• Food Science and Preservation
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• v.23 no.6
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• pp.859-865
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• 2016

Thise study aimed to determine the optimum antioxidant extraction conditions of dried Gugija (Lycium chinensis Mill). To determine the operational parameters, including ethanol concentration ($X_1$, 0~80%) and extraction time ($X_2$, 1~5 hr), a response surface methodology was applied to monitor brown color intensity, total phenolic compounds, ABTS radical scavenging activity, and $Fe^{2+}$ chelating activity. Coefficients of determinations ($R^2$) of the models were 0.8486~0.9214 (p<0.05~0.1) in dependent parameters. Brown color intensity of Gugija extracts reached a maximum of 0.75 (OD in 420 nm) under extraction conditions of 2.88 hr in 78.10% ethanol. Total phenolic compounds reached a maximum of $2,355{\mu}g$ under extraction conditions of 4.94 hr in 30.17% ethanol. ABTS radical scavenging activity was 13.83% at 4.61 hr and 16.21% ethanol. $Fe^{2+}$ chelating activity showed a maximum of 58.54% under extraction conditions of 3.39 hr in 0.76% ethanol. Optimum extraction conditions (5 hr extraction in 15% ethanol) were obtained by superimposing the contour maps with regards to total phenolic compounds, ABTS radical scavenging activity, and $Fe^{2+}$ chelating activity of dried Gugija. Maximum values of total phenolic compounds, ABTS radical scavenging activity, and $Fe^{2+}$ chelating activity under optimum extraction condition were $2,397{\mu}g$, 15.62% and 54.78%, respectively.

• Preventive Nutrition and Food Science
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• v.5 no.3
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• pp.165-169
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• 2000

Kombucha beverages were made from sweetened tea by Oriental, European and Tibetan tea fungus starters. The hot water extracts o green tea, black tea, Gugija and Omija were mixed with white and/or brown sugar, and were fermented under a static culture at 3$0^{\circ}C$. Titrable acidity, pH, color and cellulose production in kombucha beverages were evaluated. All tea fungus starters showed a higher acid production in green/black tea extracts rather than Gugija and Omija extracts. In green/black tea extracts Oriental tea fungus produced a kombucha beverage with a higher titrable acidity and lower pH than those of European and Tibetan tea fungus starters. By the static fermentation of green/black tea extract for 18 days, Oriental, Tibetan and European tea fungus starters produced cellulose pellicles of 0.43g, 0.16g, and 0.19 g (dry weight) on the top in the culture, respectively. As a mother starter, the cellulose pellicle was more efficient in acid production compared with tea fungus broth. Oriental/Tibetan mixed tea fungus showed the best acid production in the green/black tea extract supplemented with brown sugar.

• Journal of Food Hygiene and Safety
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• v.26 no.2
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• pp.100-106
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• 2011

This study was conducted to investigate the residue amount of harmful materials on the 113 commercial fruit teas (Gugija, Omija, Sansuyu) in Gwangju area. It was performed using the GC-ECD, GC-NPD, GC-MSD and the LC-UVD, LC-FLD, LC-MSD to analyze 200 pesticides. The heavy metals were determined using a Mercury analyzer and AAS. The sulfur dioxides were analyzed by modified Monnier-Williams method. The residual pesticides were detected in 4 samples (Gugija). The mean values of heavy metal contents (mg/kg) were Pb, 0.024; Cd, 0.031; As, 0.010; Hg, 0.003. The measured values of Pb, Cd, As, Hg showed within MRLs. The sulfur dioxides were over MRLs in 4 samples (Gugija). These results will be used to establish on the regulation of commercial fruit teas in Gwangju area.

• 한국약용작물학회:학술대회논문집
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• 2009.05a
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• pp.353-354
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• 2009

• Korean Journal of Agricultural Science
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• v.21 no.1
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• pp.22-27
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• 1994

Gugija, Lycium fructus, grown widely in Korea has long been used as a chinese herbal medicine. For utilization as a new resource in food industry, and as a fundamental study for processing various gugija products, the chemical compositions of Lycium fructus were studied. Three different kinds of free sugar were analyzed by HPLC, and the composions were glucose, 5.6% : fructose, 5.81% : sucrose, 4.39%, respectively. Free amino acids isolated as a major components in dried Lycium fructus were aspartic acid/asparagine, and glutamic acid/glutamine. The major fatty acids were linoleic, oleic, and palmitic acids, and these composed about 82.98~89.64% of total fatty acids. There are not much differences in contents of the major fatty acids among varieties in the fruits, Lycium fructus. The $Ca^{{+}{+}}$, $Fe^{{+}{+}}$ contents of chinese variety were higher than those of other fruit varities studied.

• Microbiology and Biotechnology Letters
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• v.40 no.2
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• pp.111-116
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• 2012

In this study, we investigated the microbial flora changes in Gugija-Liriope tuber Makgeolli during fermentation and storage periods. We brewed Gugija-Liriope tuber Makgeolli for a week through twostage fermentations and stored the fermentation broth for a month at $4^{\circ}C$ or $20^{\circ}C$. We collected the samples periodically and analyzed microbial flora changes using viable cell counts and PCR-denaturing gradient gel electrophoresis (DGGE). Yeast viable cells were seen to have decreased to 13% of pre-storage levels after storage for 15 days at $20^{\circ}C$; however significant changes were not observed during storage at $4^{\circ}C$. Prolongation of storage time dramatically decreased the availability of viable cells. Yeast viable cell numbers had decreased to 38% of pre-storage levels at $4^{\circ}C$ and 4.8% at $20^{\circ}C$ after storage for 30 days. The results of the DGGE profile for yeast showed that Saccharomyces cerevisiae and Saccharomyces sp. were the predominant strains at the beginning of fermentation and throughout the whole period of storage. Viable cell counts for total bacteria had decreased to 36% of pre-storage levels after storage for 15 days but did not significantly change for the full 30 days of storage at $4^{\circ}C$. Similarly, viable cell counts for bacteria had decreased to 5% while viable cell numbers did not significantly change for the full 30 days at $20^{\circ}C$. Viable cell counts for lactic acid bacteria were performed and the results were similar to those for total bacteria. The results of the DGGE profile for bacteria showed that Weissella cibaria was the predominant strain at the beginning of fermentation. However it had disappeared by the end of fermentation, and Lactobacillus fermentum and Pediococcus acidilactici became the predominant species during storage.

• Journal of Biosystems Engineering
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• v.26 no.2
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• pp.105-114
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• 2001

Modulus of elasticity, modulus of rigidity, damping ratio, and natural frequency of three varieties of boxthorn (Lycium chinense Mill) (Cheongyang #2, Cheongyang gugija, and Cheongyang native) branches were analyzed. Modulus of elasticity and modulus of elasticity and modulus of rigidity of the boxthorn branch was determined using standard formula after simple beam bending and torsion test, respectively, using an universal testing machine. Damping ratio and natural frequency of branches were determined using a system consisted of an accelerometer, a PC equipped with A/D converter, and a software for data analysis. Relationship between the elastic modulus and branch diameter in overall varieties and branch types showed a good correlation (r -0.81). There was, however, no correlation between torsional rigidity and branch diameter. The internal damping results were highly variable and the overall range of the damping ratio of the boxthorn branch was 0.014-0.087, which indicated that the branch was a lightly damped structure. The natural frequency of the boxthorn branch was in the range of 89-363 rad/s for the overall varieties and branch types. A good correlation (r 0.82) existed between the natural frequency and branch diameter in overall varieties and branch type.

• Journal of Biosystems Engineering
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• v.25 no.6
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• pp.511-516
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• 2000

The strength of the connecting joint of boxthorn(Lycium chinense Mill) fruits to tree twigs was determined experimentally at several pulling angles(0$^{\circ}$, 15$^{\circ}$, 30$^{\circ}$,45$^{\circ}$and 60$^{\circ}$) and at different harvesting seasons from August to November 1999 using an universal testing machine. The detachment force of mature fruits of boxthorn decreased as the pulling angle increased and varied with the harvesting season. The detachment force however did not gradually decreased as the harvesting season advanced due to difference of maturity of fruits from one harvesting season to another. Among three varieties of boxthron Cheongyang gugija Cheongyang native and Cheongyang ＃2, the maximum detachment force was 1.24 N at the pulling angle of zero degree. The highest detachment forve(1.29 N) of mature fruits of boxthorn appeared at the harvesting season of August, 1999.

• Korean journal of food and cookery science
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• v.21 no.5
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• pp.693-702
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• 2005

The purpose of this study was to provide useful information for establishing efficient marketing direction by investigating the performance (satisfaction) and importance for the quality of Korean traditional commercial beverages. The subjects were 320 participants (130 males and 190 females) in Daegu and Kyungpook. The importance and satisfaction score of Korean traditional commercial beverages were measured on a five-point Likert scale. The results are summarized as follows. The overall satisfaction score on Korean traditional commercial beverages was 2.96 points. The beverages with the highest satisfaction scores were 'green tea' (3.48 points) 'shickhae' (3.35 points) and 'rice tea' (3.34 points) whereas 'ppongip tea' (2.58 points) 'gugija tea' (2.63 points) and 'gukhwa tea' (2.64 points) scored lowly. From the analysis of the difference between importance and performance of Korean traditional commercial beverages, importance (3.11 points) was rated much higher than performance (3.66 points). In the IPA result, it was important to continuously maintain 'taste', 'hygiene', 'freshness', 'period of circulation', 'wrapping condition' etc. Some items such as 'nutrition', 'safety', 'health', and 'ingredient' did not need intensive care and operation.

• Journal of the Korean Society of Food Culture
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• v.27 no.3
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• pp.304-315
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• 2012

"Japji" was an old cookbook written in 1721. There are 27 types of foods recorded in "Japji"; 10 descriptions of Byeonggwaryu (rice cakes and cookies): Yakgwa, Junggye, Mandugwa, Chaesugwa, Umujeonggwa, Dongajeonggwa, Baekjapyeon, Aengdupyeon, Toranbyeong, and Yeot; and 16 descriptions of Chanpumryu (side dishes): Jinjumyeon, Jeunggyetang, Geumjungtang, Eoreumtang, Changjajjim, Gajijjim, Oejjim, Dubuseon, Dubuneureumi, Geneureumi, Gesanjeok, Hodojaban, Jeonyak, Seokryutang, Sungeojuak, and Yangmandu. There is also a description of Gugija (Chinese wolfberry) liquor. Here, comparative analysis based on culinary science was carried out on the Korean foods recorded in "Japji" as well as the similar foods recorded in "Gyuhapchongseo" (Women's Encyclopedia) written around 1815. Of the 27 types of Korean foods recorded in "Japji", 13 were also found recorded in "Gyuhapchongseo". The time period for "Japji" can be assumed to be 1721 based on the fact that it is written in a cursive handwriting style of Hangeul, that chili was never used as an ingredient, and that the word "Shinchuknyeon (辛丑年)" was transcribed at the beginning of the book. The dating method also included considerations of whether Neureumi was used or not as well as changes in its cooking style.