• The Korean Journal of Food And Nutrition
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• v.10 no.2
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• pp.145-150
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• 1997

This study was performed to compare the changes of quality in citron(Citrus junos Sieb) juice between sampleII stored at 5$^{\circ}C$ for 1 year after extraction and sampleI made from raw citrons by the belt-pressing extraction method. Compared with sampleI, the soluble solid of sampleII was decreased more than 1$^{\circ}$brix, and the moisture increased 3%. The acidity reduced from 5.83 to 5.23 at the pH rose from 2.68 to 2.84. Although it decreased more than 50% in vitamin C and over 20~30% in amino acid, the changes of the other proximate components, amino nitrogen and free sugar content were very little at the range 0.1~1.0%. Volatile compounds in citron juices between sampleI and II were analyzed by GC and GC-MS. Sample I and II showed about 70 of volatile compounds. But only 13 compounds were identified by mass spectrometer. Major volatile compounds were aromatic compounds of limonene, terpinene, terpineol and terpinolene. Amounts of volatile compounds in citron juices depended on the storage period. The recovery of volatile compounds of citron juices, reduced 30~50% after storage for 1 year and the trace component disappeared during storage. The sensory characteristics including color, aroma, taste and overall acceptability and sugar recipe were not significantly.

• Korean Journal of Environmental Biology
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• v.21 no.1
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• pp.31-35
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• 2003

The effects of different extraction methods on quality of citron juices were investigated in terms of chemical composition and sensory evaluation. Extraction methods employed were press-filtration with 400 mesh sieve, centrifugation, and enzyme pretreatment using pectinase. Enzyme pretreatment method showed the highest yield of juice with 68%, while press-filtration method, the lowest yield of juice with 26.3%. The pH of the juices was relatively similar at 3.29～3.34. Filter-pressed juice showed the highest concentration of soluble solid at 6.0$^{\circ}$Brix, while the juice produced using centrifugation showed the lowest concentration at 4.5$^{\circ}$Brix. In all the juices, fructose was the main soluble sugar. Concentration of organic acid was the highest with the juice produced with centrifugation so that supplementation with higher amount with sugar was needed for overall acceptability.

• 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.

• Korean Journal of Food Science and Technology
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• v.38 no.6
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• pp.742-750
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• 2006

This study was carried out to investigate the efficacy of two kinds of electrolyzed water with added 0.5% (v/v) citron juice, SAEW-CJ[Strong Acidic Electrolyzed Water with added Citron Juice, pH 2.57, ORP (oxidation-reduction potential) 1,122 mV, HClO 23.05ppm] and LAEW-CJ (Low Alkaline Electrolyzed Water with added Citron Juice, pH 4.67, ORP 997mV, HClO 42.55mV) as storing liquid for peeled taro. During storage at $5^{\circ}C$ until 30 days, SAEW-CJ and LAEW-CJ inhibited the growth of microorganisms more effectively than 0.2% (w/v) APS (aluminium potassium sulfate) and 0.85% (w/v) NaCl did. Total phenolic contents, PRO (polyphenol oxidase) activity, color differences value (${\Delta}E$) and vitamin C contents of peeled taro stored in SAEW-CJ and LAEW-CJ were lower than those stored in 0.2% APS and 0.85% NaCl. The hardness decrement of peeled taro stored in LAEW-CJ was lower than that of the others. In addition, the contents of moisture, crude protein, crude ash, total sugars, and reducing sugars were gradually decreased during storage. However, no difference by peeling methods or immersion liquid was found.

• Korean Journal of Food Science and Technology
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• v.26 no.6
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• pp.704-708
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• 1994

This study was performed to compare quality of citron juice as affected by the extraction method. The yield of citron juice was 24.49% by method I (rotary-crushing and screening), 18.09% by method II (pressing) and 12.60% by method III (belt-pressing), respectively. Juices by methods I and II had more soluble solid contents and essential oil and pulp volume than that by method III. Method III was higher in titratable acidity than methods I and II. The contents of fructose, glucose and sucrose in method III were 0.54%, 0.37% and 1.11%, respectively, which were lower values than those in other methods. But there was no siginificant difference in the contents of total sugar by the extraction method. For fatty acids composition, the contents of oleic acid in method I, palmitic acid, linoleic acid and linolenic acid in method II, and stearic acid in method III, respectively, were highest when compared with other methods. The contents of free amino acids detected in method III were smaller than those in methods I and II. Threonin was detected only in method I, methionine and cystine were not detected in methods I. II and III. But the contents of the total amino acids in method III were $1.3{\sim}1.6$ times as large as those in methods I and II.

• Food Science and Preservation
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• v.9 no.2
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• pp.154-160
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• 2002

This study was carried out to investigate the efficacy of electrolyzed oxidizing(EO) water, electrolyzed oxidizing water with 0.5% citron juice and 0.1% aluminium potassium sulfate (APS) solution as the storing liquids to maintain quality and extend shelf life of peeled taro. Water content of peeled taro increased from 80.55% to 82.12∼84.24% after 25 days storage due to moisture absorption. However, there were no significant difference between treatments. In case of color value of peeled taro, L value was slowly decreased and a, b value was generally increased. Texture of peeled taro decreased from initial 4,520$\pm$75 g to 4,160$\pm$80 g after 25 days storage in EO water with 0.5% citron juice, which is the least reduction value in all treatments. Treatment of EO water with 0.5％ citron juice maintained 6.99 mg%(57%) of total vitamin C after 25 days storage which showed highest total vitamin C content between treatments. In most treatments, total sugar was decreased in fast rate for 15 days storage and slowly decreased after 15 days storage. Free sugar content was not changed significantly during storage. In case of sucrose content which is the major portion of free sugar, reduction continued until the midst of storage. and after that it increased to 1.5∼2 times of initial contents. However, there were no differences between treatments and storage days in contents of fructose, glucose and maltose. Major amino acids in peeled taro were aspartic acid and glutamic acid with 1,084.8 and 691.8 mg/100g respectively. At 25 days of storage, aspartic acid content in treatment of EO water was increased about 13.9%. Treatment of EO water with 0.5% citron juice was the most effective in respect to the reduction ratio of total amount of essential amino acids.

• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.574-579
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• 2004

Quality characteristics of citron-treated mackerel oil and fillet during refrigerated storage were evaluated. Citron-treated and non-treated mackerel oil and fillet were estimated by periodical measurements of acid, peroxide, carbonyl, volatile basic nitrogen, trimethylamine-N, and thiobarbituric acid values. Volatile basic nitrogen and trimethylarnine-N values in mackerel fillet treated with citron for 25 days during refrigerated storage were significantly lower than those of citron non-treated mackerel fillet, with those of boiled citron water-treat group significantly decreasing compared to 1 and 2% citron extract groups. Acid, peroxide, carbonyl, and thiobarbituric acid values of citron-treated mackerel oil were significantly lower than those of citron non-treated mackerel oil throughout storage period. Overall acceptability of salted mackerel fillets treated with boiled citron water and 1% citron extract was significantly than those of control and 2% citron extract. Results indicate application of citron juice on mackerel surface may be useful to lower rancidity degree and fish odor during refrigerated storage.

• Korean Journal of Food Science and Technology
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• v.53 no.2
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• pp.187-194
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• 2021

This study aimed to optimize the preparation method of citron (Citrus junos Sieb.) beverages with hibiscus using response surface methodology (RSM). The experimental conditions were established using a central composite design with three independent variables as follows: ratios of citron (40~60%), citric acid (0.34~0.94%), and hibiscus (0.3~0.7%). The results indicate that an increase in the citron ratio contributed to increased sweetness and as the concentration of citron and hibiscus increased, the brightness of the citron beverage decreased and the yellowness increased. The citron ratio showed a significant correlation with the ABTS radical scavenging capacity. Among the 15 experimental groups, 4 representative samples showing statistical significance were selected, and sensory tests were performed, in comparison with commercially available products. As a result of the sensory test, four beverages prepared with the selected recipes showed higher preference than commercial beverages, and optimal recipe conditions were 40% citron, 0.34% citric acid, and 0.5% hibiscus.

• Journal of the East Asian Society of Dietary Life
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• v.14 no.6
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• pp.591-597
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• 2004

This study was performed to develop a standardized recipe for yuza pyun made of citron juice that is by-product of citron tea, to increase the utilization of citron. The effects of mungbean starch(15%, 18%) and dilution ratio of yuza extract(100%, 75%, 50%) on the quality characteristics were evaluated. The quality characteristics of the samples were estimated in terms of sweetness, color difference, texture profile analysis and sensory evaluation. Sweetness of the 18% mungbean groups were higher than 15% groups(p<0.001). The values of Hunter color system indicated that higher content of yuza extract tended to increase yellowness significantly(p<0.001). Texture profiles of hardness, adhesiveness, springiness, cohesiveness, gumminess of yuza pyun showed no significant differences among samples. For sensory evaluation, color and sourness were decreased as yuza extract was diluted, whereas elasticity and sweetness were increased. Yuza pyun containing 18% of mungbean starch with 50% diluted extract was the most preferred in overall acceptability. According to multiple regression analysis, color, sweetness, elasticity and sourness(in order) were important control factors in overall acceptability.

• Korean Journal of Agricultural Science
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• v.43 no.5
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• pp.705-714
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• 2016

Organic acid and sugar contents in ten kinds of juices (two orange juices, two grape juices, two aloe juices, two citron juices, one bokbunja, and one grapefruit juice) were analyzed by high-performance liquid chromatography. Citric acid was detected in all the fruit juices analyzed. Grape juices contained the highest tartaric acid content (67.85 - 99.37 mg/100 mL) while orange and grape juices contained a high content of malic acid (151.67 - 211.18 mg/100 mL). Lactic acid was detected in all the aloe juices (35.12 - 65.27 mg/100 mL) as well as in one orange (203.8 mg/100 mL) and one grape juice (112.28 mg/100 mL). Citrus fruit juices (A, A', F) showed the highest content of total organic acids as 902.81 - 1,103.7 mg/100 mL. With regard to sugar contained in the juices, lactose and maltose were not detected in any of the fruit juices. Even when comparing the same kind of fruit juice, sugar (fructose, glucose, and sucrose) content showed a significant difference (p < 0.05) depending on the manufacturer. In the grape juices, contents of fructose (6.86 - 7.51) and glucose (6.23 - 7.3 g/100 mL) were higher than in other juices. One serving size of the juices (180 mL) analyzed in this study can provide approximately 3.3 - 4.9% of total daily energy requirements when consumed as part of the 2,200 kcal/day diet required for an adult.