Earticle

This study was conducted to examine the contents of lead (Pb), cadmium (Cd), arsenic (As), and mercury (Hg) in meat and meat products in Korea. The contents of Pb, Cd, As, and Hg in 466 samples of beef, pork, chicken, duck, ham, and sausage were measured using inductively coupled plasma mass spectrometry or a mercury analyzer. Wet ashing and microwave method were compared, and the recovery and reproducibility of the microwave method were better than those of wet ashing for meat and meat products. The recovery of the microwave method was 98.1% for Pb, 104.6% for Cd, and 103.4% for As, respectively. The best result was obtained through digestion using an acid mixture (HNO3/H2O2, 6:2). Hg content was measured using a mercury analyzer. As a result, the contents of Hg and Cd in samples were lower than those of Pb and As. The average contents of Pb were 0.009 mg/kg in beef, 0.010 mg/kg in pork, 0.006 mg/kg in chicken, 0.007 mg/kg in duck, 0.005 mg/kg in ham, and 0.009 mg/kg in sausage. The average Cd contents were 0.0004 mg/ kg in beef, 0.0004 mg/kg in pork, 0.0005 mg/kg in chicken, 0.0012 mg/kg in duck, 0.0015 mg/kg in ham, and 0.0019 mg/ kg in sausage. The average As contents were 0.016 mg/kg in beef, 0.004 mg/kg in pork, 0.021 mg/kg in chicken, 0.010 mg/ kg in duck, 0.014 mg/kg in ham, and 0.018 mg/kg in sausage. The average Hg contents were 0.713 μg/kg in beef, 0.902 μg/ kg in pork, 0.710 μg/kg in chicken, 0.796 μg/kg in duck, 1.141 μg/kg in ham, and 1.052 μg/kg in sausage. Based on the results of the National Health and Nutrition Survey 2005, the levels of dietary exposure to heavy metal contaminants in meat and meat products were compared with the provisional tolerable weekly intake(PTWI) established by the Joint FAO/WHO Expert Committee on Food Additives. The average dietary exposure of the general population from meat and meat products was 0.03-0.2% of PTWI for Pb, Cd, As, and Hg, which indicates a safe level for public health at present.

The internal standard method using ion chromatography combined with tandem mass spectrometry (IC-MS/MS) for quantifying perchlorate in different types of food was established. Because the presence of ions and other biomolecules in matrices usually interrupts accurate determination of perchlorate, it is necessary to develop efficient, reproducible method to determine perchlorate concentrations in food. In this study, the internal standard method was compared with the external standard method to determine perchlorate concentrations in standard samples. The obtained method detection limit (MDL) for perchlorate was 0.005 μg/L for bottled water, 0.12 μg/L for milk, 0.27 μg/kg for rice, 0.16 μg/kg for vegetables, and 0.07 μg/kg for seaweed, respectively. The limit of quantitation (LOQ) was calculated by multiplying the MDL by 7. The recoveries of perchlorate from food samples spiked with perchlorate ranged from 98 to 105% and their percent relative standard deviation (%RSD) levels were <20%. This method was successfully applied for the quantitative determination of perchlorate in various kinds of food.

The reduction factor of pesticides is getting more crucial these days. However, most studies have focused on the relationship between pesticides and commodities. This study was conducted to examine the pesticide reduction factor based on their physicochemical properties. Five pesticides were selected among 288 insecticides by considering the presence of an ionizable group, the log P, and boiling points. The correlation coefficients between log P and removal by tap water, 5% acetic acid, 20% ethanol, and 0.15% detergent were -0.835 (p<0.001), 0.336 (p=0.221), 0.659 (p<0.01), and -0.939 (p<0.001), respectively. Removal by blanching was affected by log P as it showed a positive correlation with a log P of 0.620 (p<0.05). Removal by frying showed a strong negative correlation with a log P of -0.913 (p<0.001). The results suggest that removing pesticides was affected largely by log P and by vapor pressure during cooking, whereas during washing, the matrix of the food also contributed to the reduction.

The purpose of this study was to develop an analytical method for determining 15 polycyclic aromatic hydrocarbons (PAHs) of EU priority using gas chromatography (GC)-tandem mass spectrometry (MS). The PAHs in ground coffee were analyzed after being extracted using methods such as saponification-liquid-liquid extraction, Soxhlet extraction, and solid-liquid extraction. The solid-liquid extraction method showed the greatest repeatability and most efficient reduction of the matrix effect. GC-tandem MS for the quantification of the 15 PAHs showed better resolution and lower limit of detections (LODs) than GC-MS-selected ion monitoring (SIM) and high performance liquid chromatography with fluorescence detector. LODs of this method for the ground coffee types were 0.002-0.1 μg/kg and limit of quantifications (LOQs) were 0.006-0.2 μg/kg The recoveries ranged from 52.6 to 93.3%. Forty-six commercial types of ground coffee were analyzed to determine their PAHs contamination levels. PAHs concentration ranged from ND to 5.988 μg/kg. This study was conducted with toxicity equivalence factors, the U.S. EPA recommendation to identify dietary risks for PAHs in different types of coffee. The estimated average daily dose of PAHs was 5.24×10−8 mg/kg body weight/ day.

Garlic specific organic compounds were separated and purified using a recycling preparative high-performance liquid chromatography (HPLC) from blanched garlic cloves. Identification of the compounds involved comparing the previously reported HPLC retention times as well as other identification methods including 1H- and 13C-nuclear magnetic resonance and liquid chromatography-mass spectrometry. The yields of garlic specific organic compounds were 12.2, 42.5, 1.6, 1.2, and 4.8% on wet weight basis of garlic for alliin(S-allyl-L-cysteine sulfoxide), isoalliin(S-1-propenyl-L-cysteine sulfoxide), γ-glutamyl-S-allylcysteine, γ-glutamyl-S-1-propenylcysteine and γ-glutamyl-phenylalanine, respectively. All the compounds, except for γ-glutamylphenylalanine, contained sulfur.

In the course of our investigation for chemical constituents in the ethyl acetate layer of Korean black raspberry wine, five compounds were isolated and purified by silica gel column chromatography and high-performance liquid chromatography. The isolated compounds were identified as ethyl succinate (1), vanillic acid (2), ethyl 3,4-dihydroxybenzoate (3), furan-2-ol (4), and 4-(4-hydroxyphenyl)butan-2(S)-ol (5) based on the spectroscopic data of electrospray ionization tandem mass spectrometry and nuclear magnetic resonance. The presence of 2 in Korean black raspberry has previously reported. However, 1 and 3-5 in Korean black raspberry and its wine were isolated for the first time.

This study qualitatively and quantitatively analyzed various carotenoids, L- ascorbic acid, and tocopherol and their anti-oxidant properties from four varieties (Special, Chelsea, Cupra, and Fiesta) and three different color stages [green (GP), yellow (YP) and red (RP)] of paprika harvested in Korea. Seven carotenoids were identified, mainly lutein in GP (Special: 4.65±0.84 mg/kg fresh weight (fw)) and YP (Fiesta: 5.19±0.05 mg/kg fw), and capsorubin (3.16±0.35 mg/kg fw) and capsanthin (53.70±6.23 mg/kg fw) in Special of RP. RP was the highest in total carotenoids, L-ascorbic acid, and α-tocopherol contents, while GP was the highest in γ-tocopherol content. RP showed the strongest antioxidant activity (IC50=62.40±0.03 μg/mL in an ABTS assay and 182.77±31.74 μg/mL in a DPPH assay). Paprika in different color stages has many phytochemicals even though they have different kinds of carotenoids. Therefore, dietary intake of paprika may be helpful for improving human health.

The effect of nuruks and crude amylolytic enzyme on free amino acid and volatile components of brown rice vinegar prepared by static cultures was investigated. Five groups consisted of AV (100% nuruk without crude amylolytic enzyme), BV (75% nuruk; 25% crude amylolytic enzyme), CV (50% nuruk; 50% crude amylolytic enzyme), DV (25% nuruk; 75% crude amylolytic enzyme) and EV (100% crude amylolytic enzyme without nuruk). Free amino acid content in AV vinegar (132.06 mg%) was lower than the others (184.56-191.22 mg%). Acetic acid, 3-methyl butyl acetate, acetoin and isoamyl alcohol were major volatile components as analyzed using gas chromatography-mass spectrometry after headspace solid-phase microextraction. Acetic acid in AV and EV samples represented 67.56% and 55.53% of total GC peak area, respectively. E-nose provided different patterns in each case showing variation in sensory properties.

Greenhouse satsuma mandarins (Citrus unshiu Marc., cv. Gungchun) of an early harvesting cultivar were treated by hot water showering at 65oC for 10 s at a commercial scale in a packing house and then stored at 5oC for 3 weeks and subsequently at 18oC for 1 week (simulated shelf-life) to examine the potential use of hot water treatment (HWT) as an environmentally benign method to maintain mandarin quality characteristics during postharvest storage and sale. The respiration rate just after heat treatment or during storage was at a similar level in both the treated and untreated fruit. HWT also had no detrimental effects on quality attributes including pH, titratable acidity, soluble solids content, weight loss, firmness, and peel color. The development of stem-end rot, mold decay, and black rot was lower in the heattreated fruit compared to those in the untreated control. A sensory evaluation showed that HWT markedly improved fruit appearance, making the fruit cleaner and glossier. The results suggested that HWT can be applied to satsuma mandarin as an effective pretreatment to maintain postharvest quality during storage and marketing.

This study evaluated the quality characteristics of yukwa pellets and yukwa bases on the ratio of soju addition (0, 25, 50, 75, and 100% v/v). Yukwa base with 50% ratio of soju addition displayed the highest diameter, volume and specific volume. The yukwa base with 75% ratio of soju addition displayed the longest in length. The weight of yukwa base increased as the ratio of soju increased. Lightness increased in yukwa pellet and yukwa base as the ratio of soju increased. Lightness of yukwa base was higher than yukwa pellet, but yellowness and redness of yukwa base were lower than yukwa pellet. Air cell size of yukwa base decreased as the ratio of soju increased. The compression and cutting force of yukwa base with 50% ratio of soju addition were lowest, while yukwa base with 0% soju was highest. In the sensory evaluation, preference of color increased as the ratio of soju addition increased. Yukwa base with 50% ratio of soju addition was the highest in internal compactness, mouth-feel, and overall preference. The results show that a soju ratio of 50-75% addition for total liquid is useful in the production of high quality yukwa base.

Wild grape extract (WGE) was added into hwajeon at different concentrations (0, 5, 15, 30, 50% of water). The resulting hwajeon were analyzed for their physicochemical and sensory properties. With increasing concentrations of WGE, the pH of dough and hwajeon decreased, and their degrees brix and color intensity increased, presumably due to the presence of tartaric acid, sugar, and anthocyanin in the WGE. The WGE- enriched hwajeon showed higher hardness, gumminess, and chewiness than control hwajeon, which might have been because the sugar and tartaric acid in the WGE partially inhibited starch gelatinization during heat processing. Nevertheless, all the sensory properties and preference were higher in WGE-enriched hwajeon than controls, which could be partially attributed to the fact of that the WGE-enriched hwajeon retained relatively higher moisture. It is suggested that WGE-enriched hwajeon with high preference could be prepared without loss of hwajeon quality.

Small black beans (SBB) were germinated up to 72 h at 23oC, and 48 h germinated SBBs having the highest isoflavone content were chosen for noodle preparation. Some of the germinated SBB were treated by 20 min boiling (B) but some were not boiled (NB). For noodles, the germinated SBB flour replaced 15% or 20% of wheat flour, so five kinds of noodles were prepared and tested: control, 15B, 15NB, 20B, and 20NB. Higher amount of bean flour resulted in significant decrease of L* and increase of b* values in noodle. After 20 min cooking, the noodles containing germinated SBB flour showed less soluble sugar content in cooked water than control, and the lowest value was observed in 15B. For textural properties, the addition of SBB flour lowered hardness and adhesiveness of noodle, but increased chewiness than control. In sensory tests, the most acceptable sample was 15B because of developed texture and better appearance which seem to be good for health.

This study was performed to examine the physicochemical characteristics and sensory properties of makgeolli with dried citron peel and levels (3, 6, and 9%) of citron (Citrus junos) in makgeolli during fermentation with two-stepbrewing. The pH of makgeolli with citron dried peel increased within 5 days of fermentation, and decreased until 11 days of fermentation. Total acidity increased after 3 days of fermentation then decreased after 5 days of fermentation, but continued to increase slightly up to 12 days. Changes in alcohol content and amino acidity increased during fermentation. A sensoryevaluation of appearance, flavor, sourness, sweetness, bitterness, and overall acceptance of makgeolli with citron dried peel showed lower values than those of the control.

This study investigated the germination and reduction of microbial population in domestic (radish, Chinese cabbage, and vitamin) and imported (radish and red cabbage) sprout seeds by heat treatment (40, 50, 60, and 70oC for 15 min or 30 min). The germination ratio (define the ratio) was 45-97% at 24 h after treatment <60oC and was decreased at 70oC. In domestic radish seed, total aerobic bacteria were decrease by approximately 1.71 log CFU/g after heat treatment at 70oC for 30 min and viable coliforms were decreased to under the detection limit at temperatures over 60oC. Decrease of total aerobic bacteria and coliforms in domestic Chinese cabbage seed was 1.23-1.34 and 2.77 log CFU/g, respectively, after heat treatment over 60oC. In domestic vitamin seed, total aerobic bacteria were decreased by about 0.3 log CFU/g at 70oC for 15 min. In imported radish seed, total aerobic bacteria were decreased 2.12-2.30 log CFU/g after heat treatment over 60oC. Total aerobic bacteria in imported red cabbage seed were reduced by 0.66-0.84 log CFU/g after heat treatment over 40oC and coliforms were undetectable. In case of Bacillus cereus, there was no significant difference by heat treatment in any sample. Staphylococcus aureus and Salmonella sp. were not detected at the detection limit in any tested seeds at any temperature.

Escherichia coli O157:H7 has been considered as a significant food-borne pathogen since its role in causing hemorrhagic colitis and hemolytic uremic syndrome in humans was recognized. In this study, we developed an immunochromatography (ICG) assay for the detection of E. coli O157:H7. E. coli O157:H7 monoclonal antibody (EC MAb) and colloidal gold were conjugated and its specificity was determined by the ICG treated with EC MAb and antimouse IgG at test and control lines, respectively. The detection limit of the ICG was 1× 105 CFU/mL, and no crossreactivity was observed to other E. coli strains and major food-borne pathogens. To determine the minimum enrichment time for the ICG, meats and sprouts were inoculated with 1×10 CFU/100 μL of E. coli O157:H7. After enrichment time of 10 and 2 h for meats and sprouts, respectively, up to 1×10 CFU/100 μL of E. coli O157:H7 could be detected by ICG.

Water and ethanol extracts of 16 different Korean traditional oriental prescriptions used widely for prevention of degenerative arthritis were prepared and their total phenolic and total flavonoid contents were quantified. Additionally, antioxidant and anti-inflammatory activities of water, ethanol and enzyme-treated extracts were determined by in vitro assays. Total phenolic and total flavonoid contents of three extracts from the 16 different medicinal prescriptions varied from 10.03-78.03 and 0-16.24 mg/g, respectively. Among the three extracts of 16 different medicinal prescriptions tested, ‘Mahangeuigamtang’ showed the potent full term for DPPH (RC50=71.26, 27.33, 63.00 μg/mL) and full term for ABTS (RC50=21.11, 27.45, 152.11 μg/mL) radical scavenging activities, and its water and ethanol extracts exhibited significant cyclooxygenase-2 (COX-2) inhibitory activity (49.10 and 69.06%, respectively). Ethanol and enzyme-treated extracts of ‘Euieuiintang ’ exerted the strongest COX-2 inhibitory activity (68.23 and 75.05%, respectively). ‘Mahangeuigamtang’ and ‘Euieuiintang’ may be useful as potential therapeutic agents for treatment of degenerative diseases, such as inflammation and aging.

After Ganoderma lucidum was cultured in mushroom complete medium (MCM) supplemented with ginseng extract (GE), crude polysaccharide (GL-GE-CP) was fractionated from mycelium. Among GL-GE-CP from mycelium in MCM supplemented with 5, 10, and 15% GE (v/v ratio of MCM to GE), GL-GE- 15-CP (15% GE) most significantly enhanced macrophage stimulation and intestinal immune system modulating activity compared with GL-CP in MCM without GE. When GL-GE-15-CP was further fractionated on DEAE-Sepharose CL-6B, GL-GE-15-CP-II displayed more potent activity than subfractions from GL-CP on macrophage stimulation, interleukin-12 production, and intestinal immune system modulation (1.75-, 5.68-, and 1.76-fold, respectively). Anti-metastasis effect against colon 26-M3.1 carcinoma cells was also enhanced by GL-GE-15-CP-II (72.8% inhibition). In addition, GL-GE- 15-CP-II contained neutral sugar (83.00%) and uronic acid (9.11%), and consisted of Ara, Man, Gal and Glc (molar ratio of 0.39:0.50:0.75:1.00). Furthermore, GE supplementation helped to enhance the immunomodulation in G. lucidum, and it is assumed that neutral polysaccharides play an important role.

Polyphenols in green tea are biologically active and may interact with commonly-consumed over-the-counter (OTC) drugs in the body. In this study, modulation of cytotoxicity of polyphenon 60 (PPE, tea polyphenol mixture) with co-treatment of several OTC drugs, including ibuprofen (Ibu), acetaminophen (AAP), and aspirin was investigated in intestinal cells. PPE showed more potent cytotoxic effects on colon cancer HCT 116 cells than on normal intestinal INT 407 cells. Ibu had the strongest cytotoxic effects on both cell types. Cytotoxicity of PPE on HCT 116 and INT 407 cells was not markedly altered by co-treated OTC drugs. Cytotoxicity of the OTC drugs was not affected by PPE. When HCT 116 cells were incubated with AAP before or after PPE treatment, cytotoxicity was slightly enhanced more than their additive effect. The present study may provide basic information of possible toxicity due to interaction of the polyphenols and the OTC drugs.

Staphylococcus aureus, a major human pathogen, produces a wide array of toxins, which causes various types of disease symptoms. Prevalence of S. aureus in various foods collected during 2006-2008 in Korea was investigated. S. aureus was isolated from 275 of 5,186 (5.3%) food samples collected from hyper-markets in Korea. Seasonal temperature affected the prevalence of S. aureus in various foods with high isolation rate during the summer. Most of the enterotoxigenic strains produced enterotoxin A only or enterotoxin A in combination with another toxin. A total of 54.5% of the tested strains contained either one or more enterotoxin genes and 3.6% possessed a tst gene. This study offers basic information for securing the stability of food during storage and circulation, and provides an epidemiological tool to study the cause, origin and temporal spread of S. aureus food poisoning.

Abstract 서론 재료 및 방법 표준품 및 시약 갈근탕 발효균주 및 발효조건 HPLC 분석 발효에 의한 지표물질의 변화 분석 결과 및 고찰 유산균 발효에 의한 갈근탕의 pH 저하 발효갈근탕의 성분분석 요약 감사의 글 문헌