• Korean Journal of Food Science and Technology
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• v.29 no.6
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• pp.1166-1174
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• 1997

This study was designed to investigate the changes in physicochemical and sensory characteristics of traditional kochujang during aging, which was prepared with a different meju fermented for various periods of time. The non-volatile organic acid contents in all samples gradually increased up to 90 days of fermentation. Kochujang prepared with a 40-day-fermented meju had $1.14{\sim}2.54$ times highter organic acid content after 90 days of aging as compared to other kochujang preparations. The most abundant free sugars were found to be glucose and fructose representing $82.27{\sim}100%$ of total free sugar contents in kochujang. 17 kinds of free amino acid including Glu, Asp and Met were found in traditional kochujang aged for 90 days. Glu was noted as the most contributing amino acid to the brothy taste of kochujang in the light of increasing ratio and content of Glu among free amino acids during aging. The total free amino acid contents of kochujang increased with an Increase in fermentation time of meju. Results of sensory evaluation revealed that kochujang prepared with a 40-day-fermented meju was best in terms of flavor and taste. These results suggest that kochujang prepared with a 40-day-fermented meju had the highest quality in terms of physicochemical and sensory characteristics of kochujang.

• Korean Journal of Food Science and Technology
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• v.46 no.5
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• pp.544-548
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• 2014

This study was conducted to investigate the nutritional components and quality characteristics of the root of Allium hookeri grown in Korea and Myanmar. The root of A. hookeri grown in Hadong, Korea (KR), contained higher levels of carbohydrate, crude ash, and crude lipid, but the root of A. hookeri grown in Shan, Myanmar (MR), contained higher levels of crude protein and crude fiber. The free sugar and organic acid contents were higher in KR than in MR. Fructose, glucose, and sucrose were the major free sugars and arginine was the major free amino acid. KR contained higher amounts of essential amino acids, non-essential amino acids, ${\gamma}$-amino butyric acid, and citrulline than MR. Potassium was a prominent mineral constituent in both KR and MR, and KR contained higher mineral content than MR. KR contained twice the amount of sulfur and crude saponin, relative to MR.

• Food Science and Preservation
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• v.19 no.4
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• pp.569-576
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• 2012

This study was conducted to compare the major chemical components of Korea Crataegi fructrus (KCF) and Chinese Crataegi fructrus (CCF). Among the proximate compositions, the curde fat content of KCF was lower than that of CCF, whereas their crude protein, crude ash and carbohydrate contents were similar. CCF had a higher total free sugar content than KCF. The major free sugars of KCF and CCF were identified as fructose and glucose. The value of glutamic acid was greater in the amino acids of KCF and CCF, and KCF had higher total amino acids and essential amino acids contents than CCF. KCF also had a higher level unsaturated fatty acids than CCF. CCF had a higher organic acid content, but both KCF and CCF had high citric acid levels. and Chinese The vitamin C contents of KCF and CCF were 272.69 mg per 100 g and 262.38 mg per100 g, respectively. The mineral content of KCF was higher than that of CCF, in the following order : K > Ca > Mg > Fe. The results showed that KCF had higher total amino acid, essential amino acid, unsaturated fatty acid and mineral contents and CCF had higher free sugar and organic acid contents.

• Korean Journal of Environmental Agriculture
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• v.35 no.4
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• pp.247-255
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• 2016

BACKGROUND: Acrylamide (CAS No. 79-06-1) is known to be a carcinogenic compound, and is classified as a Group 2A compound by the International Agency for Research on Cancer (IARC, 1994). Acrylamide can be generated during the browning process via the non-enzymatic Maillard reaction of carbohydrates such as reducing sugars and of amino acids such as asparagine, both of which occur at a temperature above $120^{\circ}C$. Potato tubers contain reducing sugars, and thus, this will affect the safety of processed potato products such as potato chips and French fries. In order to reduce the level of acrylamide in potato processed products, it is therefore necessary to understand factors that affect the reducing sugar content of potatoes, such as environmental factors and potato storage conditions, as well as understanding factors affecting acrylamide formation during potato processing itself. METHODS AND RESULTS: Potatoes were cultivated in eight regions of Korea; For each of these different environments, soil physico-chemical characteristics such as pH, electrical conductivity, total nitrogen, available phosphate, and exchangeable cation content were measured and correlations with potato reducing sugar content and potato chip acrylamide levels were examined. The reducing sugar content in potato during storage for three months was determined and acrylamide level in potato chip was analyzed after processing. The storage temperature levels were $4^{\circ}C$, $8^{\circ}C$, or $10^{\circ}C$, respectively. The acrylamide content of chips prepared from potatoes stored at $10^{\circ}C$ or $20^{\circ}C$ for one month was analyzed and the different frying times were 2, 3, 5, and 7 min. CONCLUSION: This study showed that monitoring and controlling the phosphate content within a potato field should be sufficient to avoid producing brown or black potato chips. For potatoes stored at low temperatures, a reconditioning period ($20^{\circ}C$ for 20 days) is required in order to reduce the levels of reducing sugars in the potato and subsequently reduce the acrylamide and improve chip coloration and appearance.

• Korean Journal of Food Science and Technology
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• v.26 no.3
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• pp.336-342
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• 1994

Changes in physicochemical characteristics were investigated for immature barley kernels roasted at $160{\sim}220^{\circ}C$ for $1{\sim}12$ min. Only small differences in chemical constituents including starch, protein, fat, ash, total dietary fiber, and ${\beta}-glucan were observed between immature and mature barley kernels. The amounts of 75% ethanol-soluble sugars and amino acids present in immature barley kernels were considerably higher than those in mature kernels, and gradually decreased in the process of roasting. Of free sugars, sucrose, raffinose, glucodifructose($GF_{2}$) and maltose were reduced by roasting. Glucose and fructose, simple reducing sugars, decreased at the early stage of roasting, followed by a slight increase at the later stage. Starch and nitrogen contents decreased slowly, while TDF(total dietary fiber) had a tendency to increase slightly. Stacking volume of immature barley kernels increased markedly, especially at the higher temperatures. L value of immature barley decreased throughout roasting, and a, b values increased at the early stage of roasting but b value decreased with continued roasting. The degree of roasting was strongly affected by the roasting temperature. Darkness of immature barley kernel, depending on the degree of roasting, was highly associated with concentrations of brown pigments extracted from roasted immature barley kernels.

• Journal of the Korean Society of Food Culture
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• v.16 no.3
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• pp.260-267
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• 2001

This study was conducted to investigate the physicochemical characteristics of Sunchang traditional kochujang(fermented hot pepper-soy bean paste) for quality standardization. The kochujang samples, which have been fermented for 8 months in 1999, were collected from 20 firms at folk village in Sunchang area and analyzed their chemical compositions and color reference. The mean value of moisture, amino-type nitrogen, pH, acidity and salt content of the samples collected were $44.62{\pm}1.79%$, $132.66{\pm}21.67\;mg%$, $4.52{\pm}0.08$, $15.77{\pm}1.62$ and $8.76{\pm}1.55%$, respectively. The moisture, pH, acidity and salt content of each sample did not show much differences among samples. The Hunter values(L, a and b) of Sunchang traditional kochujang were $25.72{\pm}1.58$, $23.26{\pm}1.71$ and $9.86{\pm}0.94$, respectively. The mean content of amino-type nitrogen of Sunchang traditional kochujang was $132.66{\pm}21.67\;mg%$, and there were a little difference between the minimum(100.33 mg%) and the maximum(164.56 mg%). The main free sugars of Sunchang traditional kochujang were fructose($1.86{\pm}1.01%$), dextrose($4.29{\pm}2.06%$), sucrose($0.54{\pm}1.21%$), and maltose($1.48{\pm}0.77%$). The contents of fructose, dextrose, and maltose had little difference among samples. The fatty acids in Sunchang traditional kochujang were composed of palmitic, stearic, oleic, linoleic, linolenic, octadecatetraenoic, arachidonic and behenic acid. The linoleic acid(18:2) showed the highest, occuping 59.37% of the total fatty acids.

• The Korean Journal of Community Living Science
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• v.27 no.4
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• pp.851-862
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• 2016

This study was conducted to investigate the proximate composition and antioxidative activities of young barley leaf(YBL). YBL powder(all w/w) was 2.98% moisture, 17.13% crude protein, 4.00% crude fat, 10.72% crude ash, and 65.17% carbohydrate. The contents of total, insoluble, and soluble dietary fiber were $36.62{\pm}2.33$, $19.05{\pm}1.04$, and $17.57{\pm}1.01g/100g$, respectively. The essential and non-essential amino acids contained in the YBL powder accounted for 46.56% and 53.44% of the total amino acids, respectively. The major unsaturated fatty acid was linolenic acid. The ratio of polyunsaturated fatty acids to saturated fatty acids was 4.84. Only tartaric acid was detected. The contents of vitamins A, C, and E were 0.761, 398.05, and 0.936 mg%, respectively. The mineral contents of YBL powder were in the order of Na$IC_{50}$ value for the DPPH radical scavenging of the YBL ethanol extract was $365.74{\pm}6.98mg/mL$. The antioxidative index was high and was similar to that of t-butylated hydroxytouene. These results suggest that YBL can be recommended as a baby vegetable of high nutritional quality and antioxidative properties.

• Korean Journal of Medicinal Crop Science
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• v.4 no.3
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• pp.261-264
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• 1996

This study was carried out to obtain a basic informations for the improvement of human health and the development of variety through analysis of inorganic compounds, contents of amino acids and saccharids to three elephant- foots (Amporphophallus Konjac. K) collected from Kumsan, Japan and China. Mannan as a carbohydrate of major component of an elephant-food was slightly high in Kumsan than that of Japan and China variety. Degree of viscosity of an elephant-foot depends upon the soluble free sugar contents and amino acid, contents of these free sugars were high in the order of Kumsan, China and Japan elephant-foot powder. Results of analysis of inorganic compounds to an elephant-foot used; Kumsan variety was shown to be high than those of China and Japan, especially. K, P and Fe in Kumsan variety were high, while Na and Ca were appeared to be high in China elephant-foot.

• Korean Journal of Food Science and Technology
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• v.17 no.1
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• pp.8-14
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• 1985

In order to give the unique flavour of traditional Doenjang (Korean-style soybean paste) to commercially manufactured soybean paste, the addition of Bacillus licheniformis and Saccharomyces rouxii was tried and their influences were investigated. The addition of B. licheniformis and S. rouxii in soybean paste decreased the content of reducing sugars. By the addition of B. licheniformis, the contents of amino type nitrogen and titrable acidity were increased. The content of ammoniacal nitrogen was reduced and ethyl alcohol production was increased by the addition of S. rouxii. The viable counts of molds showed the decreasing tendency during the aging and it was accelerated by the addition of B. licheniformis and S. rouxii. Acetaldehyde, acetone, ethylacetate, methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol and isopropyl alcohol were detected from the vapor of all tested ripen soybean pastes, while in a traditional Doenjang, isoamyl alcohol and isobutyl alcohol were not. The B. licheniformis and S. rouxii added sample showed richest free amino acid content. In organoleptic test the B. licheniformis and S. rouxii added sample showed the most excellent overall acceptability.

• Journal of Microbiology and Biotechnology
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• v.14 no.6
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• pp.1142-1149
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• 2004

Streptococcus mutans has the capacity of inducing dental caries. Thus, to develop a novel way of preventing dental caries, a cell wall hydrolase-producing strain was isolated and its characteristics were investigated. Among 200 alkalophilic strains isolated from soil, 8 strains exhibited lytic activities against Streptococcus mutans. However, strain YU5215 with the highest cell wall hydrolase activity was selected for further study. Strain YU5215 was identified as a novel strain of Bacillus based on analyzing its 16S rDNA sequence and Bergey's Manual of Systematic Bacteriology, and thus designated as Bacillus mutanolyticus YU5215. The optimal conditions for the production of the cell wall hydrolase from Bacillus mutanolyticus YU5215 consisted of glucose ($0.8\%$), yeast extract ($1.2\%$), polypeptone ($0.5\%$), $K_{2}HPO_{4}\;(0.1\%$), $MgSO_{4}{\cdot}7H_{2}O$ ($0.02\%$), and $Na_{2}CO_{3}\;(1.0\%$) at pH 10.0. Bacillus mutanolyticus YU5215 was cultured at 30^{circ}C for 72 h to produce the cell wall hydrolase, which was then purified by acetone precipitation and CM-agarose column chromatography. The molecular weight of the lytic enzyme was determined as 22,700 Da by SDS-PAGE. When the cell wall peptidoglycan of Streptococcus mutans was digested with the lytic enzyme, no increase in the reducing sugars was observed, while the free amino acids increased, indicating that the lytic enzyme had an endopeptidase-like property. The amino terminus of the cell wall peptidoglycan digested by the lytic enzyme was determined as a glutamic acid, while the lytic site of the lytic enzyme in the Streptococcus mutans peptidoglycan was identified as the peptide linkage of L-Ala and D-Glu.