• Applied Biological Chemistry
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• v.37 no.3
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• pp.161-167
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• 1994

Soluble solids $(^{\circ}Brix)$, acid content and vitamin C content of Citrus miyakawa unshiu and C. okitsu unshiu juice harvested middle of November 1993 in Seuho-Dong and Topyung-Dong, Seogwipo-si, south area of Cheju were $10.7{\sim}11.0$, 1.04% and $41.19{\sim}44.94\;mg/100\;g$ juice, respectively. Carbohydrate was consisted of about 1/2 sucrose, 1/4 glucose, and 1/4 fructose. Fruit weight, peel thickness, soluble solids, pH, acid content and Brix/Acid ratio had a good correlation in linear function with increasing fruit size, respectively. However, hardness and edible part ratio were not showed correlation with increasing fruit size. Middle size of citrus fruit was favorable to panelists, and the citrus peel color of red yellow was more favorable than pale yellow color in sensory evaluation. Sensory evaluation score showed a linear correlation among citrus fruits of C. okitsu unshiu produced in Namwon-ri, Seuho-Dong, Seogwipo-si, south area of Cheju, and that of Chochun-ri, Ara-Dong, Cheju-si, north area of Cheju, and the score was higher according to citrus fruit produced in optimum cultivation area. With increasing Brix/Acid ratio of citrus juice, high sensory evaluation score was gained in panelists. These data obtained are supposed to be applied to the quality evaluation of Citrus unshiu produced in Cheju.

• Food Science and Preservation
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• v.21 no.2
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• pp.199-205
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• 2014

This study was conducted to investigate the physicochemical properties and antioxidant activity of black Doragi-apple juice to increase the utilization of Doragi, which is known as a high-functional horticultural crop. To prepare the black Doragi, it was steamed for 15 days at $60^{\circ}C$ and was then dried at $30^{\circ}C$ for 3 h. The five types of black Doragi-apple juice were prepared based on different mixing ratios of black Doraji extract, apple extract, and jujube extract. The mixing ratios of black Doraji extract, apple extract, and jujube extract were 3:3:1, 4:2:1, 2:4:1, 2:2:1, and 2:6:1 for samples A, B, C, D, and E, respectively. The pH and acidity of black Doragi-apple juice were within the ranges of 3.9-4.15 and 1.26-1.51%, respectively. Black Doraji-apple juice E showed the highest sugar content (9.33 $^{\circ}Brix$), reducing sugar content (85.05 mg/mL), and sugar content/acid ratio (6.98). Based on the sensory evaluation, sample C was most preferable in terms of color, taste, sugar-acid ratio, and overall preference, except for the flavor. Black Doragi-apple juice D showed a higher total polyphenol content (706 ${\mu}g/mL$) than sample C (586.22 ${\mu}g/mL$), but there was no statistically significant difference between samples C and D in terms of antioxidant activities. Therefore, it is suggested that the best mixing ratio of black Doraji extract, apple extract, and jujube extract for the production of the best black Doragi-apple juice with excellent taste and antioxidant activities is 2:4:1 (sample C).

• Food Science and Preservation
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• v.6 no.1
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• pp.7-10
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• 1999

Physicochemical properties of Satsuma mandarin(Citrus unshiu Marc. var. miyagawa) harvested in middle of November according to production areas of Cheju were investigated. Peel thickness of citrus fruits was ranged from 2.54mm to 3.13mm, and it was lower on fruits harvested in western areas than those of other areas in Cheju. Soluble solids were ranged from 10.1 to 12.0$^{\circ}$Brix, and it was lower on fruits harvested in southern areas. Acid contents of citrus juice were ranged from 1.28% to 1.42%, it was higher on fruits harvested in eastern areas, specific gravity of citrus fruits was ranged between 0.86 and 0.88. Flesh ratio was ranged from 75.1% to 77.6%, it was lower on fruits harvested in southern areas. Soluble solids, acid content and specific gravity harvested in southern areas of below 100m and over 150m sea level altitude were 11.8 and 11.2, 1.43% and 1.40%, 0.87 and 0.9, respectively. Fruits quality harvested in southern areas was better, compared to other harvest areas of Cheju.

• Food Science and Preservation
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• v.3 no.2
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• pp.131-136
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• 1996

Even though plum is well known as a health food, the available processed food of it is quite limited. Furthermore it is difficult to find an easy processing method for leading to a value added product at farmhouse. This study was investigated to effects of temperature for plum extract juice by osmosis of yellow sugar. The plum was mixed with yellow sugar at equal ratio(w/w) to obtain yellowish extracted plum juice and then located in incubator at 15, 25, 35$^{\circ}C$, respectively. The sugar content of extract was high at the early period but decreased throughout extraction period and it was about 66.1~67.4$^{\circ}$Brix. The color difference was increased yellowish throughout the extract period. The pH of it was decreased throughout extract processing but citric acid content was increased. The speed of extraction during extraction processing was more rapid at 15$^{\circ}C$ than 3$0^{\circ}C$. However sensory evaluation score of taste and flavour was obtained at 15$^{\circ}C$ than 3$0^{\circ}C$, so the prefer temperature for plum extract juice by osmosis of yellowish sugar was 15~2$0^{\circ}C$.

• Korean Journal of Food Science and Technology
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• v.27 no.3
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• pp.342-347
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• 1995

Experiments were conducted to investigate the effects of storage temperature and blanching treatment on the storage stability in order to extend the shelf life of Citrus junos. Chilling injury of Citrus junos was not observed at the temperature range of $0^{\circ}C{\sim}5^{\circ}C$. Respiration rate of Citrus junos classified into climacteric characteristics as storage time goes by increase of respiration rate. The $Q_{10}$ value of Citrus junos during storage appeared to have a narrow range of $2.3{\sim}2.4$ The decaying rate increased drastically at $20^{\circ}C$ ranging from 71.4% to 86.5%. It was not much influenced by the pretreatments but by the storage temperature. There was no difference in weight loss between the control and blanching treatment. The weight loss of Citrus junos at $20^{\circ}C$ appeared to be high during the 12 weeks period, and consequently the overall quality of Citrus junos was rapidly decreased. The ratio of brix to acid showed a slow increase for Citrus junos stored at $3^{\circ}C.\;At\;20^{\circ}C$, however, it increased rapidly and then decreased. This phenomenon was mainly due to the relatively high increase of brix, compared to the increase in acid content. Development of browning color in Citrus junos was mainly associated with Citrus junos peel, rather than with Citrus junos pulp.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.6
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• pp.721-730
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• 2017

This study determined the optimal mixing ratio of functional materials to enhance the functionality of batter for fish cutlets. An optimal mixing ratio of the hiziki Hizikia fusiformis, fig fruit Ficus carica L. and pear Pyrus pyrifolia Niitaka extracts (HFP extract) of 3:1:1 was found. The physicochemical properties of the mixture were as follows: total phelonic contents of $1187.29{\pm}41.55mg/L$, 1,1-diphenyl-2-picryhydrazyl (DPPH) radical scavenging activity of $61.50{\pm}2.33%$, ascorbic acid content of $23.68{\pm}0.02g/100g$, ${\beta}-carotene$ content of $51{\pm}3.92{\mu}g/100g$, and sugar content of $12.7{\pm}0.1Brix^{\circ}$. A mixture of the extract, Korean herbal powder, and wheat flour was prepared as the fish cutlet batter. The fish cutlet prepared with the batter had a hardness of $166-202g/cm^2$ and Hunter's color scale values L of $31.14{\pm}2.1$ to $34.62{\pm}1.3$, a of $-4.89{\pm}0.21$ to $-2.26{\pm}0.19$ and b of $-20.65{\pm}2.65$ to $28.93{\pm}3.14$. The FRAP (ferric reducing antioxidant power) and VBN (volatile basic nitrogen) of the fish cutlets were measured to evaluate functionality and determine the optimal mixing ratio for cold storage at $-12^{\circ}C$, $-18^{\circ}C$, and $-24^{\circ}C$. The optimum mixture ratio of extracts /Korean herbal powder/ wheat flour was 1:6:3.

• Korean Journal of Food Science and Technology
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• v.36 no.2
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• pp.226-232
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• 2004

Dilution concentration of watermelon juice, concentrations of added sugar, citric acid, and vitamin C, sterilization temperature and time, and natural color extracts were evaluated to determine optimum conditions for watermelon beverage production. Optimum dilution concentration of watermelon juice and optimum content of soluble solid were 40% and $12^{\circ}Brix$, respectively. Addition of 0.5 and 0.3 g/L or 1.0 and 0.3 g/L citric acid and vitamin C gave optimum sensory quality. Sterilization of watermelon beverage at above $70^{\circ}C$ decreased redness. Sterilization at $60^{\circ}C$ for 10 to 30 min or at $70^{\circ}C$ for 10 min achieved best sensory quality. Addition of 20 g/L raspberries gave best sensory quality among raspberries, omija, and borage. Hot water was better than alcohol for extraction of natural color. Ratio of extracts for optimum sensory quality was 7 : 3 for extract of 20 g raspberries/L : extract of 30 g omija/L.

• The Korean Journal of Community Living Science
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• v.21 no.4
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• pp.481-488
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• 2010

The objective of this study was the development of the preparation method of fermented turnip juice. The yields and soluble solids of fermented turnip juice were 41.2, 52.8, 56.4 and 57.4%, and 34.3, 42.4, 48.6 and 54.7 $^{\circ}Brix$ with 40, 60, 80 and 100% addition rate of turnip quantity, respectively. The major organic acids in turnip juice were succinic acid, isobutyric acid and fumaric acid, and these organic acids were decreased after fermentation. On the other hand, lactic acid, formic acid, acetic acid, propionic acid and butyric acid were produced during the fermentation. Soluble solid and pH value in fermented turnip decreased by time-dependently. Free radical scavenging activity was increased by fermentation of turnips and nitrate scavenging effects were the highest in pH 3 and increased with adding Omija or Japanese apricot. The best preparation method of fermented turnip juice was fermentation at $24^{\circ}C$ 12-15 days after adding 40% of sucrose to total quantity. As adding Omija, organic acid contents were increased and sensory evaluation was improved in fermented turnip juice.

• Korean Journal of Food Science and Technology
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• v.25 no.1
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• pp.33-38
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• 1993

In order to utilize Kumquats as a processed products, a Citrus varieties produced in Cheju island, physicochemical properties of Kumquats, sensory evaluation of frozen Kumquats, sensory evaluation and texture parameter of Kumquats processed foods were investigated. Fruit size, weight, peel ratio, peel thickness, and Brix/acid ratio of Youngpa Kumquats cultivated in green house were 29.5 mm, 16.10g, 4.63 mm and 20.0 respectively, and it was suitable for as raw-eating and processing materials. Kumquats juice consisted of 58.27% citric acid, 32.49% malic acid, 9.14% tartaric acid and 0.08% maleic acid of total organic acids. Organic acid contents of Kumquats juice was very different from Citrus unshiu juice in malic acid content. Sensory evaluation on frozen Kumquats stored at $-18^{\circ}C$ for 6 month was good for appearance, taste and texture as summer commodity. Vitamin C content of frozen Kumquats was 74.94 mg/100g, and its content was decreased slightly during fronzen storage. Hardness on Kumquats jam was lowered from 1,294 to 355 g-force as the ratio of Kumquats juice content was increased, but the changes of other texture parameter were not so large. Kumquats jam contained $40{\sim}60%$ orange juice was evaluated as superior to orange jam for panelists.

• Korean Journal of Food Science and Technology
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• v.30 no.1
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• pp.90-96
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• 1998

An experiment to make mixed juices carrying the freshness and other specific characteristics of vegetables and fruits which are useful for the prevention and treatment of various diseases was attempted on the emphases of pretreatment methods, combination of fruits and vegetables, and elimination of microorganisms. Blanch in boiling water prior to extraction for green vegetables, addition of ascorbic acid during extraction for tomatoes and apples, or addition of ascorbic acid after blanch in 3% acetic acid for carrots was effective to keep colors and suspended solids in liquid extract. On the basis of sensory evaluation the extracts from tomatoes, apples. carrots. mallows, watercreses+pine needles, Angelica keiskei Koiz, jujubes and lemons were selected and mixed at the ratio of 3 : 3 : 3 : 1/2 : 1/2 : 1/2 : 1/2 : 1/5. The mixed extracts were pasteurized for 15sec at $96^{\circ}C$ or filtered through a ultramembrane filter. While the centrifuge precipitation and retentates on the membrane filter were autoclaved and combined with ultrafiltrates. The mixed juices showed $pH\;4.07{\sim}4.10$ titratable acidity $66.35{\sim}84.08$, soluble solid $7{\sim}9^0Brix$, reducing sugar $5.42{\sim}6.97%$, glucose $1.96{\sim}2.30%$, fructose $3.46{\sim}4.14%$ and high content of K, Mg and Ca. Ultrafiltration showed better quality scores in color, juice. Peroxidase and microorganisms were inactivated by thermal treatment and ultrafiltration.