• Food Science and Preservation
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• v.8 no.4
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• pp.385-392
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• 2001

This study was to investigate the inhibiting effect of electrolyzed oxidizing (EO) water with/without freezing point depressing agents on polyphenol oxidase (PPO) activity of peeled chestnut. 0.85% sodium chloride, 0.5% citron and 0.5% lemon juice were used to freezing point depressing agents. The content of total phenolics was 13.36 mg% at the earlier stage of storage, and then suddenly increased at around 8∼1ldays. At the 11th day, PPO activity of untreated chestnut was 1,152 units, that was higher than any ethers. EO water adding lemon and citron juice showed synergistic effects on the enzyme inhibition, and their PPD activities were 143.3 and 180.22 units after 4 weeks, respectively. Sensory analysis showed that acceptance of peeled chestnuts was dependent on color and taste, which was related to PPO activity and sweetness. The peeled chestnut treated with EO water added citron or lemon juice tended to show the highest score fur acceptance.

• Food Science and Preservation
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• v.19 no.5
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• pp.652-658
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• 2012

This study, the changes in physicochemical properties and hesperidin content of Jeju-processed citrus fruits according to the harvest date were evaluate. The soluble-solid content, pH, and soluble solid-acid ratios gradually increased, but titratable acidity slightly decreased with a delay in the harvest date. The color index, lightness, yellowness, and turbidity slightly decreased whereas the redness slightly increased with a delay in the harvest date. The hesperidin content slightly decreased with a delay in the harvest date. Hesperidin, which is the major cause of juice cloudiness, decreased with a delay in the harvest date. These results suggest that later-harvested fruit juice is bound to be less cloudy.

• Korean journal of food and cookery science
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• v.25 no.6
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• pp.747-757
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• 2009

The purpose of this study was to enhance the quality of kochujang Apple juice was added to traditional Kochujang at 0%, 20%, 40%, 60 and 80%. Physicochemical and microbial characteristics were periodically investigated during at room temperature during a 90 day fermentation period. The moisture content of the apple Kochujang was higher than that of the control, while the salt content of the apple Kochujang was lower than that of the control, At first, the sweetness of the apple Kochujang showed no significant difference from the control; however, its sweetness increased during the 90 days. In all treatments, the pH value decreased during the fermentation period, while the titratable acidity increased during the fermentation period. Viscosity decreased greatly after 30 days. Sugar reduction was higher in the apple Kochujang than in the control, and its concentration increased with apple juice content. According to the analysis of free sugar, glucose, fructose, and maltose had an especially high ratio in the apple Kochujang. The organic acids detected in Kochujang were citric acid, malic acid, oxalic acid and lactic acids. The content of citric acid and malic acid were higher than the other acids in the apple Kochujang. L, a, and b values generally decreased during the fermentation period. When the Kochujang was made, the number of the total viable cells was $10^7\;CFU/g$. At room temperature, the number steadily increased up to the 30th day, then steadily decreased on the 90th day. After that, there was no significant change. The number of yeasts was $10^6\;CFU/g$ at the end of the 90th day. After the 90th day of fermentation, sensory results showed that the 60~80% apple juice Kochujang showed the best taste, appearance, texture, and overall quality.

• Journal of Applied Biological Chemistry
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• v.59 no.4
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• pp.337-343
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• 2016

The Asian pear (Pyrus pyrifolia Nakai) has historically been one of the most popular fruits in Korea because of its sweetness and juiciness. Nowadays, 81.5 % pears of the 'Niitaka' cultivar are grown in Korea, and most of these are consumed as table fruits. Due to the increase in consumer demand for novel Asian pear varieties, developing new cultivars is of great commercial interest. Since 1984, 'Niitaka' cultivar has been introduced in Korea and 13.3 % was developed into new cultivars in the last 20 years alone. Recently, the consumption rate of fresh Asian pears has been limited. The demand for pears, especially the 'Niitaka' cultivar has no longer increased. As a result, new cultivars of Asian pears have been introduced and their properties have been investigated. This review article provides an overview of the physicochemical characteristics and antioxidant activities of new cultivars of Asian pears.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.4
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• pp.569-573
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• 2001

A pectic substance from citron peel was extracted with different methods to establish the optimum extraction conditions. The extraction yields of pectin with HCl, citrate and tartrate (concentration : 0.1 N, extraction ratio : 1 : 20) were 17.9%, 15.6% and 11.4%, respectively. Six times of 65% ethanol washing step was followed after first ethanol precipitation of acid extract for pure pectin. The degree of esterification (DE) of pectins was in the range of 43.0~47.6% and intrinsic viscosity was in the range of 0.94~2.63 (η$_{sp}$ /C (dL/g)). The sugar compositions such as rhamnose, xylose, glucuronic acid, galacturonic acid, galactose and glucose were little different in three kinds of pectins except for the content of arabinose.

• Journal of the East Asian Society of Dietary Life
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• v.9 no.4
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• pp.483-488
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• 1999

Effect on iron dissolution from iron sauce pans treated with the acetic, malic, citric acid and concentration(0. 0.02. 0.04. 0.1, 0.2, 0.4. 1.0, 2.0, 4.0%) of acidity, boiling times(0, 10. 20, 30, 40, 50, 60mins.) and temperature(5, 20, 40. 60, 80, 10$0^{\circ}C$) of acidity solution and in new and used sauce pans was investigated. As acetic acid concentration increases, iron content has increased. Iron dissolution concentration from iron sauce pan for boiling in malic acid increased more than that of acetic acid and citric acid. At above 6$0^{\circ}C$, as temperature increases, concentration of iron dissolved from iron sauce pan has increased. As boiling time increases, concentration of iron dissolved from iron sauce pan has also increased. Concentration of iron by repeated use has increased. And iron concentration has dissolved in large amount from new pan rather than used pan. Concentration of iron with distilled water by repeated use has increased only slightly. But 1% acetic acid has dissolved in large quantities.

• Korean Journal of Food Science and Technology
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• v.19 no.4
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• pp.361-365
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• 1987

Experiments were carried out to study physico-chemical properties of citron and its products (Yu Ja cha). In addition, citron essence oil were analyzed by capillary gas chromatogaphy and the separated components were identified from their retention time and mass spectrum. The physicochemical properties as follows; soluble solid $8.8^{\circ}\;Bx$, acidity 2.1%, ratio of sugar and acid 4.2. Citron contained sucrose of 0.93%, glucose of 1.0% fructose of 1.17%. The following 28 components were identified in citron. The major volatile constituents of citron was limonene which accounted for 72.4% of total volatiles. Rest of the important compounds were ${\alpha}-pinene$, sabinene, myrcene, terpinene, terpinolene, ${\alpha}-copaene$, iso-caryophy-llene, ${\beta}-selinene$ and ${\alpha}-elemene$.

• Korean journal of food and cookery science
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• v.21 no.2 s.86
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• pp.243-249
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• 2005

Citrus juice, a concentrate manufactured by the Jeju Provincial Corporation, was converted into vinegar orderly by alcohol and acetate fermentation. The juice with a 6-fold dilution by distilled water was used as the sole nutrient source throughout the experiments. The diluted juice contained 12.96Brix of total sugar, $0.632\%$ of total acid and $20.23{\mu}g/ml$ of hesperidin. Naringin was not detected from the juice. Citrus wine having $5.6\~6.3\%$ alcohol was produced from the diluted juice after 3 days of fermentation at $28^{\circ}C$. A kind of citrus-malomelo-yeast CMY-28 was used for the wine fermentation. The wine was successfully fermented for 8 days at $30^{\circ}C$ after inoculation of seed vinegar which contained active cells of acid producing bacteria CV1. The inoculum size of the seed vinegar was controlled to $10\%$(v/v) of the citrus wine. The wine was converted into vinegar by the fermentation process. Citrus vinegar, the final fermentation product, was colored with very thin, radish-yellow and was transparent. It's acidity ranged between $5.8\~6.2\%$ of that of acetic acid. The vinegar attained the best score by sensory test among several natural fruit vinegars. It was clear from the results that high quality citrus vinegar could be produced from concentrated citrus juice. However, the fermentation conditions should be improved to reduce the amount of reducing alcohol.

• Korean Journal of Food Science and Technology
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• v.30 no.4
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• pp.827-831
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• 1998

Effects of pre-pressing condition on quality of pear juice were investigated. Three different types of pressed pear juices such as heated-and-pressed pear juice (HPP), blanched-and-pressed pear juice (BPP), and thawed-and-pressed pear juice (TPP) were prepared. The yield and content of soluble solids in HPP were 78% and $15.0^{\circ}Bx$ which were higher than the other treatments, respectively. Acidity and pH of all the samples were about 0.2% and 4.9, respectively. Major free sugars and organic acids in HPP, BPP, and TPP were fructose and malic acid, respectively. Major soluble minerals were K, P and Mg, and miner ones were Na and Fe. HPP showed a lowest L value, but had a highest taste.

• Journal of Sericultural and Entomological Science
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• v.43 no.2
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• pp.99-103
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• 2001

Daeseongppong, Daebungppong, Daeokppong were bred, and Shingwangppong was selected among the recommended mulberry varieties of the grown silkworm, in order to meet the increasing the interest about the mulberry fruit, The major characteristics of the mulberry fruits were also studies. The chromosome number of Daeseongppong, Daebungppong and Daeokppong are 2n=56 recognized autotetraploid, and that of Shingwangppong is 2n=42 as a triploid. Seed forming rate of Daeseongppong, Daebungppong, and Daeokppong are more than 58%, but that of the Shingwangppong is very low with 6.7%. Concerning the single fruit weight, Daeseongppong is 4.05g, Daeokppong 3.38g, Daebungppong 2.99g which belonged to big fruit group. However Shingwangppong is medium as 2.28g. The sugar contents of Shingwangppong, Daeokppong, Daebungppong, Daeseongppong are 14.8%,13.7%,13.1% and 12.7% respectively. The sugar/acidity rate of them are above 21. The fruit maturity of Shingwangppong is early, those of Daebungppong, Daeokppong are medium and that of Daeseongppong is late. Yielding Potentiality of Daebungppong is high, those of Daeseongppong, Shingwangppong are comparatively high, and that of Daeokppong is moderate. In the case of cold hardiness, those of Shingwangppong, Daeokppong, Daebungppong are comparatively good, that of Daeseongppong is weak slightly.