Earticle

Pectin was enzymatically extracted from industrial lemon pomace by using an endo-polygalacturonase from Aspergillus niger as a processing aid and compared to pectin extraction by hot hydrochloric acid. The yield of pectin was 17.6 and 20.2% with enzymatic and acidic treatments, respectively. The molecular weight distribution did not vary greatly between the samples extracted with enzyme or acid. Large differences in charge density were observed, however, when the samples were analyzed by anionic-exchange chromatography. Pectin extracted by the enzymatic treatment indicated higher charge density than that obtained by hydrochloric acid. The higher charge density could due to the presence of endogenous lemon pectinesterase, which was activated at low pH 4.5 in situ conditions during the process of enzymatic extraction, leading to low methoxylated pectin with a higher charge density.

Soy sauce was fermented at 20℃ for 100 days in onggi containers (ethnic Korean earthenware) which had been fabricated using three different glazing treatments: unglazed, glazed only on the outside, and glazed on both surfaces. The changes in microstructure and permeability characteristics of onggi containers were examined after fermentation of soy sauce. The effect of repeated use of onggi containers on the fermentation was analyzed by the contact between an aqueous model solution and the onggi containers used once for soy sauce fermentation. The levels of reducing sugar and free amino acids produced from the dissolved starch and protein, respectively, in the solution were compared between the new and reused onggi containers. The moisture permeance and gas permeabilities of the onggi jars were progressively reduced with continuing use for soy sauce fermentation, probably due to clogging of micropores by solid materials. After having been used once for fermentation, the microbial cells and/or enzymes immobilized on the surface or in the micropores of the onggi containers seemed to contribute to accelerating the hydrolytic reactions of starch and protein.

The effect of enzymatically hydrolyzed vital wheat gluten (EHG) on dough mixing and the baking quality of wheat flour frozen dough was examined. Three different proteases, pepsin, trypsin, and chymotrypsin, were tested individually, sequentially paired, or in combination of all three enzymes. Addition of 1% EHG produced no observable effect on the mixing properties of wheat flour dough. However, addition of 2.5% pepsin-hydrolyzed gluten decreased the mixing tolerance of the wheat flour, and 1% trypsin-hydrolyzed gluten increased the loaf volume of both frozen and non-frozen dough. This finding suggests that trypsin-hydrolyzed vital wheat gluten may serve as a baking additive in replacement for KBrO3 to improve frozen dough quality.

Polyphenol oxidase (PPO) was isolated from the flesh of Fuji apples by DEAE-Cellulose, ammonium sulfate precipitation, phenyl-Sepharose CL-4B, and Sephdex G-100 chromatography. The molecular mass of the purified PPO was estimated to be 40 kDa by SDS polyacrylamide gel electrophoresis. With regard to substrate specificity, maximum activity was achieved with chlorogenic acid as substrate, followed by catechin and catechol whereas, there was no detectable activity with hydroquinic acid, resorcinol, or tyrosine as substrate. The optimum pH and temperature with catechol as substrate were 6.5 and 35℃, respectively. The enzyme was most stable at pH 6.0 and unstable at acidic pH. The enzyme was stable when it was heated to 45℃ but heating at 50℃ for more than 30 min caused 50% loss of activity. Reduced ZnSO4, L-cystein, epigallocatechin-3-o-gallate (EGCG), and gallocatechin gallate (GCG) also inhibited activity.

The tocopherol and tocotrienol contents of 39 vegetable oils, margarines, butters, and peanut butters typically consumed in the Korea diet were determined by direct solvent extraction method followed by normal phase liquid chromatography. All samples were locally obtained in the Cheongju area in 2003 and 2004. The study examined data on 19 vegetable oils, 10 margarines, 6 butters, and 4 peanut butters. r-Tocopherol (r-T) and -tocopherol (r-T) were detectable in all products except butters and were usually present in the vitamin E form in greater quantity than the other isomers. Usually, r-T content was higher than r-T content in many samples. Tocotrienols were measurable in some samples but usually at levels less than the corresponding tocopherols. Three analytical method validation parameters, accuracy, precision, and specificity, were calculated to ensure the method's validity and were all confirmed to be reliable and satisfactory.

A study was conducted to develop optimal conditions for a large-scale, sequential separation method for value-added components from egg yolk. Starting with liquid egg yolk, immunoglobulin Y (IgY), phospholipids, and neutral lipids were extracted sequentially using water, ethanol, and n-hexane. The remainder was yolk proteins. Adjusting the pH of diluted egg yolk to pH 5.0-5.2 decreased phospholipids content in the supernatant after centrifugation, which was very important for preventing clogging problem of ultrafiltration filters during the subsequent concentration step for IgY separation. Extraction of precipitants after centrifugation with four volumes of 100% ethanol once removed most of the phospholipids and the purity of phospholipids was more than 85% (wt.) after drying. The subsequent extraction of precipitant from ethanol extraction with four volumes of hexane 3 times removed neutral lipids almost completely and resulted in a high protein product with minimal lipids. The sequential separation method is considered to be advantageous for large-scale separations of many valuable components from egg yolk.

Freeze concentration of milk was carried out thorough the controlled recrystallization of ice in a multi-stage freeze concentrator. Artificial temperature control was used to induce ice recrystallization via a heat and cold shock process. In each stage of freeze concentration, the recrystallization time was fixed at 1, 2, 4, and 8 hr to compare the solute concentrate, yield, Brix, ice crystal size, and freezing point at each experimental condition. Higher concentrations of milk solids were seen with increased durations of recrystallization time, and a maximum total solids in the final product of 32.7% was obtained with a ripening time of 8 hr in a second stage process. Milk solid yield decreased according to the solute concentration and recrystallization time. The results of Brix and ice crystal size showed a positive correlation with recrystallizaiton time. These results suggest the possibility of freeze concentration being of practical use in the dairy industry.

The oxidation stability of fish oil containing omega-3 polyunsaturated fatty acids (PUFAs), which is very susceptible to oxidative deterioration, needs to be improved before it can be successfully applied to functional foods. The antioxidant activities of 17 species of materials in anchovy oil (AO) were compared and a potent antioxidant was determined to improve the shelf-life of refined AO. Antioxidant activities of the 0.05% (w/w) materials in AO were compared against control during storage at for 10 days. While no antioxidant effect was shown in alpha tocopherol against control, 3 species of grapefruit seed extracts (GSEs), astaxanthin (AX), soybean lecithin, and green tea extract showed good antioxidant activities. Especially, GSE B, GSE C, and AX showed significantly high peroxide inhibitory activities (PIAs) of 16.2±2.1, 20±3.5, and 17.7±3.5%, respectively, after the 4th day (p<0.01). Radical scavenging activities (RSAs) of GSE B, GSE C, and AX were85.1±0.8 ,95.3±0.3, and 85.9±0.8%, respectively. Correlation between PIAs and RSAs was high (R2=0.926) in GSE B, GSE C, and AX. Therefore, we concluded that one of the main antioxidative mechanisms of GSEs and AX must operate through an RSA pathway. The RC50 (concentration required for 50% reduction of 1,1-diphenyl-2-picryl-hydrazyl, DPPH) of GSE C was 258 ug/mL.

The effects of gellan gum (from S. paucimobilis), EPS-CB (exopolysaccharide from S. chungbukensis), and a series of commercial gums (arabic gum, xanthan gum, guar gum, deacyl gellan gum), on the swelling, rheological, and pasting properties of non-waxy rice flour dispersions were investigated. The swelling properties of rice flours in gellan or guar gum dispersion after heating were found to have increased with increasing gum concentrations, but the swelling properties of rice flour/other gum systems decreased with increasing concentrations. The rice flour/gum mixtures showed high shear-thinning flow behavior (n=0.14-0.32), and consistency index (K) was higher in guar gum than other gum dispersions. The initial pasting temperatures and peak times increased along with increasing gum concentration. The peak viscosity of rice flour increased in guar gum and deacyl gellan dispersions, and the breakdown and setback viscosity of the rice flour paste was lowest in the xanthan gum system, but remained higher than those of the control. The apparent viscosities of the rice flour/gellan gum mixture pastes were the highest among the tested combinations.

A bacterial strain, initially identified as B1-3, was isolated from cheonggukjang, a traditional Korean dish made from fermented soybeans. Using the Biolog system and 16S rRNA sequence analysis, we identified B1-3 as Bacillus mojavensis. We manufactured a quickly fermented soybean (QFS) food product using the B. mojavensis, and guided by their 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging ability. We isolated substances with antioxidative activity from it. Using mass spectrometry (MS) and nuclear magnetic resonance (NMR) techniques, we isolated 4 compounds from the ethyl acetate (EtOAc)-soluble neutral fraction of methyl alcohol (MeOH) extracts of the QFS food product (genistein, daidzein, 3R,4R-3-methyl-3,4-dihydroxy-2-pentanone, and 3S,4R-3-methyl-3,4-dihydroxy-2-pentanone) and 3 compounds from its acidic fraction (4-hydroxyphenylacetic acid, genistin, and daidzein). Two compounds from the neutral fraction (3R,4R-3-methyl-3,4-dihydroxy-2-pentanone and 3S,4R-3-methyl-3,4-dihydroxy-2-pentanone) were not detected in nonfermented soybeans (NFS) or in the filtrate of the LB broth used to culture B. mojavensis. However, they were detected in the filtrate of the same broth when it contained 2% glucose. These results suggest that these 2 compounds were derived from glucose (or other saccharides) in the soybean during fermentation. One compound that was found in the acidic fraction (4-hydroxyphenylacetic acid) was readily detected in NFS, but not in the culture broth. This suggests that 4-hydroxyphenylacetic acid was derived from NFS. We concluded that the antioxidative activity of cheonggukjang is a result of the interactions between soybean components and the microorganisms used in the fermentation of cheonggukjang.

Component having antioxidant activity on lard during heating was separated from hexane extract of spinach, and its characteristic chemical structure was speculated through nuclear magnetic resonance spectroscopy, liquid chromatography-mass spectrometry, and Fourier transform infrared spectrophotometry. Lard was heated with hexane-, ethyl ether-, ethyl acetate-, or ethanol extract of spinach at 180℃ for 20 hr. Hexane extract of spinach, having highest antioxidant activity on lard during heating, was fractionated by silicic acid column chromatography (SACC), and SACC fractions having higher antioxidant activity on lard during heating were further separated by thin layer chromatography (TLC). Isolated compound from SACC fractions of hexane extract of spinach by TLC had sugar moieties and benzene ring along with hydroxy, carbonyl, and alkyl groups in the structure.

Strain NK181 was isolated for probiotic use from jeotkal and based on results of API 50 CHL kit and 16S rDNA sequencing was tentatively named Lactobacillus plantarum NK181. L. plantarum NK181 was highly resistant to artificial gastric juice (pH 2.5) and bile acid and demonstrated strong adherence to Caco-2 cells. In test using API ZYM kit, eight enzymes were produced. Supernatant of L. plantarum NK181 exhibited about 30% 1,1-diphenyl-2-picyryl hedrazyl (DPPH) radical-scavenging activity and reduced cholesterol by 70%. These results demonstrate potential use of L. plantarum NK181 as health-promoting probiotic.

Bacillus cereus group comprising B. cereus, B. thuringiensis, and B. mycoides was differentiated by polymerase chain reaction (PCR) and colony morphology. Prevalence of B. cereus group in rice and distribution of enterotoxin genes were determined as possible food poisoning agents. PCR using primers targeted for gyrB and cry genes could distinguish B. thuringiensis from B. cereus, and B. mycoides was differentiated by rhizoid morphological characteristics on nutrient agar. Among 136 rice and their processed products, prevalence of B. cereus group was 40%. B. cereus group consisted of 54 B. cereus, 11 B. thuringiensis, and 1 B. mycoides. Major isolates were B. cereus, with B. thuringiensis detected up to 10% among edible rice tested. Five enterotoxin genes, hbl, nhe, bceT, entFM, and cytK, were broadly distributed among B. cereus group, especially in B. cereus and B. thuringiensis. Prevalence of B. cereus group in rice and enterotoxin distribution suggest B. thuringiensis and B. cereus are toxigenic strain that should be controlled in rice and its products.

The methanol extract of waxy brown rice fermented with Agrocybe cylindracea was prepared. The extract was then freeze dried and fed to rats at the level of 0.5, 1.0, 2.0 g/kg body weight for 14 days, followed by the treatment with carbon tetrachloride for three consecutive days to induce hepatotoxicity. After sacrificing the rats, the enzyme activity of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), and r-glutamyl transpeptidase (r-GTP) in serum was determined. Biochemical analysis on serum for albumin, total protein, triglyceride, and total as well as HDL-cholesterol were carried out along with a histopathological study of liver tissues. Based on these data, we suggest that the waxy brown rice cultured with A. cylindracea may exert hepatoprotective activity against hepatotoxicity caused by chemicals such as carbon tetrachloride.

Neuronal cell death significantly contributes to neuronal loss in neurological injury and disease. Typically, neuronal loss or destruction upon exposure to neurotoxins, oxidative stress, or DNA damage causes neurodegenerative diseases such as Alzheimer's disease. In this study, we attempted to determine whether ginsenoside Rg3 from red ginseng has a neuroprotective effect via an anti-apoptotic role induced by S-nitroso-N-acetylpenicillamine (SNAP) at the molecular level. We also investigated the antioxidant effect of Rg3 using a metal-catalyzed reaction with Cu2+/H2O2. Our results showed that Rg3 (40-100 ug/mL) protected SK-N-MC neuroblastoma cells under cytotoxic conditions and effectively protected DNA from fragmentation. In the signal pathway, caspase-3, and poly (ADP-ribose) polymerase (PARP) were kept at an inactivated status when pretreated with Rg3 in all ranges. In particular, the important upstream p-Akt signal pathway was increased in a dose-dependent manner, which indicates that Rg3 may contribute to cell survival. We also found that oxidative stress can be mitigated by Rg3. Therefore, we have concluded that Rg3 plays a certain role in neurodegenerative pathogenesis via an anti apoptotic, antioxidative effect.

This study examined the effects of vacuum packaging and modified atmosphere packaging (MAP) on the meat quality of a-tocopherol supplemented broiler chicks after prolonged refrigeration. The supplemented -tocopherol levels had no effect on the body weight and feed efficiency. The dietary treatments and packaging methods had no significant effects on the level of microbial growth, lightness, and the metmyoglobin content. The vacuum packaging showed the highest level of purge loss. The broilers supplemented with either 200 or 400 IU of -tocopherol had a lower level of malondialdehyde than the control group. The vacuum packaged meats from chicks fed the control diet showed the highest levels of lipid oxidation. The lipid oxidative stability was most improved in modified atmosphere (20% CO2 + 80% N2) packaged breast meat from the broilers supplemented with either 200 or 400 IU of a-tocopheryl acetate.

Milling qualities and indigestible carbohydrate fractions (ICF) depending on harvesting time of Goami2 (G2), mutant of Ilpum (IP) rice, was examined. Fifty days after heading (DAH) maximized head rice milling quality (57.69%) and ICF content (5.09±0.36 g/100 g). ICF contents and physical properties of G2 and IP at 50 DAH were compared. ICF of G2 was three times higher than that of IP (1.61±0.09 g/100 g). Parboiling treatment increased ICF of G2 to 7.18±0.16 g/100 g. G2 showed lower water absorption index, which could lower pasting properties, but higher water solubility index, implying it contains more soluble components. Texture properties of G2 were different from those of IP, showing higher hardness, and lower adhesiveness and cohesiveness. Positive correlation was observed between ICF and hardness, but reverse correlation between ICF and cohesiveness.

In this study, we investigated the antimicrobial effect of 14 different herbal petal extracts on various foodborne and food spoilage bacteria. Herbal petal extracts were prepared with 70% ethanol followed by sequential hexane, chloroform, ethyl acetate, n-butanol, and water fractionation. Antimicrobial activity was highest in the ethanol fraction from roselle (Hibiscus sabdariffa L.) petals as determined by the paper disc method. The roselle ethanol extract retarded the growth of food spoilage bacteria in kimbap (rice rolled in dried laver). Foodborne microorganisms (e.g. Bacillus cereus and Clostridium perfringens), on the other hand, were most efficiently inhibited by the ethyl acetate fraction of the roselle petal extract as determined by growth inhibition curves. Our study shows that roselle petals harbor antimicrobial activity against foodborne and food spoilage microorganisms. The critical ingredient is highly enriched in the ethyl acetate fraction of the extract.

Basic rheological data of dandelion leaf concentrates were determined to predict processing aptitude and usefulness of dandelion leaf concentrates as functional food materials. Hot water and 70% ethanol extracts of dandelion leaves were concentrated at 5, 20, and 50 Brix, and their static and dynamic viscosities, and Arrhenius plots were investigated. Most concentrated dandelion leaves extracted with hot water and 70% ethanol showed flow behaviors close to Newtonian fluid based on power law model evaluation. Apparent viscosity of concentrated dandelion leaves extracted with hot water and 70% ethanol decreased with increasing temperature. Yield stresses of concentrated dandelion leaves extracted with hot water and 70% ethanol by Herschel-Bulkley model application were 0.020-0.641 and 0.017-0.079 Pa, respectively. Activation energies of concentrated dandelion leaves extracted with hot water and 70% ethanol were 2.102-32.669 x 103 and 1.657-5.382 x 103 J/molㆍkg with increasing concentration, respectively. Loss modulus (G") predominated over storage modulus (G') at all applied frequencies, showing typical flow behavior of low molecular solution. G' and G" of concentrated dandelion leaves extracted with hot water slowly increased with increasing frequency compared to those of concentrated dandelion leaves extracted with 70% ethanol.

We evaluated the effects of extracts of Tsunokaori tangor peel on lipopolysaccharide (LPS)-induced nitric oxide (NO) and prostaglandin ?2(PG?2) in RAW 264.7 cells. The ethyl acetate fraction of Tsunokaori tangor peel (EA-TTP) markedly inhibited the production of NO and PG?2 in LPS-stimulated RAW 264.7 cells. Consistent with these findings, the expression levels of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) proteins were down-regulated in a dose-dependent manner. Additionally, EA-TTP decreased the expression iNOS mRNA but not COX-2 mRNA. To determine the upstream signaling mechanism for the down-regulation of LPS-induced iNOS expression, we investigated the effect of EA-TTP on the degradation and re-synthesis of IxBa. EA-TTP dose-dependently delayed IxBa degradation and increased IxBa re-appearance following degradation, suggesting this as the mechanism by which EA-TTP suppressed iNOS gene expression. The EA-TTP also dose-dependently reduced the expression of the cellular stress-response protein heme oxygenase-1, and inhibited the LPS-induced sustained activation of extracellar signal-regulated kinase (ERK).

The aim of this study was to investigate the anti-inflammatory and anti-oxidant activity of Ligularia fischeri leaf extract on adjuvant induced arthritis in experimental mice. The oral administration of the L. fischeri leaf extract (LF), at doses of 100 and 200 mg/kg body weight once a day for 3 weeks, significantly reduced hindpaw swelling and the production of inflammatory cytokines (tumor necrosis factor(TNF)-a, interleukin(IL)-1B, and IL-6). Treatment with LF (100 mg/kg) also decreased the serum levels of triglyceride and low density lipoprotein(LDL)-cholesterol, and increased high density lipoprotein(HDL)-cholesterol contents compared with those of a control group. The induction of arthritis significantly increased oxidized proteins such as protein carbonyl, advanced oxidation protein products, and advanced glycation end-products in the lung, heart, and brain. Treatment with LF for 3 weeks reduced the levels of oxidized proteins. These results suggest that L. fischeri extract might be beneficial in the treatment of chronic inflammatory disorders.

Antioxidative ability of anthocyanins in water-in-oil microemulsion was examined. Microemulsion was prepared by solubilizing crude anthocyanins extracted from grape skin (Cambell early) in organic solvent (hexane) containing anionic surfactant [bis (2-ethylhexyl) sodium sulfosuccinate, AOT] and linolenic acid (10%, w/v). Lipid oxidation significantly decreased with increasing concentration of anthocyanins (5-20 uM) at micellar phase, and increasing micelle size (Wo=5-20 uM). At given micelle size (Wo=10), lipid oxidation decreased as number of micelles decreased. These results indicate antioxidative ability of anthocyanins is critically affected by water core and micelle structure formed by surfactant. Interactions between AOT and anthocyanins decreased antioxidative ability of anthocyanins. Antioxidative ability of anthocyanins significantly increased when -tocopherol was added into organic phase. This indicates of synergism between the two antioxidants.

In this study we examined the changes in weight and dimension, protein and amylose contents, and pasting properties of brown rice flour, as well as the gelatinization properties of starch, from two non-waxy japonica cultivars and one waxy japonica cultivar planted in an experimental field in 2002 under the same fertilizer conditions. The weight of both rough and brown rice increased consistently up to 42 days after flowering (DAF) for the non-waxy rice and to 35 DAF for the waxy rice. The changes in dimension of the brown rice kernel indicated that the length was maximized first, followed by breadth and then thickness. The protein content of the non-waxy rice remained fairly constant, but that of the waxy rice decreased by about 1% after 14 DAF. The amylose content of the non-waxy brown rice flour increased, but that of the waxy brown rice flour decreased during kernel development. As the kernel developed, the peak viscosity of the non-waxy rice flour increased up to 35 DAF, after which it decreased, whereas that of the waxy brown rice flour increased consistently. The gelatinization temperature of starch also increased in the waxy rice during kernel development up to 21 DAF. The gelatinization enthalpy of starch, however, increased in all rice cultivars throughout the kernel development.

Kochujang was fermented using hot red pepper, meju prepared with soybean and rice, and malt-digested syrup. To reduce salt content, mustard powder (1.2%, w/w) was added to Korean traditional kochujang with 4-10% salt, and microbial characteristics, enzyme activities, and gas formation in kochujang were evaluated during fermentation for 120 days at 25℃. Yeast numbers of all treatments maintained 2.43-2.86 log CFU/g up to 60 days fermentation, indicating salt concentration had no effect on yeast count. Activities of a- and B-amylases, and neutral and acidic proteases of kochujang added with mustard powder were slightly higher than those of control group. Total accumulative volume of gas produced during fermentation of kochujang without mustard powder (control group) was 5,892 mL/pack, but decreased to 34-99 mL/pack in low-salted kochujang (4 and 6% salt) added with mustard powder. Major gas produced was carbon dioxide (79-80%) with oxygen content less than 1.25%(v/v). Results indicate salt concentration of kochujang could be lowered up to 6-8% by addition of mustard powder without gas formation and quality alteration during distribution.

Effect of Oenanthe javanica ethanol extract (OJE) on nuclear factor-xB (NF-xB)-mediated inflammatory reaction in RAW 264.7 macrophage cells was investigated. The OJE dose-dependently inhibited secretions of tumor necrosis factor-a (TNF-a) and prostaglandins ?2 (PG?2) from lipopolysaccharide (LPS)-stimulated RAW 264.7 cells and blocked LPS-induced expression of cyclooxygenase-2. To clarify mechanistic basis for its inhibitions of NF-xB and activator protein-1 (AP-1) activations, effects of OJE on activations of NF-xB and AP-1 genes by luciferase reporter activity were examined. The LPS-stimulated activations of NF-xB and AP-1 were significantly blocked by 400 and $600 u$g/mL of OJE, implicating that OJE might regulate gene expression through more than one signaling pathway. Cytosolic degradation of I-xBa was inhibited by OJE dose-dependently, indicating that the nuclear translocation of p65 was inhibited by OJE. These findings suggest that the inhibition of LPS-stimulated COX-2 expression by OJE is due to its inhibition of NF-xB activation by blocking I-xBa degradation, which may be mechanistic basis of anti-inflammatory effects of OJE.

Saesongi (Pleurotus eryngii) was cultivated in both potato dextrose agar (PDA) and sawdust media supplemented with Ca salts. The addition of Ca phosphate and Ca carbonate to sawdust media did not affect the growth, whereas Ca sulfate addition suppressed the mycelial growth appreciably. The efficiencies of Ca accumulation in the fruiting were studied based on mycelial growth experiments on Ca-supplemented sawdust media. Supplementation with 0.1 to 5% Ca phosphate increased the Ca content in the fruiting body by 4.5-6.5 fold, to a level of 314±22.7 to 449.7±29.3.

Crude extract of young dangyuja (Citrus grandis Osbeck) fruit was investigated for its antioxidant activity as measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity. Among the samples, including 4 Citrus species and various solvent-extracted-fractions of young dangyuja fruit, the water-extracted fraction (WF) and butanol-extracted fraction (BF) showed the greatest DPPH free radical scavenging activity. WF and BF were further examined for their antioxidant activities by three different in vitro assays. The cell viability tests using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction assay showed that both fractions significantly reduced H2O2-induced cytotoxicity in HepG2 cells dose-dependently. Generation of the reactive oxygen species (ROS) was also reduced in cells pretreated with both fractions. In addition, BF showed a higher level of lipid peroxidation inhibitory capacity than WF in H2O2-treated HepG2 cells. Taken together, these results indicate that young dangyuja fruit can be used as an easily accessible source of natural antioxidants.

Octadeca-9,12-dienyl-3,4,5-hydroxybenzoate (GA-LA) was chemically synthesized from gallic acid and linoleic acid ester, and its biological functions were tested. Radical-scavenging activity of GA-LA was comparable to those of gallic and ascorbic acids at 0.24 mM, and tyrosinase inhibition effect was higher than that of ascorbic acid. Gallic and linoleic acids did not show any tyrosinase activity. Results of cyclooxygenase (COX) inhibition effect indicate GA-LA has higher selectivity in COX-1 inhibition. GA-LA from gallic and linoleic acids could be used as functional reagent for antioxidative, skin-whitening, and anti-inflammatory effects in food, pharmaceutrical, and cosmetic industries.

A combination of thymol and sodium bisulfate was found to be an effective biocidal agent against strains of Burkholderia cepacia and of Xanthomonas maltophilia that were found in the space shuttle water system. Potassium iodide (KI), the biocidal agent used in the past, had a minimum inhibitory concentration (MIC) of 50,000 ppm against the two B. cepacia (541 STS-81 and 1119 STS-91) strains, whereas that of thymol and sodium bisulfate was 2,400 and 950 ppm, which was 21 and 53 times lower than that of KI for B. cepacia, respectively. The MIC value for the combination of thymol and sodium bisulfate was 4 times lower than that for thymol or sodium bisulfate alone against B. cepacia (541 STS-81, 1119 STS-91) or Pseudomonas cepacia (ATCC 31941). The fractional inhibitory concentration (FIC) of the combination of thymol and sodium bisulfate for all organisms tested was less than 0.5, indicating a strong synergistic effect.

The food-borne pathogen Listeria monocytogenes is commonly associated with meats and unpasteurized dairy products. To identify this pathogen in meats more efficiently than has been done in the past, we purchased meats from Korean markets and performed sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and serotyping analysis on Listeria organisms isolated from meat samples. Each Listeria species showed specific protein band patterns on SDS-PAGE. Whole-cell protein SDS-PAGE profiles indicated that the organisms isolated from meats sold in local Korean markets were L. monocytogenes with the serotypes 1/2a, 1/2b, 1/2c, and 4b. We suggest that it is possible to carry out molecular subtyping of L. monocytogenes using SDS-PAGE.