• Korean Journal of Food Science and Technology
• /
• v.36 no.1
• /
• pp.14-18
• /
• 2004

Analysis methods of artificial sweeteners, aspartame, acesulfame potassium, sodium saccharin, and sucralose isolated from foods were developed using high performance liquid chromatography, HPLC conditions for aspartame, acesulfame potassium, and sodium saccharin were: column, Symmetry $C_{18}(3.9mm\;i.d{\times}150mm,\;5{\mu}m)$; mobile phase, 0.05M sodium phosphate monobasic : acetonitrile (9 : 1, pH 3.5, containing 0.01M tetrapropylammonium hydroxide); detector, UV detector at 210 nm. HPLC condition for sucralose were : column, Symmetry $C_{18}(3.9mm\;i.d{\times}150mm,\;5{\mu}m)$; mobile phase, water:methanol (7 : 3); detector, refractive index detection (sensitivity = 16). Recoveries of artificial sweeteners in foods including soft drinks, fruit and vegetable beverages, alcoholic beverages, fermented milk beverages, soybean milk, ice cream, snacks, chewing gums, jam, honey, kimchi salted food, special dietary products, processed fish products, candies, food additive mixtures, chocolate and cocoa were 76.1-101.3%, 82.3-103.2%, 83.1-103.7%, and 80,6-99.5% for aspartame, acesulfame potassium, sodium saccharin, and sucralose, respectively.

• The Korean Journal of Food And Nutrition
• /
• v.27 no.2
• /
• pp.280-286
• /
• 2014

This study investigated to changes in the sensory characteristics of cheonggukjang made with smoked soybean. The total organic acid content of cheonggukjang made with smoked soybeans (CSS) increased to about two times in comparison with cheonggukjang made with non-smoked soybeans (CNS). Among the organic acids, the amount of succinic acid was highest for both CSS and CNS. The total free sugar content of CSS ($228.6{\pm}8.8mg%$) was significantly reduced compared to that of CNS ($350.1{\pm}13.7mg%$). Further, the total free amino acid content of CSS ($10,123.3{\pm}301.4mg%$) was significantly increased compared to that of CNS ($8,912.5{\pm}286.5mg%$). The contents of sweet, savory and bitter taste compounds were significantly elevated in CSS when compared to that of CNS. However, there were no significant differences in the total content of fatty acids in CNS and CSS. The sensory evaluation of aroma, taste and overall quality of CSS were significantly increased compared to that of CNS. Taken together, it was expected that a smoking process is useful for the development of new fermented foods.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.45 no.6
• /
• pp.843-850
• /
• 2016

This study was conducted to investigate changes in isoflavone composition (glycosides and bio-active aglycones) and evaluate the quality characteristics of doenjang prepared using different Bacillus strains (KACC15935 and HJ18-9). After 60 days of fermentation, ${\beta}-glucosidase$ activity of doenjang fermented with B. subtilis HJ18-9 was higher than those of other samples. Contents of aglycones (daidzein, genistein, and glycitein) in B. subtilis HJ18-9 significantly increased up to $703.90{\pm}11.09{\mu}g/g$. In addition, total phenolic content and 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity increased markedly during fermentation. These results suggest that fermentation with B. subtilis could be used to increase ${\beta}-glucosidase$ activity with a view towards development of functional foods.

• Journal of Food Hygiene and Safety
• /
• v.32 no.4
• /
• pp.249-253
• /
• 2017

This study aimed to compare the automated most-probable-number (MPN) TEMPO BC and the quantitative mannitol-egg yolk-polymyxin (MYP) plate methods for enumeration of Bacillus cereus in food samples known to be frequently contaminated. Food products that were naturally or artificially contaminated with B. cereus were analyzed by both methods. A difference of less than 1 log (CFU/g) between the two methods was noted in 95.3% samples. There were no significant differences in artificially contaminated products between the two methods in terms of $R^2$ values for sauce products, jorim products, fish products, etc. However, a significant difference was noted for sunsik, fermented soybean products, and products. The linear equation of naturally versus artificially contaminated food was $log_{(TEMPO\;BC)}=0.8453{\times}log_{(MYP\;plate\;agar)}+0.1642$. Statistical analysis of the results showed good agreement between the two methods. Due to growing interest in food safety, the use of the TEMPO BC method may increase. In response to this trend, the results from this study will offer valuable comparative data on the feasibility of existing methods and help develop new approaches for food safety testing.

• Journal of Food Hygiene and Safety
• /
• v.18 no.3
• /
• pp.95-100
• /
• 2003

Competitive direct enzyme-linked immunosorbent assay(cdELISA) of aflatoxin $B_1$ ($AFB_1$) in deonjang(Korean-style soybean paste) and kochujang(fermented hot peppersoybean paste) and the level of $AFB_1$ in modern or traditional style deonjang and gochujang, produced in Korea, was surveyed by cdELISA. From the standard curve of the cdELISA, the detection limit of $AFB_1$ was 0.2 ng/m/. The average recovery of $AFB_1$ was 71.5% in the range of 1~100 ng/g after spiking $AFB_1$ into deonjang and it means that it could be possible to detect the $AFB_1$ in these range by the cdELISA in deonjang. Among the 30 kochujangs tested, no $AFB_1$ was detected in kochujangs. Among the 30 deonjangs, $AFB_1$ was detected in 6 ones in the range of 1.0~6.0 ng/g. The occurrence of $AFB_1$ in deonjang and kochujang tested in this study was less than the Korea Standard and Specification of aflatoxin in foods (10 ppb).

• Applied Biological Chemistry
• /
• v.22 no.2
• /
• pp.65-90
• /
• 1979

This study was conducted to establish the brewing method which would be useful for the production of Kochuzang. Kojis, which were made from various materials and microorganisms under a covered condition, were investigated and compared. Yeasts (Saccharomyces rouxii and Torulopsis versatilis) were added to Kochuzang, and the enzyme activity, microflora, chemical composition, nitrogen content, alcohol content and free sugars of Kochuzang were investigated and analysed. The results obtained are as follows: 1. Koji making (1) Glutinous rice-soybean group was superior to glutinous rice group in the saccharogenic and liquefying amylase activities of three day-Koji. (2) Protease activity (acid, neutral and alkaline) of glutinous rice-soybean Koji, which was inoculated with Aspergillus oryzae A, was increased till the 5th day, while other groups showed maximum activity after the 3rd day. (3) The maximum cellulose activity of Aspergillus oryzae B-Koji and A-Koji was observed after the 2nd day and the 3rd day, respectively. High cellulose activity of Aspergillus oryzae B-Koji and A-Koji was respectively shown in glutinous rice group and glutinous rice-soybean group at maximum. (4) Compared with glutinous rice Koji, glutinous rice-soybean Koji gave larger number of yeast and aerobic bacteria. 2. Kochuzang Fermentation (1) Each Kochuzang group shoved different liquefying and saccharogenic amylase activities. The highest activities were generally shown in 10 to 40 days after mashing and remarkably reduced in the last stage of aging. (2) Protease activities of each group were strong in order of acid, neutral and alkaline protease. Especially acid protease showed highest activity at the 40th to 50th day Kochuzang. (3) Each group showed maximum cellulase activity in the 40th and 50th day-Kochuzang and then decreased. (4) Osmophilic yeast of yeast-added Kochuzang after one-month aging was distinctively outnumbered compared with non-yeast-added Kochuzang, but two groups were similar after two months. (5) Yeast-added group and non-added group gave almost the same number of halophilic lactic acid bacteria in Kochuzang, but the non-added group gave slightly larger number of aerobic bacteria than the yeast-added group. (6) Amino nitrogen contents in all test group were increased rapidly till the 60th day of Kochuzang aged. After that the contents were increased slowly. (7) Ethyl alcohol contents of 20day-fermented Kochuzang were high in order of Saccharomyces rouxii-added group, Torulopsis versatilis-added group, Saccharomyces rouxii and Torulopsis versatilis mixed group and non-yeast-added group. But all test group showed about 2% in ethyl alcohol content after 40days of aging. (8) Alcohol content in the 7 month-aged Kochuzang of all test groups was high in order of ethyl alcohol, n-butyl alcohol, n-propyl alcohol and iso-propyl alcohol. Torulopsis versatilis-added group had the highest value of ethyl alcohol, n-propyl alcohol and n-butyl alcohol. (9) Reducing sugar in Kochuzang was increased after 20 days of aging compared with the 10days-ferment. The reducing sugar content in Saccharomyces rouxii-added group was distinctively small compared with that of other groups, decreasing after 30days of aging. (10) Rhamnose, fructose, glucose and maltose were isolated from the 10 day fermented Kochuzang. Raffinose was also found after 300 days-aged group, and fructose content was high in the 300days-aged Kochuzang. However, glucose content was smaller than that of 10days-fermented Kochuzang. (11) For the organoleptic tests of Kochuzang, taste, flavour and color of yeast-added group were superior to the non yeast-added group. Especially the complex yeast group among the yeast added groups were the best of all. Yeast-added group after 300 days of aging took higher paint in flavour test than that of non-added group. Therefore, brewing method like complex yeast added group seems to be advantageous for short time brewing Kochuzang.

• The Korean Journal of Mycology
• /
• v.25 no.1 s.80
• /
• pp.35-45
• /
• 1997

The yellow fungal isolates inhabiting at the cereals (Hwang-Kuk, HK-fungi) were widely collected from the mejus and nuluks in Korea; the meju is a raw material for Korean traditional foods for soysauce and soypaste, and the nuluk is a raw material for Korean traditional rice wine. These isolates, well known as an Aspergillus oryzae producing amylase for Korean rice wine or producing protease for soybeans, were compared with Aspergillus species known. All isolates were microscopically observed to be a species of A. oryzae or its related, but to be difficult to be identified. Thus, RAPD-DNA techniques were applied for these isolates and analyzed with nummerical values using NT-system, or Ecological programs or Factorial analyses. Several common bands of RAPD-DNA in the 28 isolates were synthesized with the different OPD primers and speculated to be used for identification of HK fungi. The HK-fungi isolated were revealed to belong to the group of A. flavus previously defined. Particularly, the isolates collected from mejus were analyzed to be more closed to A. flavus, The species of A. flavus, A. oryzae and A. sojae were grouped at the values lower than those indicating the diversity of species. In other words, these three fungal species were not distinguishable and all isolates known as a HK-fungus were very closed to A. flavus, All isolates were not diversified at groupings of RAPD-DNA, and considered to be not the natural flora at the mejus or nuluks. The meju or nuluk having the above fungi as the fungal flora were speculated to be not termed "Korean traditional foodstuffs".The yellow fungal isolates inhabiting at the cereals (Hwang-Kuk, HK-fungi) were widely collected from the mejus and nuluks in Korea; the meju is a raw material for Korean traditional foods for soysauce and soypaste, and the nuluk is a raw material for Korean traditional rice wine. These isolates, well known as an Aspergillus oryzae producing amylase for Korean rice wine or producing protease for soybeans, were compared with Aspergillus species known. All isolates were microscopically observed to be a species of A. oryzae or its related, but to be difficult to be identified. Thus, RAPD-DNA techniques were applied for these isolates and analyzed with nummerical values using NT-system, or Ecological programs or Factorial analyses. Several common bands of RAPD-DNA in the 28 isolates were synthesized with the different OPD primers and speculated to be used for identification of HK fungi. The HK-fungi isolated were revealed to belong to the group of A. flavus previously defined. Particularly, the isolates collected from mejus were analyzed to be more closed to A. flavus, The species of A. flavus, A. oryzae and A. sojae were grouped at the values lower than those indicating the diversity of species. In other words, these three fungal species were not distinguishable and all isolates known as a HK-fungus were very closed to A. flavus. All isolates were not diversified at groupings of RAPD-DNA, and considered to be not the natural flora at the mejus or nuluks. The meju or nuluk having the above fungi as the fungal flora were speculated to be not termed 'Korean traditional foodstuffs'.

• Journal of Nutrition and Health
• /
• v.39 no.7
• /
• pp.707-713
• /
• 2006

This study was conducted to investigate the side dishes preference of Korean food with 403 college students (197 males and 206 females) in Seoul using questionnaires. Regarding preference of soups, it was shown that male students liked $s{\breve{o}}ll{\breve{o}}ngt'$ang and beef soup and female students liked soybean paste soup. Male students had higher preferences for $s{\breve{o}}ll{\breve{o}}ngt'$ang, beef soup, dried pollack soup, and kimchi soup than female students (p<0.05). Both male and female students had the highest preferences for kimchi pot stew and soft-tofu pot stew, but the lowest preferences for fermented soybeans pot stew and frozen pollack pot stew (p<0.05). Stewed beef with soy sauce was preferred the most by both of them but female students had lower preferences for stewed bean with soy sauce and stewed pepper with soy sauce than male students (p<0.05). For the preference of panbroiled foods, stir-fried with marinated anchovy was disliked by both of them but stir-fried with marinated pork was shown to have high preference in male students and stir-fried with marinated kimchi was high in female students (p<0.05). Besides, roasted ribs, cucumber salad, and korean cabbage kimchi were preferred the most by both of them. But male students had higher preferences for roasted eel, grilled todok, roots of broad bellflower salad, mustard leaf kimchi, and white cabbage kimchi than female students (p<0.05).