• Journal of Food Hygiene and Safety
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• v.38 no.5
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• pp.311-318
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• 2023

This study was performed to determine the contents of propionic, benzoic, and sorbic acids in dried seasoned seafood products (n=27) sold in Korea. Propionic acid was determined using a gas chromatogramphy-flame ionization detector. Benzoic and sorbic acid were analyzed by using a high-performance liquid chromatography-diode array detector. Benzoic acid was not detected in the dried seasoned seafood products; however, propionic and sorbic acid were detected in some samples. The concentrations of propionic acid and sorbic acid were up to 125.10 mg/kg and 658.18 mg/kg in dried seasoned seafood products, respectively. Of eight samples labeled with potassium sorbate, sorbic acid was detected in seven of them. The detected sorbic acid levels in these samples met the regulations for sorbic acid usage in Korea. The propionic, benzoic, and sorbic acid contents of dried seasoned seafood products determined in this study can provide basic data for safety management of dried seasoned seafood products in future.

• Food Science and Preservation
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• v.30 no.3
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• pp.483-491
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• 2023

This study aimed to compare the bioactive compounds in Centella asiatica (C. asiatica) cultivated in a smart farm and a field and their effects on human keratinocyte cells. C. asiatica was collected in Jeju-do, Korea, and cultured in a smart farm and a field. The main bioactive compounds in the two differentially cultured C. asiatica were identified, and their activation in keratinocytes were assessed. Amplification and sequencing of the internal transcribed spacer (ITS) DNA in the nucleus and psbA-H DNA in the chloroplast were performed for species analysis. A comparison of DNA of plants reported in the NCBI GenBank was performed. The ITS DNA and psbA-H DNA sequences of C. asiatica cultivated in a smart farm and a field were consistent with No. MH768338.1 and No. JQ425422.1, respectively. Analysis of the triterpenes was performed using high performance liquid chromatography (HPLC) and as a result, C. asiatica cultured in a smart farm had more triterpenes than those cultured in a field. The effects of C. asiatica grown in a smart farm on cell proliferation and scratch recovery in HaCaT cells were greater than those grown in a field. These results suggest that C. asiatica cultivated in a smart farm can be effectively utilized as a health functional food.

• Journal of Life Science
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• v.34 no.3
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• pp.145-152
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• 2024

Seaweeds represent a widely harnessed marine resource that are valued for their abundant supply of essential nutrients, particularly proteins and amino acids. In Korea, where over 500 species of seaweed thrive and more than 50 are utilized for culinary purposes, seaweed has become a staple in regular diets. In this study, we focused on five of the most commonly consumed seaweed species in Korea: Capsosiphon fulvescens, Hizikia fusiforme, Porphyra yezoensis, Saccharina japonica, and Undaria pinnatifida. We closely examined the amino acid compositions of these five species. High-performance liquid chromatography showed that aspartic acid, glutamic acid, alanine, and leucine were the most abundant amino acids in the seaweeds. Principal component analysis revealed that the five seaweed species could be classified into three clusters according to their amino acid composition, partially corroborating findings from the phylogenetic analysis. Among various amino acids, glutamic acid, aspartic acid, and alanine were the primary amino acids driving differentiation. Notably, U. pinnatifida and C. fulvescens, which demonstrated close phylogenetic proximity, exhibited remarkably similar amino acid profiles. Conversely, although P. yezoensis and S. japonica shared a phylogenetic relationship, they displayed distinctly different amino acid compositions. H. fusiforme emerged as a distinct group in both analyses.

• Journal of Food Hygiene and Safety
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• v.39 no.5
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• pp.404-411
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• 2024

Paralytic Shellfish Poisoning (PSP) occurs when humans consume shellfish contaminated with saxitoxin (STX) and its derivatives. It causes symptoms ranging from numbness and nausea to severe muscle paralysis and respiratory failure. Toxic equivalency factors (TEFs) are used to standardize the toxic effects of various PSP toxins for risk assessment. Traditional detection methods, such as mouse bioassays, have been used to set the TEFs, but ethical concerns over in vivo studies have shifted the focus toward analytical methods, such as high-performance liquid chromatography. However, in vivo data are essential for establishing TEFs, particularly for emerging marine biotoxins. This study employed a three-level response surface pathway (RSP) design, which reduced the number of animals used to evaluate the median lethal dose (LD₅₀) of STX and its derivatives. The LD₅₀ and TEF values for STX dihydrochloride, neosaxitoxin, decarbamoylsaxitoxin, gonyautoxins 1 & 4 (GTX1&4), GTX2&3, and dcGTX2&3 were 451.3 (1.00), 306.5 (1.47), 860.9 (0.52), 644.5 (0.70), 915.3 (0.49), and 2409.3 (0.19) ㎍/kg, respectively. These TEFs closely aligned with the WHO recommendations and prior oral LD₅₀ values, with Pearson correlation coefficients of 0.969 and 0.994, respectively. This study highlights the need for accurate TEF assignments for PSP toxins and new marine biotoxins, demonstrating that the three-level RSP design balances ethical concerns and provides reliable toxicity data.

• Journal of Food Hygiene and Safety
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• v.39 no.5
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• pp.456-462
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• 2024

Azaspiracids (AZAs) are a group of shellfish toxins that cause azaspiracid shellfish poisoning (AZP). They have been detected in mussels (Mytilus edulis) and oysters (Crassostrea gigas) in the Netherlands, Ireland, Italy, France, and the United Kingdom. In this study, we aimed to develop a method for the simultaneous detection of AZAs using ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Simultaneous analyses of AZA-1, AZA-2, AZA-3, AZA-4, and AZA-5 were conducted according to AOAC ISO 17025 guidelines. Between 2020 and 2023, 467 imported shellfish were purchased from retail and wholesale markets in Korea. However, none of the samples tested positive for AZA-1, AZA-3, AZA-4, or AZA-5. Only two Arca avellana imported from Russia were positive for AZA-2 above the limit of detection (LOD) but below the limit of quantification (LOQ), with concentrations of 0.68 and 0.71 ng/g, respectively. This study found that the prevalence of AZA-2 was very low in shellfish imported into Korea.

• Animal Bioscience
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• v.37 no.10
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• pp.1799-1808
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• 2024

Objective: Traditional fermented meat products can be considered a source of bioactive peptides. Cangkuk, a traditional Indonesian fermented beef product is one source of angiotensin converting enzyme (ACE) inhibitory peptides. This study aimed to identify ACE-inhibitory peptides from Cangkuk and analyze their antihypertensive effects. Methods: The water-soluble fraction of Cangkuk was fractionated to obtain ACE-inhibitory peptides using an ethanol solvent at several concentrations and solid-phase extraction with an OASIS HLB cartridge followed by purification with reversed-phase high-performance liquid chromatography (RP-HPLC). HPLC-MS was used to identify target peptides, followed by automatic protein sequencer analysis to detect peptide sequences. Antihypertensive effects were analyzed on the water-soluble fraction and synthesized peptides. The animal model comprised 14-16-week-old male spontaneously hypertensive rats (SHRs) (~320 g average body weight) with mean systolic blood pressures (SBPs) higher than 190 mmHg. All oral doses of peptides were 1 mL in volume. Distilled water was used as a control. The antihypertensive activities of the sample and control were observed by measuring the SBP at 0, 2, 4, 6, 8 and 24 h after oral administration. Results: Two sequences of ACE inhibitory peptides were found, EAPLNPKANR (IC₅₀ value of 44.6 µmol/L) and IVG (IC₅₀ value of 97.3 µmol/L). The water-soluble fraction demonstrated an antihypertensive effect on SHRs after oral administration at 100 mg/kg body weight, maximally lowering the SBP by 14.9 mmHg 8 h after administration. The tripeptide IVG showed the highest reduction of SBP, 24.76±2.1 mmHg 8 h after administration. The decapeptide EAPLNPKANR showed the highest reduction of SBP, 21.0±1.9 mmHg, 8 h after administration. All the samples differed significantly from the control (p<0.01). Conclusion: Cangkuk has potential as a functional food ingredient acting as an antihypertensive agent.

• The Journal of the Convergence on Culture Technology
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• v.10 no.5
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• pp.775-780
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• 2024

In this study, a simultaneous analysis method was developed using reversed-phase high-performance liquid chromatography(RP-HPLC) for the main components of motion sickness medication: Dimenhydrinate, Caffeine, Methyl Paraben, and Propyl Paraben. The analysis was conducted after pretreating the four components, utilizing a C18 column with Acetonitrile and H₂O as the mobile phase. UV detection was carried out at a wavelength of 254nm. As a result of the experiment, the values of Resolution(Rs) was well over Rs > 1.5, which indicates that the separation of the four components was efficient. Additionally, the symmetry factor of the components was 0.989, 1.120, 1.256, and 1.280, respectively, showing their symmetrical stability. In the stability assessment, the calibration curves for the four components showed excellent linearity with R² > 0.9991 to 0.9998. Furthermore, the limit of detection(LOD) ranged between 0.017 to 3.060㎍/ml, while the limit of quantification(LOQ) ranged between 0.050 to 9.180 ㎍/ml. The recovery rates range from 98.28% to 101.71%, and repeatability showed precision within the range of 0.447 to 0.550, and robustness confirmed values with %RSD < 2. The quantitative analysis results of this study demonstrated the effectiveness of a simultaneous analysis method for motion sickness medication components.

• Laboratory Medicine Online
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• v.2 no.1
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• pp.10-14
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• 2012

Background: Measurement of HbA_1c levels is widely used to diagnose diabetes mellitus and to evaluate and monitor plasma-glucose concentrations over 6-8 weeks. In this study, we evaluated the diagnostic performance of the newly developed latex immunoturbidimetric method by using Autolab HbA_1c. Methods: We analyzed and compared the diagnostic performance of Autolab HbA_1c with that of Toshiba 200FR between April 2009 and July 2009. According to guidelines (EP5-A2, EP6-P, EP9-A2) of the clinical and laboratory standards institute (CLSI), we compared linearity, precision and correlation of Autolab HbA_1c with those of G7 (Tosoh Corp., Kyoto, Japan) by using high-performance liquid chromatography (HPLC) method. Results: Data obtained using Autolab HbA_1c showed good linearity in mixtures of samples with low (3.1%) and high (15.1%) levels of HbA_1c (r²=0.9997). In the analysis of within-run precision of the samples with HbA_1c levels of 5.1% and 12.1%, the SDs were 0.04 and 0.06 and covariances of these samples were 0.8% and 0.5%, respectively. In the Deming regression model, the regression equation was as follows: Autolab HbA_1c=1.0859×Tosoh HPLC-0.6957. Conclusions: In this study, Autolab HbA_1c method showed better performance characteristics than Tosoh G7 did. In reference review, there was no interference of variant hemoglobin. The data acquisition time of Autolab HbA_1c was lower than that of Tosoh G7. The advantages of Autolab HbA_1c are that it can be used as an autoanlyzer in routine chemical analysis, it does not require pre-analytical treatment, and the samples are automatically treated with distilled water for hemolysis.

• Korean Journal of Food Science and Technology
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• v.44 no.3
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• pp.263-268
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• 2012

Novobiocin is a coumarin-containing antibiotic, and has a longer half-life in various animals than other veterinary medicines. A simple and rapid high-performance liquid chromatography assay for the determination of residual novobiocin levels in chicken, beef and milk has been developed and validated. The separation condition for HPLC/UVD was optimized by a MG II $C_{18}$ (4.6 mm $ID{\times}250$ mm, 5 ${\mu}m$) column with 0.1% formic acid in $H_2O$/0.1% formic acid in Acetonitrile (40/60, v/v) as the mobile phase at a flow rate of 1.0 mL/min and the detection wavelength was set at 340 nm. Residues were extracted from tissue by blending with methanol. After liquid-liquid partitioning, lipid materials were removed with n-hexane and purification as Silica (1 g, 6 mL) cartridge with 10 mL acetone/dichloromethane (10/90, v/v). Limit of quantification and linearity performed by the analytical method were 0.02 mg/kg and 0.999 ($r^2$), and the recovery range was $88.8{\pm}5.6-100.3{\pm}4.4$, $88.8{\pm}7.2-97.0{\pm}3.2$ and $88.1{\pm}4.3-92.8{\pm}3.6%$. It is expected that this analytical method with regards to novobiocin in chicken, beef and milk could be applied as an official method to administer food safety on veterinary medicines.

• Journal of Life Science
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• v.19 no.7
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• pp.994-1002
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• 2009

A bacteriocin-producing bacterium identified as Bacillus licheniformis was isolated from soybean sauce. Antibacterial activity was confirmed by paper disc diffusion method, using Micrococcus luteus as a test organism. The bacteriocin also showed antibacterial activities against Bacillus sphaericus, Lactobacillus bulgaricus, Lactobacillus planiarum, Paenibacillus polymyxa, and Pediococcus dextrinicus. Optimal culture conditions for the production of bacteriocin was attained by growing the cells in an MRS medium at a pH of 6.5~ 7.0 and a temperature of 37$^\circ$C for 36$\sim$48 hr. Solvents such as chloroform, ethanol, acetone, and acetonitrile had little effect on bacteriocin activity. However, about 50% of bacteriocin activity diminished with treatment of methanol and isopropanol at the final concentration of 50% at 25$^\circ$C for 1 hr. It was stable against a pH variation range from 3.0 and 7.0, but the activity reduced to 50% at a pH range from 9.0 to 11.0. It's activity was not affected by heat treatment at 100$^\circ$C for 30 min and 50% of activity was retained after heat treatment at 100$^\circ$C for 60 min, showing high thermostability. The bacteriocin was purified to a homogeneity through ammonium sulfate precipitation, SP-Sepharose ion-exchange chromatography, and reverse-phase high-performance liquid chromatography (HPLC). The entire purification protocol led to a 75-fold increase in specific activity and a 13.5% yield of bacteriocin activity. The molecular weight of purified bacteriocin was estimated to be about 2.5 kDa by tricine-SDS-PAGE.