among variety and maturity whereas the moisture contents showed differences among the variety and maturity. Jecy Sweet in mature stage showed the highest values in soluble solid, crude protein, crude lipid, and crude ash. The changes in chemical components of kiwifruit by maturity stage were as follows: during ripening, the glucose and the fructose contents increased considerably with the decrease of sucrose content. Potassium, phosphorus, sodium, and magnesium were estimated as the major minerals in kiwifruit and Jecy Sweet contained the highest amounts of potassium and magnesium. At maturity stage, ascorbic, malic and lactic acid were increased with the decrease of citric acid content. The polyphenol contents were 26.81~56.10 ${\mu}g/g$ and 8.64~26.45 ${\mu}g/g$, respectively, in immature and mature fruits. During ripening, the polyphenol content was decreased. The DPPH radical scavenging activity of methanol extracts were 84.47~89.37% and 43.94~76.96% at 500 ppm, respectively, in immature and mature fruits. The immature varieties of kiwifruit have a high DPPH radical scavenging activity. Therefore the chemical composition and physiological activity of kiwifruit was affected by variety and maturity.

• Journal of agriculture & life science
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• v.46 no.6
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• pp.17-24
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• 2012

Soil types for cultivated crops are approximately compose of volcanic ash soils for black(21%) and dark brown soils(41%), and non-volcanic ash soil of red-yellow soil(17%) in Jeju Island. The effects of these soils on fruit qualities of kiwifruit 'Jecy Gold'(Actinidia chinensis cv. Jecy Gold) were investigated in non-heating plastic house. Soil moisture potential was the lowest in the red-yellow soil during fruit growth. However, transverse diameter of fruit in the red-yellow soil was tends to be smaller than in volcanic ash soils, but longitudinal length of fruit was not shown difference by soil types during fruit maturation. Soluble solids in fruit was not differed by soil types until 140 days after of anthesis, after that the red-yellow soil was the highest. No difference on acid contents and hardness of fruit by soil types. Fructose, glucose and sucrose contents in harvested fruit were $4.45{\pm}2.08$, $5.43{\pm}1.13$, and $2.40{\pm}0.40%$ for the red-yellow soil, $2.51{\pm}0.55$, $3.52{\pm}0.86$, and $0.79{\pm}0.33%$ for the black soil and $2.54{\pm}0.47$, $3.52{\pm}0.73$, and $0.73{\pm}0.38%$ for the dark brown soil, respectively. These results show that soluble solid and free sugars in fruit were affected by soil types. It is estimated that soil moisture was rapidly drought in the red-yellow soil of non-volcanic ash soil than in the black and dark brown soils of volcanic ash soil.

• Korean Journal of Food Science and Technology
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• v.44 no.5
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• pp.540-544
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• 2012

The aim of this study was to evaluate the antioxidant activity, total phenolics, flavonoids, and vitamin C contents in peels of 11 commercial fruits commonly consumed in the Republic of Korea. The antioxidant activities were evaluated by ABTS, DPPH radical scavenging methods and reducing power. The peels of plum (Prunus spp.) and golden kiwifruit (Actinidia chinensis) exhibited the highest values of antioxidant activity and total phenolics, while the highest level of ascorbic acid was recorded in the peel of citrus fruit (p<0.05). There were positive correlations between the antioxidant activity assessed by both reducing power and ABTS methods and total polyphenol content ($R^2$=0.6356), suggesting that phenolic compounds are the major contributors to these activities. The results indicate that plum and golden kiwifruit peels can be used as natural antioxidant ingredients and in production of functional foods in the Korean diet.

• Korean Journal of Breeding Science
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• v.43 no.5
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• pp.448-456
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• 2011

We used suppression subtractive hybridization (SSH) combined with mirror orientation selection (MOS) method to screen differentially expressed genes from red-fleshed kiwifruit 'Hongyang'. As a result, the 288 clones were obtained by subcloning PCR product and 192 clones that showed positive clones on colony PCR analysis were selected. All the positive clones were sequenced. After comparisons with the NCBI/Genbank database using the BLAST search revealed that 30 clones showed sequence similarity to genes from other organisms; 10 clones showed significant sequence similarity to known genes. Among these clones, 3 clones (AcF21, AcF42 and AcF106) had sequence homology to 1-aminicyclopropane-carboxylic acid (ACC)-oxidase (ACO) that known to be related to fruit ripening. The expression patterns of differentially expressed genes were further investigated to validate the SSH data by reverse transcription PCR (RT-PCR) and quantitative real-time PCR (qReal-time PCR) analysis. All the data from qReal-time PCR analysis coincide with the results obtained from RT-PCR analysis. Three clones were expressed at higher levels in 'Hongyang' than 'Hayward'. AcF21 was highly expressed in the other genes at 120 days after full bloom (DAFB) and 160 DAFB of 'Hongyang'.