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1.
Compr Psychiatry ; 127: 152432, 2023 11.
Article in English | MEDLINE | ID: mdl-37856975

ABSTRACT

BACKGROUND: This study estimated the association between pre-pandemic social network properties and symptoms of posttraumatic stress during the coronavirus disease 2019 (COVID-19) pandemic in South Korea. METHODS: We conducted four online mental health surveys during COVID-19 (from March 14, 2020, to December 11, 2021) among individuals enrolled in a community-based cohort study (previously recruited from 2013 to 2018). Among 4060 people interviewed at the pre-pandemic baseline, 2652 individuals (men = 951, women = 1701) who responded to at least one of the four surveys conducted were included. At baseline, each individual's social network, including size and average closeness, was measured in an egocentric way. Post Traumatic Stress Disorder Checklist for DSM-5 (PCL-5) was measured at each survey point. A generalized linear model and a generalized linear mixed model were used after stratified by sex. RESULTS: Among men, network size was negatively associated with total PCL-5 score (b = -0.42, SE = 0.16, p = 0.002). The magnitude of the association increased over time and was maximal by the 4th survey (b = -0.65, SE = 0.31, p = 0.037). Among women, average closeness was negatively associated with the total PCL-5 score (b = -1.16, SE = 0.37, p = 0.002). In analyses disaggregated by symptom clusters, social networks were associated explicitly with symptoms of intrusion and mood but not with avoidance and arousal symptoms. CONCLUSION: In this cohort of adults followed for more than a year during the outbreak of COVID-19 in South Korea, social networks established before the onset of the COVID-19 pandemic had a protective association against developing symptoms of PTSD during the first two years of the pandemic.


Subject(s)
COVID-19 , Stress Disorders, Post-Traumatic , Adult , Male , Humans , Female , Stress Disorders, Post-Traumatic/diagnosis , Stress Disorders, Post-Traumatic/epidemiology , Stress Disorders, Post-Traumatic/psychology , Cohort Studies , Pandemics , COVID-19/epidemiology , Social Networking
2.
Sci Rep ; 12(1): 14707, 2022 08 29.
Article in English | MEDLINE | ID: mdl-36038711

ABSTRACT

Identification of soft rot disease in napa cabbage, an essential ingredient of kimchi, is challenging at the industrial scale. Therefore, nondestructive imaging techniques are necessary. Here, we investigated the potential of hyperspectral imaging (HSI) processing in the near-infrared region (900-1700 nm) for classifying napa cabbage quality using nondestructive measurements. We determined the microbiological and physicochemical qualitative properties of napa cabbage for intercomparison of HSI information, extracted HSI characteristics from hyperspectral images to predict and classify freshness, and established a novel approach for classifying healthy and rotten napa cabbage. The second derivative Savitzky-Golay method for data preprocessing was implemented, followed by wavelength selection using variable importance in projection scores. For multivariate data of the classification models, partial least square discriminant analysis (PLS-DA), support vector machine (SVM), and random forests were used for predicting cabbage conditions. The SVM model accurately distinguished the cabbage exhibiting soft rot disease symptoms from the healthy cabbage. This study presents the potential of HSI systems for separating soft rot disease-infected napa cabbages from healthy napa cabbages using the SVM model, especially under the most effective wavelengths (970, 980, 1180, 1070, 1120, and 978 nm), prior to processing. These results are applicable to industrial multispectral images.


Subject(s)
Brassica , Hyperspectral Imaging , Least-Squares Analysis , Spectroscopy, Near-Infrared/methods , Support Vector Machine
3.
Epidemiol Health ; 44: e2022064, 2022.
Article in English | MEDLINE | ID: mdl-35940179

ABSTRACT

OBJECTIVES: The aim of this study was to explore factors affecting attitudes toward coronavirus disease 2019 (COVID-19) vaccination, including socio-demographic characteristics and mental health status during the pandemic. METHODS: This study analyzed responses from 1,768 participants who were originally included in a community cohort study and responded to 3 online surveys related to COVID-19 (March 2020 to March 2021). The k-means method was used to cluster trust in and intention to receive COVID-19 vaccination. Baseline (2013-2018) socio-demographic characteristics, physical health status, and depressive symptoms were analyzed as exposure variables, and current mental health status was included in the analyses. RESULTS: Almost half of all participants were classified into the moderate trust and high intention cluster (n=838, 47.4%); those with high trust and high intention accounted only for 16.9%. They tended to be older, had high-income levels, and engaged in regular physical activity at baseline (p<0.05), and their sleep quality and psychological resilience were relatively high compared to other groups. CONCLUSIONS: Our results suggest that more efforts are required to enhance the perceived need for and trust in COVID-19 vaccination.


Subject(s)
COVID-19 , Intention , Humans , Longitudinal Studies , Cohort Studies , Mental Health , COVID-19 Vaccines , Trust , COVID-19/epidemiology , COVID-19/prevention & control , Vaccination , Republic of Korea/epidemiology
4.
Front Microbiol ; 13: 885413, 2022.
Article in English | MEDLINE | ID: mdl-35663872

ABSTRACT

Processes in the food industry that use large amounts of water have been an important cause of waterborne disease outbreaks, as they expose individuals to risks for waterborne disease transmission. Developing technologies to ensure the hygiene and safety of food-processing steps is an urgent concern from an economic perspective. Furthermore, economic benefits can be derived if the processed water can be reused under microbiologically safe conditions. Among the major manufacturing processes in the kimchi industry, the brining process for salted kimchi cabbages requires a considerable amount of brine (approximately 2,000-2,500 l/1,000 kg of raw cabbage). The aim of this study was to establish virucidal conditions with ultraviolet-C light-emitting diodes (UVC LEDs) that can ensure the microbiological safety of brine water samples with various turbidities for reuse after disinfection. For quantitative analysis, first of all, magnetic bead separation (MBS) technique was used to capture and recover the human norovirus (HuNoV) virus particles; propidium monoazide (PMA) combined with RT-qPCR (PMA-RT-qPCR) was subsequently used to selectively detect infectious norovirus. Overall, as the turbidity of the brine water samples increased, the reduction in the HuNoV genogroup II genotype 4 (HuNoV GII.4) levels by UVC LED disinfection decreased. The derived inactivation rate constant (kinac ) and inactivation curves (calculated using the log-linear model) were studied as a function of turbidity based on the exponential one-phase inactivation kinetics of HuNoV. Using an impeller system set at 100 rotations/min (rpm) with an eight-nephelometric turbidity unit (NTU) sample (the lowest turbidity studied), the kinact based on the levels of viral genomic RNA concentrations was approximately 2.15-fold higher than that observed without rotation (0 rpm). Moreover, the kinact increased 1.69-fold with a 56-NTU sample (the highest turbidity studied) when the impeller system was set at 100 rpm. UVC LED treatment decreased the HuNoV GII.4 population more effectively in conjunction with the impeller system (100 rpm) than without the impeller system. Our novel findings and model provide fundamental and scientific data that may help reuse brine water and ensure its microbiological safety through disinfection. Our study highlights the benefits of UVC LED treatment in successfully eliminating waterborne viruses in a prompt, resistance-reducing, and energy-efficient approach at the laboratory scale, which lays the foundation for future plant-scale studies of UVC LED-disinfection systems.

5.
Front Psychiatry ; 13: 893290, 2022.
Article in English | MEDLINE | ID: mdl-35733804

ABSTRACT

Background: This study aimed to investigate how social networks are associated with cognitive function in the middle-aged and elderly Korean population. Methods: A total of 7,704 individuals over the age of 50 were included from the baseline recruitment of the Cardiovascular and Metabolic Diseases Etiology Research Center cohort from the years 2013 to 2018. Egocentric social network characteristics including network size, intimacy, and frequency of face-to-face meetings were measured as exposures, and the Korean version of Mini-Mental State Examination (K-MMSE) score was measured to reflect general cognitive function as an outcome. We also stratified the analysis by income level into tertiles, with income caps of 42,000 thousand won and 72,000 thousand won. A general linear regression model was used, adjusting for age, gender, socioeconomic factors, lifestyle factors, depressive symptoms, and study settings. Results: Social network properties were positively associated with cognitive function in both men and women. However, the specific estimates varied according to gender and income level. In men, frequency was most significantly associated with cognitive function (standardized ß = 0.093, p-value <0 .0001). In women, the strength of the association with cognitive function was found in size (standardized ß = 0.055, p-value = 0.001). The effect modification of income level could be seen in the association between frequency and cognitive function. The strongest association between frequency and cognitive function was found in the middle income group in men (standardized ß = 0.114, p-value = 0.0063), and the low income group in women (standardized ß = 0.076, p-value = 0.0039). Conclusion: There were positive associations between social network properties (i.e., size, intimacy, and frequency of face-to-face meetings) and cognitive function. The degree of association varied according to social network properties, gender, and income level. Overall, among social network properties, social network size was an important factor in the cognition of women, whereas frequency was important in the cognition of men.

6.
Food Sci Biotechnol ; 31(1): 131-138, 2022 Jan.
Article in English | MEDLINE | ID: mdl-35059237

ABSTRACT

This study aimed to evaluate the virucidal effect and potential use as a disinfectant of undiluted and diluted slightly acidic electrolyzed water (SAEW) on human noroviruses (HuNoVs) using the in vitro suspension test and in food test. The oxidization reduction potential of SAEW gradually decreased with the increase in distilled water volume. Moreover, as the volume of distilled water and the dilution ratio increased, the available chlorine concentration of the samples significantly decreased from 31.2 ± 0.63 (SAEW) to 1.3 ± 0.21 (1:10 dilution of SAEW solution) (p < 0.05). Undiluted SAEW presented the lowest pH (5.56 ± 0.02) and as SAEW was diluted in distilled water, the pH of the sample increased. Considering the standard reduction values of pathogenic virus (> 4.00 log reduction), the reduction value of HuNoVs in cabbage samples was 4.65 (GI.6) and 4.28 (GII.4) log. These results suggest the potential application of SAEW for inactivating HuNoVs in the food industry. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10068-021-01011-w.

7.
Int J Mol Sci ; 22(24)2021 Dec 14.
Article in English | MEDLINE | ID: mdl-34948233

ABSTRACT

Fatty acid synthase (FASN) plays an important role in cancer development, providing excess lipid sources for cancer growth by participating in de novo lipogenesis. Although several inhibitors of FASN have been developed, there are many limitations to using FASN inhibitors alone as cancer therapeutics. We therefore attempted to effectively inhibit cancer cell growth by using a FASN inhibitor in combination with an inhibitor of a deubiquitinating enzyme USP14, which is known to maintain FASN protein levels in hepatocytes. However, when FASN and USP14 were inhibited together, there were no synergistic effects on cancer cell death compared to inhibition of FASN alone. Surprisingly, USP14 rather reduced the protein levels and activity of FASN in cancer cells, although it slightly inhibited the ubiquitination of FASN. Indeed, treatment of an USP14 inhibitor IU1 did not significantly affect FASN levels in cancer cells. Furthermore, from an analysis of metabolites involved in lipid metabolism, metabolite changes in IU1-treated cells were significantly different from those in cells treated with a FASN inhibitor, Fasnall. These results suggest that FASN may not be a direct substrate of USP14 in the cancer cells. Consequently, we demonstrate that USP14 regulates proliferation of the cancer cells in a fatty acid synthase-independent manner, and targeting USP14 in combination with FASN may not be a viable method for effective cancer treatment.


Subject(s)
Cell Proliferation , Fatty Acid Synthase, Type I/metabolism , Neoplasm Proteins/metabolism , Neoplasms/enzymology , Ubiquitin Thiolesterase/metabolism , A549 Cells , Fatty Acid Synthase, Type I/genetics , HEK293 Cells , Humans , MCF-7 Cells , Neoplasm Proteins/antagonists & inhibitors , Neoplasm Proteins/genetics , Neoplasms/genetics , Neoplasms/pathology , Pyrroles/pharmacology , Pyrrolidines/pharmacology , Ubiquitin Thiolesterase/antagonists & inhibitors , Ubiquitin Thiolesterase/genetics , Ubiquitination/drug effects , Ubiquitination/genetics
8.
J Psychosom Res ; 148: 110552, 2021 09.
Article in English | MEDLINE | ID: mdl-34171768

ABSTRACT

OBJECTIVE: We aimed to investigate the mental health impact of COVID-19 on a demographically well-characterized population cohort by gender and previous depression status. METHODS: Among people who participated in a community cohort study between 2013 and 2018 with previous depression measurement, a total of 1928 people without quarantine experience (680 men and 1249 women) were included after responding to an online survey in March 2020. In the 2020 survey, people were queried about daily needs supply, social support, risk perception, change during the COVID-19 pandemic, as well as mental health indices measuring loneliness, anxiety symptoms, post-traumatic stress disorder (PTSD), and depression. Separate analyses by gender were conducted to assess the association between COVID-19-related experiences and each mental health index, using multivariable logistic regressions with additional adjustment and stratification with pre-existing depression status. RESULTS: We could not observe significant gender differences for depression, anxiety, PTSD, and loneliness at 55 days after the start of the COVID-19 outbreak. Most external support, including daily needs supply and social support, protected men and women from experiencing severe anxiety (for life supply, OR = 0.92 (95%CI 0.88-0.97) (men) and OR = 0.95 (95% CI 0.91-0.99) (women); for social support, OR = 0.92(both for men and women, p < 0.01)). The results were similar for depression and PTSD. External support showed a larger reduction in the likelihoods for anxiety and depression during the COVID-19 pandemic among people with pre-existing depression compared to previously healthy people, and it was more prominent in men. CONCLUSION: COVID-19 significantly affected the mental health of both men and women in the early period of the pandemic. Having enough supply of daily needs and social support seems important, especially for people with previous depression.


Subject(s)
COVID-19/epidemiology , Depression/epidemiology , Health Surveys , Mental Health/statistics & numerical data , Adult , Aged , Anxiety/epidemiology , Causality , Female , Humans , Male , Middle Aged , Pandemics , Prospective Studies , SARS-CoV-2 , Stress Disorders, Post-Traumatic/epidemiology , Time Factors
9.
J Affect Disord ; 290: 109-116, 2021 07 01.
Article in English | MEDLINE | ID: mdl-33993077

ABSTRACT

BACKGROUND: The present study aimed to investigate the association between resilience and cognitive function of middle-aged Koreans in a longitudinal setting. METHODS: We utilized the baseline and 5-year follow-up data from the Cardiovascular and Metabolic Diseases Etiology Research Center study. The final number of participants included in the analysis was 397 (108 men, 289 women, mean age 55.4 years) who had valid measurements of both baseline resilience and Mini-Mental State Estimation at follow-up. The resilient people at baseline were operationally defined as the people who had at least one negative experience in the Life Experience Survey without depression, which was defined as a Beck Depressive Inventory-Ⅱ score of 20 or above. Cognitive function was evaluated by the Korean version of the Mini-Mental State Examination in both surveys. A generalized linear model was applied after adjusting for confounders. The association between resilience and cognitive function was further analyzed using stratification by median age and education level. RESULTS: At follow-up, only in men, the resilience group showed a higher MMSE level compared to the reference group (ß = 1.3, p = 0.002). Stratified by median age, both the younger group (ß = 1.2, SE = 0.5, p = 0.031) and the older group among men (ß = 2.1, SE = 0.7, p = 0.0069) showed a positive association between resilience and cognitive functions. However, when stratified by education level, only the low-education group presented the association (ß = 1.7, SE = 0.5, p = 0.002). In women, no significant results were found. LIMITATION: This study had limited number of participants. CONCLUSION: Resilience at baseline was associated with more well-preserved cognitive function at follow-up in men.


Subject(s)
Resilience, Psychological , Cognition , Female , Follow-Up Studies , Humans , Longitudinal Studies , Male , Mental Status and Dementia Tests , Middle Aged , Surveys and Questionnaires
10.
Brain Behav ; 11(5): e02091, 2021 05.
Article in English | MEDLINE | ID: mdl-33638932

ABSTRACT

BACKGROUND: There are several ways to determine psychological resilience. However, the correlation between each measurement is not clear. We explored associations of baseline relative "resilience" and risk with later self-reported trait resilience and other biological/mental health indices. METHODS: We utilized baseline and follow-up survey data from 500 participants aged 30-64 in the community cohort. Baseline "relative" resilience was defined by: (a) negative life events (NLEs) in the six months before baseline and (b) depressive symptoms at baseline, yielding four groups of individuals: i) "Unexposed and well," "Vulnerable (depression)," "Reactive (depression)," and "Resilient." "Trait" resilience at follow-up was self-reported using the Connor-Davidson Resilience Scale (CD-RISC). Associations between relative resilience at baseline, CD-RISC, and heart rate variability (HRV) indices at follow-up were assessed with generalized linear regression models after adjustments. Associations between baseline resilience and subsequent loneliness/depression indices were also evaluated. RESULTS: Overall trait resilience and its subfactors at follow-up showed strong negative associations with "Reactive" at baseline (adj-ß for total CD-RISC score: -11.204 (men), -9.472 (women)). However, resilience at baseline was not associated with later HRV, which was compared with the significant positive association observed between CD-RISC and HRV at the same follow-up time point. The "Reactive" exhibited significantly increased depressive symptoms at follow-up. The overall distribution pattern of CD-RISC subfactors differed by baseline resilience status by sex. CONCLUSIONS: The "relative" resilience based on the absence of depression despite prior adversity seems to be highly related with trait resilience at follow-up but not with HRV. The sub-factor pattern of CD-RISC was different by sex.


Subject(s)
Resilience, Psychological , Female , Heart Rate , Humans , Male , Mental Health , Prospective Studies , Psychometrics , Self Report , Surveys and Questionnaires
11.
J Food Sci Technol ; 58(1): 389-396, 2021 Jan.
Article in English | MEDLINE | ID: mdl-33505084

ABSTRACT

Kimchi is a traditional Korean fermented vegetable, which is also widely consumed in Japan and China. However, little is known about the kimchi proteome. In this study, Korean and Chinese kimchi proteomes were evaluated by shotgun proteomics. A total of 250 proteins were annotated, and 29 of these were expressed at > 1% of the average relative abundance. Discrimination of the geographical origins of Korean and Chinese kimchi samples was possible using multivariate analysis of the proteomic data, and 23 proteins were expressed differently between the two types (p < 0.001), and represent possible markers to discriminate between Chinese and Korean kimchi. This study provides important insights into the kimchi proteome and illustrates the proteomic differences caused by geographical origin.

12.
J Microbiol Biotechnol ; 31(1): 70-78, 2021 Jan 28.
Article in English | MEDLINE | ID: mdl-33203818

ABSTRACT

Identifying the extracellular metabolites of microorganisms in fresh vegetables is industrially useful for assessing the quality of processed foods. Pectobacterium carotovorum subsp. carotovorum (PCC) is a plant pathogenic bacterium that causes soft rot disease in cabbages. This microbial species in plant tissues can emit specific volatile molecules with odors that are characteristic of the host cell tissues and PCC species. In this study, we used headspace solid-phase microextraction followed by gas chromatography coupled with mass spectrometry (HS-SPME-GC-MS) to identify volatile compounds (VCs) in PCC-inoculated cabbage at different storage temperatures. HS-SPME-GC-MS allowed for recognition of extracellular metabolites in PCC-infected cabbages by identifying specific volatile metabolic markers. We identified 4-ethyl-5-methylthiazole and 3-butenyl isothiocyanate as markers of fresh cabbages, whereas 2,3-butanediol and ethyl acetate were identified as markers of soft rot in PCC-infected cabbages. These analytical results demonstrate a suitable approach for establishing non-destructive plant pathogen-diagnosis techniques as alternatives to standard methods, within the framework of developing rapid and efficient analytical techniques for monitoring plant-borne bacterial pathogens. Moreover, our techniques could have promising applications in managing the freshness and quality control of cabbages.


Subject(s)
Gas Chromatography-Mass Spectrometry/methods , Pectobacterium/metabolism , Solid Phase Microextraction/methods , Volatile Organic Compounds/analysis , Acetates , Biomarkers , Brassica , Butylene Glycols , Odorants/analysis , Plant Diseases , Temperature
13.
J Food Sci ; 85(12): 4170-4179, 2020 Dec.
Article in English | MEDLINE | ID: mdl-33190231

ABSTRACT

Cabbage kimchi, a popular side dish in Korean cuisine, produces several fermentation by-products (FBPs). Kimchi is praised for its flavor, taste, and texture when suitably fermented at 0.7% to 0.9% total acidity, or a pH of approximately 4.1. Beyond this acidity level, the quality of the product decreases, negatively impacting consumers' purchase preferences. Therefore, the current study seeks to develop an optimally fermented (OptF) kimchi indicator that can be inserted into product packaging to evaluate its utility at 4 and 10 °C. A gradual change in the total color difference (ΔE) was observed during the kimchi fermentation stage, and the highest ΔE values were observed at 4 (34.87) and 10 °C (37.99), after 9 weeks. Moreover, the color-change response function value F(Xc) was more linear at 4 and 10 °C (0.981 and 0.984, respectively) compared to the ΔE over time, during kimchi fermentation. Coefficients of determination for F(Xc)-carbon dioxide (0.983), F(Xc)-pH (0.979), and F(Xc)-titratable acidity (0.974) were sufficient to meet the optimal polynomial regression model, while that for F(Xc)-lactic acid bacteria (0.881) was not. Standardized residuals of predicted data indicated that 95% of the residuals were in the range of -2.0 to 2.0. The regression analysis further suggested that the OptF kimchi indicator could be used as a kimchi fermentation indicator. PRACTICAL APPLICATION: Cabbage kimchi, a traditional Korean fermented food, produces several fermentation by-products. After the optimal fermenting stage, the sensory evaluation of cabbage kimchi and consumers' purchase preference decreases. This study describes an optimally fermented kimchi indicator and its utility at 4 and 10 °C. Our results demonstrate the ability of this indicator to predict the freshness and fermentation stage of kimchi without the need for sensory evaluation. This method could help increase the purchase preference for commercial kimchi.


Subject(s)
Brassica rapa/chemistry , Fermentation , Fermented Foods/standards , Food Technology/methods , Brassica rapa/microbiology , Colorimetry , Fermented Foods/analysis , Food Microbiology , Lactobacillales/growth & development , Taste
14.
J Food Sci ; 85(12): 4359-4366, 2020 Dec.
Article in English | MEDLINE | ID: mdl-33216385

ABSTRACT

Long-term storage of chili pepper powder results in physicochemical and microbiological changes that decrease its commercial value; these changes occur owing to fungal growth and production of off-flavor compounds. Herein, long-term-stored chili pepper powder (LSCPP) and fresh chili pepper powder (FCPP) were analyzed using internal transcribed spacer sequencing and volatile organic compound fingerprinting by headspace capillary-gas chromatography-ion mobility spectrometry. Fungal analysis detected only Xeromyces bisporus with high accuracy in all the analyzed LSCPP samples. However, the proliferation of X. bisporus on nonspecific spots complicated the distinguishing process between the two groups based solely on fungal analysis. Therefore, nine compounds (three ketones, one alcohol, two aldehydes, one ester, one furan, and one sulfur compound) obtained by autoxidation and fungal metabolism were selected as potential markers for distinguishing LSCPP and FCPP. These above-mentioned substances, which were confirmed as off-flavor species owing to "stale" odor, emitted lipid fragrance and were used to successfully distinguish LSCPP from FCPP using principal component analysis and linear discriminant analysis. PRACTICAL APPLICATION: According to the research results, it was possible to discriminate between long-term stored and fresh chili pepper powders using nine VOC markers for quality control in industry. In addition, the fungus generated from long-term storage of chili pepper powder was Xeromyces bisporus, which was confirmed to be safe for intake because it does not form secondary toxic metabolites.


Subject(s)
Capsicum/chemistry , Eurotiales/isolation & purification , Food Storage/methods , Gas Chromatography-Mass Spectrometry/methods , Ion Mobility Spectrometry/methods , Powders/chemistry , Volatile Organic Compounds/analysis , Aldehydes/analysis , Capsicum/microbiology , Gas Chromatography-Mass Spectrometry/instrumentation , Ion Mobility Spectrometry/instrumentation , Taste , Vegetables/chemistry , Vegetables/microbiology
15.
ACS Omega ; 5(33): 20825-20830, 2020 Aug 25.
Article in English | MEDLINE | ID: mdl-32875217

ABSTRACT

Quinolizidine alkaloids (QAs) are toxic secondary metabolites of Lupinus plants. This study reports the simultaneous quantification of five alkaloids from Lupinus angustifolius L. and its processed foods by ultraperformance liquid chromatography with electrospray ionization mass spectrometric detection. After optimizing the extraction conditions, the analytical method was validated for the QAs in lupin beans and in three major processed foods through detection and quantification limits, linearity, precision, and accuracy. The detection and quantification limits of the QAs were 0.5-1.7 and 1.5-5.7 mg kg-1, respectively. The linearity was greater than 0.9992 and the precision was less than 3.1%. The recoveries of three different concentrations of each QA were 89.5-106.2%. For both raw lupin beans and processed foods, lupanine was the major QA, and 13-hydroxylupanine and angustifoline were detected in lower amounts. This method could be widely used for accurate risk assessment of QAs.

16.
J Microbiol Biotechnol ; 29(10): 1580-1590, 2019 Oct 28.
Article in English | MEDLINE | ID: mdl-31474094

ABSTRACT

Capsaicinoids in red pepper powder are known to show anti-bacterial effects; however, their effects during kimchi fermentation are not known. This study aimed to investigate the effects of various concentrations of capsaicinoids on kimchi fermentation. Five sets of kimchi samples were prepared using 0 mg/kg (control), 98.34 ± 5.34 mg/kg (mild), 243.47 ± 3.71 mg/kg (medium), 428.63 ± 30.78 mg/kg (hot), and 1,320.49 ± 28.27 mg/kg (extreme) capsaicinoid. The characteristics of each kimchi sample, including pH, acidity, organic acid, sugars, sugar alcohol, capsaicinoid content, and microbial community were periodically investigated during fermentation. Kimchi with red pepper powder shows significantly higher acidity than control kimchi, whereas pH values were the same. Organic acid in kimchi with red pepper powder was higher than in control kimchi, probably caused by higher lactic acid bacteria (LAB) counts in kimchi samples with red pepper powder. Our results show that addition of red pepper powder decreased Leuconostoc spp. counts in the bacterial community. In particular, Lactobacillus sakei and Leuconostoc gelidum counts increased and decreased, respectively, with increasing capsaicinoid content of red pepper powder added to kimchi. Overall, the results of this study indicate that physicochemical properties and LAB such as L. sakei and L. gelidum are influenced by capsaicinoid content. However, further studies are necessary to investigate the effects of the percentage of red pepper powder in kimchi on fermentation to provide practical guidelines for producing standardized kimchi.


Subject(s)
Brassica/microbiology , Capsaicin/analysis , Fermented Foods/analysis , Fermented Foods/microbiology , Microbiota , Acids/analysis , Bacteria/classification , Bacteria/genetics , Bacteria/growth & development , Bacteria/isolation & purification , Capsicum/chemistry , Fermentation , Food Microbiology , Hydrogen-Ion Concentration , Sugars/analysis
17.
J Sci Food Agric ; 99(14): 6474-6481, 2019 Nov.
Article in English | MEDLINE | ID: mdl-31294829

ABSTRACT

BACKGROUND: Kimchi, a Korean food, is now produced and consumed in many other countries. In this study, the macro, trace, and toxic element content in varieties of kimchi from Korea and China was evaluated. A health-risk assessment, involving the calculation of estimated dietary intake values, was undertaken. To discriminate among samples with different origins, linear discriminant analysis (LDA) and principal component analysis (PCA) were applied. RESULTS: The analytical methods used for analyses were successfully validated. In the quantification of elements, no significant differences were detected in the concentrations of the elements that were analyzed. Based on the fresh weight of kimchi, among the macro elements, the concentrations of Na and K were relatively high, with values of 4181.9-9919.8 mg kg-1 and 1661.8-6623.5 mg kg-1 , respectively. Among the trace elements that were analyzed, zinc in Korean samples, and strontium in Chinese samples showed the highest concentrations, at 2.67 and 2.98 mg kg-1 , respectively. Concentration levels of the toxic trace elements were within permissible limits. The amount of daily intake and provisional daily intake of each element calculated based on kimchi intake confirmed its safety for consumption. Linear discriminant analysis and PCA successfully discriminated among the samples of Chinese and Korean origin. CONCLUSION: The provisional daily intake of the toxic elements was within provisional tolerable daily intake values. The normal intake of kimchi could not pose a threat upon consumption. © 2019 Society of Chemical Industry.


Subject(s)
Fermented Foods/analysis , Trace Elements/analysis , Vegetables/chemistry , China , Consumer Product Safety , Discriminant Analysis , Humans , Principal Component Analysis , Republic of Korea , Risk Assessment , Trace Elements/toxicity
18.
Nutr Res Pract ; 13(2): 87-94, 2019 Apr.
Article in English | MEDLINE | ID: mdl-30984352

ABSTRACT

BACKGROUND/OBJECTIVES: Oxidative stress is a major effector of various diseases; accordingly, antioxidants are frequently ingested in order to prevent or alleviate disease symptoms. Kimchi contains various natural antioxidants, and it is known that the functional activity varies depending on the ingredients and fermentation state. Black raspberries (BR) contain various bioactive compounds with antioxidant effects. This study investigated the antioxidant and liver-protection effects of kimchi supplemented with black raspberry juice powder (BJP). MATERIALS/METHODS: BJP-added kimchi (BAK; at 0.5%, 1%, and 2% concentrations of BJP) and control (without BJP) were prepared and fermented at 4℃ for 4 weeks. Changes in the antioxidant effects of BAK during fermentation were investigated. In addition, the protective activity of BAK against oxidative stress was investigated in a liver cirrhosis-induced animal model in vivo. RESULTS: BAK groups showed the acidity and pH of optimally ripened (OR) kimchi at 2 weeks of fermentation along with the highest lactic acid bacterial counts. Additionally, BAK groups displayed a higher content of phenolic compounds and elevated antioxidant activities relative to the control, with the highest antioxidant effect observed at 2 weeks of fermentation of OR 1% BAK. After feeding the OR 1% BAK to thioacetamide-induced liver cirrhosis rats, we observed decreased glutamate oxaloacetate transaminase and glutamate pyruvate transaminase activities and elevated superoxide dismutase activity. CONCLUSIONS: These findings showed that the antioxidant effects of OR BAK and feeding of OR 1% BAK resulted in liver-protective effects against oxidative stress.

19.
Environ Health Toxicol ; 30: e2015007, 2015.
Article in English | MEDLINE | ID: mdl-26602558

ABSTRACT

OBJECTIVES: The widely promising applications of graphene nanomaterials raise considerable concerns regarding their environmental and human health risk assessment. The aim of the current study was to evaluate the toxicity profiling of graphene family nananomaterials (GFNs) in alternative in vitro and in vivo toxicity testing models. METHODS: The GFNs used in this study are graphene nanoplatelets ([GNPs]-pristine, carboxylate [COOH] and amide [NH2]) and graphene oxides (single layer [SLGO] and few layers [FLGO]). The human bronchial epithelial cells (Beas2B cells) as in vitro system and the nematode Caenorhabditis elegans as in vivo system were used to profile the toxicity response of GFNs. Cytotoxicity assays, colony formation assay for cellular toxicity and reproduction potentiality in C. elegans were used as end points to evaluate the GFNs' toxicity. RESULTS: In general, GNPs exhibited higher toxicity than GOs in Beas2B cells, and among the GNPs the order of toxicity was pristine>NH2>COOH. Although the order of toxicity of the GNPs was maintained in C. elegans reproductive toxicity, but GOs were found to be more toxic in the worms than GNPs. In both systems, SLGO exhibited profoundly greater dose dependency than FLGO. The possible reason of their differential toxicity lay in their distinctive physicochemical characteristics and agglomeration behavior in the exposure media. CONCLUSIONS: The present study revealed that the toxicity of GFNs is dependent on the graphene nanomaterial's physical forms, surface functionalizations, number of layers, dose, time of exposure and obviously, on the alternative model systems used for toxicity assessment.

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