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Chlorophyll-rich samples, such as kale, interfere with the analysis of residual pesticides and adversely affect the integrity of tandem mass spectrometers. Dispersed solid-phase (d-SPE) extraction using graphitized carbon black effectively removes pigments from kale extracts; however, it also reduces the recoveries of 30 pesticides. To overcome this, alternative sorbents, including ENVI-Carb, ChloroFiltr, and Z-Sep+, were evaluated in this study. A sorbent combination based on 50 mg of Z-Sep+ was most advantageous (21/30), good precision (

In the present study, to verify the effect of polysaccharides derived from persimmon leaves (PLE) at epithelial-to-mesenchymal transition (EMT), A549 cells were treated with TGF-β1 alone or co-treated with TGF-β1 and PLE (50 and 75 μg/mL). PLE-treated cells showed higher expression of E-cadherin and lower expression of N-cadherin and vimentin compared to TGF-β1-treated cells by inhibiting the levels of transcription factors, including Snail, Slug, and ZEB1, all associated with EMT. PLE also significantly decreased migration, invasion, and anoikis resistance through TGF-β1 mediated EMT suppression, whereby PLE inhibited the levels of MMP-2 and MMP-9 while cleaving PARP. These inhibitory effects of PLE against EMT, migration, invasion, and anoikis resistance were determined by activating the canonical SMAD2/3 and non-canonical ERK/p38 signaling pathways. Therefore, these results suggest that PLE could be used as a potential chemical therapeutic agent for early metastasis of lung cancer in vitro.

In this study, the determination of iodine in 123 different types of foods was conducted. Iodine-selective electrode, microwave digestion/inductively coupled plasma mass spectrometry and tetramethylammonium hydroxide extraction/ inductively coupled plasma mass spectrometry (TMAH/ICP-MS) methods were tested to achieve the highest recoveries for the determination of iodine. Among them, TMAH/ICP-MS method was the most effective with respect to analytical recoveries (90–99%), limits of detection (0.013 µg/kg) and quantification (0.04 µg/kg) values. The intra- and inter-day relative standard deviations for iodine SRM were

In the present study, an aptamer-based fluorescent assay was developed to detect fipronil in liquid eggs, using a carboxyfluorescein (FAM)-labeled aptamer (FAM aptamer) and partially complementary DNA labeled with carboxytetramethylrhodamine (TAMRA cDNA). The fipronil amount in analytical samples was determined by measuring FAM fluorescence at 522 nm. In the absence of fipronil, FAM fluorescence is effectively quenched by fluorescence resonance energy transfer (FRET) phenomenon generated by the hybridized structure of the FAM aptamer and TAMRA cDNA. In contrast, in the presence of fipronil, FAM fluorescence is gradually recovered in a fipronil concentration-dependent manner because the FAM aptamer has a stronger affinity for fipronil than for TAMRA cDNA. The proposed analytical method for fipronil involves a simple one-step procedure of mixing the sample solution without any washing step, and the results can be obtained in approximately 30 min. Under optimized conditions, the developed assay showed a linear response to fipronil in the egg sample in the range of 25-300 ppb with a detection limit of 53.8 ppb (0.068 mg/kg) and recovery rates in the range of 94.7-114.4%. Additionally, the assay selectivity for fipronil was investigated against eight pesticides, and it showed good specificity for fipronil. Compared with conventional liquid chromatography-mass spectrometry (LC-MS), the proposed method provides a simple, easy, and fast method to detect fipronil in egg samples without requiring bulky and expensive instruments and complicated and laborious processes. We believe this detection method could be a promising platform for fipronil detection in real food samples.

Newly developed magnetic carbon particles prepared from coffee grounds were used as the sorbent for the magnetic solid-phase extraction of eight phthalic acid esters (PAEs) from plastic bottled water prior to their analysis by GC-MS. The method, which uses coffee-ground particles coated with iron oxide, was validated, and exhibited linearities for the eight PAEs, with coefficients of determination above 0.998 in the 0.005 to 0.1 mg/L concentration range. Limits of detection and limits of quantification of 0.00003 to 0.002 mg/L and 0.0001 to 0.005 mg/L, respectively, were achieved, with recoveries (%) ranging between 77% and 120%, and relative standard deviations for intra- and interday precisions below 16.3% at three fortification levels. No PAE residues were detected when the developed and validated method was applied to 10 real plastic bottled water samples. Taken together, the developed magnetic solid-phase extraction method is a useful tool for monitoring phthalate esters in aqueous samples. PRACTICAL APPLICATION: The development of a new, inexpensive, and efficient magnetic sorption material derived from spent coffee grounds, and its ability to determine phthalate esters in aqueous solutions was described by GC-MS/MS. The developed magnetic solid-phase extraction method is a useful tool for monitoring phthalate esters in aqueous samples.

Biphenyl-degrading bacteria were isolated from contaminated soil and identified as Comamonas species. Among these strains, C. thiooxydans N1 was the most suitable for biphenyl degradation. When 1200 µg/mL of biphenyl was used, it was completely degraded within 24 h. A simple, rapid, and precise, high-performance liquid chromatography (HPLC) method for quantifying biphenyls and their metabolites in the culture medium was optimised and validated. The proposed method was performed using reverse-phase HPLC equipped with a Luna C18 column. The mobile phase was water and acetonitrile (30/70, v/v) under isocratic conditions, and biphenyls and their metabolites were quantified on a SHIMADZU HPLC system with a diode-array detection detector at 254 nm. Peak identity was confirmed by ultraviolet spectroscopy and gas chromatography-mass spectrometry. Validation was performed according to European Union requirements (2002/657/EC) for linearity, accuracy, repeatability, reproducibility, limit of detection, limit of quantification, and detection capability. Linearity was observed in the concentration range of 0.04-20 µg/mL with a high coefficient of determination (R2 ≥ 0.999). The validated method was applied to determine the content of biphenyl and its metabolites in the culture medium.

Conjugated linoleic acid (CLA) isomers are potent health-promoting fatty acids. This study evaluated the probiotic properties of 10 strains of high CLA-producing lactic acid bacteria (LAB) isolated from Jeot-gal, a high-salt, fermented seafood. Two isolates, Lactiplantibacillus plantarum JBCC105683 and Lactiplantibacillus pentosus JBCC105676, produced the largest amounts of CLA (748.8 and 726.9 μg/mL, respectively). Five isolates, L. plantarum JBCC105675, L. pentosus JBCC105676, L. pentosus JBCC105674, L. plantarum JBCC105683, and Lactiplantibacillus paraplantarum JBCC105655 synthesized more cis-9, trans-11-CLA than trans-10, cis-12-CLA (approximately 80:20 ratio). All the strains survived severe artificial acidic environments and showed antimicrobial activity and strong adhesion capability to Caco-2 cells as compared to the commercial strain Lactocaseibacillus rhamnosus GG. Among them, Pediococcus acidilactici JBCC105117, L. paraplantarum JBCC105655, and L. plantarum JBCC105683 strongly stimulated the immunological regulatory gene PMK-1 and the host defense antimicrobial peptide gene clec-60 in Caenorhabditis elegans. Moreover, three strains showed a significant induction of tumor necrosis factor-α, interleukin (IL)-1β, IL-6, IL-12, and IL-10 production in RAW 264.7 macrophages, indicating that they were promising candidates for probiotics with high CLA-converting activity. Our results indicate that the newly isolated CLA-producing LAB might be useful as a functional probiotic with beneficial health effects that modulate the immune system.

Pesticides are used to increase crop yields and preserve quality by protecting crops against pests; however, their overuse can adversely affect human health and the environment. Herein, we report the development of a multi-pesticide screening method using optimized QuEChERS coupled with liquid chromatography/quadrupole time-of-flight (QTOF) mass spectrometry for the analysis of 13 pesticides in wheat flour. Mass accuracies with errors of less than 2.4 ppm were obtained for all analysed pesticides, and the method provided satisfactory recovery and linearity. Repeatabilities of 0.3-12.7% and reproducibilities of 2.5-15.2% were observed in full-scan TOF mode. The performance of the developed full-scan TOF method was compared to that obtained in high-resolution multiple reaction monitoring (MRM-HR) mode. The limits of quantification for the full-scan TOF and MRM-HR modes ranged from 2 to 10, and 3 to 9 μg kg

A new solid phase microextraction (SPME)-Arrow method was evaluated for the analysis of volatile compounds in kanari-aekjeot, a Korean traditional salt–fermented sand lance sauce, and compared it to the standard headspace–SPME method. Factors observed to affect the extraction, including the fiber used, extraction temperature, extraction time, and NaCl concentration were carefully optimized. The Carboxen/Polydimethylsiloxane fiber exhibited the highest extraction efficiency for both analytical methods and was selected for further optimization of the extraction. The major volatile compounds extracted using both methods were 3-methyl butanoic acid, butanoic acid, acetic acid, 2,6-dimethylpyrazine, and benzaldehyde. The relative concentration (mg/L) of 3-methyl butanoic acid was 1.4-fold higher when using SPME. However, the SPME-Arrow method was more effective at extracting aromatic compounds including alcohol, aldehydes, and pyrazine. In particular, 3-methyl-1-butanol, 2-furanmethanol, and phenylethyl alcohol could only be detected using SPME-Arrow due to its larger sorbent volume. Thus, SPME-Arrow was evaluated as being more suitable for the extraction of pyrazines in sand lance fish sauce and might be useful for determining a broader range of volatile compounds in complex fermented foods.

Herein, a QuEChERS (quick, easy, cheap, effective, rugged, and safe) procedure together with liquid chromatography and tandem mass spectrometry was applied to the multi-residue analysis of 203 pesticides in strawberries. To reduce the amount of co-eluents, we compared several dispersive solid-phase extraction cleanup procedures and found that cleanup using octadecylsilane provided the best recoveries. Spiked-sample recoveries of 70–120% with relative standard deviations of 0.99), and the limits of quantification (LOQs) were lower than the maximum residue limits recommended by the European Commission and Korea Food and Drug Administration. The developed method was applied to real samples, revealing that their pesticide contents exceeded the corresponding LOQs. The obtained results demonstrate that octadecylsilane-based dispersive solid-phase extraction is a rapid and high-throughput cleanup procedure for the multi-residue analysis of pesticides in strawberries.

Biogenic amines (BAs) are widely present in nearly all fermented foods and beverages, and excess consumption can cause adverse health effects. To prepare BA-free Korean black raspberry wine (BRW), four autochthonous starter yeast strains without hazardous BA synthesis activity were selected and their physiological and biochemical properties were examined. The selected strains were identified as Saccharomyces cerevisiae based on 26S rDNA sequencing and microsatellite analysis. Molecular fingerprinting revealed that isolates were quite different from commercial wine yeast S. cerevisiae (52.4% similarity), but genetically relevant to commercial beer yeasts. The four S. cerevisiae strains produced over 10% ethanol during BRW fermentation. In addition, the fermented BRW with these strains showed higher levels of total flavonoids and similar antioxidant activity compared to the control sample. Potentially hazardous BAs that commonly occur in black raspberry extract (BRE) such as cadaverine, histamine, and spermidine were also not detected in the fermented BRW. Thus, we suggest that our strains are promising fermentation tools to ensure high quality and enhanced functionality in the production of BA-free BRW.

Agricultural water is closely linked to surface and ground water as well as soil, hence, ensuring its safety is an important endeavor. We used the &ldquo, quick, easy, cheap, effective, rugged, and safe&rdquo, (QuEChERS) method to analyze multi-residue pesticides in agricultural water by using a combined-sorbent-based clean-up procedure. Among the various sorbents examined, clean-up using ENVI-Carb combined with a primary secondary amine sorbent delivered the highest recovery of multi-residue pesticides (&gt, 93.9%). While the developed method showed satisfactory linearity (R2 &gt, 0.9991), precision, and specificity, recovery was low for pyrazolate (29.1%) and thidiazuron (59.2%). The limits of detection and quantification for the 55 pesticides targeted in this study were in 0.02&ndash, 3.0 &mu, g L&minus, 1 and 0.1&ndash, 9.9 &mu, 1, respectively. The developed method was used to identify and quantify multi-residue pesticides during sample analysis. The results suggest that the QuEChERS method employing a combination of ENVI-Carb and another sorbent can be applied for the effective analysis of multi-residue pesticides in agricultural water.

This study aimed to comparatively analyze the volatile flavor of rooibos tea (Aspalathus linearis) obtained by two commonly used flavor extraction methods, simultaneous distillation–extraction (SDE) and steam distillation under reduced pressure (DRP). The tea obtained by the two extraction methods, were analyzed by gas chromatography–mass spectrometry to identify volatile aroma-related compounds. Descriptive sensory analysis of the extracted rooibos tea flavor was carried out by a trained panel (n = 7). Fifty volatile compounds were identified, including 26 and 25 aroma-active compounds by SDE (45.9 µg/g) and DRP (37.5 µg/g), respectively. SDE recovered larger quantities of alcohols, acids, and esters, whereas DRP was useful for analyzing thermally unstable volatile compounds, including various alcohols, aldehydes, and hydrocarbons. Descriptive sensory analysis revealed that ketones and phenolic compounds may be responsible for the sensory attributes woody and grassy green, whereas the aldehydes and acidic compounds may contribute to floral and fruity.

In order to improve the slow ethanol fermentation during acetic acid fermentation process of black raspberry vinegar (BRV), the microbiological and physicochemical aspects of the effects of indigenous Saccharomyces cerevisiae JBCC-21A were examined. The selected S. cerevisiae JBCC-21A showed better growth and ethanol production rates than the commercial yeast strains. The ethanol production rate was 3-times faster than the traditional method. Acetic acid fermentation by S. cerevisiae JBCC-21A began 10 days earlier than the traditional method and reached up to 60 g/L acetic acid. Bacterial counts revealed Acetobacter pasteurianus was the only dominant species throughout the inoculated acetic acid fermentation. The physicochemical and functional properties of the fermented vinegar using indigenous S. cerevisiae JBCC-21A maintained a high quality similar to the traditional method, while being the faster fermentation process. Thus, it is suggested that inoculation of the indigenous S. cerevisiae strain in order to shorten the fermentation time without affecting the quality of traditional BRV.

Certain strains of lactobacilli have been reported to exert favorable effects on atopic dermatitis (AD). Jeotgal, a traditional Korean food, is a salted fermented seafood known to harbor many lactic acid bacteria. In the present study, two novel lactobacillus strains were isolated from Jeotgal, and their anti-AD effects were investigated. Lactobacilli isolated from Jeotgal were identified, according to conjugated linoleic acid-producing activity, as Lactobacillus plantarum (JBCC105645 and JBCC105683). AD-like skin lesions were induced in BALB/c mice using dinitrofluorobenzene (DNFB). Ear swelling, histological analysis and serum immunoglobulin E (IgE) levels in mice were evaluated to investigate the anti-AD effects of lactobacilli. Cytokine production of ex vivo cluster of differentiation (CD)4+ T cells, and interleukin (IL)-12 production of in vitro macrophages were also evaluated to establish a putative mechanism of the action of lactobacilli. Administration of JBCC105645 or JBCC105683 suppressed ear swelling and serum IgE levels in DNFB-treated mice (P

The monitoring of food quality and safety requires a suitable analytical method with simultaneous detection in order to control pesticide and herbicide residues. In this study, a novel analytical method, referred to as &ldquo, dispersive solid&ndash, liquid extraction&rdquo, was applied to monitor seven sulfonylurea herbicides in strawberries. This method was optimized in terms of the amount of C18 and the volume of added water, and it was validated through satisfactory linearities (R2 &gt, 0.99), recoveries of 70% to 84% with acceptable precisions, and limits of quantification lower than the maximum residue limits for the seven sulfonylurea herbicides in strawberries. The cleanup efficiency of the dispersive solid&ndash, liquid extraction technique was compared to that of the QuEChERS- (&ldquo, quick, easy, cheap, effective, rugged and safe&rdquo, ) based method with dispersive solid phase extraction. The recoveries of the former were found to be comparable to those involving QuEChERS C18 cleanup (recoveries of 74%&ndash, 87%). The method was used to determine sulfonylurea herbicide residues in ten strawberry samples. None of the samples had herbicide residues higher than that of limit of quantifications (LOQs) or maximum residue limits (MRLs). The results suggest that the dispersive solid&ndash, liquid extraction method combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) is effective for the analysis of sulfonylurea herbicide residues in strawberries.

Biogenic amines (BAs) are widely present in nearly all fermented foods and beverages, and excess consumption can cause adverse health effects. To prepare BA-free Korean black raspberry wine (BRW), four autochthonous starter yeast strains without hazardous BA synthesis activity were selected and their physiological and biochemical properties were examined. The selected strains were identified as Saccharomyces cerevisiae based on 26S rDNA sequencing and microsatellite analysis. Molecular fingerprinting revealed that isolates were quite different from commercial wine yeast S. cerevisiae (52.4% similarity), but genetically relevant to commercial beer yeasts. The four S. cerevisiae strains produced over 10% ethanol during BRW fermentation. In addition, the fermented BRW with these strains showed higher levels of total flavonoids and similar antioxidant activity compared to the control sample. Potentially hazardous BAs that commonly occur in black raspberry extract (BRE) such as cadaverine, histamine, and spermidine were also not detected in the fermented BRW. Thus, we suggest that our strains are promising fermentation tools to ensure high quality and enhanced functionality in the production of BA-free BRW.

The present study aimed to investigate the occurrence of emerging mycotoxins in cereals (n = 61) and cereal-based products (n = 36) collected from Korean market. First of all, using the quick, easy, cheap, effective, rugged and safe (QuEChERS) extraction method, and ultrahigh-pressure liquid chromatography (UPLC) with triple quadruple tandem mass spectrometry (MS/MS), we developed a simple and fast method for quantitative determination of eight emerging mycotoxins including alternariol (AOH), alternariol monomethyl ether (AME), tentoxin (TEN), beauvericin (BEA) and enniatins (ENs; ENA, ENA1, ENB and ENB1). The developed analytical method was validated in parameters of linearity, precision and accuracy. For UPLC-MS/MS analysis, the recoveries of emerging mycotoxins from spiked samples at three concentration levels ranged from 82.7% to 108.8% with RSDs between 0.4% and 14.7%. Analytical methods were applied to determine the contamination of mycotoxins in cereal and cereal-based product samples. Sixty-three of the total 97 samples were contaminated with at least one emerging mycotoxin. The maximum number of emerging mycotoxins observed in a single sample was six out of eight analytes. The highest level of contamination was detected in cereal at 70.9 μg/kg for alternariol monomethyl ether (AME). However, currently there is no international standard for emerging mycotoxins in food. Accordingly, it is necessary to establish a database of emerging mycotoxins contamination through continuous monitoring.

The ability to readily determine the composition of brown rice vinegar is important for quality assurance purposes. To that end, solid–phase microextraction (SPME)–Arrow method was optimized for the determination of volatile organic compounds (VOCs) from brown rice vinegar. Compared to traditional SPME fibers, SPME–Arrow has a larger sorbent-phase volume and is more durable. The SPME–Arrow conditions, including coating material, extraction temperature, extraction time, and NaCl concentration, were examined, which led to optimum extraction conditions that include: carboxen/polydimethylsiloxane (CAR/PDMS) fiber, 50°C, 30 min of SPME–Arrow, and 0% NaCl (i.e., no added NaCl). The developed method was compared to an optimized method based on conventional SPME. Twelve major VOCs, including acetates, alcohols, aldehydes, acids, and furan derivatives, were extracted by SPME–Arrow, while only seven VOCs were extracted using the traditional SPME. Moreover, SPME–Arrow extracted more 1.3–2 times more VOCs than SPME. Hence, the CAR/PDMS SPME–Arrow fiber is suitable for acquiring VOC profiles from brown rice vinegar.

In this study, deep eutectic solvents (DESs) coupled with ultrasound-assisted extraction (UAE) were evaluated and optimized for the extraction of major flavonoids from common buckwheat sprouts. Initially, 18 different choline chloride (CC)-based DESs were evaluated as potential extraction solvents, and 80% CCTG (CC-based DES composed of triethylene glycol and 20 vol% water) extracted significantly higher (p 0.05) amounts of flavonoids than other DESs studied. The extraction efficiency of 80% CCTG was even higher (p 0.05) than that of methanol for the extraction of vitexin and quercetin-3-O-robinobioside. Procedure using 80% CCTG and UAE were optimized; an extraction temperature of 56 °C and extraction time of 40 min were considered optimal. The optimized extraction procedure was reliable and efficient for the extraction of major flavonoids from common buckwheat sprouts. In addition, flavonoids could be efficiently recovered from DES extracts with high recovery yields (97%) by using a C18 solid-phase extraction.

A high concentration of histamine, one of the biogenic amines (BAs) usually found in fermented foods, can cause undesirable physiological side effects in sensitive humans. The objective of this study is to isolate indigenous Acetobacter strains from naturally fermented Bokbunja vinegar in Korea with reduced histamine production during starter fermentation. Further, we examined its physiological and biochemical properties, including BA synthesis. The obtained strain MBA-77, identified as Acetobacter aceti by 16S rDNA homology and biochemical analysis and named A. aceti MBA-77. A. aceti MBA-77 showed optimal acidity % production at pH 5; the optimal temperature was 25 °C. When we prepared and examined the BAs synthesis spectrum during the fermentation process, Bokbunja wine fermented with Saccharomyces cerevisiae showed that the histamine concentration increased from 2.72 of Bokbunja extract to 5.29 mg/L and cadaverine and dopamine was decreased to 2.6 and 10.12 mg/L, respectively. Bokbunja vinegar prepared by A. aceti MBA-77 as the starter, the histamine concentration of the vinegar preparation step was decreased up to 3.66 mg/L from 5.29 mg/L in the wine preparation step. To our knowledge, this is the first report to demonstrate acetic acid bacteria isolated from Bokbunja seed vinegar with low spectrum BA and would be useful for wellbeing vinegar preparation.

BACKGROUND The aim of this study was to elucidate the changes in microbial community and biochemical and physiological properties of traditional Muju black raspberry (Robus coreanus Miquel) vinegar (TMBV) during fermentation by culture-independent methods. RESULTS During vinegar fermentation, ethanol produced up to 120 g L−1 until day 35, with continuously increasing yeast concentration to a total of log 7.6 CFU mL−1. After day 35, acetic acid bacteria (AAB) concentrations rose to log 5.8 CFU mL−1 until day 144. Denaturing gradient gel electrophoresis analysis showed that Saccharomyces cerevisiae was detected until day 87 of the fermentation, at which point Acetobacter pasteurianus gradually took over as the dominant species. Total sugar was reduced to 6.6 °Brix and total acidity produced up to 44 g L−1. CONCLUSION In this study, we established the physicochemical analysis and growth dynamics of yeast and AAB during alcoholic and acetic acid fermentation of black raspberry by a traditional method. Overall, S. cerevisiae and A. pasteurianus species appeared to dominate the TMBV fermentation. In conclusion, this study demonstrated a suitable fermentation system for TMBV by the static surface method. © 2015 Society of Chemical Industry

Streptococcus mutans plays a key role in the development of dental caries and promotes the formation of oral biofilm produced by glucosyltransferases (GTFs). Bacillus velezensis K68 was isolated from traditional fermented foods and inhibits biofilm formation mediated by S. mutans. Gene amplification results demonstrated that B. velezensis K68 contained genes for the biosynthesis of 1-deoxynojirimycin (1-DNJ), a known GTF expression inhibitor. The presence of the GabT1, Yktc1, and GutB1 genes required for 1-DNJ synthesis in B. velezensis K68 was confirmed. Supernatant from B. velezensis K68 culture medium inhibited biofilm formation by 84% when S. mutans was cultured for 48 h, and inhibited it maximally when 1% glucose was added to the S. mutans culture medium as a GTF substrate. In addition, supernatant from B. velezensis K68 medium containing 3 ppb 1-DNJ decreased S. mutans cell surface hydrophobicity by 79.0 ± 0.8% compared with that of untreated control. The supernatant containing 1-DNJ decreased S. mutans adherence by 99.97% and 98.83% under sugar-dependent and sugar-independent conditions, respectively. S. mutans treated with the supernatant exhibited significantly reduced expression of the essential GTF genes gtfB, gtfC, and gtfD compared to that in the untreated group. Thus, B. velezensis inhibits biofilm formation, adhesion, and GTF gene expression of S. mutans through 1-DNJ production.

In order to improve the slow ethanol fermentation during acetic acid fermentation process of black raspberry vinegar (BRV), the microbiological and physicochemical aspects of the effects of indigenous Saccharomyces cerevisiae JBCC-21A were examined. The selected S. cerevisiae JBCC-21A showed better growth and ethanol production rates than the commercial yeast strains. The ethanol production rate was 3-times faster than the traditional method. Acetic acid fermentation by S. cerevisiae JBCC-21A began 10 days earlier than the traditional method and reached up to 60 g/L acetic acid. Bacterial counts revealed Acetobacter pasteurianus was the only dominant species throughout the inoculated acetic acid fermentation. The physicochemical and functional properties of the fermented vinegar using indigenous S. cerevisiae JBCC-21A maintained a high quality similar to the traditional method, while being the faster fermentation process. Thus, it is suggested that inoculation of the indigenous S. cerevisiae strain in order to shorten the fermentation time without affecting the quality of traditional BRV.

An analytical method involving QuEChERS (quick, easy, cheap, effective, rugged, and safe) sample preparation, followed by LC-MS/MS and GC-MS/MS was developed and validated for the determination of 60 pesticides in eggs. Recoveries of 70-120% were achieved for selected pesticides and relative standard deviations20% were obtained for most analytes at three concentrations. The limit of quantification was10 µg kg

Volatile organic compounds (VOCs) associated with spoilage are attracting the attention as potential markers for monitoring meat quality. The objective of the present study was to evaluate the use of spoilage-associated VOCs as marker compounds for the assessment of beef spoilage during storage at 4 °C in air and when vacuum packed. We used headspace solid-phase microextraction coupled with gas chromatography time-of-flight mass spectrometry to determine the levels of VOCs formed during storage. Correlation analysis and multivariate analyses (principal component and hierarchical clustering analysis) were used to select several VOCs that most contribute to sensory changes, and to classify beef samples based on the degree of spoilage assessed by sensory panelists, respectively. Levels of acetic acid, ethanol, 2-methylbutan-1-ol, 3-methylbutan-1-ol, 2,3-butanediol, 2-butanone, diacetyl, 2-heptanone, 3-octanone, and acetoin significantly (p

Oxygen generating (OG) hydrogels immobilizing glucose oxidase (GOx, EC 1.1.3.4) and peroxidase (PO) (EC 1.11.1.7) were prepared using a γ-ray irradiation polymerization technique, and the properties were examined. In physiological tests of the OG hydrogels ranging from 15 to 70 kGy, GOx or PO showed higher gel contents at 87% for the poly(vinyl alcohol) (PVA) hydrogel and 90% for the poly(vinylpyrrolidone) (PVP) hydrogel. The optimal irradiation conditions affecting the entrapment ratio for preparing the OG hydrogel was 35 kGy for the PVP hydrogel, and both enzymes (GOx, 95% and PO, 89%). Optimal GOx and PO activity of the prepared OG hydrogel occurred at pH 6.0 and 35 °C, and both enzymes showed stable activity under acidic conditions. The optimal glucose condition was 4 mg, which resulted in a maximum oxygen generating yield by the OG hydrogels. When oxygen concentration was compared, the OG hydrogels showed higher oxygen pressure than that of control hydrogels without the GOx and PO enzymes. Moreover, the OG hydrogel continuously converted potassium iodide to iodine in a glucose dosage and time dependant manner for 15 h, producing approximately 0.1 M iodine in 5 h.

This study examined the efficient production and optimal separation procedures for pure L-threo-3,4-dihydroxyphenylserine (L-threo-DOPS) from a mixture of diastereomers synthesized by whole-cell aldol condensation reaction, harboring diastereoselectivity-enhanced L-threonine aldolase in Escherichia coli JM109. The addition of the reducing agent sodium sulfite was found to stimulate the production of L-threo-DOPS without affecting the diastereoselectivity ratio, especially at the 50 mM concentration. The optimal pH for diastereoselective synthesis was 6.5. The addition of Triton X-100 also strongly affected the synthesis yield, showing the highest conversion yield at a 0.75% concentration; however, the diastereoselectivity of the L-threonine aldolase was not affected. Lowering the temperature to 10°C did not significantly affect the diastereoselectiviy without affecting the synthesis rate. At the optimized conditions, a mixture of L-threo-DOPS and L-erythro-DOPS was synthesized by diastereoselectivity-enhanced L-threonine aldolase from E. coli in a continuous process for 100 hr, yielding an average of 4.0 mg/mL of L-threo-DOPS and 60% diastereoselectivity (de), and was subjected to two steps of ion exchange chromatography. The optimum separation conditions for the resin and solvent were evaluated in which it was found that a two-step process with the ion-exchange resin Dowex 50 W × 8 and activated carbon by washing with 0.5 N acetic acid was sufficient to separate the L-threo-DOPS. By using two-step ion-exchange chromatography, synthesized high-purity L-threo-DOPS of up to 100% was purified with a yield of 71%. The remaining substrates, glycine and 3,4-dihydroxybenzaldehyde, were recovered successfully with a yield of 71.2%. Our results indicate this potential procedure as an economical purification process for the synthesis and purification of important L-threo-DOPS at the pharmaceutical level.

Fermented sugar-soaked black soybean snacks (FSBSS) were prepared using optimized conditions at 2 times sugar soaking process to give a desirable form and texture after fermentation with Lactobacillus plantarum (LP) and Bacillus subtilis (BS) for 48 h. The prepared FSBSS showed higher total polyphenol and flavonoid contents than an unfermented (NF) sample; total isoflavone content increased approximately 31 and 17% (LP and BS, respectively), as compared to NF. γ-Aminobutyric acid was also contributed by LP and BS, indicating significantly higher contents of 16.9 and 21.6 mg/g (LP and BS, respectively) compared to NF (15.2 mg/g). Moreover, the FSBSS showed antioxidant activities on DPPH, superoxide, and hydroxyl radicals as compared to NF. Based on the results, the newly developed FSBSS using solid-fermentation indicate a useful and convenient way to replace traditional soybean products from the standpoint that also provides an easy means to supply high nutritive and functional properties.

The aim of this study was to elucidate the changes in microbial community and biochemical and physiological properties of traditional Muju black raspberry (Robus coreanus Miquel) vinegar (TMBV) during fermentation by culture-independent methods.During vinegar fermentation, ethanol produced up to 120 g L(-1) until day 35, with continuously increasing yeast concentration to a total of log 7.6 CFU mL(-1) . After day 35, acetic acid bacteria (AAB) concentrations rose to log 5.8 CFU mL(-1) until day 144. Denaturing gradient gel electrophoresis analysis showed that Saccharomyces cerevisiae was detected until day 87 of the fermentation, at which point Acetobacter pasteurianus gradually took over as the dominant species. Total sugar was reduced to 6.6 °Brix and total acidity produced up to 44 g L(-1) .In this study, we established the physicochemical analysis and growth dynamics of yeast and AAB during alcoholic and acetic acid fermentation of black raspberry by a traditional method. Overall, S. cerevisiae and A. pasteurianus species appeared to dominate the TMBV fermentation. In conclusion, this study demonstrated a suitable fermentation system for TMBV by the static surface method. © 2015 Society of Chemical Industry.