• Korean journal of food and cookery science
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• v.19 no.6
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• pp.737-744
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• 2003

The effects of xylitol and/or erythritol as the alternative ingredients to sugar on the quality characteristics of Yuza tea were studied. The relative sweetness of xylitol and erythritol to a 10％ sucrose solution were 1.10 and 0.71 respectively and there were no change after the addition of the acid and flavoring agent. The sensory characteristics of Yuza tea with xylitol were quite similar in many attributes to Yuza tea with sugar, while Yuza tea with erythritol had many undesirable attributes. Yuza tea with a mixture of xylitol and erythritol(1:1) was less sweet and less acceptable than Yuza tea with sugar. The consumer acceptance test showed that the overall acceptability of Yuza tea made with xylitol was similar to the Yuza tea with sugar. Adding sucralose to the Yuza tea with a mixture of xylitol and erythritol improved the sweetness and overall acceptability in the consumer acceptance test. The pH value of the erythritol Yuza tea was 3.16 and showed a significantly lower value than the 3.39 of sugar and xylitol. The refractive index of the sugar Yuza tea was the highest at 21.03$^{\circ}$Bx. The vitamin C content of Yuzachung with sugar was 34.5mg/100g and the dietary fiber content was 2,80g/100g. Xylitol Yuzachung showed the highest a and b values, but when it was diluted with water to make Yuza tea, the intensity of the color was not significantly different from the Yuza tea with sugar.

• Korean journal of food and cookery science
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• v.20 no.4
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• pp.403-408
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• 2004

The purposes of this study were to investigate the physicochemical characteristics and storage stabilities of various sauces with added Yuza(Citrus Junos). Yuza consisted of three parts: peeled (46.17%), fleshed (43.74%) and seeded (10.09%). Yuza juice revealed 11.33% extraction yield, pH 2.85, 4.18% total acidity, 11 $^{\circ}$Brix, 1.16% transmittance and 2.63 $^{\circ}$Brix/acid ratio. Five kinds of sauces with added Yuza juice were Yuza red pepper paste sauce, Yuza soybean sauce for meat, Shabu shabu Yuza sauce, Korean Yuza vegetable sauce and Japanese Yuza soybean sauce. These sauces showed slight changes in pH, total acidity, total bacterial counts and overall sensory characteristics during storage period (60 days). In conclusion, Yuza juice could be applied to various sauces, which remained usable for 60 days.

• The Korean Journal of Food And Nutrition
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• v.21 no.2
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• pp.135-142
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• 2008

This study investigated to develop new functional yogurt added domestic yuza(Citrus junos). In order to make the most effective yogurt, yuza extract and fructose were mixed at different proportions. DPPH free radical scavenging activity of yuza yogurts increased dependent on concentration. The results of the DPPH free radical scavenging activity, the 1% yuza yogurt was proven to be the best. The overall sensory score for yogurt made from adding 1% yuza ethanol extract was the best of tested yogurts. The antioxidant activity(DPPH free radical scavenging activity) was the highest in 1% yuza yogurt. The quality characteristics of prepared yogurt were evaluated in terms of acid production(pH and titratable acidity), viscosity, color and levels of lactic acid bacteria during storage period. During storage, the quality of yogurt made from adding yuza extract was better than control(without yuza extract). The sedimentation of curd was repressed a little by adding 1% yuza extract.

• Korean journal of food and cookery science
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• v.24 no.2
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• pp.198-205
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• 2008

The influence of the yuza juice addition on quality of the doenjang was investigated by analyzing their chemical properties. The 80 days pre-fermented(PFD) and non-fermented(NFD) doenjangs used in the present study were mixed with yuza juice designed at different ratio (0, 1, 3, 5% (w/w)), These doenjangs were fermented for 60 days and then analyzed chemical properties, respectively. The moisture content was higher in yuza juice added groups than control group. But Ash, crude lipid and crude protein contents were higher in control than yuza juice added groups. The pH and formol-N were higher in yuza juice added NFD groups however, acidity was reversed. Among the free sugars, glucose contents was the highest. And, free sugars contents were higher in yuza juice added PFD groups than control group. Five kinds organic acids were detected, and succinic acid content was the highest. The organic acid contents were higher in proportion to adding volume of yuza juice, in all groups. The contents of Free amino acids were higher in yuza juice added PFD groups and among these, 1% yuza juice added PFD group(3970.0 mg%) was the highest. Hunter L value was lower by yuza juice added volume and higher in PFD groups. Hunter a and b values were non-significantly difference in PFD and NFD, respectively.

• Korean journal of food and cookery science
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• v.29 no.6
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• pp.733-739
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• 2013

This study investigates the characteristics of mayonnaise adding yuza juice, a byproduct of yuza tea, to it. The mayonnaise was prepared by adding yuza juice at 0(control), 25, 50, 75, 100%. In order to analyze the characteristics of the mayonnaise, we examined the color, viscosity, emulsion stability and sensory acceptability. The L, a, ${\Delta}E$ values of mayonnaise mixed with yuza juice were similar to or lower than control. As the content of yuza juice increased, the viscosity and emulsion stability, that is the physical quality of the mayonnaise, improved significantly(p<0.05). With regard to sensory evaluation, mayonnaise mixed with yuza juice had better flavor, taste, texture and overall acceptability(p<0.05). These results suggest that yuza juice is good ingredient to improve the quality and sensory acceptability of mayonnaise.

• 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 food and cookery science
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• v.24 no.2
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• pp.222-227
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• 2008

The objective of this study was to evaluate the antioxidant activity of yuza chocolate,and to determine the optimum ratio of yuza powder for its preparation. Yuza peel and flesh powders were added to chocolate at weight percentages of 0, 3, and 6%, respectively. Color values (L-value, redness, and yellowness), total phenol content, total antioxidant capacity, DPPH radical scavenging activity, and sensory characteristics were then measured in the samples of yuza-containing chocolate. As the amount of yuza powder increased, total phenol content, antioxidant capacity, and radical scavenging activity increased. Depending on the level of yuza powder, significant differences (p <0.05) were shown in aroma, taste, bitterness, and overall acceptability however, there were no significant differences in texture. In terms of sensory acceptability, the addition of 3% yuza peel powder to chocolate was optimal.

• The Korean Journal of Food And Nutrition
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• v.20 no.4
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• pp.392-398
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• 2007

In this study we investigated the physical and sensory characteristics of sponge cakes prepared with different levels(0, 2, 4, 6, 8 and 10%) of freeze-dried steamed garlic and Yuza(Citrus junos Sieb ex Tanaka) powder, combined at the same ratio. The cake height and specific loaf volume were highest in the 4% steamed garlic and Yuza powder group. Moisture contents were significantly higher in the 2 and 4% steamed garlic and Yuza powder groups than in the other groups. With increasing steamed garlic and Yuza powder content, the L- and b-values of the crust decreased, but the a-value increased, when compared to the control group. The L-value of the crumb was insignificant within each group. Compared to the a-value of the $0{\sim}2%$ added groups, the a-value of the $4{\sim}10%$ added groups, increased with increasing steamed garlic and Yuza powder contents. However the b-value decreased in the 8 and 10% steamed garlic and Yuza powder groups. The hardness and chewiness of the $6{\sim}10%$ added groups, and the gumminess of the 10% addition group, were significantly higher than in the control group. The results of the sensory evaluation showed there were not significant differences amoung the groups, except for moistness. Therefore, we suggest that the recommended optimal level of steamed garlic and Yuza powder in sponge cake is a 4% addition.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.3
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• pp.224-231
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• 2009

Volatile components in Olive Flounder fed diets containing 0, 2,5, 5.0, and 7.5% yuza (Citrus junas Sieb ex Tanaka) for 4 months were investigated. Samples were extracted by solid-phase micro extraction and analyzed by gas chromatography/mass spectrometry. Among 89 compounds detected, 82 were positively identified. Volatile compounds of Olive Flounder fed the unsupplemented diet comprised 12 acids, 10 alcohols, eight aldehydes, five aromatic compounds, nine esters, 12 hydrocarbons, four ketones, two monoterpenes, and one miscellaneous compound. Compounds identified in Olive Flounder fed the yuza-supplemented diets consisted of 10 esters, 11 monoterpenes, 13 sesquiterpenes, and two miscellaneous compounds, with the other compounds being the same as in the control. The most abundant class of compounds in flounders fed the yuza-supplemented diet was the monoterpenes, which included limonene, $\beta$-terpinene, $\beta$-trans-ocimene, and $\alpha$-terpinolene. Of the 13 sesquiterpenes identified in flounder fed the yuza-supplemented diet, bicyclogermacrene was the major volatile compound followed by allo-aromadendrene, trans-caryophyllene, and $\delta$-cadinene. Bicyclogermacrene and germacrene D content increased significantly as the yuza supplementation increased.

• The Korean Journal of Food And Nutrition
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• v.26 no.4
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• pp.685-692
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• 2013

Yuza (Citrus junos) has 3 varieties with variable physiochemical properties. This study analyzed these volatile compounds and physiochemical properties according to variety. Three Yuza varieties, native (Citrus junos I), improved I (Citrus junos I+Poncirus trifoliata), improved II (Citrus junos I+C. junos II) were used. The native Yuza weighted more than the improved varieties, but the peel ratio (weight of peel versus pulp) was high in improved one. Protein and ash contents were high in Improved I than native one. Native had 29.6mg% vit. C in pulp and improved I had 57.7mg% vit. C in peel. Free sugar was mainly fructose, and the main organic acid was citric acid in Yuza. Improved I Yuza had high free sugar contents, and the organic acid levels were high in improved II Yuza. Linoleic acid was the most prevalent fatty acid in Yuza; it was distributed in peel or pulp. The most common volatile flavor component was dl-limonene (64~70%); improved II Yuza showed significantly higher contents of dl-limonen and ${\gamma}$-terpinen. Total phenol level of Yuza was identical in all types, but peels had 2.5 times more than pulps.