• Journal of Korean Society of Forest Science
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• v.106 no.3
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• pp.310-319
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• 2017

This study categorized the damaged trees by Supervised Classification using time-series-aerial photographs of Bukhan, Cheonggae and Suri mountains because oak wilt disease seemed to be concentrated in the metropolitan regions. In order to analyze the spatial characteristics of the damaged areas, the geographical characteristics such as elevation and slope were statistically analyzed to confirm their strong correlation. Based on the results from the statistical analysis of Moran's I, we have retrieved the following: (i) the value of Moran's I in Bukhan mountain is estimated to be 0.25, 0.32, and 0.24 in 2009, 2010 and 2012, respectively. (ii) the value of Moran's I in Cheonggye mountain estimated to be 0.26, 0.32 and 0.22 in 2010, 2012 and 2014, respectively and (iii) the value of Moran's I in Suri mountain estimated to be 0.42 and 0.42 in 2012 and 2014. respectively. These numbers suggest that the damaged trees are distributed in clusters. In addition, we conducted hotspot analysis to identify how the damaged tree clusters shift over time and we were able to verify that hotspots move in time series. According to our research outcome from the analysis of the entire hotspot areas (z-score>1.65), there were 80 percent probability of oak wilt disease occurring in the broadleaf or mixed-stand forests with elevation of 200~400 m and slope of 20~40 degrees. This result indicates that oak wilt disease hotspots can occur or shift into areas with the above geographical features or forest conditions. Therefore, this research outcome can be used as a basic resource when predicting the oak wilt disease spread-patterns, and it can also prevent disease and insect pest related harms to assist the policy makers to better implement the necessary solutions.

• Journal of Korean Society of Forest Science
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• v.109 no.2
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• pp.169-178
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• 2020

This study aimed to compare the organic carbon stocks of Cryptomeria japonica and Chamaecyparis obtusa stands established under a similar-site environmental condition in South Korea. C. japonica and C. obtusa stands adjacent to each other from 13 representative regions were chosen to evaluate the carbon stocks of tree biomass, forest floor, and mineral soils. Mean stand ages were 45 years for C. japonica and 43 years for C. obtusa, respectively. Tree density was significantly lower in C. japonica (989 tree ha^-1) than in C. obtusa (1,223 tree ha^-1) stands, whereas diameter at breast height and dominant tree height values were significantly higher in C. japonica (27.4 cm and 20.4 m, respectively), compared with C. obtusa (23.9 cm and 17.9 m, respectively) stands. The total carbon stocks of tree biomass were linearly related with stand basal area (C. japonica: r² = 0.82; C. obtusa: r²= 0.92; P< 0.05), whereas stand density and site index were not correlated with the carbon stocks of tree biomass (P > 0.05). The carbon stocks of aboveground tree biomass were significantly higher in C. obtusa (117.7 Mg C ha^-1), compared with C. japonica (95.5 Mg C ha^-1) stands, whereas carbon concentration and stocks of the forest floor and mineral soil layers were insignificantly different between the C. japonica and C. obtusa stands. The results indicated that trees in C. obtusa stands sequestrated more carbon dioxide, compared with C. japonica stands, whereas carbon stocks in the forest floor and mineral soil layers were unaffected by stand development processes of the different tree species.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.4
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• pp.537-543
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• 2014

Three different granule powders of Citrus Hallabong were prepared with different ratios of fresh juice and citric acid (J10C3=10.0:3.08, J08C4=8.75:4.33, J07C5=7.5:5.58) at fixed quantities of juice powder (70%), pressed cake powder (10%), and additives (6.92%), and their physicochemical properties were measured and compared with targeted commercial product (CP). The moisture content of Hallabong granules (HG) was 5.08~5.44% (w/w), which was two times higher than that of CP. Titratable acidities increased with higher citric acid content and were 1.7~2.3 times lower in HG compared to that of CP. Soluble solids of HG increased with higher citrus juice content ($90{\sim}98^{\circ}Brix$) and were slightly lower than that of CP. Vitamin C contents of HG increased with higher citrus juice content and were 5.8~7.6 times lower than that of CP. In terms of color difference, L and b values of HG were higher while a value was lower than those of CP. Bulk and compaction densities of HG were 0.541~0.660 g/mL and 0.561~0.689 g/mL, respectively and were similar to those of CP. Water solubility and swelling capacity were 66.6~72.0% and 3.84~6.40 g/g, respectively, and were similar to those of CP. Hygroscopicity of HG after an hour of elapsed time was 1.6~1.8 times higher than that of CP. Sensory evaluation test showed that color, sweetness, and overall acceptance of HG were not significantly different from those of CP, whereas flavor and bitterness of HG were lower than those of CP. In conclusion, convenient food granules could be made with Citrus Hallabong juice and pressed cake, which is similar to the commercial product.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.4
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• pp.522-529
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• 2014

Sea tangle (Laminaria japonica) is well known as having anti-diabetic and hypolipidemic effects in animals as well as in humans. In this study, we evaluated the effects of sea tangle-added patty on postprandial blood glucose and lipid profiles in borderline-hypercholesterolemic (cholesterol ${\geq}200$ mg/dL) adults. Eleven subjects voluntarily participated in the experiment, and each subject provided written consent. Experimental patty (E) was made by adding 2.25 g of sea tangle powder as a substitution to 1.125 g each of pork and chicken. In the first week, 200 g of Control patty (C) was provided to each subject, who had fasted more than 12 hours. In the second week, the same amount of E patty was supplied under the same conditions. Serum glucose levels increased significantly less at 30, 60, and 120 min after consumption of E patty compared to the levels at all time points after eating C patty. Thus, the change in the area under curve (${\Delta}AUC$) of serum glucose levels through 120 minutes was lower when consuming E patty compared to C patty. Although serum C-peptide concentrations were not significantly different at all time points between the two patties, the ${\Delta}AUC$ of serum C-peptide concentrations through 120 minutes was lower when consuming E patty compared to C patty. However, there were no differences in serum levels of triglyceride, total cholesterol, LDL-C, and HDL-C at 30, 60, 120, 180, and 240 min between the two patties. Further, each ${\Delta}AUC$ of these lipid levels through 240 minutes was not significantly different between the two patties. The results indicate that sea tangle-added patty may decrease postprandial plasma glucose concentrations and reduce insulin secretion, although it might not ameliorate serum lipid profiles in adults with borderline-hypercholesterolemia.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.4
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• pp.592-603
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• 2014

We developed various recipes of turmeric powder (Curcuma longa L.) added to milk bread and assessed the individual effects of seven ingredients [milk ($X_1$), turmeric powder ($X_2$), bread improver ($X_3$), fresh yeast ($X_4$), butter ($X_5$), sugar ($X_6$), and salt ($X_7$)] as well as the 2-way interaction effects of the ingredients on the sensory characteristics of breads using fractional factorial design method. The center and end points of each component were determined via literature review and multiple test baking. Seven trained sensory test panels evaluated the outside appearance (OA), inside appearance (IA), and flavor & texture (FT) of 38 breads using 46 items of sensory evaluation. Findings are as follows: for the OA, $X_1$ (P<0.05) and $X_4$ (P<0.0001) exhibited significant individual effects, whereas $X_1*X_7$, $X_2*X_5$, $X_3*X_6$, and $X_4*X_6$ indicated significant interaction effects (P<0.05). For the IA, $X_1$ (P<0.0001), $X_4$ (P<0.0001), $X_6$ (P<0.05), $X_2*X_4$ (P<0.05), and $X_3*X_6$ (P<0.01) showed individual and interaction effects, respectively. For the FT, $X_1$ and $X_2$ showed the most significant individual effect (P<0.0001), followed by $X_4$, $X_5$ and $X_6$ (P<0.05) in descending order. $X_4*X_7$ indicated the only significant interaction effect. We computed the magnitudes of the 2-way interaction effects of the ingredients with a distinct emphasis. Model equations predicting the levels of the ingredient effects on the breads were also provided via regression analyses. In summation, $X_4$ appeared to be the most significant component affecting the sensory characteristics based on its individual and 2-way interaction effects. Further, $X_6$, $X_1$, $X_2$, and $X_5$ indicated both individual and interaction effects. $X_3$ and X7 showed only interaction effects. The center point effect appeared to be unequivocal for whole sensory characteristics. Findings of the present study may provide insights into the selection of ingredients to derive an optimal model for turmeric powder-added bread using the response surface method hereafter.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.11
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• pp.1796-1800
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• 2014

Trienzyme digestion (AOAC Official Method 2004.05) procedure using protease, ${\alpha}$-amylase, and chicken pancreas conjugase was evaluated to determine its usefulness in the microbiological quantitation of total folate in foods. Folate values obtained by alkali hydrolysis (Korean Food Standards Codex) were compared to those obtained by the trienzyme method for four certified reference materials (CRM) representing diverse matrixes. Trienzyme treatment increased measurable folate from most CRM compared to levels found after alkali hydrolysis. The largest increases were observed with CRM 487 (pig liver, 5.8-fold) and CRM 121 (whole meal flour, 3.1-fold) after trienzyme digestion. Using trienzyme digestion method, total folate contents of raw and blanched edible plants were determined. Eleutherococcus senticosus ($146.9{\mu}g/100g$) showed the highest total folate content, followed by Aster glehni F. Schmidt ($142.8{\mu}g/100g$) and Ledebouriella seseloides H. Wolff ($140.4{\mu}g/100g$) on a wet weight basis. Blanching of samples resulted in an insignificant decrease in folate content for five samples and 11~63% reduction for nine samples. Our finding suggests that trienzyme digestion method is accurate for the determination of food folate in leafy vegetables.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.11
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• pp.1785-1790
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• 2014

This study was carried out to compare the physicochemical characteristics and sensory qualities of Sikhye (Korean traditional rice beverage) prepared with foxtail millet, proso millet, and sorghum. The cultivated varieties were Setaria italica Beauv. cv. Samdamae (SDM) and Samdachal (SDC), Panicum miliaceum L. cv. Ibaekchal (IBC), Sorghum bicolor (L.) Moench cv. Nampungchal (NPC), Donganme (DAM), Oryza sativa cv. Ilpum (IP), and Baegokchal (BOC). The brix degrees of SDM, SDC, IBC, NPC, DAM, IP, and BOC Sikhye were 9.53, 8.63, 5.67, 7.57, 6.27, 12.50, and $12.27^{\circ}Bx$, respectively. There were no significant differences in pH (5.99~6.10) among the groups. The highest turbidity was 1.07 in DAM Sikhye. The L-value, a-value, and b-value were 30.85~41.11, -0.34~2.52, and 2.56~5.67, respectively. Total polyphenol contents of SDM, SDC, IBC, NPC, DAM, IP, and BOC Sikhye were 241.52, 213.69, 202.34, 258.25, 193.24, 160.81, and $170.31{\mu}g\;GAE/mL$, respectively. Total flavonoid contents of Sikhye were $19.21{\sim}54.30{\mu}g\;CE/mL$. The highest DPPH and ABTS radical scavenging activities were $16.85{\pm}0.39$ and $64.75{\pm}2.92mg\;TE/100mL$ in DAM Sikhye, respectively. Finally, the sensory evaluation results indicate that there were significant differences in appearance, aroma, and taste between the groups, and SDM Sikhye was similar with IP and BOC.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.11
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• pp.1674-1680
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• 2014

The aim of this study was to investigate the protective effects of methanolic extracts of cooked mixed grain rice samples, including grain rice (sorghum, black bean, proso millet, and Job's tears) mixed with fermented brown rice (GR), GR added with 0.5% water extract of Sanghwang mushroom (GRS) or 0.1% curry (GRK), and traditional five grain mixed rice (TMR, Ohgokbap), on $H_2O_2$-induced oxidative injury in LLC-PK1 pig renal epithelial cells. White rice (WR) was used as a positive control. Cells were first exposed to $H_2O_2$ ($250{\mu}M$) for 4 hr, followed by treatment with $100{\mu}g/mL$ of different GR extracts for 24 hr. $H_2O_2$ significantly induced cell damage (P<0.05). Cellular levels of reactive oxygen species (ROS), lipid peroxidation, and antioxidant enzymes, including catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-px), were measured. In addition, mRNA levels of antioxidant enzymes were determined by RT-PCR assay. Mixed grain rice, particularly GRS and GRK, were able to reduce cellular levels of ROS, decrease lipid peroxidation, and also increase mRNA expression of antioxidant enzymes compared to other samples. These results suggest that mixed grain rice, specifically GRS and GRK, have strong protective effects against $H_2O_2$-induced oxidative injury in LLC-PK1 cells through inhibition of lipid peroxidation, reduction of ROS levels, and elevation of antioxidant enzyme activities.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.1
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• pp.89-95
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• 2013

Biological and functional characteristics of lactic acid bacteria (LAB) were investigated in mustard stem/leaf kimchi (MK), cabbage kimchi (CK), young radish kimchi (YRK), and cubed radish kimchi (CRK). LAB of young radish kimchi were mainly composed of bacilli in contrast to the other kimchi. 89.2% LAB isolated from all kimchi harbored plasmids. However, LAB had an average of $4.1{\pm}0.5$ plasmid bands in YRK, more than MK, CK, and CRK. Exopolysaccharides were produced by 10.9~11.1% of LAB, and were especially by LAB isolated from radish kimchi. A significant percentage of LAB (69.5%) had antibacterial activity against one sensitive strain or more. LAB from CK, YRK and CRK had antimicrobial activities against Bacillus sp., Listeria monocytogenes, and Salmonella Typhimurium, while the LAB from MK had activities against Vibrio parahaemolyticus higher than those from the other kimchi. In YRK and CRK, acid-tolerant LAB were twice as prevalent as those in MK and CK. Bile-tolerant LAB isolated from CRK were more prevalent than other kimchi. When $10^8$ CFU of LAB were added to Caco-2 cells, 12.1% of LAB isolated from all kimchi showed similar adherent activity to Lactobacillus rhamnosus GG. LAB of MK particularly adhered to Caco-2 cells, 2.0~4.1 fold higher than LAB in the other kimchi. From these results, biological and functional characteristics of LAB varied according to the type of kimchi and LAB existing in kimchi were limited to their respective species.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.11
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• pp.1829-1836
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• 2013

This study is carried out to investigate the physicochemical characteristics, microbial population, and sensory characteristics during fermentation of Korean traditional rice wine with addition of glutinous rice. The fed-batch fermentation of rice was performed by Nuruk and yeast for 10 days at $28^{\circ}C$ in a water bath. The four fermentation batches included 0, 10, 15 and 20% of glutinous rice based on the total rice contents. The growth of total viable cells, lactic acid bacteria (LAB), and yeasts were similar among the four batches during the fermentation period. The population for total viable cells and LAB were increased for the first 3 days, and decreased slowly until 10 days. The number of yeast cells was rapidly decreased after day 6, when the alcohol content reached about 15% for all the fermentation batches. Physicochemical characteristics, such as pH, total acidity, and reducing sugars, were not different with the increase of additional glutinous rice contents. The ethanol production was higher in Korean traditional rice wine from non-glutinous rice (17.1%) than ones from glutinous rice (15.8~16.7%). For the sensory evaluations, Korean traditional rice wine with 15% glutinous rice was highly preferred due to the highest sweetness.