• 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.24 no.4
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• pp.460-465
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• 2008

The objective of this study was to evaluate the antioxidant properties and sensory qualities of citron peel tea, and to determine the optimum ratio of citron peel powder for its preparation. Yuza peel powders were prepared with citron peel tea at weight 2 and 3 g, respectively. Then, color values(L-value, redness, and yellowness), total phenol content, total antioxidant activity, DPPH radical scavenging activity, and sensory characteristics were measured in the tea samples. The pH of the citron peel tea decreased with increasing preparation temperature. And as the amount of citron peel powder increased, total phenol content, antioxidant capacity, and radical scavenging activity increased. The level of total phenolics in the tea had a higher correlation with total antioxidant capacity($r^2$ = 0.731). Depending on the level of added yuza powder, significant differences(p < 0.05) were shown for aroma, color, and overall acceptability however, there were no significant differences in sourness and bitterness.

• 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 Environmental Agriculture
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• v.36 no.1
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• pp.36-42
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• 2017

BACKGROUND: Yuza seed by-product has been produced in a large amount from the agricultural farms in the southern area of Korea. It has been mostly abandoned after commercial process for the production of juice, jam and tea. The study on the reuse of the yuza seed by-product has received much attention as a bio-resource material for the production of active compound in agriculture. METHODS AND RESULTS: Insecticidal rhamnolipid-producing Pseudomonas sp. EP-3 was grown in mineral salt media with the yuza seed by-product at 2, 20, 50 and 100 g/L. The growth of EP-3 was accompanied by a increase in insecticidal activity against green peach aphid. The highest insecticidal activity was observed when EP-3 was grown in the medium containing 50 g/L of the seed sample, producing approximately 996 mg/L of rhamnolipid at 96 h. Palmitic acid, stearic acid, oleic acid and linoleic acid were determined as the major fatty acids of the seed sample. The EP-3 cultures grown on the fatty acid mixture extracted from the seed sample showed a aphid mortality similar to that of cultures grown on the seed sample. The EP-3 cultures grown on 50 g/L of the seed sample showed aphid mortality more than 90% under greenhouse conditions. CONCLUSION: This study suggested that the yuza seed by-product may be used as a renewable material for microbial production of rhamnolipid against green peach aphid.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.36 no.2
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• pp.137-143
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• 2010

Yuza (Citrus junos Sieb ex TANAKA) is a citrus fruit that is cultivated in northeast Asia. Citron is known for containing abundant antioxidants such as vitamin C, flavonoids, for example hesperidin and hesperetin, and terpenoids such as limononin. When mature citron is processed for tea or other beverage food products in Korea, massive amounts of seeds and pericarp are remained as waste. This study aimed to exploit the processed remnant of Citron for developing functional cosmetic applications. Ethanol extracts of Yuza seed and pericarp did not show significant radical scavenging activities measured by DPPH (2,2-diphenyl-1-picrylhydrazyl) method. But they contained significantly high phenolic compounds. Cultured human dermal fibroblasts and HaCaT keratinocytes were irradiated with 25 mJ UVB and the citron extracts were added to the medium of each culture. Cellular damages caused by UVB irradiation were prevented by the addition of the Yuza extract. In addition, the reduction of the enhanced MMP-1 expression after irradiation of UVB in human dermal fibroblasts was observed. Also the increased level of pro-inflammtory TNF-$\alpha$ in the UVB irradiated HaCaT cells was decreased. The collagen expression was enhanced by the extract. Yuza extract markedly inhibited melanin production from $\alpha$-MSH treated B16F1 melanoma cells. Melanin assay, tyrosinase zymography results indicated that Yuza extract had strong depigmenting activity. In conclusion, Yuza ethanol extracts have good anti-photoaging and strong anti-melanogenic efficacies.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.9
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• pp.1256-1263
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• 2015

Citrus junos Sieb. ex Tanaka has been traditionally called Yuza in Korea and is used as a cuisine material or tea as well as medicinal herb. In this study, we evaluated the immune-enhancing effect of Citrus junos ethanol extract (CJE) on RAW264.7 mouse macrophage and primary immunocytes. CJE treatment showed increased macrophage activity in a dose-dependant manner. CJE also enhanced natural killer (NK) cell activity. We measured lactate dehydrogenase (LDH) level as a measurement of NK cell cytotoxicity against YAC-1 lymphoma cells. CJE treatment showed an increased LDH level in a dose-dependent manner. Finally, we evaluated the effect of CJE on mouse primary splenocyte proliferation. CJE treatment slightly increased splenocyte proliferation compared to the control. The results of this study suggest that CJE can help immune function via macrophage cytokine production, increased NK cell activity, and splenocyte proliferation.