Earticle

To revise the dithiocarbamates residue analysis method and survey the residues in agricultural products that were treated with these fungicides in Korea, we purchased 20 types of foodstuffs (rice, potato, cabbage, apple etc.) from markets in five major cities. 236 samples of the purchased foodstuffs were then analyzed for the presence of dithiocarbamates by HPLC/UV and HPLC/APCI-MS. The R2, LOD and LOQ in the range of 0.5-107.3 mg/L were as follows: DCC: y=174.34x+18.315, R2=0.9999, 0.01 mg/L, and 0.04 mg/L; EBDC: y=227.38x−14.715, R2=1.0000, 0.01 mg/L and 0.02 mg/L; PBDC: y=38.46x−21.412, R2=0.9999, 0.04 mg/L, and 0.1 mg/L; ETU: y=52.752x−4.4819, R2=0.9−998, 0.02 mg/L and 0.03 mg/L; PTU: y=128.28x+4.4624, R2=0.9998, 0.02 mg/L, and 0.04 mg/L. The levels of DDC, EBDC, PBDC, ETU and PTU in 20 agricultural products fortified to 10.0-107.3 mg/L ranged from 61.7-117.5%, 65.3-110.1%, 61.5-109.6%, 69.3-116.3% and 70.2-97.2%, respectively. Overall, dithiocarbamates were detected in 100 samples and the detection ratio was 42.4%. Among these, only 3 samples (1.3%) of Lycii fructus had residue levels that were above the action limits, while the remaining samples (233 samples) contained levels of dithiocarbamates below the detection limit or below the Korea MRLs (Maximum Residue Limits).

Bisphenol A diglycidyl ether (BADGE) and bisphenol F diglycidyl ether (BFDGE) were obtained by a polymerization reaction of epichlorohydrin (ECH) with bisphenol A (BPA) or bisphenol F (BPF). These compounds are commonly used as monomers or additives such as a polymerization stabilizer and a hydrochloric acid scavenger of epoxy resin, polyvinyl chloride (PVC)-containing organosols and polyester lacquers, that are applied to the internal surface of most canned foods to impart chemical resistance. The unreacted BADGE, BFDGE and their reaction products migrating from epoxy resin, PVC-containing organosol and/or polyester lacquer-based food packaging materials into the foods have recently become an issue of great concern because of increased customer demand for safety. This study was conducted to develop a rapid and sensitive simultaneous analysis method based on HPLC/FLD and HPLC/APCI-mass and to evaluate the concentration of BADGE, BFDGE and their metabolites, BADGE·H2O, BADGE·2H2O, BADGE·HCl, BADGE·2HCl, BADGE·HCl·H2O, BFDGE·H2O, BFDGE·2H2O, BFDGE·HCl, BFDGE·2HCl and BFDGE·HCl·H2O for 133 canned food samples. The method provided a linearity of 0.9997-0.9999, a limit of detection of 0.01-0.13 μg/mL, a limit of quantitation of 0.03-0.44 μg/mL and a recovery (%) of 85.64-118.18. The number of samples containing BADGE, BFDGE or their metabolites were: 28/133 (21.1%), with levels of 0.400-0.888 mg/kg being observed for aqueous foods (19/133) and 0.093-0.506 mg/kg being observed for oily foods (9/133).

Naturally present antioxidants, tocopherols, carotenoids, and phospholipids in the bran and germ oils from Keumkang (K-WBG oil) and Dark Northern Spring wheats (DNS-WBG oil) were determined during storage under 1700 lux light at 5oC by HPLC. Oil oxidation was monitored by peroxide values (POV) and conjugated dienoic acid content. The results showed that antioxidants were degraded during storage of the WBG oils under light, with higher degradation rates for carotenoids and phospholipids in the K-WBG oil compared to the DNS-WBG oil. Light increased oil oxidation and the rate of oxidation was higher in K-WBG oil than in the DNS-WBG oil. There was a high correlation between POV and residual amounts of antioxidants during photo-oxidation, with phospholipids showing the greatest effects on POV. This study suggests that a higher amount and lower degradation rate of phospholipids in the DNS-WBG oil contributed to its higher photo-oxidative stability compared to the K-WBG oil.

Microbial-fermented tea (MFT), which is made by microorganisms through fermentation, is a popular beverage in Asia, especially in the Yunnam province, China. In this study, changes of the chemical constituents and antioxidant activity during the manufacturing process of MFT were investigated. MFT were respectively prepared from fresh leaves of three different tea species (Yabukita, Daecha, and Korean wild cultivar) and a processed green tea (Korean wild cultivar). The color of the tea infusions gradually changed to red and yellow as a function of fermentation time. Total nitrogen and caffeine contents were not significantly changed. Whereas, the chlorophyll, tannin, and total catechins contents gradually decreased. Interestingly, the epicatechin and epigallocatechin contents increased up to 25 days of fermentation and then decreased. Change of the chemical constituents of all samples showed the same patterns. The antioxidant activity of MFT from Daecha and Yabukita slightly decreased as increasing fermentation time. However, the range over which the antioxidant activity of MFT from Korean wild cultivar and green tea were not changed. This research suggests that it may be possible to manufacturing possibility of MFT using Korean wild cultivar and processed green tea.

This study was conducted to monitor aflatoxins in various medicinal herbs, providing available data for the safety of those products. To monitor aflatoxins in medicinal herbs, a total of 400 samples of 40 different herbs were collected in commercial retailers in Seoul, Daejeon, Gwangju, Daegu, and Busan from March to August, 2008. The samples that passed the sensory evaluation were tested for aflatoxins. Aflatoxins in samples were analyzed by HPLCflorescence coupled with photochemical enhancement. Samples were extracted with 70% methanol and then diluted to the appropriate concentration. A refining process was performed using an immunoaffinity column. The analytical method used in this study was validated. The R2 value for aflatoxin B1 was 0.99946, and the detection range was from 0.25 to 10.0 ng/mL. The accuracy of the analysis was ranged from 83.2% to 101.8%. The relative standard deviation (RSD) in the aflatoxin B1 analysis was 3.4%, demonstrating the precision of this method. In addition, the detection limit and quantitative analysis limit of aflatoxin B1 was 0.53 μg/kg and 1.76 μg/kg, respectively. These results indicated that the analytical method used in this study was appropriate. The results of HPLC showed that 1% (4 samples) of the samples may contain aflatoxins. The concentration of quantified aflatoxin was 2.3 μg/kg for both Quisqualis fructus and Remotiflori radix samples. The other samples were below the limit of quantification. Moreover, the concentration of aflatoxin B1 which is made by specific fungi were below the level of regulation. Only 20% of aflatoxin B1 were transferred to hot water. Therefore, the levels of aflatoxins in medicinal herbs were considered to be safe especially considering the aflatoxin transfer ratio.

This study was conducted to compare the physicochemical properties of powdered green teas produced in Korea and Japan including particle size, color, chlorophyll, caffeine and theanine. The average particle size of Korean powered green tea (14.63-25.39 μm) was similar to that of Japanese powdered green tea (15.46-21.02 μm). The surface color of shade-cultivated Haenam Green Tea (HN-1) had the highest negative ‘a’ value, which represents ‘green’ color. When the TCD (total color difference value) was measured in the samples, HN-1 was most similar to the premium powdered green tea of Japan (JA-1). Domestic shade-cultivated powdered green teas had 1.5–2 times greater chlorophyll content than powdered green teas produced from plants that were not cultivated in the shade. The presence of chlorophyll a resulted in a higher intensity of green color than the presence of chlorophyll b. A significant negative correlation was also observed between the color and the chlorophyll a, chlorophyll b and total chlorophyll contents. Specifically, chlorophyll a had the greatest impact on the green color of powdered green tea. The content of catechins, caffeine and theanine in Korean powdered green teas ranged from 14.679-20.128, 1.496-3.237 and 0.926-1.977 g/100 g, respectively. The caffeine and theanine contents were high in shade-cultivated powdered green teas. Based on the above results, domestic powdered green teas cultivated under shaded conditions had a quality similar to that of medium-quality green teas produced in Japan, and the overall quality of Korean powdered green tea was poorer than that of Japanese powdered green tea.

The process of the preparation of branched-chain amino acid (BCAA)-enriched hydrolysates from corn gluten was optimized through the parameters of pre-treatment (heating and cellulosic hydrolysis), hydrolysis method (acid, protease, and microbe plus protease), concentration, and spray drying condition. The protein yield of corn gluten was increased by heating and cellulase treatments. Among three different hydrolysis methods, the combined use of microbes and protease was the most effective in terms of free amino acid (FAA) and BCAA content of the corn gluten hydrolysates. In addition, the FAA and BCAA content in the hydrolysates prepared by microbial and enzymatic combined treatment were improved by a concentration process. Spray drying conditions for the preparation of the powder from the hydrolyzed reactant were an inlet temperature of 185oC, outlet temperature of 80oC, and the use of maltodextrin as an anticaking agent. Thus, this study established an economical process for preparation of value-added hydrolysates of excellent productivity and quality, in terms of high BCAA content and product stability.

To reduce the astringent taste of lotus root, the effects of various treatment methods such as drying, soaking, steaming and roasting on the physicochemical properties and sensory characteristics were investigated. The following process conditions were selected: 1) drying (D), 2) soaking followed by drying (SK→D), 3) steaming followed by drying (ST→D), 4) drying followed by roasting (D→R), 5) soaking and then drying followed by roasting (SK→D→R), 6) steaming and then drying followed by roasting (ST→D→R). The tannin content of the lotus root was lowest when it was treated by steaming followed by drying (ST→D). The astringent taste of lotus root was reduced by steaming, and the roasted taste was improved by roasting in terms of sensory and flavor characteristics. Consequently, lotus root treated by steaming and then drying followed by roasting (ST→D→R) showed the highest preference with respect to astringent and roasted taste.

This study was conducted to investigate the shelf-life and quality of breads made with 0.5, 1 and 2% of Myagropsis myagroides fermented ethanol extracts (MOE). The total microbial count in breads made with 2% MOE decreased to about 1.6 log cycles as compared to that of breads not containing MOE. The protection index measured by rancimat increased with an increase in the quantity of MOE in the breads. During the storage period, the pH value was not different between breads containing MOE and breads not containing MOE. The lightness and redness of the breads decreased with an increase in the quantity of MOE, while the yellowness increased. In the sensory evaluation, the breads containing 0.5% MOE were more preferred than the breads not containing MOE. These results suggest that the addition of 0.5% MOE to breads has a good effect on improving the shelf-life and overall quality.

Quality characteristics such as alcohol, acid, and sugar contents of takju brewing mashes prepared using several yeasts were investigated during 12-days of fermentation. Among the yeasts examined, S. cerevisiae led to the highest level of ethanol (10.2-13.4%) and total minor alcohols (0.729-0.831 mg/mL). Regardless of the yeasts used, the acidity showed drastic changes (pH from 3.4-4.2 down to 2.4-2.7) during the first 2 days, and displayed negligible changes from day 4. The total acid contents rapidly increased to the first 4 days of fermentation and leveled off from 4 to the end of fermentation period. The common organic acid components were lactic, succinic and acetic acids. The total and reducing sugar contents varied depending on the yeasts used, with mashes prepared using S. coreanus and S. rouxii producing the maximum total sugar contents (5.43-5.5%) at the end of fermentation. The reducing sugar showed its maximum (7.53- 14.89%) at day 2, after which it decreased to its minimum levels (3.04-4.52%). The common free sugar components were glucose and fructose, while S. ellipsoideus led to a higher free sugar level (0.35-5.29%).

The use of deodorizing plant products such as persimmon leaves, pine needles and fennel seeds to mask the characteristic odor of kimchi has been proposed. Therefore, in this study, the effect of deodorizing plants on kimchi fermentation and the profile of volatile flavor compounds was investigated. During sensory evaluation tests of sour and fermentation odors of kimchi, plant extract-added kimchi showed higher sensory scores than chopped plant-added kimchi. Additionally, kimchi containing pine needle extracts (0.3-0.6%) and fennel seed extracts (0.05-0.1%) showed higher sensory scores than untreated kimchi. In addition, pine needle extract and fennel seed extract had a significant influence on kimchi fermentation characteristics such as pH, total acidity and the concentration of lactic acid bacteria. The volatile flavor compounds of kimchi and deodorizing plant extracts were also analyzed using GC/MS and the correlation of volatile flavor compounds in kimchi, plant extracts and plant-added kimchi was examined. The results revealed that the sour and fermentation odors of kimchi were reduced using deodorizing plant extracts by changing the kimchi fermentation characteristics.

Black garlic has recently received significant attention due to its various health functional properties, and there has been an increase in demand for its use as a functional food. This study was performed to determine the optimum concentration for the fermentation of black garlic yakju. In addition, the antioxidant activity of the fermented black garlic yakju was examined. The alcohol content in the black garlic yakju significantly increased for 6 days and the pH gradually increased as the concentration of black garlic increased. The reducing sugar content at each black garlic concentration was maximal when it was fermented for 24 hours, and then rapidly decreased at longer fermentation periods. The main organic acids were lactic, citric, malic and oxalic acid. Also, the lactic acid content increased as the concentration of the black garlic increased where as the content of other organic acids decreased. The total polyphenol content, ferric ion reducing antioxidant power (FRAP) activity and DPPH (1,1-diphenyl-2-picryl-hydrazyl) free radical scavenging activity of black garlic yakju increased as the concentration of black garlic increased. The sensory characteristics of fermented black garlic yakju were evaluated in terms of color, flavor, taste and overall acceptability, and the highest overall acceptability value was obtained for yakju containing a black garlic concentration of 1-3%. Therefore, the optimum concentration of black garlic was determined to be 1% for the production of high quality black garlic yakju.

In order to investigate the effects of different milling degrees on the quality of glutinous rice wines, the physicochemical properties and volatile compounds of various wines were evaluated. Sample wines prepared from glutinous rice with 90, 80, and 70% milling yields were analyzed for ethanol, pH, total acids, amino acids, soluble solids, coloring degree, UV absorbance, reducing sugars, organic acids, free sugars and volatile compounds. After fermentation for 17 days, ethanol contents in the wines ranged from 15.2 to 15.85%, while total acid levels ranged from 0.31 to 0.35%. The amino acid contents in four samples ranged from 0.63 to 0.73%, while soluble solid contents ranged from 11.4 to 13.1oBx. The wine prepared from glutinous rice with a 30% degree of milling showed the highest coloring degree, UV absorbance and reducing sugar content among four samples. Furthermore, this wine had the highest levels of malic acid and acetic acid, while the glutinous rice wine prepared from rice with a 0% degree of milling had the highest levels of succinic acid and lactic acid. In all the glutinous rice wines tested, the most abundant free sugar was glucose followed by maltose. With increasing degree of milling, the alcohol, amino acid and organic acid contents of the glutinous rice wines decreased, whereas soluble solids, coloring degree, UV absorbance, reducing sugar and free sugar contents increased. Volatile compounds were identified using GC-MSD, and thirty-nine esters, seven alcohols, six acids, one aldehyde, four alkanes, one alkene and two miscellaneous compounds were identified in the glutinous rice wines. Using relative peak area, it was determined that other than ethyl alcohol, hexadecanoic acid ethyl ester was the major component and was primarily found in the range of 11.566-18.437%. Succinic acid diethyl ester and isoamyl laurate decreased with an increasing degree of milling, whereas hexanoic acid ethyl ester and 2-octenoic acid ethyl ester increased. Overall, it was shown that different milling degrees greatly affected the physicochemical and volatile characteristics of the glutinous rice wines.

To obtain functional materials from a submerged culture of Hericium erinaceum, a suitable basal medium for flask culture was screened and the optimal culture conditions in a jar fermenter were investigated with the addition of ginseng extracts (GE) to the basal liquid medium. Of all tested basal liquid media, the mushroom complete medium (MCM) supplemented with 0.5% of GE produced the highest mycelial dry weight (MDW) of 5.91 g/L in the flask, which reached a plateau at 25oC, pH 5.5 after 10 days. The submerged culture conditions for the mass production of mycelia in a 50 L jar fermenter were also optimal at 25oC, pH 5.5, 120 rpm agitation speed and 0.4 vvm aeration rate. Under these conditions, the maximum MDW was produced, which reached a value of 4.28 g/L within 5 days. When we investigated the effects of the amount of GE in the MCM on the production of MDW in the jar fermenter, the addition of 5% GE (HE-GE-5) under the optimal culture conditions produced the maximum MDW (4.93 g/L). In addition, the crude polysaccharide of HE-GE-5 contained mainly neutral sugars (63.2%) with considerable amounts of uronic acid (19.3%) and a small amount of proteins (8.8%) and it had potent immunostimulation properties.

In this study, the anti-oxidant, anti-tumorigenic, anti-hypertensive, anti-thrombic, anti-diabetic, and antiinflammatory properties of 18 different species of genus Pleurotus were investigated. In addition, the amino acid, β-glucan, and polyphenol content were also measured. All species contained more than 20 mg% of polyphenol with the highest contents found in Pleurotus cornucopiae var. citrinopileatus (yellow pleurotus) (39.13±0.82 mg%). The β-glucan contents was also the highest in yellow Pleurotus (37.67±0.22%) followed by Won-Hyeong1 (C, 28.75±0.61%) and Jang-an PK (A, 27.95±0.33%). The yellow Pleurotus exhibited the highest antioxidant activity as assessed by the DPPH scavenging rate with an IC50 value of 2.94±0.44 mg/mL. Ethanol extracts from the yellow Pleurotus treated at 1% concentration showed cytotoxic activity up to 36.9% in the human embryonic kidney 293T cell lines. The yellow Pleurotus also showed the highest inhibitory effects on ACE activity (60.52±0.2%). Finally, the yellow Pleurotus exhibited anti-diabetic and antiinflammatory properties as shown by inhibition of α-amyloglucosidase activity (50.5±0.8%) and nitric oxide production (68.4±0.3%). Taken together, our data indicate the yellow pleurotus is a promising functional food ingredients.

Curcuminoids are polyphenolic compounds and include curcumin and its derivatives possessing a yellow color. In the present study, changes in the chemical stability and antioxidant activities of curcuminoids, including curcumin, demethoxycurcumin (DMC), and bisdemethoxycurcumin (BMC), were investigated under various processing conditions. The yellowness of a mixture of the curcuminoids (79.4% curcumin, 16.8% DMC, and 3.8% BMC) at 405 nm was proportional to their amounts analyzed by HPLC. The curcuminoids became less stable with increases of pH and temperature during storage. Exposing a solution of the curcuminoids to autoclave conditions (121oC, 1.2 atm for 15 min) decreased residual curcuminoid levels by 80-90%; however, as a powder under the same conditions the curcuminoids were much more stable with less than 10% loss. After autoclave treatment, scavenging activities of the curcuminoids for DPPH and ABTS radicals were reduced by 10.3 and 33.4%, respectively, whereas nitric oxide scavenging activity was slightly increased. The residual levels of curcumin, DMC, and BMC after autoclaving were 0.7, 1.4, and 0.9%, respectively, indicating that curcumin was the most sensitive to autoclave treatment. The results indicate that under processing conditions, pH and temperature markedly affect the stability of curcuminoids and major losses of curcuminoids occur after autoclaving. These conditions should be considered when processing foods containing curcuminoids.

To obtain the best yield of the beneficial ingredients in green tea, such as catechins, green tea powder is most often prepared by ethyl alcohol extraction. However, the taste, cost and composition of ethyl alcohol extract is different from aqueous spray-dried green tea extract (aq-GTE). Specifically, aq-GTE has a better flavor, lower production costs and higher purity when compared to ethyl alcohol extract. In this study, we elucidated the effect of aq-GTE on diet-induced obesity in male C57BL/6J mice following dose-dependent oral administration of aq-GTE. After eight weeks, the body weight was reduced by 13-17% in mice fed 200 mg/kg bw aq-GTE (12.468±0.45 g; p<0.05) and 20-25% in mice fed 400 mg/kg bw aq-GTE (11.259±0.61 g; p<0.05) when compared with the high-fat diet (HFD) control group mice (14.714±0.95 g; p<0.05). The correlation between epididymal fat accumulation and body weight also decreased by approximately 26.6% (p<0.05) in mice fed a HFD with aq-GTE 400 mg/kg bw. Finally, serum parameters such as the triglyceride, glucose and cholesterol levels in the HFD groups were reduced by the aq-GTE 400 mg/kg bw diet. Analysis on glutamic-pyruvic transaminase, blood urea nitrogen and development of hepatic steatosis revealed no histologic evidence of hepatotoxicity in HFD mice fed aq-GTE. Overall, our results imply that aq-GTE is able to regulate body weight and fat accumulation in mice.

The in vivo and in vitro effects of oriental herb extracts of Cassia obtusifolia, Taraxacum platycarpum and Ulmusmacrocarpa on anti-atopic allergic reaction were evaluated in this study. A mixture of these extracts exhibited more potent anti-allergic activities in human mast cells than those from individual extracts. The herbal mixture significantly inhibited the release of compound 48/80-induced β-hexosaminidase release in the human mast cell line, HMC-1. The mixture also suppressed the production of PMA and A23187-induced inflammatory cytokines in HMC-1 cells. To further investigate the in vivo effects of the herbal mixture, a Dermatophagoides farinae (DF)-induced atopic dermatitis mouse model was utilized. Oral administration of the herbal mixture significantly decreased the ear thickness and swelling in DF treated NC/Nga mice in a dose dependent manner. Furthermore, serum levels of IgE and interleukin-4 (IL-4) were significantly decreased, whereas interferon-gamma (IFN-γ) levels were increased in the mixture administrated groups when compared to the control. Taken together, our data indicate the possibility of using a mixture of the oriental herb extract to relieve symptoms of atopic dermatitis.

The physicochemical properties such as blue value, iodine affinity, degree of polymerization (DP), α-amylase digestibility, particle size, RVA pasting, and gel hardness of 4 different millet starches (foxtail, waxy foxtail, proso, and waxy proso) were investigated. The iodine affinity value of the four samples were 4.22, 0.49, 1.07, and 0.21%, and the DP values were 1830, 3880, 4660, and 4130, respectively. The levels of α-amylase digestibility of the raw starches were 20.1, 30.7, 18.2 and 35.6%, respectively. The mean size of the proso millet starch was the smallest, 8.25 μm, and the size distribution of the particles was the narrowest among all the samples. Foxtail starch showed the largest peak viscosity and setback viscosity in RVA pasting.

The quantitative sensory profiles of rice wines made with nuruks using eight different cereal ingredients were developed using sensory descriptive analysis. Two appearances, eight aromas, eight flavors and tastes, and two mouthfeel related sensory attributes were evaluated by a panel of 10 judges. The sample made of black rice nuruk had the highest intensity in red color, while the other samples had similar ranges in yellow color. The mean sensory intensities of the samples prepared with black rice and glutinous rice nuruks were high in ‘sweet’, ‘fruit taste’, ‘pungent’, and ‘sour’, while those samples prepared using non-glutinous rice, buckwheat, hull-less barley, unpolished rice nuruks had overall high intensities in ‘grain’, ‘fermented aroma’, ‘bitter’, and ‘astringent’ attributes. Based on the principal component analysis of the descriptive data, samples were primarily separated along the first principal component, which accounted for 53% of the total variance between the rice wines with high intensities of ‘red color’, ‘sweet’, and ‘fruit taste’ versus ‘bitter’, ‘astringent’, and ‘yellow color’.