• Journal of Food Hygiene and Safety
• /
• v.30 no.1
• /
• pp.92-97
• /
• 2015

The aim of this study is to examine the removal efficiency of pathogen (Escherichia coli O157:H7 and Salmonella typhimurium) on meat and fish products (packing condition: vacuum or not and storage temperature: $4^{\circ}C$ or $-20^{\circ}C$) repeatedly exposed at low-dose gamma irradiation. In case of meat products (beef and chicken), E. coli O157:H7 was not observed at the level of 2 kGy single gamma irradiation and 0.5 kGy repeated gamma irradiation and S. Typhimurium was not observed at the level of 2 kGy single gamma irradiation and 1 kGy repeated gamma irradiation. In case of fish products, E. coli O157:H7 and S. Typhimurium were not detected at the level of 0.5 kGy single and repeated gamma irradiation. These results showed that microorganisms on fish products were more efficiently removed than those of meat products with low-dose gamma irradiation. Generally, each packing condition made no difference. However, the products (fish and meat) stored at $-20^{\circ}C$ needed more higher dose gamma irradiation than products at $4^{\circ}C$.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
• /
• 1998.05a
• /
• pp.167-167
• /
• 1998

• Journal of the East Asian Society of Dietary Life
• /
• v.19 no.5
• /
• pp.798-802
• /
• 2009

This study was performed to assess the presence of contaminated microorganisms of Escherichia coli, Clostridium perfringens, and Bacillus cereus in the 112 commercial Saengshik products. E. coli was not detected in all the samples, but C. perfringens was detected in 11 products (9.8%). The number of the bacteria was less than 100 CFU/g, which was satisfactory to KFDA microbiological requirement. B. cereus was detected less than $10^2{\sim}10^3$ CFU/g in 7 products and $10^3{\sim}10^4$CFU/g in 13 products out of 25 products. Those detected bacteria from tryptose sulphite cycloserine agar and mannitol egg yolk polymyxin agar showed the typical characteristics of Gram positive and contained lecithinase, which can decompose egg-yolks layers in the biochemical test. Therefore, much more attention must be applied to satisfy the B. cereus requirement for Saengshik products sold in the market.

• Natural Product Sciences
• /
• v.14 no.3
• /
• pp.161-166
• /
• 2008

A mixture of sixteen cerebrosides, which comprised four cerebroside molecular species (PL-1 ${\sim}$ PL-4) was separated from the roots of Paeonia lactiflora. The structures of cerebrosides were characterized as $1-O-{\beta}$-D-glucopyranosides of phytosphingosines, which comprised a common long-chain base, (2S,3S,4R,8E/Z)-2-amino-8-octadecene-1,3,4-triol with eight fatty acids or 2-hydroxy fatty acids of varying chain lengths ($C_{16}$, $C_{18}$, $C_{20-26}$) linked to the amino group. Aralia cerebroside and its 8Z isomer (PL-1), $1-O-{\beta}$-D-glucopyranosyl-(2S,3S, 4R,8E/Z)-2-[(2'R)-2'-hydroxytetracosanoylamino]-8-octadecene-1,3,4-triol (PL-2), $1-O-{\beta}$-D-glucopyranosyl-(2S,3S,4R, 8E/Z)-2-[(2'R)-2'-hydroxydocosanoylamino]-8-octadecene-1,3,4-triol (PL-3), and $1-O-{\beta}$-D-glucopyranosyl-(2S,3S,4R, 8E/Z)-2-[(2'R)-2'-hydroxytricosanoylamino]-8-octadecene-1,3,4-triol (PL-4) were identified as major components of these cerebroside molecular species. All the major cerebrosides were shown to be a mixture of geometrical isomers (8E and 8Z) of phytosphingosine-type glucocerebrosides possessing 2R-hydroxy fatty acids. In addition, three ${\beta}-sitosterol$ derivatives and adenosine were also separated. The structures of these isolates have been determined on the basis of chemical and spectroscopic evidence.

• Food Science and Preservation
• /
• v.31 no.2
• /
• pp.235-244
• /
• 2024

A nonthermally sterilized raw apple vinegar was manufactured using an ultra-fine filtration process (0.2 ㎛ membrane filter) and its quality was comparable to commercially available vinegar products. First, using apple concentrate as a raw material, it was possible to produce non-thermal sterilized Using a two-stage fermentation process of alcohol and acetic acid fermentations, a non-thermally sterilized raw apple vinegar with pH 2.94 and an acidity of 6.20% was produced from an apple concentrate. The fermentation process increased the browning index significantly. However, the fundamental quality parameters of the non-thermal sterilized raw apple vinegar (A) with sterilized apple vinegar (B) did not differ significantly. The pH (2.92-2.95) of apple vinegar (A and B) was higher than that (pH 2.65-2.70) of commercial vinegar (C and D), and the total acidity, which is in the range of 6.20-6.21% and 6.53-6.90%, respectively, was higher in samples C and D than in samples A and B. However, four kinds of organic acids were detected in non-thermal sterilized raw apple vinegar (A), and its total organic acid content (6,245.00 mg%) was significantly higher than that of other samples (B, C, D) (p<0.05). In particular, malic acid content, as a main organic acid in apples, was very high in sample (A) (244.83 mg%) and sample (B) (210.21 mg%), compared to commercial products C (125.78 mg%) and D (86.90 mg%). The total polyphenol content and antioxidant activity of fermented apple vinegar (A, B) were more than twice as high as those of commercial products (C, D). Vinegar A had higher total polyphenol content than vinegar B. The above results suggest it is possible to manufacture and commercialize non-thermal sterilized raw apple vinegar with higher organic acid content and antioxidant properties using ultra-fine filtration.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.40 no.2
• /
• pp.235-244
• /
• 2011

The physicochemical properties and quality changes in salted and dried brown croaker products using deep seawater salt were investigated for preparation with different pretreatment, salting and drying conditions. Optimum salt concentration, salting time and drying time for product were 20% of body weight, 12 hrs at room temperature ($25{\pm}2^{\circ}C$), and 24 hrs at $30{\pm}2^{\circ}C$, respectively. The volatile basic nitrogen (VBN), peroxide value (POV), viable cell count and acid value (AV) of viscera and blade removed products were 18.9~22.4 mg%, 21.0~32.5 meq/L, and 2.3~4.4 mg/mL, $2.0\sim3.5{\times}10^3$ CFU/g, respectively and only viscera removed products were 31.2~38.1 mg%, 40~55.2 meq/L, 7.0~11.5 mg/mL, $4.1\sim5.5{\times}10^3$ CFU/g, respectively. Changes in quality of salted and dried brown croaker products were investigated during storage at room temperature and $5{\pm}2^{\circ}C$. The POV, AV and viable cell counts of salted and dried brown croaker products increased in commercial salt used and only viscera removed products compared with deep seawater salt used and viscera and blade removed products during storage time. Results in this study showed that the deep seawater salt was very effective for quality control of salted and dried brown croaker products and pretreatment method was a very important factor for preparation products. The optimum conditions for preparation of salted and dried brown croaker product were 20% of body weight for salt concentration, 12 hrs at $25{\pm}2^{\circ}C$ for salting time, and 24 hrs at $30{\pm}2^{\circ}C$ for drying time. Optimum storage time for quality maintenance was 14 days at $5{\pm}2^{\circ}C$.

• Natural Product Sciences
• /
• v.7 no.2
• /
• pp.38-44
• /
• 2001

NAD(P)H:quinone reductase (QR), known as DT-diaphorase, is a kind of detoxifying phase II metabolic enzyme catalyzing hydroquinone formation by two electron reduction pathway from quinone type compounds, and thus facilitating excretion of quinoids from human body. With the usefulness of QR induction activity assay system for the modulation of toxicants, in the course of searching for cancer chemopreventive agents from natural products, the methanolic extracts of approximately two hundreds of oriental medicines were primarily evaluated using the induction potential of quinone reductase (QR) activity in cultured murine Hepa1c1c7 cells. As a result, several extracts including Hordeum vulgare, Momordica cochinchinensis, Strychnos ignatii, Houttuynia cordata, and Polygala japonica were found to significantly induce QR activity. In addition, the methylene chloride fraction of H. vulgare, one major dietary food source, showed potent induction of QR activity $(CD=6.4{\mu}g/ml)$. Further study for isolation of active principles from these lead extracts is warranted for the discovery of novel cancer chemopreventive agents.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1996.04a
• /
• pp.180-180
• /
• 1996

Previous studies have shown that kainic acid (KA) causes an elevation of hippocampal proenkephalin mRNA level. However, the role of proto-oncogene products, such as c-Fos, c-Jun and Fra proteins in the regulation of KA-induced proenkephalin mRNA increase in the hippocampus has not been well characterized. Thus, in the present study, the effect of cycloheximide (CHX) on KA-induced proenkephalin mRNA and immediate early gene products induction was examined. After pretreating with either vehicle or CHX (20 mg/kg, s.c.) for 30 min, KA (10 mg/kg) was administered s.c. The animals were sacrificed 1,2, or 8 hrs after KA administration. Total RNA and were isolated for Northern blot assay, and proteins were isolated for Western and electrophoretic gel-shift assays. First, we found that CHX inhibited KA-induced proenkephalin mRNA increase without altering intracellular proenkephalin protein level. Secondly, Western blot assays showed that KA increased c-Fos, c-Jun and Fra proteins at 1,2, and 8 hrs and CHX inhibited these immediate early gene products. Finally, electrophoretic gel shift assays revealed that KA increased both AP-1 and ENKCRE-2 DNA binding activities. Furthermore, CHX attenuated KA-induced AP-1 and ENKCRE-2 DNA binding activities. Both AP-1 and ENKCRE-2 DNA binding activities were abolished by cold AP-1 or ENKCRE-2 oligonucleotides, and further reduced by antibodies against c-Fos or c-Jun. Antibody against CREB reduced ENKCRE-2, but not AP-1, DNA binding activity. Our results suggest that on-going protein synthesis is required for elevation of hippocampal proenkephalin mRNA level induced by KA. All c-Fos, c-Jun, and Fra proteins appears to be involved in the regulation of hippocampal proenkephalin mRNA level induced by KA (This study was supported by a grant from KOSEF).

• Food Science of Animal Resources
• /
• v.34 no.6
• /
• pp.742-748
• /
• 2014

This study was conducted to evaluate the activities of antioxidant enzyme (glutathione peroxidase (GSH-Px)) and lysosomal enzymes (alpha-glucopyranosidase (AGP) and beta-N-acetyl-glucosaminidase (BNAG)) of the longissimus dorsi (LD) muscle from Hanwoo (Korean cattle) in three freezing conditions. Following freezing at -20, -60, and $-196^{\circ}C$ (liquid nitrogen), LD samples (48 h post-slaughter) were treated as follows: 1) freezing for 14 d, 2) 1 to 4 freeze-thaw cycles (2 d of freezing in each cycle), and 3) refrigeration ($4^{\circ}C$) for 7 d after 7 d of freezing. The control was the fresh (non-frozen) LD. Freezing treatment at all temperatures significantly (p<0.05) increased the activities of GSH-Px, AGP, and BNAG. The $-196^{\circ}C$ freezing had similar effects to the $-20^{\circ}C$ and $-60^{\circ}C$ freezing. Higher (p<0.05) enzymes activities were sustained in frozen LD even after 4 freeze-thaw cycles and even for 7 d of refrigeration after freezing. These findings suggest that freezing has remarkable effects on the activities of antioxidant enzyme and lysosomal enzymes of Hanwoo beef in any condition.

• Korean Journal of Food Science and Technology
• /
• v.32 no.5
• /
• pp.1002-1008
• /
• 2000

The purpose of this study was to provide the fundamental information for establishing the database needed to estimate total intakes of trans fatty acids in Korea. The amounts of trans fatty acids contained in 164 samples including 25 samples of margarines, 21 samples of shortenings, 19 samples of vegetable salad and cooking oils, 53 samples of confectionery products, 18 samples of bakery products, 19 samples of dairy products, and 9 samples of animal fats and meats were analyzed by capillary gas liquid chromatography. The average amounts of trans fatty acids in those foods were calculated and expressed as gram per one serving. Then, the average daily intakes of trans fatty acids per capita were estimated using the analyzed amounts of trans fatty acids and the amount of yearly production for those foods. The amounts of trans fatty acids per 100 g of lipids were $2.11{\sim}33.83%$ (14.66% on average) in margarines, $1.47{\sim}44.48%$ (14.21% on average) in shortenings, $0.18{\sim}3.82$ (1.54% on average) in vegetable salad and cooking oils, $0{\sim}45.81%$ (10.92% on average) in confectionery products, $0{\sim}18.32%$ (7.87% on average) in bakery products, $0.90{\sim}4.54%$ (2.27% on average) in dairy products, and $0.61{\sim}6.07%$ (2.24% on average) in animal fats and meats. Major isomers of trans fatty acid in the sample foods were $C_{18:1}$ and $C_{18:2}$. As a result, the korean average daily intake of trans fatty acids in korea was estimated to be 2.3 g per capita. The amounts of trans fatty acids consumed from each selected food were as follows: 0.35 g from margarines, 0.57 g from shortenings, 0.11 g from vegetable salad and cooking oils, 0.65 g from confectionery products, 0.07 g from bakery products, 0.14 g from dairy products and 0.21 g from animal fats and meats.