Jae Hyung Mah, Young Hun Jin, Jun Hee Lee and Jae Hoan Lee
Korea University, Republic of Korea
Posters & Accepted Abstracts: J Food Process Technol
Kimchi is a Korean traditional fermented vegetable listed on Food Codex Alimentarius in 2001. Kkakdugi (Korean radish kimchi) is almost as popular as Baechu (Chinese cabbage) kimchi in Korea and the source of beneficial lactic acid bacteria (LAB). Although health benefits of the LAB in kimchi have been reported in numerous articles, there have also been several studies describing that some LAB results in an important level of biogenic amines (BA) in other fermented foods (e.g., sausage and cheese). Nonetheless, insufficient research has been conducted regarding the potential hazard of BA in kkakdugi. In this study, BA content in various kkakdugi samples was measured to estimate the BA-related risks. Most samples contained low levels of respective BA. However, histamine level over safety limit (100 mg/kg) was detected in one sample, in which putrescine level was also relatively high. Another sample showed the highest concentration of putrescine up to approximately 1,000 mg/ kg and, consequently, had total BA content over the recommended safety level (1,000 mg/kg). Meanwhile, there appeared to be a moderate positive relationship (R2=0.7) between tyramine content and acidity (an indicator of kimchi ripening) of the samples. Taken together, most of kkakdugi samples were considered safe for consumption, but the causes of perceived risk related to BA needed to be considered. To understand the bacterial contribution to BA in kkakdugi, BA production by LAB strains from respective samples was also determined. Most LAB strains produced BA at low levels although some strains isolated from over-ripened kkakdugi samples had the relatively high capacity to produce tyramine, which agrees with the relationship between tyramine content and acidity of samples. Further studies on BA production (especially histamine and tyramine) by the LAB are necessary to reduce BA content in kkakdugi.
Jae Hyung Mah has completed his BS, MS and PhD from Korea University, Republic of Korea and Postdoctoral studies from University of Wisconsin-Madison and Washington State University, USA. He is a Professor of Food and Biotechnology at Korea University, Sejong Campus, Republic of Korea. He has published about 50 papers in reputed journals and has been serving as an Editorial Board Member and Referee for several peer-reviewed journals in food science and technology. His researches focus on the analyses of hazardous chemicals and microorganisms in fermented foods and development of novel protective and preservative strategies such as application of genetically designed starter culture to food fermentation and inactivation kinetics of foodborne pathogenic and spoilage microorganisms exposed to chemical, physical and biological intervention treatments.