• Korean journal of food and cookery science
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• v.30 no.1
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• pp.64-75
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• 2014

Freeze-drying process was used for 10 major protein foods referred by the Korea Health Statistics 2011 as follows; chicken, pork, beef, eggs, tofu, squid, soybean, mackerel, anchovy, and pollack/frozen pollack. Boiled samples and re-hydrated samples after freeze-drying were prepared for analysis. The weight variation, the chromaticity, the mechanical texture and sensory properties by eight trained panelists were measured. In the ratio of re-hydration, the anchovy showed the highest value(89.40%), followed by eggs, and squid showed the lowest value(35.51%). Changes of Hunter color value were observed among all samples. For rates on changes of hardness, every sample was increased except for eggs(p<.05). Among the 9 samples, except for eggs, chicken showed the lowest rate of increase in hardness(125.44%) while squid showed the highest rate of increase in hardness(1335.1%). Except for eggs and pork, eight samples represented differences in sensory properties, especially in juiciness and tenderness(p<.05). As a result, we found that egg is the most suitable for freeze-drying among 10 protein sources followed by pork and chicken.

• Korean Journal of Food Science and Technology
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• v.25 no.2
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• pp.136-141
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• 1993

A curd yogurt was prepared from milk added with skim milk powder or four kinds of cereal. The effect of cereals at 2%(w/v) level on the pattern of volatile aroma compounds in curd yogurt was investigated. Acetaldehyde, acetone, ethanol, diacetyl, butanol and acetoin in curd yogurt were detected by gas chromatographic analysis. Among these compounds, acetaldehyde, ethanol, diacetyl and acetoin were produced during fermentation by Lactobacillus acidophilus (KCTC 2182). The addition of cereals did not affect markedly general pattern of volatile aroma compounds in curd yogurt. The amount of acetoin and ethanol markedly increased until the first 6 hours of fermentation, and then increased mildly until 24 hours. The amount of diacetyl markedly increased until the first 6 hours and then decreased slightly. Acetaldehyde was first detected by gas chromatograph after 18 hours of fermentation.

• Korean Journal of Food Science and Technology
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• v.25 no.2
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• pp.130-135
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• 1993

A curd yogurt was prepared from milk added with skim milk powder of four kinds of cereal. The effect of cereals at 2%(w/v) level on acid production by lactic acid bacteria in milk was investigated. The effect of cereals on quality of curd yogurt (apparent viscosity, sensory property) was also examined. Addition of cereals markedly stimulated acid production by lactic acid bacteria. Among three organisms tested, L. acidophilus produced more acid than others. Apparent viscosity of curd yogurt added with corn was the highest while that with barley was the lowest. Curd yogurt fermented with L. acidophilus showed characteristics of thioxotropic flow. Apparent viscosity of curd yogurt added with cereal markedly increased between 6 and 24 hours of fermentation. Sensory property of curd yogurt added with wheat was judged as better than reference sample, but that with barley was lodged as the worst among all samples.

• Journal of Nutrition and Health
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• v.13 no.1
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• pp.43-48
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• 1980

In order to identify the taste components of Kochuzang (red pepper paste), glutinous rice Kochuzang were prepared with addition of Saccharomyces rouxii and Torulopsis versatilis respectively. The nitrogen compounds were determined during the fermentation period at intervals and the amino acid components of 210 days aged glutinous rice Kochuzang were measured. Results are as follows; 1) The increment of amino-N and soluble-N of Kochuzang were increased remarkably during fermentation period untill 60 day but after that period, the increment was slowly changed. 2) Ammonia-N of Kochuzang was increased slowly during aging period but after that time, the amount was decreased slightly. 3) Amino-N ratio and Nitrogen solubility of 300 days aged Kochuzang were 23.71-25.38% and 54.12-56.19% respectively. 4) 17 Kinds of amino acid were identified at 210 days aged Kochuzang those were Lysine, Histidine, Arginine, Aspartic acid, Threonine, Serine, Glutamic acid, Proline, Glycine, Alanine, Valine, Methionine, Isoleucine, Leucine, Phenylalanine, Tryptophane and Tyrosine. 5) Total amino acids were 3.5-4.1% which consists of Glutamic acid, 0.95-1.05%, Aspartic acid, 0.63-0.65% and Serine, Proline, Alanine, Valine, Leucine were 0.22-0.28% respectively but Methionine, Histidine and Arginine were below 0.1%, and Tyrosine, Tryptophane and Phenylalanine existed in Kochuzang in small quantities.

• Toxicological Research
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• v.31 no.3
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• pp.279-288
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• 2015

N-nitrosamines, which are classified as carcinogens by IARC and US EPA, can be easily found in various foods. They are reaction products between nitrogen oxide and secondary amines, but can also be generated during fermentation. Ever since the 1960s, when nitrite, used as a preservative in processed meats, was suspected to generate N-nitrosamines, the usage of the food additive has been debated. However, the benefit of nitrite in food supply could not be ignored and the risk-benefit analysis has become a key issue in the use of the additive. For a risk analysis, an accurate estimation of the hazardous material is necessary; therefore, analytical methods for nitrosamines have continuously evolved from the 1950s. Solid supported liquid-liquid extraction and solid phase extractions have replaced the distillation for the clean-up steps, and tandem mass spectrometry is employed for higher selectivity and sensitivity. In the present study, for a better estimation of N-nitrosamine intake, the total diet study samples were prepared for the N-nitrosamines analysis. In order to obtain the most sensitive results, a partial preparation procedure was developed and modified for different food matrices. Among seven N-nitrosamines (N-nitrosodimethylamine, N-nitrosomethylethylamine, N-nitrosodiethylamine, N-nitrosodibutylamine, N-nitrosopiperidine, N-nitrosopyrrolidine, and N-nitrosomorpholine) analyzed in the present study, N-nitrosodiethylamine has shown the highest detection rate in agricultural foods, while N-nitrosodimethylamine has appeared most frequently in livestock and fishery food products. The concentration of N-nitrosodimethylamine was the highest in seasoning.

• Korean Journal of Community Nutrition
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• v.18 no.4
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• pp.333-343
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• 2013

It is important to prepare and execute the menu plan for proper and balanced intake of nutrients in the adolescence. This study investigated the new approach for planning menu by ordinary meal pattern based on cooked foods groups. The amounts of cooked foods in the menu plan assumed to be single serving size. The middle school second graders participated for the study. A total of 313 questionnaires were analyzed using CAN-pro 3.0 and SPSS WIN 12.0 program. The average content of energy in the menu plan was 2,453 kcal, the average ratios of energy contribution by carbohydrate, protein and fat were 54.3%, 17.9%, 27.8%, respectively. A total of 56.9% menu plans (94.9% of male and 8.7% of female students') were below the lowest limit of optimum carbohydrate energy ratio of 55%. A total of 29.1% menu plans (33.1% of male and 23.9% of female students') were exceed the highest limit of optimum fat energy ratio of 30%. The NAR of minerals and vitamins were all 1.0 except for calcium (0.92) and folate (0.88). When INQ of the individual cooked food groups were calculated, kimch was the highest in all minerals and vitamins examined, suggesting that kimch may be the best source for all minerals and vitamins, including calcium and folate with the minimum change in energy content. In conclusion, the menu plan by ordinary meal pattern in this study was low in carbohydrate, high in fat, and contained enough minerals and vitamins except for calcium and folate for middle school students.

• Microbiology and Biotechnology Letters
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• v.44 no.1
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• pp.62-67
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• 2016

Hydrolytic enzyme activities, including those of ${\beta}$-glucosidase, ${\beta}$-glucuronidase, ${\beta}$-xylosidase, ${\beta}$-galactosidase, ${\beta}$-arabinofuranosidase, ${\beta}$-arabinosidase, and ${\beta}$-arabinopyranosidase, which are useful for bioconversion, were explored in lactic acid bacteria isolated from Korean traditional fermented foods. Nine bacterial strains were selected for the fermentation of green tea extract prepared by supercritical fluid extraction. Changes in the concentrations of catechin, epicatechin, epicatechin gallate, epigallocatechin, and epigallocatechin-3-gallate in green tea extract were investigated after fermentation by the selected lactic acid bacteria strains. The strain Leuconostoc mesenteroides MBE1424, which showed the highest ${\beta}$-glucuronidase enzyme activity among the tested bacterial strains, increased the epigallocatechin content of the green tea extract by 60%. In addition, L. mesenteroides MBE1424 was more resistant than the control strain at high temperature and showed a maximum specific growth rate at $40^{\circ}C$. L. mesenteroides MBE1424 was presumed to have an enzyme system containing ${\beta}$-glucuronidase with utility in the bioconversion of green tea extract.

• Applied Biological Chemistry
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• v.29 no.4
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• pp.375-380
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• 1986

The result of analysis of ingredient of Kochujang is as follows. The experiments were prepared with wheat flour (WF) and glutinous rice(GR) ; the experimental A type is made of full WF, B type, WF 75% and GR 25%, C type, WF 50% and GR 50% and D type, only full GR. The N content of crude protein and amino type N is higher in the order of A, B, C, and D types, ethyl alcohol is higher in the order of D, C, B, and A types in aging process. The pH is some what higher in A type but in moisture and NaCl, not much difference were shown in the experimental types. The isolated sugars of Kochujang ripened for 90 days analyzed out glucose, fructose, maltose and rhamnose with glucose being the largest in quantity. Glucose is higher in A type, fructose in B type. The alcohols of the ripened Kochujang analyzed out n-propyl, iso-butyl, and iso-amyl alcohol, the content of which is below 3.2mg% and did not show much difference in each experimental types.

• Journal of Nutrition and Health
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• v.5 no.1
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• pp.33-42
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• 1972

This study was designed to investigate the nutritional value of fermented soybean bran as animal feed. Natural soybean bran has low protein quality and high cellulase contents. The soybean bran was supplemented by urea and ammoniumsulfate as N-source for incubation of Aspergillus niger. After incubation of soybean bran with Aspergillus niger, the nutritional quality of protein and riboflavin contents were increased in general and more in aging process than in fermentation. In order to elucidate the biological efficiency of prepared soybean bran, 120 male weanling rats were divided into 22 groups, five rats each, and were fed by standard casein diet mixed with soybean bran in the proportion of 1/10, 1/15, 1/20 respectively. The animals were kept under the experimental diet for nine weeks. In the result of this study, food efficiency ratio showed higher in the groups of urea and ammonium-sulfate-add group than row soybean bran group but the former group is lower than the later in the body weight gains. Protein efficiency ratio was also same trend. It was noteworthy that the nitrogen retention rate in total body on the basis of urinary nitrogen excretion and dietary intake nitrogen and in big organ such as liver and spleen were higher in fermented group than raw soybean bran fed group. It was worth while to treat the soybean bran in first place fermentation and further aging process to elevate the biological efficiency and effect of nutritional values specifically of protein and of riboflavin.

• Applied Biological Chemistry
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• v.27 no.1
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• pp.7-13
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• 1984

The effects of various nutrients added to soy milk on the growth of Lactobacillus acidophilus were investigated. Soy milk was prepared from defatted soy flour and various nutrients such as sugars, growth stimulating agents, amino acid and milk by-products. The growth curve obtained from the experiment suggested that the log phase ended after 12hr. Glucose and fructose greatly enhanced the acid production by L. acidophilus. The optimum concentration of these two sugars in the media was approximately 3% each. Among the tested growth stimulating agents, yeast extract stimulated the acid production by L. acidophilus, and the optimum concentration of this additive was approximately 0.5%. L-methionine reduced the acid production by L. acidophilus. Whey powder and skim mills powder did not significantly stimulated the growth and acid production by L. acidophilus. Concentration of protein in soy milk did not affect the growth and acid production by L. acidophilus.