Simultaneous Determination of Preservatives,Artificial Sweeteners,and Synthetic Dyes in Kimchi by Ultra-Performance Liquid Chromatography Electrospray Ionization Tandem Mass Spectrometry (UPLC-ESI-MS/MS)

Abstract

A simple and rapid method was developed for the simultaneous determination of five preservatives, six artificial sweeteners, and nine synthetic dyes in kimchi using ultra-performance liquid chromatography electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS) with multiple reaction monitoring (MRM). The chromatographic separation was performed in 5.5?min using an Acquity UPLC BEH C18 column (100?mm × 2.1?mm, 1.7?µm) with a mobile phase composed of 0.002% trifluoroacetic acid and 10?mM aqueous ammonium acetate or 9:1 (v/v) methanol:acetonitrile. Linear calibration curves were obtained with correlation coefficients above 0.98. The limits of quantification ranged between 0.227 and 8.569?ng/mL, while the recovery values in kimchi samples were from 83.1 to 113.5%. Forty kimchi samples were analyzed for the food additives, with sweeteners detected in more than half of these samples. The most commonly detected sweetener was saccharin, and six of the kimchi samples contained a combination of sweeteners; dulcin, sucralose, acesulfame K, preservatives, and synthetic dyes were not detected. Based on these results, the developed method can be used for the rapid quality control of food additives in kimchi.     

Degradation of bisphenol A by <Emphasis Type="Italic">Bacillus pumilus</Emphasis> isolated from kimchi,a traditionally fermented food

Novel bisphenol A (BPA)-degrading bacterial strains, designated as BP-2CK, BP-21DK, and BP-22DK, were isolated from kimchi, a traditionally fermented food. These isolates were identified as Bacillus pumilus and efficiently degraded BPA in a medium supplemented with nutrients such as peptone, beef extract, and yeast extract. Strains BP-2CK, BP-21DK, and BP-22DK successfully degraded 25, 25, and 50 ppm of BPA, respectively, and all strains exhibited BPA-degrading activity in the presence of 10% NaCl. Accumulation of the metabolites including 4-hydroxyacetophenone, one of the intermediates produced by the other BPA-degrading bacteria, was not observed in BPA degradation by the isolated strains. These results indicate that the isolated food-derived bacteria are applicable for the construction of efficient and safer systems for the removal of BPA.     

Determination of Capsaicinoids in Red Pepper Products from South Korea by High-Performance Liquid Chromatography with Fluorescence Detection

This study aimed at determining the concentrations of the major capsaicinoids, namely, capsaicin and dihydrocapsaicin, in commonly consumed red pepper products from South Korea. The capsaicinoids were extracted with 95% methanol and determined by high-performance liquid chromatography with florescence detection. The analytical method was validated by quality assurance parameters such as the linearity, limits of detection and quantification, precision, and accuracy. Satisfactory results were obtained in accordance to the specified criteria for application of analytical techniques in food. The concentration of capsaicinoids was the highest for red pepper powder (4.18–139.4?mg/100?g), followed by gochujang (0.93–23.20?mg/100?g), kimchi (0.05–1.16?mg/100?g), and sliced kimchi (0.06–0.88?mg/100?g). Comparing the capsaicinoid contents in samples from different production areas, no significant differences were found. This research concluded that the capsaicinoid content of red pepper products provided valuable information regarding the samples.