Green Tea Extract is an Effective Antioxidant for Retarding Rancidity of Yukwa (Rice Snacks) Fried in Soybean and Rice Bran Oils

  • Park, Jae-Hee (Department of Food and Nutrition, Changwon National University) ;
  • Kim, Chang-Soon (Department of Food and Nutrition, Changwon National University)
  • Published : 2002.09.01


Yukwa is a popular Korean traditional fried rice snack. The high fat content and porous structure of Yukwa cause it to rapidly become rancid, presenting difficult challenges for commercial distribution. In this study, an-tioxidant activities of green tea extracts (GTE) were evaluated in Yukwa fried in soybean oil (SBO), rice bran oil (RBO) and winterized rice bran oil (WRBO) during storage at 4$0^{\circ}C$ for 12 weeks. Lipid oxidation of Yukwa was determined by acid value (AV), peroxide value (POV), p-anisidine value(AnV), totox value and sensory evaluation. The addition of GTE to the oils reduced the increases in AV, POV, AnV, and totox. Totox increased most vapidly in Yukwa fried in SBO, fellowed by RBO>WRBO>SBO+200 ppm GTE>RBO+200 ppm GTE > WRBO + 200 ppm GTE (p<0.05). Sensory evaluation revealed that the addition of 200 ppm GTE delays rancidity in Yukwa by 7~8 weeks; providing compelling evidence that GTE is an effective antioxidant for Yukwa.


  1. Labuza TP. 1971. Kinetics of lipid oxidation in foods. CRC Crit Rev Food Technol 2: 355-394
  2. Gray JI. 1978. lipid oxidation review. J Am Oil Soc 55: 539- 546
  3. Gamez-Meza N, Noriega-Rodriguez JA, Medina-Juarez LA, Ortega-Garcia J, Cazarez-Casanova R, Angulo-Guerrero O. 1999. Antioxidant activity in soybean oil of extracts from thompson grape bagasse. JAOCS 76: 1445-1447
  4. Ahn CK, Lee YC, Yeom CA. 2000. Antioxidant and mixture effects of curry spices extrats obtained by solvent extraction. Korean J Food Sci Technol 32: 491-499
  5. Cho HS, Ahn MS. 1999. Antioxidant effect of phenolic acids in defatted perilla flour on soybean oil. Korean J Food Sci Technol 15: 55-60
  6. Ji CI, Byun HS, Kang JH, Lee TG, Kim SB, Park YH. 1992. The antioxidative activities of spices extracts on edible soybean oil. J Korean Soc Food Nutr 21: 551-556
  7. Jung IC, Park S, Park KS, Ha HC, Kim SH, Kwon YI, Lee JS. 1996. Antioxidative effect of fruit body and mycelial extracts of pleurotus. J Food Sci Technol 28: 464-469
  8. Choe WK, Park JH, Kim SH, Lee DY and Lee YC. 1999. Antitumor effects of green tea catechin on different cancer cells. Korean J Nutr 32: 838-843
  9. Lee YJ, Ahn MS, Hong KH. 1998. A study on the content of general compounds, amino acid, vitamins, catechins, alkaloids in green, oolong and black tea. J Fd Hyg Safety 13: 377-382
  10. Park JH, Kim CS. 2001. Antioxidant activity of green tea extract and $\delta$-tocopherol on lipid oxidation of Yukwa (Korean glutinous rice fried snack). J Human Ecology (Changwon National Univ) 5: 173-186
  11. Chen ZY, Wang LY, Chan PT, Zhang Z, Chung HY, Liang C. 1998. Antioxidative activity of green tea catechin extract compared with that of rosemary extract. JAOCS 75: 141- 1145
  12. Lee CH, Maeng YS. 1987. A literature review on traditional Korean cookies, Hankwa. Korean J Dietary Culture 2: 55- 69
  13. Shin DH, Choi U. 1993. Shelf life extension of Yukwa by O2 preventive packing. Korean J Food Sci Technol 25: 243- 246
  14. Park YJ, Chun HS, Kim SS, Lee JM, Kim KH. 2000. Effect of nitrogen gas packing and γ-oryzanol treatment on the shelf life of Yukwa. Korean J Food Sci Technol 32: 317-322
  15. Sugiura. 1970. Official methods of tea analysis. Bulletin of Japanese Tea Experience Station 6: 167
  16. Lee SA, Kim CS, Kim HI. 2000. Studies on the drying methods of Gangjung pellets. Korean J Soc Food Sci 16: 47-56
  17. AOCS. 1990. Official methods and recommended practices of the AOCS. 4th ed. American oil chemists' society, Champaign, IL
  18. Jamilah B, Cheman YB, Ching TL. 1998. Antioxidant activity of Citrus hystrix peel extract in refined bleached deodorized palm olein during frying of fish crackers. J Food Lipids 5: 149-157
  19. Ho CT, Chen CW. 2000. Natural antioxidants. AOCS press, Champaign, IL. p 213-223
  20. Tompkins C, Perkins EG. 1999. The evaluation of frying oils with the p-anisidine value. JAOCS 76: 945-948
  21. Man CMD, Jones AA. 1993. Shelf life evaluation of foods. Blackie Academic and Professional, London. p 211
  22. Lee KH, Park HC, Huh ES. 1998. Statistics and data analysis method for food and nutrition specialists using SPSSWIN. Hyoil press, Seoul
  23. Giese J. 1996. Antioxidants: tools for preventing lipid oxidation. Food Technol 50: 73-81
  24. Park BH, Choi HK, Cho HS. 2001. An tioxidant effect of aqueous green tea on soybean oil. J Korean Soc Food Sci Nutr 30: 552-556
  25. Korean Food and Drug Administration. 2000. Food Code. 18: 123
  26. Shin DH, Kim MK, Chung TK, Lee HY. 1990. Shelf-life study of Yukwa (Korean traditional puffed rice snack) and substitution of puffing medium to air. Korean J Food Sci Technol 22: 266-271

Cited by

  1. Effects of the addition of green tea powder on the quality and antioxidant properties of vacuum-puffed and deep-fried Yukwa (rice snacks) vol.55, pp.1, 2014,
  2. Quality Characteristics during Storage of Yackwa added with Ethanol Extract from Ulmus davidiana vol.28, pp.3, 2015,
  3. Shelf Life Extension of Non-Dairy Cream with the Addition of Natural Antioxidants vol.40, pp.5, 2011,