Quantitative Analysis of Microbiological Profiles of Retailed White Rice

시판 백미의 미생물학적 프로파일 정량분석

  • Received : 2011.05.24
  • Accepted : 2011.08.12
  • Published : 2011.09.30

Abstract

Rice has been the most important staple food in everyday meals of Korean people for thousands of years. Nowadays, it is getting increasingly used as flour ingredients in a variety of processed foods, so that it is consumed in more diversified ways. As a consequence, production volume of rice flour to manufacture rice cakes, noodles, breads, or confectioneries is recently getting increased in Korea. But there are not sufficient research outcomes to guarantee Korean consumers microbiological qualities of rice flour as well as rice. As a preliminary experiment, therefore, the microbiological profiles (aerobic mesophilic bacteria (AMB), spore-forming aerobic bacteria (SAB), lactic acid bacteria (LAB), yeasts and molds (YM), and Escherichia coli and coliforms) have been monitored for nine retailed white rice samples in this study. AMB counts ranged $10^2-10^6$ CFU/g for all the nine white rice samples. All the nine rice samples have SAB counts within a narrow range $(1.0{\times}10^2-2.5{\times}10^3$ CFU/g). LAB was detected in two white rice samples ($4.0{\times}10^2$ and $3.7{\times}10^3$ CFU/g), YM was detected in one white rice sample ($2.0{\times}10^2$ CFU/g) only. E. coli was not detected from all the nine samples. Coliforms were detected in one white rice sample ($4.1{\times}10$ CFU/g) only. All the rice samples were conclusively considered to have various microorganisms, though most of them are harmless and some, such as coliforms, may be harmful.

쌀의 미생물학적 프로파일을 규명하기 위하여 잔류 미생물들을 총호기성균, 포자형성 호기성균, 젖산균, 진균, 그러고 대장균 및 대장균군 등의 5개 미생물 group으로 구분하였다. 그리고 이들 5 개 미생물 group에 대하여 총 9개 국내 시판 백미 검체별로 잔류 미생물 정량분석을 수행하였다. 9개 백미 검체 중 백미 1 검체의 총호기성균수($2.4{\times}10^6$ CFU/g)가 가장 높았으며, 9개의 백미 검체의 평균 총 호기성 균수는 $3.9{\times}10^5$ CFU/g으로 측정되었다. 쌀 검체별 호기성 포자형성균수는 모든 9종의 백미 검체가 $1.0{\times}10^2$-$2.5{\times}10^3$ CFU/g 범위에 있었다. 쌀 검체별 젖산균은 총 9개 백미 검체중 2개 백미 검체에서만 검출되었다. 백미 2 검체의 젖산균수가 $3.7{\times}10^3$ CFU/g, 백미 4 검체의 젖산균수가 $4.0{\times}10^2$ CFU/g으로 각각 검출되었다. 쌀 검체별 진균수는 총 9개의 백미검체 중 백미 1 검체에서만 검출되었으며, 검체의 진균오염정도는 백미 1 검체의 진균수가 $2.0{\times}10^2$ CFU/g으로 검출되었다. 쌀 검체별 대장균수는 총 9개의 모든 백미 검체에서 대장균이 검출한계이하 수준으로 존재하는 것으로 확인되었다. 대장균군의 경우 백미 4 검체의 대장균군수가 $4.1{\times}10$ CFU/g으로 검출되었다. 그리고 다른 모든 백미 검체에서는 대장균군이 검출한계이하 수준으로 존재하는 것으로 확인되었다.

Keywords

References

  1. Keum J.S.: 쌀의 영양과 쌀 가공식품. Korean J. Food Preserv., 9, 38-54 (2010).
  2. Shin M.S.: 미래의 녹색 식품산업을 주도할 쌀 가공산업의 활성화. Korean J. Food Preserv., 9, 16-37 (2010).
  3. Min Y.T.: 쌀 소비촉진을 통한 쌀 산업안정방안. Korean J. Food Preserv., 9, 13-15 (2010).
  4. Keum J.S.: 미곡 가공기술 혁신을 통한 쌀 소비확대방안. Korean J. Food Preserv., 9, 49-59 (2010).
  5. Kim S.H, Kim K.P, Jang S.S, Shin E.M, Kim M.J, Oh S, Ryu S.: Prevalence and toxigenic profiles of Bacillus cereus isolated from dried red peppers, rice, and Sunsik in Korea. J. Food Prot., 72, 578-582 (2009).
  6. Park Y.B, Kim J.B, Shin S.W, Kim J.C, Cho S.H, Lee B.K, Ahn J, Kim J.M, Oh D.H.: Prevalence, genetic diversity, and antibiotic susceptibility of Bacillus cereus strains isolated from rice and cereals collected in Korea. J. Food Prot., 72, 612- 617 (2009).
  7. Park S.K, Ko Y.D, Kwon S.H, Shon M.Y, Lee S.W.: Occurrence of off-odor and distribution of thermophilic bacteria from rice and cooked rice stored at electric rice cooker. Korean J. Food Preserve., 10, 70-74 (2003).
  8. Kim K.A, Jeon E.R.: Physicochemical properties and hydration of rice on various polishing degrees. Korean J. Food Sci. Technol., 28, 959-964 (1996).
  9. 식중독 통계 시스템. Korea Food and Drug Administration
  10. Kim S.R, Shim W.B, Park S.J, Ha S.H, Yoon H.S, Ha S.D, Kim K.S, Lee K.H, Kim M.G, Kim K.Y, Lim C.H, Chung D.H.: Investigation of the level of microbial contamination in the environment for juice production. Korean J. Food Sci. Technol., 37, 287-293 (2005).
  11. Ankolekar C, Rahmati T, Labbé RG.: Detection of toxigenic Bacillus cereus and Bacillus thuringiensis spores in U.S. rice. Int. J. Food Microbiol., 128, 460-466 (2009). https://doi.org/10.1016/j.ijfoodmicro.2008.10.006
  12. Kim M.J, Kim B.H, Han J.K, Lee S.Y, Kim K.S.: Analysis of quality properties and fermentative microbial profiles of Takju and Yakju brewed with or without steaming process. J. Fd. Hyg. Safety., 26, 64-69 (2011).
  13. Cho J.I, Kim K.S, Bahk G.J, Ha S.D.: Microbial assessment of wild cabbage and its control. Korean J. Food Sci. Technol., 36, 162-167 (2004).
  14. Shin Y.P, Choi J.W, Yeon J.H, Lee M.J, Lee D.H, Kim K.S, Park K.H, Ha S.H.: Assessment of contamination levels of foodborne pathogens isolated in major RTE foods marketed in convenience stores. Korean J. Food Sci. Technol., 37, 274-278 (2005).
  15. Lu ZH, Zhang Y, Li LT, Curtis RB, Kong XL, Fulcher RG, Zhang G, Cao W.: Inhibition of microbial growth and enrichment of gamma-aminobutyric acid during germination of brown rice by electrolyzed oxidizing water. J. Food Prot., 73, 483-487 (2010). https://doi.org/10.1016/j.jprot.2009.06.010
  16. Nishino N, Hattori H, Kishida Y.: Alcoholic fermentation and its prevention by Lactobacillus buchneri in whole crop rice silage. Lett. Appl. Microbiol., 44, 538-543 (2007). https://doi.org/10.1111/j.1472-765X.2006.02105.x
  17. Aydin A, Aksu H, Gunsen U.: Mycotoxin levels and incidence of mould in Turkish rice. Environ. Monit. Assess., (2010).
  18. Sage V Foods: Standard spec sheets. (http://www.sagevfoods. com/MainPages/Products/Rice-Flour.htm).