• Applied Chemistry for Engineering
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• v.25 no.3
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• pp.318-323
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• 2014

In order to analyze the effect of maleic anhydride (MAH) content and styrene monomer (SM)/MAH mole ratio on reactive extrusion of maleic anhydride grafted random polypropylenes (MAH-g-rPP), MAH-g-rPPs were prepared by using a twin screw extruder. MAH contents were 0.5, 1.0, 3.0, and 5.0 phr and SM/initiator mole ratio was 0.0, 1.0, and 2.0. Dicumyl peroxide (DCP) was used as an initiator. The graft degree of MAH was confirmed by the existence of carbonyl group (C = O) stretching peak at $1700cm^{-1}$ from FT-IR spectrum. The degree of graft reaction increased up to 3.0 phr MAH and showed the optimum value at 1.0 SM/MAH mole ratio from the area ratio of C = O and C-H stretching peak. Thermal and crystallization properties of MAH-g-rPP and PP/MAH-g-rPP/pulp composites were investigated by DSC, TGA, XRD, and POM. There was a decrease in non-isothermal crystallization temperature of PP/MAH-g-PP/pulp composites. Based on tensile properties and SEM pictures for the fractured surface of PP/MAH-g-PP/pulp composites, MAH content of 1.0 wt% and SM/MAH mole ratio of 1.0 were the optimum formulation as the compatibilizer. The rheological properties of the composites were measured by dynamic Rheometer to compare the processability of the composites with and without compatibilizer. The power law index showed slightly low value at the composites with compatibilizer.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.8
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• pp.1221-1226
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• 2016

This study investigated changes in the S-allyl-L-cysteine (SAC) content of garlic using different cooking methods. Methods for determining SAC were validated by determining specificity, linearity, limit of detection (LOD), limit of quantification (LOQ), precision, and accuracy using an high-performance liquid chromatography-fluorescence detection system. Results showed high linearity in the calibration curve with a coefficient of correlation ($R^2$) of 0.9999. The LOD and LOQ values for SAC were 0.15 and $0.47{\mu}g/mL$, respectively. The relative standard deviations for intra- and inter-day precision of SAC were less than 5%. The recovery rate of SAC was in the range from 97.35% to 97.47%. The SAC content of raw garlic was 2.77 mg/g, and there was no significant difference in SAC content according to blanching and microwave treatment. However, SAC content upon boiling and autoclaving at $110^{\circ}C$ and $121^{\circ}C$ increased from 3.50~9.16 mg/g, 6.52~16.21 mg/g, and 14.15~50.24 mg/g with increasing cooking temperature and time, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.6
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• pp.703-712
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• 2017

In this study, the fat contents and fatty acid compositions of Korean beef (tenderloin, loin, strip loin, chuck roll, foreshank, top blade, top round, brisket point, center of heel, and ribs) and pork (tenderloin, loin, shoulder loin, foreshank, jowls, ham, eye of round, belly, skirt meat, and ribs) parts were investigated. The fat contents of Korean beef ranged from 5.25% (top round) to 35.94% (brisket point). The major fatty acids were palmitic acid (C16:0), stearic acid (C18:0), and oleic acid (C18:1, n-9); especially, oleic acid was the most abundant. Loin had similar fat content as ribs, but there were some differences in fatty acid composition. Linolenic acid (C18:3, n-3) and linoleic acid (C18:2, n-6) were the most abundant fatty acids in strip loin and ribs (38.63 mg/100 g and 564.71 mg/100 g, respectively). Arachidonic acid (C20:4, n-6) was only found in strip loin, top blade, and ribs, and its amounts were in the following order: ribs (2.50 mg/100 g)> strip loin (1.33 mg/100 g)> top blade (1.19 mg/100 g). Total trans-fatty acid (TFA) content of top round was the lowest among all parts, and the ratio of unsaturated fatty acid (UFA) was the highest in foreshank. The fat contents of pork ranged from 4.16% (tenderloin) to 18.47% (belly), but there was no significant difference in fat content between tenderloin, loin, foreshank, ham, and eye of round. The major fatty acids were palmitic acid, stearic acid, oleic acid, and linoleic acid, and their amounts were in the following order: oleic> palmitic> linoleic> stearic acid. Docosahexaenoic acid (C22:6, n-3) was only detected in belly, and the TFA content of belly was the highest. The ratio of UFA was highest in ham. These findings will be useful in the development of standardization data on fatty acid composition in different parts of Korean beef and pork.

• Korean Journal of Medicinal Crop Science
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• v.26 no.5
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• pp.408-416
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• 2018

Background: The ginsenosides Rb1 (G-Rb1) and Rg1 (G-Rg1) are used as marker compounds, and are the principal bioactive compounds assessed in the quality control of white ginseng. This study was conducted to analyze white ginseng samples of different and to obtain useful data for the quality control of white ginseng. Methods and Results: The variation in the content of G-Rb1 and G-Rg1 was evaluated among 35 samples of 4-, 5-, and 6-year-old white ginseng. The content of both G-Rb1 and G-Rg1 did not significantly differ among ages, and the relative ratio of the maximum to the minimum content of these within ginseng of the same ages was more than two. However, the ratio of G-Rb1 to G-Rg1 content in the 5- and 6-year-old ginseng was significantly higher than that in the 4-year-old one. According to the 'Ginseng industrial act', the standard (w/w, %) minimum $G-Rg_1$ and $G-Rb_1$ content is 0.10% and 0.20% or more, respectively. Among the 35 samples examined, the content of $G-Rg_1$ was found to be 0.124 - 0.399% with none being less than the standard level, while that of $G-Rb_1$, was 0.147 - 0.595%, with 4 samples (11.4%) failing to meet the standard levels. The content of $G-Rg_1$ and $G-Rb_1$ did not show a constant relationship with the size of ginseng. Conclusions: In our study, the content of both G-Rg1 and G-Rb1 varied widely, and there was no significant difference among cultivation ages. The results of the present study might provide useful information for the quality control of raw ginseng and processed white ginseng using marker compound.

• Journal of the Korean Chemical Society
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• v.19 no.2
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• pp.142-146
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• 1975

The formation of iron oxide hydroxide in a ferrous sulfate was studied in different contents of iron in the solution at a temperature range of 90 to $100^{\circ}C$ under 1${\sim}$3 atmospheres. The Mohr's salt thus formed was hydrolyzed under 1 to 3 atmospheres, in 14 to 72 g/l of iron content in the solution pH 3 or 6 for two hours at 90 to $100^{\circ}C$. The results obtained was as follows; 1) In Mohr's salt solution, as the iron content was increased, with decreasing the concentration of hydrogen ion, the yield of iron oxide hydroxide was gradually increased. 2) When iron content in Mohr's salt solution was 42.81 g/l, 91.5% of iron was recovered in the form of $\alpha$-goethite similar to yellow grade of natural goethite. 3) When $\alpha$-goethite obtained was calcined of $500^{\circ}C$, it was turned into ${\alpha}$-ferric oxide with a redish brown colour.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.9
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• pp.1265-1270
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• 2011

We evaluated changes in the chemical composition of rough rice (Oryza sativa L.) according to germination period. Rough rice was germinated at $37^{\circ}C$ for 8 days. Crude protein content increased from 71.67 mg/g in raw rough rice to 85.20 mg/g after 8 days of germination. Crude lipid content increased from 2.19% to 3.58% (p<0.05), whereas crude ash was not significantly changed. Phytic acid content decreased from 6.25 mg/g in raw rough rice to 1.54 mg/g after 8 days of germination. Free fatty acid content increased from 0.17% to 0.32% during 8 days of germination. Major fatty acids were palmitic, oleic, and linoleic acids, and total fatty acid content increased up to 95%. Vitamin E and ${\gamma}$-oryzanol contents in raw rough rice were 2.94 mg/100 g and 6.47 mg/g, respectively, increased to 5.55 mg/100 g and 8.16 mg/g after 4 days of germination, and then decreased afterward. These results indicate that the optimum germination period of rough rice for increasing functional components may be 3~4 days.

• Food Science and Biotechnology
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• v.17 no.1
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• pp.31-37
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• 2008

The distributions and content of geometrical isomers of conjugated linoleic acids (CLA) in dairy foods such as milk, yogurt, and cheese, produced or being sold in the Quebec province of Canada, were investigated by gas chromatographic analysis. The mean contents of total CLA (mg/g fat) were $5.06{\pm}0.74$ in 4 low-fat milk samples, $14.14{\pm}4.95$ in 6 yogurt samples, and $18.22{\pm}7.89$ in 5 natural ripened cheeses. Among the yogurt samples, YY contained the highest content of total CLA ($20.68{\pm}5.17\;mg/g$ fat). Among the cheese samples, Gruyere contained the highest amount of total CLA ($29.86{\pm}0.62$) as well as c-9,t-11 ($22.03{\pm}0.36\;mg/g$ fat), followed by Jarlsberg ($22.76{\pm}0.14$), Provolone ($16.42{\pm}0.52$), Cheddar ($13.83{\pm}0.81$), and Swiss ($8.23{\pm}1.11$). Based on the distribution ratios of CLA isomers in these dairy foods, the c-9,t-11 isomer appeared to be the major CLA isomer in both the low-fat milk ($89.87{\pm}2.39%$) and yogurt ($90.98{\pm}4.42%$). In the cheeses, however, the ratio of c-9,t-11 ($54.86{\pm}13.06%$) was slightly higher than that of c-10,c-12 ($40.81{\pm}13.40%$).

• Journal of Life Science
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• v.32 no.9
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• pp.667-677
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• 2022

Dolsan mustard seeds (DMS) were added in whole, crushed, and roasted form at 0.5 g (S-1), 1.0 g (S-2), and 1.5 g (S-3), respectively to broth and heated for 10 or 15 min. After cooling, the quality characteristics were measured. Salinity and pH decreased with boiling time. The antioxidant activities of the experimental broth were measured in terms of total polyphenol content, total flavonoid content, electron donating ability (EDA), 2,2-azino-bis (3-ethyl-benzothizoline-6-sulfonic acid) (ABTS) radical scavenging activity, and ferric reducing antioxidant power (FRAP). The overall, antioxidant activity was higher in broths containing 1.0 g and 1.5 g DMS than in those containing 0.5 g DMS and the activity increased with increasing boiling time. Sinigrin was not detected in the control group, and no significant difference in sinigrin content was noted among broths containing different concentrations of DMS. A high glutamic acid content was detected in the control broth, whereas glutamic acid, aspartic acid, glycine, proline, alanine, and arginine were detected in the broths containing DMS. The free amino acid contents, particularly aspartic acid and glutamic acid contents, were high in umami. Volatile components, such as 2-propenyl-isothiocyanate (ITC), allylthiocyanate, n-butyl ITC, and 3-butenyl ITC, were detected in the DMS-containing broths. Sensory evaluation revealed that a higher amount of DMS added and a longer heating time increased the overall taste preference, and the difference was statistically significant. The purpose of this study was to present basic data on the quality characteristics of DMS-added broths to aid in the development of new products using DMS.

• Food Science and Preservation
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• v.23 no.2
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• pp.211-217
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• 2016

This study was carried out to determine the shelf-life of cricket powder and investigate the changes in its quality during storage. To determine the shelf-life, cricket powder was stored at temperatures of 25, 35, and $40^{\circ}C$ for 6 months. The changes in quality parameters of the cricket powder, such as moisture content, color, acid value, volatile base nitrogen (VBN), fatty acid, growth of microorganisms, and sensory appeal were investigated. The moisture content of the cricket powder increased during storage but did not show any significant difference at 6 months of storage. L value was increased at $25^{\circ}C$ storage but decreased at 35 and $40^{\circ}C$. However, there were no significant different in a and b values. The acid value decreased more rapidly at higher temperatures, while the VBN content was not changed. The major composition of fatty acids of cricket powder were palmitic acid, oleic acid, and linoleic acid. Their content was not changed at various the storage temperatures. No aerobic and coliform bacteria grew in the powder during the whole storage period. Cricket powder stored at $25^{\circ}C$ and $35^{\circ}C$ showed similar scores in sensory evaluation, but it storaged at $40^{\circ}C$ showed the significant difference (p<0.05). Moisture content, acid value, oleic acid, and flavor were selected as the criteria for shelf-life establishment of cricket powder. Based on these parameters, especially the moisture content, the shelf life of cricket powder was likely to be 18 months when stored at $25^{\circ}C$.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.6
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• pp.808-813
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• 2004

This study was conducted to evaluate the effects of adding glucose (G), sorbic acid (S), pre-fermented juice of epiphytic lactic acid bacteria (FJLB) and their combinations on the fermentation qualities and residual mono-and di-saccharides compositions of guineagrass silage. The additives used in this experiment were 1% glucose, 0.1% sorbic acid and FJLB at a theoretical application rate of 9.0${\times}$105 CFU $g^{-1}$ on the fresh weight basis of guineagrass, respectively. There was a total of eight treatments in this experiment: (1) C (without additives), (2) FJLB, (3) S, (4) G, (5) FJLB+S, (6) FJLB+G, (7) S+G, (8) FJLB+S+G. After 30 days of storage, the silos were opened for chemical analyses. Based on the results, all additives were efficient in improving the fermentation quality of guineagrass silage. This was well indicated by significantly (p<0.05) lower pH and BA content and significantly (p<0.05) higher LA content in the treated silages except for the FJLB than in the C. However, there was only a slight increase in LA for the FJLB as compared with the C, which might be due to the low WSC content of the original guineagrass (34.4 g $kg^{-1}$). When the FJLB+S and FJLB+G were added, there were significant (p<0.05) decreases in pH and significant (p<0.05) increases in LA as compared with the FJLB alone. This indicated that the G, S and FJLB were of synergestic effects on the silage fermentation quality. The G combination treatments including the G alone showed large improvements in the fermentation quality as compared with the treatments without the G. This suggested that adding fermentable substrates (G) to plant materials such as guineagrass, which contain low WSC, intermediate population of epiphytic LAB, CP and DM content, is more important and efficient for improving the fermentation quality of silages than adding a number of species of domestic LAB (FJLB) and aerobic bacteria inhibitor (S).