• 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.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.

• 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.

• Journal of Food Hygiene and Safety
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• v.19 no.3
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• pp.126-131
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• 2004

This study was conducted to investigate of inhibition activity of yuza (Citrus junos) extracts and juice on nitrite scavenging and N-nitrosodimethylamine (NDMA) formation in model system. Yuza juice was separated into organic acid, ascorbate and phenolic portion using sep-pak $C_{18}$ cartridge, respectively. Nitrite scavenging activity and inhibition of NDMA formation from yuza extract has shown higher inhibition with pH of reaction condition lower and amount of added sample more. And peel extract of yuza was higher than those of flesh extract. Nitrite scavenging activity was excellent juice portion rather that 3 portions. Of the 3 portions, it activity was the highest in the organic acid portion, and decreased in the following order; phenolic acid, ascorbate portion. Therefore, organic acid of yuza was suggested to expect effective ihhibitor of NDMA formation.

• 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.

• The Korean Journal of Food And Nutrition
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• v.27 no.6
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• pp.1051-1058
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• 2014

Yuza (Citrus junos) had 3 varieties and they had variable physiochemical properties. This study analyzed free sugar, hesperidine, naringin, flavonoid contents and antihypertensive activities according to variety and harvest time of Yuza. Three Yuza varieties, native (C. junos I), improved I (C. junos I + Poncirus trifoliata), improved II (C. junos I + C. junos II) were used. Harvest time could influence biochemical properties of Yuza such as acidity and $^{\circ}brix$. When the Yuza harvested at behind of season, the sugar/acid ratio went up because the acidity was decreased but sugar content was increased. Fructose content was dramatically high at November, Yuza of the season. Total flavonoids was high in pulp parts of improved II and in juice of native one harvested at October. The content of hesperidin and naringin in peels and juices were high in immature fruits fresh-picked at July since then they were decreased steadily and there were no difference according to varieties. The angiotensin converting enzyme (ACE) inhibition was powerful at pulp of Yuza in particular native one picked at November.