• The Korean Journal of Pesticide Science
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• v.4 no.1
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• pp.71-75
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• 2000

This experiment was conducted to evaluate the effect of fruit quality, ethylene evoluoon and storage in apple 'Tsugaru' as influenced by aminoethoxyvinylglycine(AVG) and several surfactants. When treated with AVG+Silwet L-77, there were few significant differences in soluble solid and acidity as compared with control, but dichlorprop treatment significantly increased in soluble solid and decreased in acidity. Color development was decreased when treated with AVG+Silwet L-77. AVG+Silwet L-77 treatment decreased in ethylene evolution, and increased in storage. It can be concluded that fruit can be left in trees longer and still maintain storage, and more fruit is able to go to fresh market into long-term storage, which increase the market-ability of apple.

• Agricultural and Biosystems Engineering
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• v.2 no.2
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• pp.59-62
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• 2001

The starch content of apples, which is related to the maturity and ripeness, was quantified by using a computer vision system. The stained area was measured by image analysis when an apple slice was stained with KI/I$_2$ solution. The ratio of stained area of the apple slice to its whole area, so called the starch index, was defined as an indicator of the starch content. When Tsugaru apples were manually sorted into immature, turing and mature groups, their starch indices were 0.374, 0.312 and 0.129, respectively. The starch index had relationships to various physicochemical properties of Tsugaru apples. At the statistically significant level of 0.1%, it was correlated with the pH value, bio-yield force, rupture force and color of intact and skin-removed apples. At the 1% significant level, it had the correlation with the density and moisture content.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11b
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• pp.204-209
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• 2000

At harvest, the starch contents of apples, which were related to their maturity, were quantified by using image analysis. The stained area was measured by a computer vision system when an apple slice was stained with KI/I$_2$ solution. The stained area ratio of the stained area of the apple slice to its whole area, or the starch index, was defined as an indicator of starch content. When Tsugaru apples were manually sorted into immature, turning and mature groups, their starch indices were 0.374, 0.312 and 0.129, respectively. Meanwhile, the starch index had correlation to various physicochemical properties of Tsugaru apples. At the statistically significant level of 0.1 %, it was correlated with the pH value, bio-yield force, rupture force and color of intact and skin-removed apples. At the 1 ％ significant level, it had the correlation with the density and moisture content.

• Food Science and Preservation
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• v.6 no.4
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• pp.357-364
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• 1999

Modified atmosphere packaging(MAP) technology was applied to ‘Tsugaru’apple (Malus domestica Borkh) in order to extend the shelf-life of apples during distribution. ‘Tsugaru’apples were packed with the PE film of 40 $\mu\textrm{m}$ thickness(40LD), the PE film modified by the addition of 5% (w/w) zeolite (40CK), and the PE film bags containing the ethylene absorbent (40LP). Quality indices of ‘Tsugaru’apples during storage at 10$^{\circ}C$ were measured in terms of weight loss, soluble solids content, pH, titratable acidity, flesh firmness, peel color and sensory properties. Oxygen, carbon dioxide and ethylene concentration in the film bags changed rapidly at the early stage of storage. Weight loss of the control increased up to 3.0% after 60 days storage while those of the packed apples remained less than 0.6%. No significant differences in soluble solids content and titratable acidity could be found in all the treatments, but significant differences in pH between the control and the packed apples. Higher firmness was kept in 40LD and 40LD than other treatments during storage. Color of the peel changed rapidly in control but slowly in 40LD and 40LP. ‘Tsugaru’apples Packed with Packaging films showed a good visual and sensory quality. Results suggest that packaging treatment with LDPE of 40 $\mu\textrm{m}$ thickness and ethylene absorbent can be used for extending the shelf-life of ‘Tsugaru’apples during distribution.

• Food Science and Preservation
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• v.7 no.2
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• pp.133-138
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• 2000

The research was conducted to measure the effect of temperature on respiratory and quality characteristics of 'Tsugaru' apple(Malus domestica Borkh) during storage at 4$^{\circ}$C, 10$^{\circ}$C and 20$^{\circ}$C. Respiration rate of the apple just after harvest was 7.57 mL CO$_2$/kg/h at 20$^{\circ}$C. It was decreased rapidly and was 2.86 mL CO$_2$/kg/h after storage for 45 days at 20$^{\circ}$C. The apples showed the highest ethylene production rate at 10$^{\circ}$C and 20$^{\circ}$C after 14 days, and at 4$^{\circ}$C after 28 days during storage. Weight of the apple was reduced by 2.9% after 120 days at 4$^{\circ}$C and by 6.1% after 45 days at 20$^{\circ}$C. Color difference of peel and pH increased with the temperatures but titratable acidity and flesh firmness showed the reverse trends during storage. According to the subjective quality test, it could be suggested that the shelf-life of the apple is 86 days at 4$^{\circ}$C, 65 days at 10$^{\circ}$C and 37 days at 20$^{\circ}$C, respectively.

• Korean Journal of Food Science and Technology
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• v.37 no.6
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• pp.922-927
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• 2005

Total and individual organic acid contents of Malus domestica Borkh, cultivars, Tsugaru, Fuji Jonathan (Hong-Ok), and New Jonagold(Sin-Heung) apples, were investigated. Average titratable acidities measured by titration method and total organic acids content determined by HPLC were 241.64-444.52 and 364.23-680.80mg%, respectively. Average total organic acid contents were Jonathan 630.80mg%, New Jonagold 471.04mg%, Fuji 403.80mg%, and Tsugaru 364.23mg%, Contents of DL-malic, citric, fumaric, and quinic acid were 351.98 (Tsugaru)-579.88mg% (Jonathan), 2.14 (Fuji)-12.95mg% (Jonathan), 0.012 (Fuji)-0.060mg% (Jonathan), and 8.91 (Tsugaru)-14.20mg% (Fuji), respectively. Succinic acid was detected only from Jonathan (27.53mg%) and New Jonagold (5.20mg%), while maleic acid was not detected from all cultivars. Ratio of L-malic acid and DL-malic acid contents were 0.98-1.02 in all apple cultivars.

• Preventive Nutrition and Food Science
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• v.16 no.4
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• pp.370-375
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• 2011

The antioxidative activity and the polyphenolic composition were examined in four different cultivars of apple (Malus domestica), 'Fuji', 'Tsugaru', 'Hongro' and 'Kogetsu', and their parts (peel, core, pulp and juice). The total phenolics, flavonoids and anthocyanins differed among the tested cultivars and parts. Peel parts had the highest total phenolics and anthocyanin content. Contributions of those phenolics to total antioxidative activity were determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging assays, and the linoleic acid oxidation assay. Concentration of phenolics contributes significantly to the total antioxidative activity of apples. Clearly, apple peels, especially from Hongros and Kogetsus, possess high levels of phenolic compounds and antioxidants. Therefore, apple peels may potentially function as a value-added ingredient.

• Food Science and Preservation
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• v.12 no.6
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• pp.511-515
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• 2005

The responses of 'Tsugaru' apple and 'Baekhyang' peach fruits treated with 1-MCP, the ethylene inhibitor, were compared. In Tsugaru apple fruits, the reduction of flesh firmness and titratable acidity were significantly retarded for 2 weeks by the treating fruits with 1 or 5 ppm of 1-MCP immediately after harvest The respiration decreased continually for 2 weeks and the onset of ethylene production were also retarded severely. However, in Baekhyang peach fruits, the effects of 1-MCP treatment on the respiration and ethylene production were only transient and the firmness reduction was retarded slightly by the repeated 1-MCP treatments. The responsiveness of the Baekhyang peach fruits on ethylene seems to be recovered rapidly after 1-MCP treatment. In case of Baekhyang fruits, the 1-MCP should be treated repeatedly for effective ethylene inhibition, and the ethylene accumulation should be avoided during the 1-MCP treatment.

• Horticultural Science & Technology
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• v.17 no.6
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• pp.750-752
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• 1999

This experiment was conducted to evaluate preharvest drop control in 'Tsugaru' apple with combined treatments of aminoethoxyvinylglycine (AVG) and several adhesive agents. AVG+Silwet L-77 at $75+1,000mg{\cdot}L^{-1}$ was most effective among the tested combinations. Little or no significant difference was observed among the different application times of AVG+Silwet L-77. AVG+Silwet L-77 significantly reduced preharvest drop while increasing fruit weight, fruit length, diameter and fruit firmness. All the tested combinations were generally effective in reducing preharvest drop as compared to dichlorprop and in maintaining better fruit quality.

• Korean Journal of Food Science and Technology
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• v.38 no.1
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• pp.22-27
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• 2006

Contents of free sugars and sorbitol and their distributional profiles in Tsugaru, Fuji, Jonathan (Hong-Ok), and New Jonagold (Sin-Heung) apple cultivars were evaluated. Average total sugar contents of Tsugaru, Fuji, Jonathan, and New Jonagold were 9.62, 11.79, 11.20, and 10.28%, respectively. HPLC results showed sucrose, glucose, fructose, and sorbitol contents of apples ranged 0.72-3.26, 1.81-3.16, 5.08-6.96, and 0.22-0.96%, respectively. Ratios of individual sugar and sorbitol to sum of fructose, glucose, sucrose, and sorbitol (TS+S) were estimated for all apples. Fructose/TS+S and glucose/TS+S ratios did not differ significantly among cultivars, whereas sucrose/TS+S and sorbitol/TS+S ratios varied. Fructose/glucose ratios were 2.295, 2.244, 2.161, and 2.393 for Tsugaru, Fuji, Jonathan, and New Jonagold, respectively.