Detection of 1,4-dihydroxy-2-naphthoic Acid from commercial makgeolli products

Abstract

To support beneficial effects of makgeolli for human health, we investigated for the presence of 1,4-dihydroxy-2-naphthoic acid (DHNA), a bifidogenic growth stimulator (BGS), from commercial makgeolli products. Among eleven makgeolli products (A∼K), four showed positive peaks for DHNA in high performance liquid chromatography analysis. Makgeolli product A in particular contained the highest concentration of DHNA (0.44 ppm), as confirmed by liquid chromatography-mass spectrometry. Furthermore, BGS activity of the makgeolli product A was higher than those of products in which DHNA was not detected. These results indicate that makgeolli can be a good source for DHNA and that DHNA-enriched makgeolli could be developed by modifying manufacturing procedures and controlling its microbiota.

Keywords: 1,4-dihydroxy-2-naphthoic acid; bifidogenic growth stimulator; makgeolli.

Fig. 1

HPLC chromatograms (A, B) and LC-MS spectra (C, D) for DHNA standard and commercial makgeolli product A sample. The arrows indicate peaks for DHNA and the circles indicate spectra of molecular masses (m/z) for a de-protonated DHNA ion [M-H]⁻.

Fig. 2

BGS activity of commercial makgeolli samples for B. longum (A) and B. lactis (B). B. longum or B. lactis: B. longum FI10564 or B. lactis BL 750 strain was inoculated alone; Product A, B, or H: B. longum FI10564 or B. lactis BL 750 strain was inoculated with commercial makgeolli product A, B, or H sample. Values are mean±SD (n=3). Means having different letters are significantly different by Duncan’s multiple range tests (p<0.05).