Earticle

This study was performed to investigate the taste composition and biological activities of cheonggukjang containing Rubus coreanum to improve cheonggukjangs' flavor and consumption. In R. corenum cheonggukjang (RCC), the total content of soluble sugars, including glucose, fructose, maltose, and sucrose, was 1,052.1 mg/100 g. Glutamic acid, phenlylalanine, leucine, cystine, and tyrosine were the major amino acids, and the ratio of sweet to bitter components was higher in RCC than in general cheonggukjang (GC). The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities of the extracts, in decreasing order, were found to be: ethanol extract> water extract> chloroform extract, at all concentrations. The water extract had the highest SOD-like activity (10.2%) at a concentration of 0.5 mg/mL, whereas the chloroform extract showed the highest SOD-like activity (19.1%) at a concentration of 2 mg/mL. The nitrite scavenging ability was higher at pH 1.2 than at pH 3.0 or 6.0, and had a positive correlation with the extract concentration. The chloroform extract had the highest nitrite scavenging ability (84.6%) at a concentration of 2 mg/mL and pH 2.0.

The effects of wasabi stalk on the taste and storage characteristics of baechukimchi were assessed in the final product. Wasabi stalk was added in different ratios: 0, 1, 3, 5, or 7%(w/v) of Chinese cabbage. As the fermentation progressed, the pH of the product dropped. Total acidity increased in all treatments during fermentation. The total vitamin C content increased during the first 8 to 13 days of fermentation. Reducing sugar decreased in all treatment as fermentation continued. The numbers of total cells and lactic acid bacteria increased until they peaked, and then began decreasing as fermentation continued. With regard to acceptability characteristics, the 3% treatment was most favored. With simple regard to the quantitative level of wasabi stalk addition, the 3% treatment was most appropriate under all testing conditions. In conclusion, stalk seems to be an economical and natural additive which has effects on extension of the shelf life of baechukimchi.

Anti-obesity effects of β-cyclodextrin in obese C57BL/6J mice induced by a high fat diet (HD) were observed. The administration of β-cyclodextrin reduced the gain of body weight, abdominal fat, liver weight, the lipid deposits of hepatocytes and the size of adipocytes in the HD group. In serum analysis, the total and low-density lipoprotein-cholesterols were significantly decreased in the β-cyclodextrin-supplemented HD group than in the HD group. However, high-density lipoprotein-cholesterol was not changed in these groups. In hypothalamic homogenates, the decrease of neuropeptide Y and increase of -melanocyte stimulating hormone were detected in the β-cyclodextrin-supplemented HD group compared to that in the HD group. These effects of β-cyclodextrin were similar to those of Garcinia cambogia, which is widely used as a natural anti-obesity product. These results suggest that β-cyclodextrin has anti-obesity effects through the lowering of the abdominal fat pad and inhibits the central effects of hunger.

Sweet potato starch was modified using Thermus aquaticus α-1,4-glucanotransferase (TaaGT), and its structural and rheological properties were investigated. TaaGT-modified starch had a lower amylose level and molecular weight than raw starch. The chain length distribution showed an increased number of short and long branched chains and the formation of cycloamyloses. Compared with raw starch, TaaGT-modified starch displayed a lower gelatinization enthalpy and a wider melting temperature range. The X-ray diffraction of TaaGT-modified starch was a weak V-type pattern with distinct sharp peaks at 13 and 20℃. Scanning electron micrographs of modified starch exhibited big holes on the surface and the loss of granular structure. The frequency sweep measurement revealed that the gel of TaaGT-modified starch was more rigid than raw starch gel. However, the structure of modified starch gel was destroyed by heating at 75℃ , and a firm gel was re-formed by subsequent storage at 5℃, indicating thermoreversible property.

In the present study, chronic effects of the hot water extracts of walnut seed (Juglans regia L.) (WSE) and Nelumbo nucifera seed (NSE) were investigated in mice exposed to 2 hr of restraint stress each day for 4 weeks. Corticosterone levels in serum were significantly increased in the vehicle-treated stressed group (25㎍/dL) compared to that in the control group (13㎍/dL). This stress induced gastric redness and lesions. However, treatment with WSE and/or NSE significantly protected the stomach from this lesion by 50-60% compared to that in the vehicletreated group. In the amygdala, the administration of WSE and/or NSE also reduced the immediate early gene (c-fos) expression by 70-90% vs. the vehicle-treated group. These suggest that WSE and/or NSE may reduce the appearance of symptoms induced by stress and these materials are useful as anti-stress foods, as natural products tend to be relatively safe compared to chemical products.

Elaeocarpus sylvestris var. ellipticus (E.S.), which contains 1, 2, 3, 4, 6-penta-O-galloyl-beta-D-glucose (PGG), is reported to have the ability to scavenge oxygen radicals, thereby protecting rat neuronal cells from oxidative damage. The potential of an E.S. extract, which contains a rich PGG, to protect radiosensitive lymphocytes and intestinal crypt cells from radiation injury induced by a single whole-body irradiation (WBI) in vivo was investigated. Our results demonstrated that in immune cells, E.S. treatment decreased the percent of tail DNA, a parameter of DNA damage, compared with levels in untreated, irradiated controls. Furthermore, apoptosis was significantly decreased in lymphocytes and intestinal crypt cells of E.S.-treated mice compared with irradiated controls. These results suggest that the E.S. extract can strengthen the radioresistance of radiosensitive lymphocytes and crypt cells by preventing apoptosis. Therefore, it was concluded that E.S. extract has the radioprotective effects in vivo through an inhibition of apoptosis.

The effect of gamma irradiation on the prevention of breeding a patulin-producing mold and reducing patulin content was evaluated in an apple model system. Penicillium griseofulvum, a patulin-producing standard mold strain was artificially inoculated into apples and a gamma irradiation was performed. The D10-values of the conidia of P. griseofulvum in an aqueous suspension and the apple model system were calculated at 0.28 and 0.48 kGy, respectively. The viable cell counts of the inoculated conidia in the apples showed 2 decimal point reductions at a dose of 1 kGy. Breeding and growth of the survived conidia was prevented during 10 weeks of post-irradiation storage period, especially at 4℃. The concentration of patulin in the non-irradiated apples was gradually increased and reached about 950 ppm at 25℃ and 410 ppm at 4℃, but the production of patulin was not observed during storage after 1 kGy of gamma irradiation.

New gluten-free food product (tarhana) was produced using rice and com flours. Chemical and sensory properties of the tarhana samples were investigated and compared with those of traditional wheat tarhana. Generally, sensory analysis results indicated that utilization of com and rice flours in tarhana resulted in acceptable soup properties in terms of some of the sensory properties. The changes in electrophoretic properties of the proteins of the tarhana samples were also studied during the tarhana production. Sodium dodecyl sulfate-polyacryamide gel electrophoresis (SDS-PAGE) results showed that relative intensities of some of the protein bands in tarhana samples generally decreased during fermentation. The decrease was more obvious at the larger molecular weight region. Corn and rice tarhana seem to be promising food products for the celiac patients who have limited choice of cereal based foods.

The physicochemical and in vitro physiological properties of soluble dietary fiber (SDF) from wax gourd (Benincasa hispida) pulp and peel were investigated. The pulp was composed of 11.4% SDF and 24.3% insoluble dietary fiber (IDF), while the peel contained 3.2% SDF and 43.3% IDE The predominant sugar in the SDF of the wax gourd pulp and peel was uronic acid, followed by galactose and rhamnose. The SDFs from the wax gourd pulp and peel gave similar elution patterns, with 4 main neutral sugar and uronic acid peaks eluted by 0.4, 0.5, 1, and 2 M ammonium acetate buffer. The pulp SDF had a much higher glucose retardation index (GRI) than the peel SDF for all measurement times. The pulp SDF showed strong growth-inhibiting activity against Escherichia coli and Clostridium perfringens, whereas the peel SDF produced strong growth-promoting activity against Bifidobacterium longum, Bifidobacterium infantis, and Lactobacillus brevis when compared to glucose.

The method of yeast propagation has an influence on yeast physiology, fermentation ability, flocculation rate, and taste stability of beer. In order to find optimal conditions for propagation, several parameters were investigated in combinations. The bottom brewing yeast grown at 10℃ indicated that a higher flocculation capacity during the 1 fermentation. However, the taste stability and the aroma profile were not affected by parameters of propagation investigated. The beer quality was rather affected by storage duration. In addition, a correlation between tasting and chemiluminescence was found at the beer, which was produced using bottom brewing yeast. The propagation at 10-25℃ with addition of zinc ion indicated the best condition to improve fermentation ability, flocculation rate, and filterability for bottom brewing yeast, whereas the propagation at 30℃ with addition of zinc ion showed the best condition to increase fermentation ability for top brewing yeasts.

Anti-inflammatory potential of the enzymatic extract prepared by Kojizyme (ECK), a component of brown seaweeds Ecklonia cava (Alariaceae, Phaeophyta) in vivo was investigated. For the application of mouse ear edema model, 12-O-tetradecanoylphorbol acetate (TPA) was used, a topical inducer of a long-lasting inflammatory response. Our results demonstrated that ECK inhibited ear edema when topically applied to mouse ear skin. In histological evaluation, the inhibition activity of ECK on TPA-induced inflammation is similar to that of dexamethasone, although less strong. In addition, the mRNA expression levels of IL-1β, IFN-γ, TNF-α, and cyclooxygenase-2 (COX2) and the immunoreactivity to inducible nitric oxide synthase (iNOS) and COX2 expressed mainly in inflammatory cells were down-regulated by ECK. These results indicate that ECK has anti-inflammatory effects through the inhibition of Th1 cytokines and 2 inducers of inflammation in TPA-induced ear skin edema.

Texture analysis, sensory evaluation, and scanning electronic microscopic (SEM) observation were conducted to evaluate the effects of different calcium salts (calcium lactate, calcium acetate, and calcium chloride) and vitamin C on the textural properties of kimchi, gamma-irradiated at 25 kGy. Increase of the hardness and sensory score were observed in the kimchi pretreated with calcium salt or vitamin C as compared with the untreated and irradiated kimchi. And the hardness and sensory quality of the co-pretreated sample with 0.01% of calcium lactate and 0.3% of vitamin C were the highest after 30 days at 35℃, which indicates that the co-pretreatment is effective in preventing a decrease of the texture and sensory qualities of kimchi by gamma irradiation. Also, this result was supported by the SEM observation.

The aim of this study was to produce resistant starch preparations from acid-modified com starches prepared at various hydrolysis levels (0.5-4.0 hr). Effect of autoclaving cycles on resistant starch (RS) formation was investigated. Molecular weight distribution, pasting and functional properties of acid-modified com starches were determined. For RS formation native and acid-modified starch samples were gelatinized and autoclaved (1 or 2 cycles). While native and acid-modified starches did not contain any RS, the levels increased to 9.0-13.5% as a result of storage at 95℃ after first autoclaving cycle. Second autoclaving cycle together with storage at 95℃ brought final RS contents of the samples incubated at 4 and 95℃ after the first cycle to comparable level. As acid modification level increased, the amount of high molecular weight fractions decreased, resulting in significant decreases in viscosities (p<0.05). The samples produced in this study had low emulsion stability and capacity values.

Bacillus cereus causes two different types of food poisoning syndromes: diarrhea and emesis. The diarrheal syndrome is attributed to various enterotoxins, including nonhemolytic enterotoxin, hemolytic enterotoxin, and enterotoxin-T, whereas the emetic syndrome is caused by the dodecadepsipeptide toxin cereulide. A multiplex polymerase chain reaction (PCR) assay was developed to rapidly detect and identify B. cereus strains. Three primer pairs specific to regions within genes encoding nonhemolytic enterotoxin (nheA), molecular chaperonin (groEL), and cereulide synthetase (ces) were used to identify and differentiate between the enterotoxin-producing and emetic toxin-producing B. cereus strains. The cereulide-producing emetic B. cereus showed 3 PCR products of 325, 405, and 685 bp for the groEL, ces, and nheA genes, respectively, whereas the enterotoxin-producing B. cereus showed 2 PCR products without a ces gene specific DNA fragment. Specific amplifications and differentiations by multiplex PCR assay were obtained using 62 B. cereus strains and 13 strains' of other bacterial species. The detection limit of this assay for enterotoxin-producing strain and emetic toxin-producing strain from pure cultures were 2.4×10¹ and , 6.0×10² CFU/iube, respectively. These results suggest that our multiplex PCR method may be useful for the rapid detection and differentiation of B. cereus strains in foods.

The proteolytic enzyme from Saccharomyces sp. B101 was purified to homogeneity by ammonium sulfate fractionation, ultrafiltration, diethyl aminoethyl (DEAE)-Sephadex A-50 ion-exchange chromatography, and Sephadex G-100 gel filtration chromatography from the culture supernatant of Saccharomyces sp. B101. The specific activity and the purification fold of the purified enzyme were 4,688.9 unit/mg and 18, respectively. The molecular weight of the purified enzyme was estimated to be 33 kDa by sodium dodecylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The optimum pH and temperature for the enzyme activity were pH 8.5 and 30℃, respectively. The enzyme activity was relatively stable in the pH range of 6.5-8.5 at below 35℃. The salt-tolerance and stability for the enzyme activity were relatively stable even at NaCl concentrations of 10 and 15%. The activity of enzyme was inhibited by Ag²+ and , and Fe²+, activated by Mn²+. In addition, the enzyme activity was potently inhibited by ethylenediaminetetraacetic acid (EDTA) and phenylmethyl sulfonylfluoride (PMSF). Based on these findings we concluded that the purified enzyme was a serine protease. Km and Vmax values for hammastein milk casein were 1.02 mg/mL and 278.38 unit/mL, respectively.

The antioxidative effect of doenjang (fermented soybean paste) and onion added in the seasoned pork, bulgogi was evaluated and the optimum mixture ratio of ingredients in seasoning sauce has been established using mixture experimental design (MED). When the seasoned pork, bulgogi was prepared with soy sauce 12% (control), doenjang 9% (in replacement of soy sauce 9%) added group (DG), and doenjang 9% and onion 33.4% (in replacement of water 33.4%) added group (DOG), and stored at -25℃ for 6 months, the peroxide value (POV) and thiobarbituric acid (TBA) value of control, DO, and DOG were all lower than that of control from the initial stage of storage. The antioxidative effect of seasoned pork was found to increase with the replacement of doenjang in seasoning sauce for pork bulgogi. Moreover, antioxidative effects in DOG increased more synergistically. Therefore, the lipid oxidation stability of pork bulgogi was improved by the addition of doenjang and onion onto the seasoning sauce. The optimum mixture ratio of seasoning sauce for pork bulgogi followed up by the MED was found to be doenjang 7.10%, soy sauce 9.46%, onion 19.72%, and water 42.58% with excellent sensory quality.

Effect of acetylated starches (acetylated rice starch and acetylated tapioca starch) on rheological properties of hot pepper-soybean paste (HPSP) at different mixing ratios of rice flour (RF) and acetylated starch (AS) (10/0, 9/1, 8/2, and 7/3) was evaluated in steady and dynamic shear. All HPSP samples at 25℃ exhibited shear-thinning (n=0.31-0.36) and thixotropic behavior with high yield stresses and their steady flow curves were well described by power law and Casson models. The presence of AS resulted in the decrease in consistency index (K), apparent viscosity (ηa,100), and yield stress (σoc), and their predominant decreases were noticed at higher ratio of RF to AS (7/3 ratio). Arrhenius temperature relationship represents variation with temperature in the range of 5-35℃ with the high determination coefficients (R²=0.97-0.99). Dynamic moduli (G', G", and η*) values of HPSP samples mixed with AS were lower than those of HPSP with no added AS within the experimental range of frequency (0.63-62.8 rad/sec). Steady and dynamic shear rheological properties of HPSP samples seem to be greatly influenced by the presence of acetylated starch.

A major polyphenolic compound extracted from omija (Schisandra chinensis) fruit was structurally identified, and its composition of major nutrients was investigated as well in this study. A dominating high performance liquid chromatography (HPLC) peak of water-extracted anthocyanin represented 94.1% of total absorbable compounds at 520 nm, which was further identified with HPLC-mass spectrometry (MS). As a result, mass-to-charge ratio (m/z) of the predominant anthocyanin was determined to be 727, and it was identical to molecular mass of cyanidin-3-xylosylrutinoside (Cya-3-O-xylrut). This is the first report that colorant of omija is predominantly composed of Cya-3-O-xylrut. Omija fruit contained exclusively 3 types of monosaccharide such as glucosc (0.68 g), galactose (0.01 g), and fructose (0.52 g) per 100 g of fruits. Several organic acids, citric (3.29 g), malic (1.4 g), acetic (0.4 g), and succinic acids (0.36 g) per 100 g of fruits, were detected by high performance anion exchange chromatography (HPAEC) analysis. During the compositional analysis of tree amino acid by HPLC, it was noticed that omija fruit contained substantial amount (0.01 g/100 g of fruits) of γ-amino butyric acid (GABA).

Guar gum and k-carrageenan were investigated as a substitutes for phosphate in pork meat processing. Emulsion-type pork sausages were prepared in which 0.5% phosphate was used for the control, and either k-carrageenan or guar gum were added at levels of 0.1 or 0.5% for comparison. The hydrocolloid compounds significantly enhanced water holding capacity and cooking loss. However, hardness, cohesiveness, and chewiness were not well-maintained when compared to the control; this was attributable to the altered water distribution as well as enhanced water holding capacity of the sausages by the addition of k-carrageenan and guar gum. Furthermore, the phosphate-free sausages had similar storage stability as the phosphate-added sausage. Overall, the results suggest that k-carrageenan or guar gum can be used in place of phosphate in conventional processing to successfully prepare phosphate-tree pork sausages.

This study was performed to determine physicochemical and sensory quality of low-fat pork loaf containing silkworm powder and vegetable worm (Paecilomyces japonica). Total 2% of fat replacer (soy protein isolate:maltodextrin:k-carrageenan:water=1:0.5:0.5:10, w/v) was added. The loaf was separated into CTL (control), T1 (0.2% silkworm powder), T2 (0.2% vegetable worm), T3 (0.4% silkworm powder), T4 (0.4% vegetable worm), T5 (0.1% silkworm powder+0.1% vegetable worm), and T6 (0.2% silkworm powder+0.2% vegetable worm). Pork loaf of T3 showed the highest pH value and cooking loss of pork loaves containing silkworm and vegetable worm was higher than control at day 5. 2-Thiobarbituric acid reactive substances of T2 and T5 showed significantly lower values than control and those additives may reduce lipid oxidation of meat. Overall acceptability was not adversely influenced by silkworm powder and vegetable worm at day 0 and 5. These results indicated that those silkworm powder and vegetable worm could be utilized for pork product industry.

Ginsenosides are responsible for the pharmacological and biological activities of ginseng. In this study, ginsenoside Rh1 and compound K were isolated and purified from fermented ginseng substrate and their anti-allergic effects were assessed in compound 48/80-induced anaphylactic shock model. The fermented ginseng substrate was extracted by methanol and ginsenoside Rh1 and compound K were efficiently purified by preparative high performance liquid chromatography (prep HPLC). Their quality and quantity were analyzed by liquid chromatography-mass spectrometer (LC-MS) and HPLC. Ginsenoside Rh1 showed better anti-allergic effects than compound K in compound 48/80-induced anaphylactic shock model. This study suggested that fermented ginseng extracts with enriched Rh1 may be utilized as a potential biomaterial of functional food for the alleviation of allergic symptoms.

The objective of this study was to determine storage stability and antioxidant effect of T1, ascorbic acid (0.6%); T2, ethanol extracts of Bacillus polyfermenticus (5%); T3, mixture with ascorbic acid (0.3%), and ethanol extracts of B. polyfermenticus (2.5%) during the storage period. The pH of sausage decreased constantly during storage (p<0.05). Thiobarbituric acid reaction substance (TBA) values were lower in all treated samples compared to the control (p<0.05). Longer storage periods resulted in higher TBA values (p<0.05). Volatile basic nitrogen (VBN) value in T1, T2, and T3 were significantly lower than control (p<0.05). The L* value of T1, T2, and T3 had higher than control. The a* value of T2 was significantly lower than control, T1, and T3 during storage period (p<0.05). The b* value of T2 had significantly higher compared to the other sausage samples during storage period (p<0.05). Total microbial counts in the sausages samples significantly increased as storage period increased (p<0.05). Further studies are needed to develop various meat products to extend the storage stability using B. polyfermenticus SCD.

Com and rice starches were physically modified by planetary mill. While native starches showed high peak viscosities (1,001 and 563 cp), it decreased largely (42 and 20 cp for rice and com starch, respectively) after 2 hr of physical modification. When two starches were co-ground, peak viscosities decreased more largely than single ground one only in 30 min, indicating the pasting properties could be easily changed by co-grinding. Especially, the higher the amount of com starch, the viscosity decreased more largely, which means that paste stability could be controlled also by changing the ratio of com and rice starch. Mean particle size increased with physical modification time since particles became spread because of shear force. There were also changes in surface morphology after physical modification. Fluid property, such as mean time to avalanche (MTA), was improved (from 6.16±0.47 and 8.37±1.23 sec to 5.47±0.78 and 5.26±1.37 sec for rice and com starch, respectively) by physical modification. Pasting property, such as swelling power, was also improved by physical modification. These mean that native starches can be applied to both conventional powder and new paste-food industry more efficiently by physical modification.

Mercury and methylmercury concentrations were measured in 225 marine fish samples purchased from retail markets in 5 major Korean cities in 2005. The results showed that the concentrations of mercury and methylmercury ranged from 0.006-0.455 (mean=0.054±0.025) mg/kg and 0.004-0.120 (mean=0.021±0.008) mg/kg, respectively, in fish caught from the coastal waters of the Korean Peninsula. The concentrations in deep-sea fish including tuna ranged from 0.066-2.315 (mean=0.095±0.640) mg/kg for mercury and 0.027-0.897 (mean=0.281±0.182) mg/kg for methylmercury. The estimated weekly intakes (EWIs) of mercury and methylmercury reached 3.92 and 4.70% of the provisional tolerable weekly intakes (PTWI), respectively. Consequently, the levels of mercury and methylmercury in marine fish from current retail markets do not pose any significant health risks for Koreans.

Effect of various temperatures on enterotoxin production of Bacillus cereus 4 different cereal grains (brown rice, glutinous rice, barley, and Job's tear) was studied. When B. cereus was inoculated to 4 grains, no toxin was detected within 24 hr at 20 and 25℃ although the population reached approximately 8-10 log CFU/g. However, enterotoxin was detected in all samples above 30℃. When the temperature was increased to 35℃, toxin production was observed in the range of 6.11 and 6.26 log CFU/g on brown rice and glutinous rice, respectively. At 40℃, toxin production was detected after 6 hr with the lowest bacterial population of 5.32 and 5.04 log CFU/g, whereas enterotoxin was produced in the range of 6.86 and 7.77 log CFU/g on barley and Job's tear at 40℃. Different types of food affected enterotoxin production of B. cereus. These results suggest that enterotoxin production was more significantly regulated in incubation temperatures than the number of B. cereus.

A multiplex polymerase chain reaction (PCR) method was developed to simultaneously detect 4 varieties of genetically modified (GM) cotton. The event-specific primers were used to distinguish the 4 varieties of GM cotton (MON1445, MON15985, MON88913, and LLcotton25) using multiplex PCR. The acyl carrier protein 1 (Acp1) gene was used as an endogenous reference gene of cotton in the PCR detection. The primer pair Acp1-AF/AR containing a 99 bp amplicon was used to amplify the Acp1 gene and no amplified product was observed in any of the 13 different plants used as templates. This multiplex PCR method allowed for the detection of event-specific targets in a genomic DNA mixture of up to 1% GM cotton containing MON1445, MON15985, MON88913, and LLcotton25.

Size effects of rice product powders on physical properties including suspension stability were investigated in this study. Endosperm, bran, and husk powders of rice with different size particles were prepared using the pin crusher or the ultrafine air mill. The physical properties of the powders were examined using particle size analysis, scanning electron microscopy, and spectrophotometry. The peak of the volume-weighted particle distribution of ultrafine endosperm particles was at 5.4㎛ whereas those of the bran and the husk appeared at 65 and 35㎛, respectively. Ultrafine particles of the endosperm and the husks dispersed better than larger-sized particles. As time elapsed, the dispersibility decreased, but the ultrafine particles were precipitated at the slowest rate. Our results suggest that ultrafine particles, including future nanosized particles, provide improved solubility and dispersibility resulting in better stability in the food colloidal suspension.

The mutagenicity after heating of different sugars (glucose, fructose, galactose, and tagatose) on the non-enzymatic browning reaction in different sugars and glycine model system was investigated. The model system containing 0.2 M glycine and 0.2 M of different sugars in 10 mL water was heated at 150±5℃ for 30 min. After heating, degree of non-browning reaction intensity and mutagenicity using Salmonella typhimurium TA 98 were examined. Heated glycine model systems containing different sugars increased their mutgenicity ranged from 30 to 372 revertant colonies. After heating for 40 min, mutagenicity was achieved with glycine model systems containing 4 different sugars with by 145, 356, 206, and 369 revertants per plate, respectively. The glycine model systems containing fructose or tagatose were significantly (p<0.05) higher mutagenic activity than glycine model systems containing glucose or galactose after 40 min of heating. The linear regression between Maillard reaction intensity and mutagenic activities (slope=32.38, R²=0.93) indicates that mutagenicity could be fully ascribed to Maillard reaction products.

This study was carried out to investigate the bactericidal efficacy of concentration (0.1, 0.2, and 0.4 ppm) and exposure time (10 and 30 min) of ozone on bacterial reduction rate of Salmonella typhimurium KCTC 2541 and Staphylococcus aureus ATCC 13515 in the distilled water (DW), and DW supplemented with 0.2% soluble starch (SS), and metal ion (MC) using argentums (Ag) and copper (Cu). The significant bactericidal differences of S. aureus were showed in the treatments of DW and SS, respectively, at the concentration of ozone above 0.1 ppm for 10 min, comparing the respective initial bacterial counts. The bacterial reduction of S. aureus was more sensitive than that of S. typhimurum at the same concentration of ozone. The bacterial reduction rate of SS treatment was slightly lower than that of DW treatment at the same concentration of ozone (p<0.05), however, the bacterial reduction rate of strains improved in the MC treatment compared to the DW treatment at the same concentration of ozone.

This study employed high performance liquid chromatography (HPLC) coupled to an on-line ABTS+ radical scavenging detection (RSD) system along with HPLC-electro spin impact/mass spectrometry (ESI/MS), to rapidly determine and identify antioxidant compounds occurring in blueberry extract. The extract was separated by HPLC, and then the radical scavenging activities of the separated compounds were evaluated by the on-line coupled ABTS+-RSD system. The negative peaks of the ABTS+-RSD system, which indicates the presence of antioxidant activity, were monitored by measuring the decrease in absorbance at 734 nm. The active components in the blueberry extract were identified by HPLC-ESI/MS using their MS spectra and retention times. According to the data acquired from the on-line HPLC-ABTS+-based assay and HPLC-ESI/MS systems, the antioxidant compounds detected in the blueberry extract were identified as chlorogenic acid and 11 anthocyanins.