• Korean Journal of Food Science and Technology
• /
• v.33 no.1
• /
• pp.72-77
• /
• 2001

The effect of gamma-irradiation on the microbiological and general quality changes of the kochujang(Korean hot pepper paste) was studied. Kochujang was prepared, irradiated at 5, 10 and 20 kGy, and then stored at $25^{\circ}C$ for twelve weeks. The results showed that the Bacillus were decreased by 5 log cycles with dose of 20 kGy with 3.94 kGy of $D_{10}$ value. Yeast and Lactobacillus cells were nearly eliminated by 10 kGy. The formation of $NH_2-nitrogen$ and reducing sugar, enzyme activity, acid production and browning were not affected by gamma irradiation. Therefore, it was considered that the kochujang treated with gamma irradiation maintained better microbial quality than that of the control with storage.

• Asian-Australasian Journal of Animal Sciences
• /
• v.21 no.3
• /
• pp.364-370
• /
• 2008

Chemical analysis and in vitro studies were conducted to investigate the nutritive value for ruminants of cell mass from lysine production (CMLP) which is a by-product of the lysine manufacturing process. Proximate analysis, protein fractionation, and in vitro protein degradation using protease from Streptomyces griseus and strained ruminal fluid were carried out to estimate ruminal protein degradability of CMLP with two reference feedstuffs-soybean meal (SBM) and fish meal (FM). Amino acid composition and pepsin-HCl degradability were also determined to evaluate postruminal availability. CMLP contained 67.8% crude protein with a major portion being soluble form (45.4% CP) which was composed of mainly ammonium nitrogen (81.8% soluble CP). The amount of nucleic acids was low (1.15% DM). The total amount of amino acids contained in CMLP was 40.60% DM, which was lower than SBM (47.69% DM) or FM (54.08% DM). CMLP was composed of mainly fraction A and fraction B2, while the protein fraction in SBM was mostly B2 and FM contained high proportions of B2 and B3 fractions. The proportion of B3 fraction, slowly degradable protein, in CP was the highest in fish meal (23.34%), followed by CMLP (7.68%) and SBM (1.46%). CMLP was degraded up to 51.40% at 18 h of incubation with Streptomyces protease, which was low compared to FM (55.23%) and SBM (83.01%). This may be due to the insoluble portion of CMLP protein being hardly degradable by the protease. The in vitro fermentation by strained ruminal fluid showed that the amount of soluble fraction was larger in CMLP (40.6%) than in SBM (17.8%). However, because the degradation rate constant of the potentially degradable fraction of CMLP (2.0%/h) was lower than that of SBM (5.8%/h), the effective ruminal protein degradability of CMLP (46.95%) was slightly lower than SBM (53.77%). Unavailable fraction in the rumen was higher in CMLP (34.0%) compared to SBM (8.8%). In vitro CP degradability of CMLP by pepsin was 80.37%, which was lower than SBM (94.42%) and FM (89.04%). The evaluation of protein degradability using different approaches indicated that soluble protein in CMLP may supply a large amount of ammonia in the rumen while insoluble protein can be by-passed from microbial attacks due to its low degradability. The results from this study suggest that CMLP can be used as a protein supplement to ruminants for supplying both non-protein nitrogen to rumen microbes and rumen undegradable protein to the host animal.

• Food Science and Preservation
• /
• v.20 no.5
• /
• pp.699-704
• /
• 2013

Buckwheat Soksungjang (BS) is a bealmijang manufactured with buckwheat and soybeans. We manufactured BS using Bacillus subtilis HJ18-4 (HJ18-4), which has high enzyme activities and antibacterial effects. HJ18-4 was inoculated in a different process during the BS manufacturing, which was the meju-making time (Treat 1), and the salt water time was added (Treat 2). The physiochemical and microbial characteristics of the BS were analyzed. As a result, the total aerobic counts (7~8 log CFU/mL) in the BS increased after 15 days of fermentation. Especially, Treat 1 showed higher total aerobic counts and amino-type nitrogen (65.38~202.52 mg%) than Treat 2. During the BS fermentation, the reduction of the sugar contents and the enzyme (protease and amylase) activities decreased. In the relative quantitative expression level of PlcR, Treat 1 did not show toxin gene expressions at the end of the fermentation on Day 23. Treat 1 showed suitable B. cereus physiochemical quality characteristics and inhibition effects. When the modified-form type of fermented soybean paste was manufactured with a single starter, it could not reproduce the natural fermentation quality. These results suggest that the addition of a starter (HJ18-4) in the Meju manufacturing process could enhance the quality characteristics of the manufactured BS via natural fermentation and by suppressing B. cereus.

• The Korean Journal of Mycology
• /
• v.40 no.4
• /
• pp.235-243
• /
• 2012

We studied the effect of fermented Rhus verniciflua stem bark (FRVSB) extract (used in herbal med-icine by Koreans) on the microbial growth and enzyme activity of 12 soybean-fermenting microorganisms, including Bacillus spp., lactic acid bacteria, yeast, and other harmful bacteria. The ethanol and methanol extracts of FRVSB inhibited the growth of Bacillus subtilis, Bacillus licheniformis, Bacillus cereus, and Zygosaccharomyces rouxii, and in the disk diffusion assay, their inhibition zone diameters were 11.06-12.23, 12.32-18.38, 11.47-11.84, and 13.59-14.21 mm, respectively. The water extract did not show any inhibitory effect. In fact, the water extract addition enhanced the growth of B. subtilis and B. licheniformis by 1.3-4.5 fold and that of B. cereus by 1.2-1.4 fold. However, the water extract did not affect the growth of Lactobacillus plantarum, Lactobacillus mesenteroides, Saccharomyces cer-evisiae, and Escherichia coli. The addition of water extract increased the amylase and protease activity of B. subtilis and B. licheniformis.

• Archives of Pharmacal Research
• /
• v.25 no.6
• /
• pp.770-780
• /
• 2002

The airway surface liquid (ASL), often referred to as mucus, is a thin layer of fluid covering the luminal surface of the airway. The major function of mucus is to protect the lung through mucociliary clearance against foreign particles and chemicals entering the lung. The mucus is comprised of water, ions, and various kinds of macromolecules some of which possess the protective functions such as anti-microbial, anti-protease, and anti-oxidant activity. Mucus glycoproteins or mucins are mainly responsible for the viscoelastic property of mucus, which is crucial for the effective mucociliary clearance. There are at least eight mucin genes identified in the human airways, which will potentially generate various kinds of mucin molecules. At present, neither the exact structures of mucin proteins nor their regulation are understood although it seems likely that different types of mucins are involved in different functions and might also be associated with certain airway diseases. The fact that mucins are tightly associated with various macromolecules present in ASL seems to suggest that the defensive role of ASL is determined not only by these individual components but rather by a combination of these components. Collectively, mucins in ASL may be compared to aircraft carriers carrying various types of weapons in defense of airborne enemies.

• Journal of the East Asian Society of Dietary Life
• /
• v.23 no.1
• /
• pp.92-97
• /
• 2013

This study was conducted to understand the quality characteristics of salt fermented anchovies with heat treatment by measuring their chemical compositions. The heat-treated and non-heat treated salt fermented anchovies contained, respectively, 63.21 and 66.51% of moisture, 2.24 and 2.12% of total nitrogen (TN), and 1,537 and 1,520 mg/100 g of amino nitrogen (AN). In addition, heat-treated and non-heat-treated salt fermented anchovies contained 127 and 134 mg/100 g of volatile basic nitrogen (VBN), respectively. Moreover, measured the microbial level of heat-treated and non-heat-treated salt fermented anchovies was $2.58{\times}10^4$ and $3.61{\times}10^2$ CFU/mL, respectively. Also, the heat-treated and non-heat-treated salt fermented anchovies 3.65 and 0.30 units of protease activities, respectively. The total free amino acid contents in heat-treated and non-heat-treated salt fermented anchovies was 4,964 and 6,638 mg/100 g, respectively. The major free amino acid were glutamic acid, leucine, lysine, alanine, valine, isoleucine. Our results provide the characteristics of salt fermented anchovies and encourage their application for the food industry and cooking.

• Microbiology and Biotechnology Letters
• /
• v.48 no.1
• /
• pp.64-71
• /
• 2020

A total of 262 bacterial strains were isolated from clay minerals, bentonite and zeolite, in Gyeongsangbukdo, Republic of Korea, and their hydrolytic enzyme activities were analyzed. Most of the isolated strains belonged to Micrococcales and Bacillales order. Of strains, 96 strains produced α-amylase activity, 42 strains showed cellulase activity, 111 strains had pectinase activity, and 70 strains showed protease activity. Among them, 177 isolates exhibited one or more of the hydrolytic enzyme activities and in particular Bacillus cereus MBLB1321, B. albus MBLB1326 and KIGAM017, B. mobilis MBLB1328, MBLB1329 and MBLB1330 showed all of the enzyme activities. These results demonstrate the diversity of functional Bacillus species in clay minerals as vital sources for the discovery of industrially valuable hydrolytic enzymes, which have a great commercial prospect in various bio-industrial applications.

• Journal of Microbiology and Biotechnology
• /
• v.11 no.6
• /
• pp.1099-1101
• /
• 2001

In an attempt to search for serotonin N-acetyltransferase (arylalkylamine N-acetyltransferasem, AA-NAT) inhibitors from microbial metabolites, we fecund the culture broth of Penicillium sp. 80722 which showed a strong inhibitory activity against AA-NNT. The active principle has been identified as citrinin hydrate through bioassay-guided fractionation of cultural broth, and structure elucidation derived by spectroscopic analyses. Citrinin hydrate inhibits AA-NAT with an $IC_50$ value of $173{\mu}M$ in a dose-dependent manner. Although citrinin hydrate was previously isolated as human rhinovirus 3C-protease inhibitor, this was recognized as the first AA-NAT inhibitor isolated from natural sources.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.27 no.3
• /
• pp.448-454
• /
• 1998

Meju for doenjang and kochujang was prepared as a model at Sunchang areaand monitored with major changes. Kochujang meju was prepared on September 12 and doenjang meju on November 12, 1995. Kochjang meju was found to be naturally fermented at 80~90% RH, 15~2$0^{\circ}C$ and doenjang meju was at 80~90% RH and 0~5$^{\circ}C$. The shapes of kochujang meju and doenjang meju were doughnut-type and rectangular, respectively. Weight losses during fermentation were 48% and 28%, respectively. The pH drop and acip production of kochujang meju were negligible. However, pH of doenjang meju decreased from 6.29 to 5.88 and acidity increased from 0.08 to 0.23% as lactic acid. Protein in meju was found to be rapidly solubilized during the early stage of fermentation. Soluble protein cotents of kochujang meju after 7 days and 60 days were 8.23%, respectively. The doenjang mejus were 2.15% after 20 days and 5.72% after 60 days. Soluble suger content increased with the fermentation time. The soluble sugar content was higher in kochjang meju. Acidic protease was highly produced during meju fermentation. $\alpha$-Amylase and $\beta$-amylase were detected in the kochujang meju, of which glutinous rice consisted, but negligible in doenjang meju. Lipase was detected in kochujang meju, but was, negligible in doenjang meju. Microbial population increased drastically after 7 days of fermentation in kochujang meju and 20 days of fermentation in doenjang meju.

• Preventive Nutrition and Food Science
• /
• v.16 no.4
• /
• pp.348-356
• /
• 2011

The effects of Glycyrrhiza uralensis and Brassica juncea on the quality and palatability of low-salt gochujang were investigated in terms of the microbial characteristics, enzyme activities, pH, acidity, amino nitrogen and sensory evaluation during 40 days of fermentation. The proliferation of fungi in low-salt gochujang with added G. uralensis and B. juncea were inhibited, while the numbers of total viable bacteria and lactic acid bacteria were not affected. In terms of ${\alpha}$-amylase and ${\beta}$-amylase activity, no significant difference was observed by the salt concentration or additives. However, lowering the salt concentration increased protease activity. The amount of amino-nitrogen in low-salt gochujang at 20 days was similar to that in the control gochujang at 40 days. In the sensory test, low-salt gochujang was preferred compared to control gochujang (8.5% salt). Particularly, the 4.3% salt gochujang with additives was the most preferred.