Korean Journal of Food Science and Technology (한국식품과학회지)

Korean Society of Food Science and Technology (한국식품과학회)
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Effects of Roasting Condition on the Quality Characteristics and Oxidative Stabilities of Rice Germ

볶음 조건이 쌀눈의 품질 특성 및 산화안정성에 미치는 영향

  • Ko, Soon-Nam (Department of Food and Nutrition, College of Health Sciences, Korea University) ;
  • Kim, Chul-Jin (Korea Food Research Institute) ;
  • Kim, In-Hwan (Department of Food and Nutrition, College of Health Sciences, Korea University)
  • 고순남 (고려대학교 병설 보건대학 식품영양과) ;
  • 김철진 (한국식품개발연구원) ;
  • 김인환 (고려대학교 병설 보건대학 식품영양과)
  • Published : 2003.06.01
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Abstract

In order to compare quality characteristics and oxidative stabilities of rice germs prepared under different roasting conditions, sensory evaluation, color value, tocols (tocopherol+tocotrienol) contents, and peroxide value were investigated. Optimum roasting temperatures for the best acceptability were 20, 10, and 6 min at 170, 180 and 190, respectively. Hunter color a values of rice germ increased as roasting temperature and time increased, whereas L value decreased. Peroxide values of unroasted, and roasted rice germs at $170^{\circ}C$ for 20 min, $180^{\circ}C$ for 10 min, and $190^{\circ}C$ for 6 min were 2.0, and 145.6, 169.5, and 182.9 meq/kg, respectively, after 9 days storage at $60^{\circ}C$. Four tocopherol and three tocotrienol isomers were identified, whereas no ${\beta}$-tocotrienol was detected. The major tocopherol and tocotrienol isomers in rice germ were ${\alpha}$-tocopherol and ${\alpha}$-tocotrienol, respectively. ${\alpha}$-Tocopherol content in roasted rice germ decreased significantly during storage, whereas those of ${\beta}$- and ${\gamma}$-tocopherols slowly decreased. ${\delta}$-Tocopherol had the highest stability among tocopherol isomers in roasted rice germ. Similar trends were observed in tocotrienol isomers.

본 연구는 다양한 볶음 조건에서 볶지 않은 쌀눈과 볶은 쌀눈의 품질 특성을 조사하기 위하여 관능검사, 색, tocols 함량 및 과산화물가를 측정하여 평가하였다. 관능검사와 색으로 선정된 쌀눈의 가장 기호도가 우수한 최적 볶음 조건은 $170^{\circ}C$ 20분, $180^{\circ}C$ 10분, $190^{\circ}C$ 6분이었다. 쌀눈의 Hunter a 값은 볶음 온도와 시간이 증가할수록 증가하였던 반면 L값은 볶음 과정이 진행될수록 감소하였다. 지질산화안정성에 있어서는 볶지 않은 쌀눈이 볶은 쌀눈보다 안정하였으며, $60^{\circ}C$에서 저장 9일 후 POV는 볶지 않은 쌀눈의 과산화물가는 2.0 meq/kg인데 반해 $170^{\circ}C$ 20분 처리구는 145.6 meq/kg, $180^{\circ}C$ 10분 처리구는 169.5 meq/kg, $190^{\circ}C$ 6분 처리구는 182.9 meq/kg으로 과산화물의 생성 속도가 현저하게 다름을 보여주었다. 또한 모든 쌀눈 처리구에서 4가지의 tocopherol과 3가지의 tocotrienol이 확인되었으나 ${\beta}$-tocotrienol은 검출되지 않았다. 쌀눈의 주요 tocols는 ${\alpha}$-tocopherol과 ${\alpha}$-tocotrienol이었으며 $60^{\circ}C$ 저장 중 모든 볶음 처리구에서 tocol isomer의 영향은 ${\alpha}$-tocopherol이 가장 현저한 감소를 보인 반면 ${\beta}$-tocopherol과 ${\gamma}$-tocopherol은 서서히 감소하였다. ${\delta}$-tocopherol은 tocopherol 이성체 중에 가장 높은 안정성을 보였으며 저장일별 tocotrienol 이성체들의 지질산화안정성도 tocopherol과 유사한 경향을 보였다.

Keywords

References

  1. Ministry of Agricultural and Forestry. Agricultural and Forestry Statistical Yearbook, Vol. 2002, pp. 232. National Agricultural Products Quality Management Service (NAQS) of the Ministry of Agriculture and Forestry (MAF), Seoul, Korea (2002)
  2. Choi, O.K., Yun, S.K. and Hwang, S.Y. The chemical components of Korean rice germ. Korean J. Dietary Culture 15: 253-258 (2000)
  3. Juliano, B.O. Polysaccharides, proteins, and lipids of rice, pp. 59-174. In: Rice: Chemistry and Technology. Juliano, B.O. (ed.). The American Association of Cereal Chemists, Inc., St. Paul, Minnesota, USA (1994)
  4. Kawabata, K., Tanaka, T., Murakami, T., Okada, T., Murai, H., Yamamoto, T., Hara, A., Shimizu, M., Yamada, Y., Matsunaga, K., Kuno, T., Yoshimi, N., Sugie, S. and Mori, H. Dietary prevention of azoxymethanc-induced colon carcinogenesis with ricegerm in F344 rats. Carcinogenesis 20: 2I09-21I5 (1999)
  5. Rogers, E.J., Rice, S.M., Nicolosi, R.J., Carpenter, D.R., McClelland, C.A. and Romanczyk, Jr. L.J. Identification and quatitation of $\gamma$-oryzanol components and simultaneous assessment of tocols in rice bran oil. J. Am. Oil Chem. Soc. 70: 301-307 (1993) https://doi.org/10.1007/BF02545312
  6. Lioyd, B.J., Siebenmorgen, T.J. and Beers, K.W. Effects of commercial processing on antioxidants in rice bran. Cereal Chern. 77: 551-555 (2000) https://doi.org/10.1094/CCHEM.2000.77.5.551
  7. Orthoefer, F.T. Rice bran oil: Healthy lipid source. Food Technol. 50(12): 62-64 (1996)
  8. Qureshi, A.A., Mo, H., Packer, L. and Peterson, D.M. Isolation and identification of novel tocotrienols from rice bran with hypocholesterolemic, antioxidant, and antitumor properties. J. Agric. Food Chem. 48: 3130-3140 (2000) https://doi.org/10.1021/jf000099t
  9. Yamamoto, A., Fuji, Y., Yasumoto, K. and Mitsuda, H. Product specificity of rice germ lipoxygenase. Lipids 15: 1-5 (1980) https://doi.org/10.1007/BF02534108
  10. Chung, R.L., Chen, J.C., Chu, J. and Tzen, J.T. Characterization of seed oil bodies and their surface oleosin isoforms from rice embryos. J. Biochem. 120: 74-81 (1996) https://doi.org/10.1093/oxfordjournals.jbchem.a021396
  11. Shin, D.H. and Chung, J.K. Changes during storage of rice germ oil and its fatty acid composition. Korean J. Food Sci. Technol. 30: 77-81 (1998)
  12. Shin, D.H. and Chung, J.K. Chemical composition of the rice germ from rice milling and its oil stability during storage. Korean J. Food Sci. Technol. 30: 241-243 (1998)
  13. Kim, I.H., Kim, C.J., You, J.M., Lee, K.W., Kim, C.T., Chung, S.H., and Tae, B.S. Effect of roasting temperature and time on the chemical composition of rice germ oil. J. Am. Oil Chem.Soc. 79: 413-418 (2002) https://doi.org/10.1007/s11746-002-0498-2
  14. AOCS. Official Methods and Recommended Pratices of the American Oil Chemist's Society. 4th ed. AOCS press, Champaign, IL, USA (1990)
  15. SAS Institute, Inc. SAS User's Guide. Statistical Analysis Systems Institute, Cary, NC, USA (1990)
  16. Park, K.D., Choi, J.H. and Sung, H.S. Color evaluation of commercial dehydrated tea-products by hunter-lab tristimulus colorimeter. J. Korean Soc. Food. Nutr. 11: 25-30 (1982)
  17. Ryu, K.C., Chung, H.W., Lee, G.D. and Kwon, J.H. Color changes and optimization of organoleptic properties of roasted polygonatum odoratum tea. J. Korean Soc. Food Sci. Nutr, 26: 83I-837 (1997)
  18. Lane, R.H., Quereshi, A.A. and Salser, W.A Tocotrienols and tocotrienol-like compounds and methods for their use. U.S. Patent 5,591,772 (1997)
  19. Kim, Y.E., Kim, I.H. and Lee, Y.C. Effects of roasting process and antioxidants on oxidative stability of perilla oils. Korean J. Food Sci. Technol. 29: 379-382 (1997)
  20. Kim, H.W. Studies on the antioxidative compounds of sesame oils with roasting temperature. Korean J. Food Sci. Techno!. 32: 246-251 (1997)
  21. Moreau, R.A., Hicks, K.B. and Powell, M.J. Effects of heat pretreatment on the yield and composition of oil extracted from com fiber. J. Agric. Food Chem. 47: 2867-2871 (1999)