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Watery kimchi is a traditional fermented food served with its soup. In this study, we collected 21 samples of yeolmu mul kimchi (YMK), dongchimi (DC), and nabak kimchi (NK), respectively, which are the most popular watery kimchi in Korea. A composite sample of each watery kimchi was prepared for estimation of their bioactive compounds and antioxidant activities. Of the three kimchi types, YMK had the highest total carotenoid content (63.78 ± 4.88 mg/100 g, of which lutein, capsanthin, and β-carotene were the main carotenoids), and DC had the lowest (3.50 ± 0.12 mg/100 g). YMK also had the highest contents of chlorophyll (250.1 ± 3.91 mg/100 g), ascorbic acid (447.16 ± 8.95 mg/100 g), and capsaicinoids (2.51 ± 0.09 mg/100 g) compared to DC and NK. The lactic acid content was highest in NK (582.72 ± 29.10 mg/100 g). Moreover, YMK showed significantly higher antioxidant activity (ABTS and DPPH) than DC and NK (p < 0.05). Chlorophyll and antioxidant activity showed a strong positive correlation (p < 0.01). The results of this study highlighted watery kimchi as a potentially valuable source of bioactive compounds, and the carotenoids and capsaicinoids were affected by the supporting ingredients used in watery kimchi. Furthermore, watery kimchi provides 4.11% of the recommended daily intake of vitamin A according to the 2020 Korean dietary reference intakes. [ABSTRACT FROM AUTHOR]

Agricultural products are consumed as major staple foods; these are the main factors responsible for polycyclic aromatic hydrocarbon (PAH) exposure to humans. We analyzed the concentrations of eight PAHs (PAH8) in commonly consumed 359 agricultural samples that are commonly consumed in Republic of Korea. These food samples were divided into four groups (fatty-solid, fatty-liquid, nonfatty-solid, and nonfatty-liquid) and eight different food categories (cereals, potatoes, pulse crops, seeds and nuts, vegetables, mushrooms, fruits, and regional tap water). The chronic daily intake and margin of exposure (MOE) were estimated based on daily consumption data and benzo[a]pyrene equivalents. In our total diet studies, the major contributor to the total PAH8 concentration (ΣPAH8) in agricultural samples was dried jujube (2.32 μg/kg), followed by griddled milk bread (1.25 μg/kg) and stir-fried black sesame (1.17 μg/kg). The integrated toxic equivalent concentrations based on BaP (ΣTEQbap; integrated toxic benzo[a]pyrene equivalent quantity) considering the relative toxicity, ranged from 0.12 and 1.6 μg/kg. The PAH8 risk assessment in agricultural products was expressed as the MOE value. The worst scenario (when Not Detected = Limit of Detection) showed the interpretation of the MOE result as a 'possible concern' to consume bread products (bread, rye bread, milk bread, and cornbread). The preceding experiments were carried out mainly on commercially processed foods and their raw foods. Unlike such routine testing, our total diet study-based monitoring is designed to monitor PAH8 levels in which agricultural products are analyzed after being processed as usual consumption. [ABSTRACT FROM AUTHOR]

Maesil extract, a fruit-juice concentrate derived from Prunus mume prepared by fermenting with sugar, is widely used with increasing popularity in Korea. Biogenic amines in maesil extract were extracted with 0.4 M perchloric acid, derivatized with dansyl chloride, and detected using high-performance liquid chromatography. Among 18 home-made maesil extracts collected from different regions, total biogenic amine content varied from 2.53 to 241.73 mg/L. To elucidate the effects of soaking and fermentation time on biogenic amine content in maesil extract, maesil was soaked in brown sugar for 90 days and the liquid obtained was further fermented for 180 days at 15 and 25 °C, respectively. The main biogenic amines extracted were putrescine and spermidine and the total biogenic amine content was higher at 25 °C than at 15 °C. Soaking at 15 and 25 °C increased the total biogenic amines content from 14.14 to 34.98 mg/L and 37.33 to 69.05 mg/L, respectively, whereas a 180 day fermentation decreased the content from 31.66 to 13.59 mg/L and 116.82 to 57.05 mg/L, respectively. Biogenic amine content was correlated with total amino acid content (particularly, arginine content). Based on these results, we have considered that biogenic amine synthesis can be reduced during maesil extract production by controlling temperature and fermentation time. [ABSTRACT FROM AUTHOR]

Ethyl carbamate (EC) is a carcinogen mostly found in fermented foods and alcoholic beverages. In Korea, the consumption, as well as domestic production and import of alcoholic beverages, has increased over the past decade, thus increasing the risk of EC exposure. In this study, we estimated the EC content of 145 alcoholic beverages using gas chromatography-mass spectrometry (GC-MS) and optimized the hydromatrix method for solid-phase extraction with improved absolute recovery of EC and better repeatability than the Chem-Elut method of AOAC. The margin of exposure (MOE) approach and cancer risk assessment were performed to assess the risk of EC from alcoholic beverages in Korean. The EC content in some of the alcoholic beverages was not detectable; however, the maximum value was 329.7 μg/kg. Moreover, alcoholic beverages with stone fruit as a component revealed high EC contents. The daily intake of alcoholic beverages by the Korean population of alcohol-drinking adults ranged from 184.2 to 237.1 g/day, depending on gender and age groups. Of the 145 alcoholic beverages, the contributions of soju and beer to the exposure of EC in the Korean population were found to be maximum. MOE and cancer risk for the Korean average drinker were 14,874 and 1.01 × 10−6, respectively, whereas in drinkers of the 95th percentile (P95), they were 2951 and 5.08 × 10−6, respectively. This study indicated that the risk of exposure to EC is of lower concern in average drinkers than in heavy drinkers in the Korean population. • A modified AOAC method for ethyl carbamate (EC) analysis was optimized. • 145 alcoholic beverages available in Korean market were analyzed for EC exposure. • Samples with stone fruits had high EC content. • Soju and beer were the major contributors to EC exposure. • MOE approach and cancer risk assessment showed higher risk for heavy drinkers. [ABSTRACT FROM AUTHOR]