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.
The associations between hypertension, diabetes, and dyslipidemia with Bell's palsy have been controversial and only a few studies have assessed risk factors for Bell's palsy based on ...population-based data. The aim of the present study was to evaluate whether sociodemographic factors such as sex, age, residence, household income, and metabolic diseases such as hypertension, diabetes, and dyslipidemia were risk factors for Bell's palsy using the National Health Insurance Service National Sample Cohort data of Korea. Patients who visited an outpatient clinic twice or more or had one or more admission and received steroid medication under the International Classification of Diseases diagnostic codes for Bell's palsy from 2006 to 2015 were defined as patients with Bell's palsy in this study. The associations between sociodemographic factors and metabolic diseases to Bell's palsy were analyzed with univariate and multivariate Cox proportional hazard regression models. There were 2708 patients with Bell's palsy recorded from 2006 to 2015. Male sex, advanced age, residence in a location other than the capital and metropolitan cities, hypertension, and diabetes were significant risk factors for Bell's palsy. This study is significant for patients and providers because we analyzed the relationships using a population-based database over a long-term follow-up period.
Animals often must decide whether or not to consume a diet that contains competing attractive and aversive compounds. Here, using the fruit fly, Drosophila melanogaster, we describe a mechanism that ...influences this decision. Addition of bitter compounds to sucrose suppressed feeding behavior, and this inhibition depended on an odorant-binding protein (OBP) termed OBP49a. In wild-type flies, bitter compounds suppressed sucrose-induced action potentials, and the inhibition was impaired in Obp49a mutants. However, loss of OBP49a did not affect action potentials in sugar- or bitter-activated gustatory receptor neurons (GRNs) when the GRNs were presented with just one type of tastant. OBP49a was expressed in accessory cells and acted non-cell-autonomously to attenuate nerve firings in sugar-activated GRNs when bitter compounds were combined with sucrose. These findings demonstrate an unexpected role for an OBP in taste and identify a molecular player involved in the integration of opposing attractive and aversive gustatory inputs.
•Control of sweet/bitter taste interaction by an odorant-binding protein•Inhibition of sweet-activated gustatory neurons by an odorant-binding protein•Bitter compounds inhibit the sweet response by binding to OBP49a
Bitter compounds inhibit sugar-responsive neurons through a poorly understood mechanism. Jeong et al. find that a Drosophila odorant-binding protein is released from accessory cells, binds bitter tastants, and acts at the surface of sugar neurons to inhibit their activity.
Cross‐contamination of Pectobacterium carotovorum subsp. carotovorum (PCC) from a stainless‐steel surface to cabbage (Brassica rapa L. subsp. pekinensis) was evaluated. To investigate the PCC ...transfer pattern from mechanical knife surfaces to cabbage during 100 cuts, two mathematical models (power and logarithmic model) were fitted to the mean log10 detection data from cabbage. Overall, regression analysis determined that the best‐fitting regression curves of planktonic cells and detached cells from biofilms transferred onto fresh cabbage were Y = 3.7X–0.41, RMSE = 0.371 and Y = 4.6X–0.35, RMSE = 0.254, respectively. For salted cabbage, the best‐fit regression curves of planktonic cells and biofilm were Y = 5.8X–0.38, RMSE = 0.209 and Y = 5.4X–0.23, RMSE = 0.195, respectively. Our data provide a meaningful indication of the level of PCC cross‐contamination.
The inhibitory effect of bioactive components from Houttuynia cordata (H. cordata) on advanced glycation end-products (AGEs) by trapping methylglyoxal (MGO) was investigated. MGO and its adducts of ...quercitrin, chlorogenic acid, rutin was analyzed by using liquid chromatography-mass spectrometry (LC-MS/MSn). The remaining MGO were 52.3, 26.7, and 9.4% for chlorogenic acid, quercitrin, and rutin, respectively and the mono- or di-MGO conjugated adducts of quercitrin and rutin were identified at 24 h of reaction. The formation of AGEs was detected through the reaction of glucose with protein by the fluorescence method. During the glycation reaction, quercitrin, rutin, and methanol extract of H. cordata decreased the production level of AGEs by 91–94.6 %. H. cordata containing chlorogenic acid, quercitrin, and rutin may have potential role in minimizing AGEs formation.
•Quercitrin, rutin, and cholorgenic acid were identified as major polyphenols in 50% methanol extract of Houttuynia cordata.•H. cordata extract as well as its polyphenols scavenged MGO.•MGO formed mono- or di-MGO adducts of quercitrin and rutin.•H. cordata extract as well as its polyphenols inhibited AGE formation during glycation reaction.•Methanol extract of H. cordata inhibited the formation of AGEs though trapping MGO.
RT-qPCR allows sensitive detection of viral particles of both infectious and noninfectious viruses in water environments, but cannot discriminate non-infectious from infectious viruses. In this ...study, we aimed to optimize RT-qPCR-based detection of chlorine-inactivated human norovirus (NoV) and pepper mild mottle virus (PMMoV) in suspension by pretreatment with an optimal combination of a monoazide and a detergent that can efficiently penetrate damaged viral capsids. Four methods were compared to determine the efficacy of chlorine disinfection (at 1, 3, and 5 min mg/L): (A) RT-qPCR alone, (B) RT-qPCR assay preceded by magnetic bead separation for enrichment of viral particles (MBS-RT-qPCR), (C) MBS-RT-qPCR assay with pretreatment with propidium monoazide (PMA-MBS-RT-qPCR), and (D) PMA-MBS-RT-qPCR assay with pretreatment with sodium lauroyl sarcosinate (INCI-PMA-MBS-RT-qPCR). On the basis of a PMA optimization assay, 200 and 300 μM PMA were used in subsequent experiments for NoV GII.4 and PMMoV, respectively. Optimal INCI concentrations, having minimal influence on NoV GII.4 and PMMoV, were found to be 0.5% and 0.2% INCI, respectively. For NoV GII.4, there were significant differences (P < 0.05) in log10 genome copies between the PMA-treated and the INCI + PMA-treated samples (log10 genome copies differed by 1.11 and 0.59 log10 for 3 and 5 min mg/L of chlorine, respectively). For PMMoV, INCI induced differences in log10 genome copies of 0.92, 1.18, and 1.86, for 1, 3, and 5 min mg/L of chlorine, respectively. Overall, the results of this study indicate that an optimal combination of PMA and INCI could be very useful for evaluating disinfection methods in water treatment strategies.
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•Propidium monoazide (PMA) pretreatment improves RT-qPCR detection of NoV and PMMoV.•Sodium lauroyl sarcosinate (INCI) pretreatment further improves virus detection.•Chlorine disinfection (1–5.0 min mg/L) effectively reduces NoV and PMMoV titers.•PMA and INCI might help evaluate disinfection methods in water treatment strategies.
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.
The geographical origin of kimchi is of interest to consumers and producers because the prices of commercial kimchi products can vary significantly according to the geographical origin. Hence, social ...issues related to the geographical origin of kimchi in Korea have emerged as a major problem. In this study, the geographical origin of kimchi was determined by comparing the mass fingerprints obtained for Korean and Chinese kimchi samples by MALDI-TOF MS with multivariate analysis. The results obtained herein provide an accurate, powerful tool to clearly discriminate kimchi samples based on their geographical origin within a short time and to ensure food authenticity, which is of significance in the kimchi industry. Furthermore, our MALDI-TOF MS method could be applied to determining the geographical origin of other fermented-salted vegetables at a reduced cost in shorter times.
Slightly acidic electrolyzed water (SAEW) is an effective disinfectant used to control food poisoning bacteria. In this study, we evaluated the sterilization effect of an SAEW stock solution and ...5–90% SAEW solutions, and the potential for bacterial reactivation after disinfection. SAEW stock solution at ACC of 31.2 ± 0.22 mg/L, pH of 5.51 ± 0.01, ORP of 895 ± 6 mV for disinfection effect assessment was used. SAEW at a concentration of 40% resulted in a >6 log reduction in Yersinia enterocolitica in a suspension test and on cabbage. Analysing the bactericidal efficacies of 5–90% SAEW indicated that a concentration of >70% SAEW thoroughly eliminated Y. enterocolitica. Additionally, SAEW-sterilized cabbage was stored at 5 °C, 10 °C, 20 °C, and 30 °C for one week to investigate the resilience of the damaged bacteria. Following the disinfection with 40% SAEW, cabbage must be stored at a low temperature of <10 °C to prevent the regrowth of Y. enterocolitica. The results from this study support the use of >70% SAEW and indicate that the storage temperature of cabbage following the disinfection and washing are important for ensuring food safety.
•Diluted slightly acidic electrolyzed water (SAEW) is an effective disinfectant.•The oxidation reduction potential of the SAEW dilution was related to efficacy.•SAEW (40%) resulted in a >6 log reduction, and >70% SAEW eliminated Y. enterocolitica.•For 40% SAEW, cabbage must be stored at <10 °C to prevent bacterial reactivation.
Circulating neutrophil gelatinase-associated lipocalin (NGAL) is associated with obesity-related metabolic disorders. This study investigated the relationship between serum NGAL and early alteration ...of metabolic parameters in non-diabetic Korean women, particularly with respect to saturated fat (SFA) intake. Anthropometric parameters, fasting glycemic status, and levels of lipids, oxidative stress/inflammatory markers, and NGAL were measured in 82 non-diabetic Korean women Super-healthy group (n=57) with 0 metabolic syndrome risk factor (MetS RF) and MetS-risk group (n=25) with MetS RF≥1. Age, weight, waist circumference, blood pressure, fasting glucose, HbA1C, triglyceride, LDL and total-cholesterol, and NGAL levels were higher, and HDL-cholesterol was lower in the MetS-risk group than in the Super-healthy group. Age-adjusted serum NGAL levels were higher in the MetS-risk group than in the Super-healthy group. NGAL increased proportionally with increase in MetS RFs (p=0.038) and correlated positively with BMI, triglycerides, LDL- and total-cholesterol, interleukin-6, white blood cell count, and neutrophil%, and negatively with HDL-cholesterol and superoxide dismutase activity. Serum NGAL levels positively correlated with SFA intake before and after adjustment (age and BMI). Serum NGAL levels were higher in high-SFA consumers ≥7g/day, ≥7% of total calorie intake (TCI) than in low-SFA consumers (<7g/day, <7% of TCI). Serum NGAL levels were highest in the MetS-risk group consuming higher SFA and lowest in the Super-healthy group consuming lower SFA. However, serum NGAL did not significantly differ between the low-SFA consuming MetS-risk and Super-healthy groups. The relationship between circulating NGAL and early alteration of metabolic parameters is associated with dietary SFA intake in non-diabetic Korean women.
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