• Agricultural and Biosystems Engineering
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• v.1 no.1
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• pp.43-48
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• 2000

Mechanical properties of the apple flesh were tested with compression test apparatus constructed by this study. The computer program was developed for measuring mechanical properties, and analyzing data obtained from the study. Compression tests on the apple flesh were performed at four levels of specimen diameter, three levels of specimen length, and at constant loading rate(25mm/min). Five replications were made at each treatment combination. Effect of specimen size on the mechanical properties of the apple flesh was investigated.

• The Korean Journal of Food And Nutrition
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• v.31 no.6
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• pp.858-864
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• 2018

To improve the utility of apple, apple flesh (Malus domestica cv. Fuji), pomace and peels were dried and then extracted using solvents (water, 70% and 100% ethanol). The contents of polyphenols, flavonoids, ascorbic acid, ursolic acid and antioxidant activities were measured as extracted from the apple flesh, pomace and peel. The content of polyphenols was the highest in the apple peel when 100% ethanol was extracted. The content of flavonoids was about 3~8 times higher in apple peel than those of flesh and pomace, and 70% ethanol extract was the highest content. Ascorbic acid content was the highest in apple peel as well as flavonoid content. The content of ursolic acid in the apple flesh was not detected in water and ethanol extraction. In the case of apple pomace and peel, ursolic acid was not detected in water extract but it was detected when ethanol was extracted. The content of ursolic acid was highest in the apple peel. In the case of antioxidative activity, DPPH and ABTS radical scavenging ability showed the highest ability when apple peel was extracted with 70% ethanol.

• Journal of Plant Biotechnology
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• v.44 no.4
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• pp.372-378
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• 2017

For comparison of the transcription profiles in apple (Malus domestica L.) cultivars differing in flesh color expression, two cDNA libraries were constructed. Differences in gene expression between red flesh apple cultivar, 'Redfield' and white flesh apple cultivar, 'Granny Smith' were investigated by next-generation sequencing (NGS). Expressed sequence tag (EST) of clones from the red flesh apple cultivar and white flesh apple cultivar were selected for nucleotide sequence determination and homology searches. High resolution melting (HRM) technique measures temperature induced strand separation of short PCR amplicons, and is able to detect variation as small as one base difference between red flesh apple cultivars and white flesh apple cultivars. We applied high resolution melting (HRM) analysis to discover single nucleotide polymorphisms (SNP) based on the predicted SNP information derived from the apple EST database. All 103 pairs of SNPs were discriminated, and the HRM profiles of amplicons were established. Putative SNPs were screened from the apple EST contigs by HRM analysis displayed specific difference between 10 red flesh apple cultivars and 11 white flesh apple cultivars. In this study, we report an efficient method to develop SNP markers from an EST database with HRM analysis in apple. These SNP markers could be useful for apple marker assisted breeding and provide a good reference for relevant research on molecular mechanisms of color variation in apple cultivars.

• Journal of Biosystems Engineering
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• v.28 no.3
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• pp.239-244
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• 2003

The potential use of ultrasonic technique for firmness measurement of apples was evaluated. Mechanical properties(bioyield deformation, bioyield strength, rupture deformation, ultimate strength, and elastic modulus) and ultrasonic parameters (ultrasonic velocity, attenuation coefficient and the first peak frequency) of the apple flesh during the storage time were measured and analyzed. Ultrasonic parameters were determined from the measurement of ultrasonic wave transmission through the apple flesh specimen. Mechanical properties were obtained by universal testing machine. The bioyield strength, rupture strength, elastic modulus, ultrasonic velocity, and the first peak frequency of the apple flesh decreased with the storage time. The bioyield deformation, rupture deformation, and ultrasonic attenuation coefficient increased with the storage time. The correlation analysis between ultrasonic parameters and mechanical properties and the storage time was performed. The high correlations were found between the storage time and the ultrasonic parameters, and these relationships seem to be useful for determining the firmness of the apple flesh.

• Culinary science and hospitality research
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• v.24 no.1
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• pp.105-113
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• 2018

In this study, optimized pre-treatment conditions were investigated to improve the quality of gochujang apple jangachi. The moisture content was decreased by 14% in 60% sugar solution and 17% in 30% salt solution during 12 hours. On the one hand, in the case of dry sugar and salt method, moisture content was decreased rapidly by 20% and 24%, respectively during 12 hours. Compared with the sugar and salt solution method, the dry sugar and salt method was more effective in reducing moisture content during 12 hours. In the case of osmotic dehydration of the apple parts in the dry sugar method, the moisture content of the flesh, flesh including peel, and peel of apple decreased by 23%, 20%, and 16%, respectively during 6 hours. However, in the dry salt method, the moisture content of the flesh, flesh including peel, and peel of apple decreased by 19%, 12% and 13%, respectively during 2 hours. During this time, the pH tended to decrease, regardless of the presence of sugar and salt. Total acidity was slightly increased in the case of salt. In hot air drying after osmotic dehydration, the moisture content of flesh including peel of apple decreased from 64% and 67% to 31% and 27%, respectively at 90 minutes, and from 64% and 67% to 11% and 18% at 150 minutes, respectively. The moisture content of the peel decreased from 51% to 10% at 120 minutes. As a result of the sensory evaluation, the overall acceptance of the flesh and flesh including peel was highly evaluated, resultantly, the products were considered to be suitable for the production of gochujang apple jangachi.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.4
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• pp.557-563
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• 2015

To observe the functionality of Fuji apples, this study compared and analyzed the general and anti-oxidative components of apples based on production region. This study found that DPPH radical scavenging activities among parts of apple from the Chungju region were 82.84% in peels, 26.98% in peel-flesh, and 18.89% in apple flesh, and these values were lower than those from other regions (P<0.01). Antioxidative was 48.64% in the apple core, which was higher than those in peel-flesh and apple flesh. ABTS radical scavenging activity was highest (79.80%) in peels of apples from the Andong region, whereas values in peel-flesh and apple flesh were highest in apples from the Yesan region (P<0.01). For antioxidative activities in the apple core, apples from the Chungju region showed more than twice the value (52.34%) of other regions. Phenol contents in peels were significantly high [12.03 mg gallic acid equivalent (GAE)/g] in apples from the Muju region, whereas phenol contents in peel-flesh were high (6.01 mg GAE/g) in those from the Andong region. Antioxidative activity in apple flesh was significantly high (5.57 mg GAE/g) in apples from the Yesan region. For antioxidative activities in the apple core, apples from Chungju region showed a relatively high value (6.53 mg GAE/g) (P<0.01), although values were low in apple peel, peel-flesh, and apple flesh. For the combined amount of flavonoids, values in apples from the Yesan region were high in apple peel, peel-flesh, and apple core [56.23 mg quercetin equivalent (QE)/g (P<0.01), 4.05 mg QE/g (P<0.05), and 4.00 mg QE/g (P<0.01), respectively], whereas flavonoid content in apples from the Andong region was high in apple flesh [4.35 mg QE/g (P<0.01)]. The results show that anti-oxidative activities were relatively higher in apple peel than flesh.

• Horticultural Science & Technology
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• v.34 no.2
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• pp.257-268
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• 2016

Physiological characteristics of five new apple cultivars from the Korean apple breeding program were evaluated as a function of harvest time and storage after harvest. Internal ethylene concentration (IEC), flesh firmness, soluble solids concentration (SSC), and titratable acidity (TA) were measured in 'Summer Dream', 'Summer King', 'Green Ball', 'Picnic', and 'Hwangok' apples at harvest, during shelf life at $20^{\circ}C$, and one day after cold storage at $0.5^{\circ}C$ in air. IEC increased during shelf life in 'Summer Dream', 'Summer King', and 'Green Ball' but not in 'Picnic' or 'Hwangok', regardless of harvest time. Flesh firmness decreased towards harvest time and decreased gradually with time in cold storage only in the former three cultivars. In turn, IEC increased during cold storage in the first three cultivars but not for the last two cultivars, irrespective of harvest time. Changes in SSC and TA did not consistently relate to harvest time or storage period but TA tended to decrease as IEC increased. Furthermore, IEC was negatively correlated with flesh firmness except in the 'Green Ball' cultivar but the significance level was much greater in 'Summer Dream' and 'Summer King' (p < 0.0001) than in 'Picnic' (p < 0.01) or 'Hwangok' (p < 0.05) cultivars. Flesh firmness was positively correlated with TA in the first three cultivars but not in the last two cultivars. Overall, the results indicate that cultivars for which IEC increased after harvest had reduced flesh firmness and TA after storage.

• Journal of Biosystems Engineering
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• v.35 no.2
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• pp.124-131
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• 2010

Chlorophyll fluorescence has been researched for assessing fruit post-harvest quality and condition. The objective of this preliminary research was to investigate the potential of fluorescence spectroscopy for measuring apple fruit quality. Ultraviolet (UV) and blue light was used as an excitation source for inducing fluorescence in apples. Fluorescence spectra were measured from 'Golden Delicious' (GD) and 'Red Delicious' (RD) apples using a visible/near-infrared spectrometer after one, three, and five minutes of continuous UV/blue light illumination. Standard destructive tests were performed to measure fruit firmness, skin and flesh color, soluble solids and acid content from the apples. Calibration models for each of the three illumination time periods were developed to predict fruit quality indexes. The results showed that fluorescence emission decreased steadily during the first three minutes of UV/blue light illumination and was stable within five minutes. The differences were minimal in the model prediction results based on fluorescence data at one, three or five minutes of illumination. Overall, better predictions were obtained for apple skin chroma and hue and flesh hue with values for the correlation coefficient of validation between 0.80 and 0.90 for both GD and RD. Relatively poor predictions were obtained for fruit firmness, soluble solids content, titrational acid, and flesh chroma. This research has demonstrated that fluorescence spectroscopy is potentially useful for assessing selected quality attributes of apple fruit and further research is needed to improve fluorescence measurements so that better predictions of fruit quality can be achieved.

• Korean journal of applied entomology
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• v.21 no.4 s.53
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• pp.222-226
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• 1982

Changes in levels of phenolic compounds such as total phenols, flavonols and anthocyanins in Macrophoma-infected apples were studied at various developmental stages of apple fruits. The amounts of total phenols in apple fruit flesh and peel drastically decreased as apples became mature. Apple rot resulted in concentration of total phenols somewhat lower than those of healthy apple flesh. The decline in amount of total phenols was distinct in infected fruit flesh of the cultivar Fuji, which was more susceptible to Macrophoma sp. than the cultivar Miller. Higher amounts of total phenols were found in infected than in heathy fruit peel. In the case of the cultivar Miller, increased accumulation of total phenols was pronounced in infected peel. Apple rot resulted in concentrations of flavonols much higher than those of healthy apples. In particular, the drastically increased accumulation of flavonols was detected in infected peel at the first collection on 10 July, when the cultivars tested were completely resistant to Macrophoma sp. Production of anthocyanins was increased considerably by apple rot: anthocyanins in infected fruits of the cultivar Miller increased markedly as compared with their concentration from healthy fruits. These results suggest that the altered phenolic metabolism in apple fruits may be associated with the development of apple rot.

• Horticultural Science & Technology
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• v.30 no.1
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• pp.50-55
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• 2012

This study was carried out to evaluate the effect of pre-harvest factors on fruit quality and the incidence of storage disorders in 'Fuji' apple during CA storage. Incidence of storage disorders varied, depending on the growing regions, field conditions, and altitude of the orchards. Results indicated that fruit maturity may play a crucial role in the incidence and severity of flesh browning and watercore. The incidence of these storage disorders increased with fruit maturity until 180 days after full bloom (DAFB). In addition, occurrence of watercore was correlated with the incidence of flesh browning during CA storage. The incidence of flesh browning was positively correlated with the sum of the diurnal temperature range from September through October and amount of precipitation from August to October in 1996-1999 growing years. These results suggested that 'Fuji' apple should be harvested no later than 180 DAFB because the late harvested fruits were prone to development of watercore which was correlated with the incidence of flesh browing during CA storage in Korea.