• Korean Journal of Food Science and Technology
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• v.33 no.4
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• pp.469-473
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• 2001

Fuji apples were sliced and dipped in distilled water, 1% (w/v) ascorbic acid and 1% (w/v) oxalic acid. After minimal processing, the slices were packaged with three films which have different gas transmission rate and stored in cold room$(0-2^{\circ}C)$. The visual quality, gas composition, pH, texture, soluble solids content and titratable acidity were determined. The most deteriorative effects on quality were produced by browning of flesh. Ascorbic acid inhibited the development of browning and extended storage life from 7 days of control to 14 days at $0-2^{\circ}C$. Minimally processed Fuji apple treated with ascorbic acid and P640 film showed exhausting of oxygen in the packaging after 14 days. It showed only a slight reduction of pH from 3.73 to 3.72. The visual quality, gas composition, pH, texture, soluble solids content, titratable acidity were slightly changed, indicating that higher quality was maintained during storage. Ascorbic acid inhibited the development of browning and extended storage life of fresh-cut Fuji apple.

• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.147-152
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• 1999

HPLC was used for determining polyphenols which are known as the functional compounds in the unripe apples Fuji and Aori. The changes in their contents caused by heat treatments were monitored. The carbohydrate contents in Fuji and Aori were 14.1% and 13.5% respectively. Both apple juices showed pH 3.2 and $8.0\;brix^{\circ}$, which were relatively low levels. The major polyphenols were composed of (+)-catechin, chlorogenic acid, (-)-epicatechin, and tannic acid. Total polyphenol contents in Fuji and Aori were 0.11, 0.12% by Folin-Denis method. HPLC analysis of polyphenols showed that four major components were contained by 0.06% in Fuji and 0.07% in Aori. Chlorogenic acid was three times higher in Fuji than in Aori. After water blanching, the area percent of polyphenols resulted in an increase by 3.54% in Fuji but a decrease by 2.93% in Aori. Pasteurization of juices led to decrease by 1.39% and 3.31% respectively. Blanching and pasteurization of unripe apple juices induced negligible changes in polyphenol contents during storage. During concentration, polyphenol contents increased in proportion to the concentration of unripe apple juices.

• Food Science and Biotechnology
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• v.18 no.3
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• pp.636-640
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• 2009

The effect of post-cut vanillin treatment at high concentrations on changes of quality and microorganism in fresh-cut apples was studied. Apples (Malus domestica Borkh. cv. Fuji) were sliced, treated by dipping in different vanillin solution, 0, 40, 80, and 120 mM, packed in polyethylene bag, and then stored for up to 3 weeks at $4^{\circ}C$. Changes in total aerobic bacteria, yeast and molds, browning, soluble solids, and titratable acidity during storage were investigated. Growth of total aerobic bacteria throughout storage was strongly inhibited by vanillin regardless of treatment concentrations. Growth of yeast and molds was inhibited by vanillin of all concentrations until 2 weeks of storage. Levels of browning index, soluble solids, and titratable acidity were not significant difference among the treatment conditions until 2 weeks of storage. However, when stored for 3 weeks, browning index increased more at 80 or 120 mM vanillin, while soluble solids and titratable acidity more be decreased by 120 mM vanillin as compared with other treatment conditions. These results show that the usage of vanillin in processing of fresh-cut apples had a limitation for maintaining quality.

• Applied Biological Chemistry
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• v.30 no.3
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• pp.278-284
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• 1987

As a basic research for inhibition of enzymatic browning of apples during dehydration or processing, polyphenol oxidase was extracted from Fuji apples to investigate heat inactivation, chemical inhibition and other properties. Polyphenol oxidase showed the highest activity at $20^{\circ}C$ and pH 5.5 with catechol as substrate, and the Michaelis constant of 0.14 M under the same condition of substrate and pH. The thermal inactivation followed pseudo first-order kinetics to have activation energy of 23.0 kcal/mol and z value of $19.7^{\circ}C$. As for substrate specificity the polyphenol oxidase showed high affinity toward the o-diphenolic compounds, particularly chlorogenic acid. Neither the m- and p-dihydroxy phenols nor monophenols were attacked. Browning by polyphenol oxidase was completely inhibited at the concentrations of 10mM for potassiummetasulfite and thiourea and 1mM for L-cysteine, ascorbic acid and sodium diethyldithiocarbamate.

• Applied Biological Chemistry
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• v.30 no.3
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• pp.285-290
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• 1987

As a basic research for inhibition of enzymatic browning of apples during dehydration or processing, peroxidase was extracted from Fuji apples to investigate heat inactivation, and chemical inhibition. Peroxidase showed the highest activity at $35^{\circ}C$ and pH 5.5 using substrates of p-phenylenediamine and $H_2O_2$. The thermal inactivation followed biphasic kinetics to have activation energy (Ea) of 48.2kcal/mol and z value of $11.2^{\circ}C$ for the heat labile fraction and Ea of 36.3kcal/mol and z value of $14.9^{\circ}C$ for the heat resistant fraction. Browning by peroxidase was completely inhibited at the concentrations of 10mM for sodium diethyldithiocarbamate and potassium metabisulfite and 1mM for L-cysteine and ascorbic acid.

• Horticultural Science & Technology
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• v.19 no.3
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• pp.358-361
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• 2001

Factors affecting fruit conformation of 'Fuji' apples (Malus domestica Borkh.) were investigated through correlation study of fruit weight, seed numbers, and seed weight in relation to fruit conformation indices. Apples were harvested from two orchards in 'Andong' and 'Youngyang' areas at commercial maturity and grouped by fruit weight. Average number of seeds and seed weight were 8.9 and 0.64 g in 'Andong' orchard, while 6.3 and 0.47 g in 'Youngyang' orchard, respectively. When pooled data from the both orchards were analyzed, correlation of fruit weight with seed weight was significantly positive, whereas that with seed number was not significant. Fruit shape index determined by length/diameter ratio was positively correlated with fruit weight, while relationship of the shape index with seed number or with seed weight was not significant. Asymmetry index tended to be low in apples from the 'Andong' orchard in which higher seed numbers and seed weight were observed. The asymmetry index showed highly negative correlations with seed numbers and with seed weight.

• Research in Plant Disease
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• v.24 no.4
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• pp.321-327
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• 2018

In 2018, symptoms of black rot on apple (Malus pumila var. dulcissima KOIDZ) cv. Fuji were observed in Yeongcheon-si, Korea. The fruit decay symptoms consisted of purple pimples spots, black rot around the seed cavity (calyx end), mummified fruit. To isolate the causal agent, small fragment (2 to 3 mm) of decayed tissue from the lesion margin were placed on WA or PDA. Fungal colonies on PDA produced dense white aerial mycelium, becoming dark gray with age. Pycnidia and conidia were observed under a light microscopy. The shapes of conidia were aseptate, ovoid, rounded at both ends, and $21.7-28.3{\times}9.9-15.3{\mu}m$. Based on morphological and cultural characteristics, this fungus was identified as Diplodia seriata. To confirm its identity, two loci (ITS and ${\beta}$-tubulin) were sequenced for molecular identification. BLAST searches indicated 100% identity with D. seriata. A pathogenicity test was conducted with isolates on Fuji apples. The apples were inoculated with mycelial plugs (5 mm) from 7-day-old cultures of the putative pathogens. All inoculated apples developed rot symptoms identical to the original symptoms, from which D. seriata were reisolated, fulfilling Koch's postulates. This study is the first report of black rot caused Diplodia seriata on apple.

• Current Research on Agriculture and Life Sciences
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• v.32 no.4
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• pp.211-214
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• 2014

This study investigated the effects of using a pollen suspension for artificial pollination on the labor costs, fruit set, and fruit quality attributes of 'Fuji' apples. The pollen germination rate was 20% in a 20% fructose solution after 6 hours, and the pollen remained stable for 6 hours in the same solution. The king fruit per flower cluster exhibited a normal fruit set, regardless of the treatment. Plus, none of the artificial pollination applications affected the fruit length/diameter ratio, flesh firmness, soluble solids concentration, or titratable acidity in the harvested 'Fuji' apple fruits. However, the labor savings were significantly higher with the pollen suspension treatment when compared with the cotton swab or love-touch. Therefore, the labor cost was four-fold less in use of pollen suspension than in use of cotton swab for artificial pollination.

• Current Research on Agriculture and Life Sciences
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• v.1
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• pp.141-150
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• 1983

This report decribes the changes of internal browning and PPO in apples, when the method of storage was changed in the condition of low temperature. Internal browning was found more Fuji harvested in November than Fuji in October. The degree of internal browning was the highest during the storage of 0.09mm 2% and 0.06mm 2%, 0.06mm 20% was followed. In the subatmospheric storage with complete remove of $CO_2$ internal browning was not observed. During the storage of P.E. film bag, Fuji havested in November was higher than in October, and Fuji on 0.09mm 2% was higher than in 0.06mm, and Fuji during the storage of P.E. film bag was increased in PPO activity and PPO specific activity. During the subatmospheric storage with complete remove of $CO_2$, PPO activity of Fuji was little changed, but it's PPO specific activity was continuously decreased. PPO activity of Ralls was more higher than PPO activity of Fuji. PPO activity and PPO specific activity during the early stage of storage and the end stage of storage were little changed. Internal browning of Fuji was more effected $CO_2$ injury than chilling injury. There is no relation between internal browning and degree of PPO activity was effected by $CO_2$ and slightly related with internal browning.

• Korean Journal of Plant Resources
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• v.36 no.5
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• pp.517-526
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• 2023

The harvest time of the late-ripening 'Fuji' apple (Malus × domestica) is variable, depending on the coloration of the fruit skin. Ethephon, a plant growth regulator, promotes the ethylene production and induces physiological responses associated with fruit maturation in climacteric fruit crops, such as apples. This study aimed to investigate the effect of ethephon treatment on fruit characteristics after fruit enlargement, with the objective of proposing an economical and stable harvest control method for 'Fuji'/M.26 apples. Fruit characteristics were assessed at 10-days intervals following the application of 100 mg/L ethephon and mixture of 100 mg/L ethephon and 0.5% CaCl₂ at 145 days after full bloom (DAFB). Starch contents of ethephon-treated (ET) and ethephon with CaCl₂-treated (EC) apples began to decrease from 155 DAFB, and the starch contents of ET and EC at 10 days before harvest were similar to those of control at harvest time. Red coloration of fruit skin in EC was lower compared to ET but higher than control. The average fruit firmness was low in ET, while the control and EC exhibited similar levels of firmness. Fruit sugar acid ratios did not show significant differences between treatments. However, the titratable acidity of EC was significantly lower than that of the control at 10 days before harvest. Moreover, fruit sugar acid ratio of ET and EC at 10 days before harvest in 2021 was similar to their sugar acid ratio at harvest time. Therefore, it was thought that fruit maturation and skin coloration could be accelerated by 10 days from the harvest time through the combined treatment of 100 mg/L ethephon and 0.5% CaCl₂ at the end of fruit enlargement in 'Fuji'/M.26.