Department of Bioresources and Food Science, Konkuk university1
The aim of this study was to evaluate the changes of fruit quality, flavonoid contents and antioxidant activity of Yuzu (Citrus junos Sieb. ex Tanaka) from Go-heung and Jeju according to harvest time. Samples were harvested from August to December on the 1st of every month. August and September samples were green colored, whereas November and December samples were yellow. The fruit shape index decreased, changing from globular to elliptical, whereas the °birx increased with ripening stage. The yuzu from Jeju was larger than that from Go-heung in each month of cultivation. August samples exhibited the highest amounts of phenolic compounds. In addition, samples from Jeju had higher total phenolic content than those from Go-heung. The content of phenolic compounds decreased with ripening until October and then increased subsequently. Antioxidant activity of the yuzu was evaluated by FRAP and DPPH methods. The antioxidant activity showed a similar trend as total phenolic content. Immature yuzu fruit was found to exhibit the highest amount of flavonoids such as naringin and hesperidin. November and December samples showed almost the same contents of flavonoids. The flavonoid content of yuzu fruit harvested from Jeju was higher than that from Go-heung. Overall, the samples harvested at the early stage, in the month of August, exhibited the highest flavonoid content, phenolic content and antioxidant activity. As the health benefits of these compounds has been demonstrated in various studies, the immature yuzu appears to be preferable for use as a raw material for formulation of pharmaceutical products as well as for functional food production after a proper in-vivo and in-vitro medical tests.
1. Azuma, K., M. Nakayama, M. Koshioka, K. Ippoushi, Y. Yamaguchi, K. Kohata, Y. Yamaguchi, H. Ito, and H. Higashio. 1999. Phenolic antioxidants from the leaves of Corchorus olitorius L. J. Agric. Food Chem. 47:3963-3966.
2. Benzie, I.F.F. and J.J. Strain. 1996. The ferric reducing ability of plasma (FRAP) as a measure of ‘‘antioxidant power’’: the FRAP assay. Anal. Biochem. 239:70-76.
3. Blois, M.S. 1958. Antioxidant determination by the use of a stable free radical. Nature 181:1199-1200.
4. Böhm, H., H. Boeing, J. Hempel, B. Raab, and A. Kroke. 1998. Flavonols, flavone and anthocyanins as natural antioxidants of food and their possible role in the prevention of chronic diseases. Z. Ernahrungswiss. 37:147-163.
5. Cha, J.Y., S.Y. Kim, S.J. Jeong, and Y.S. Cho. 1999. Effects of hesperetin and naringenin on lipid concentration in orotic acid treated mice. Kor. J. Life Sci. 9:389-394.
6. Chae, S.C., E.G. Kho, S.H. Choi, and G.C. Ryu. 2008. Protective effect naringin on carbon tetrachloride induced hepatic injury in mice. J. Environ. Toxicol. 23:325-335.
7. Eun, J.B., Y.M. Jung, and G.J. Woo. 1996. Identification and determination of dietary fibers and flavonoids in pulp and peel of Korean tangerine (Citrus aurantium var.). Kor. J. Food Sci. Technol. 28:371-377.
8. Hertog, M.G., E.J. Feskens, P.C. Hollman, M.B. Katan, and D. Kromhout. 1993. Dietary antioxidant flavonoids and risk of coronary heart disease: the zutphen elderly study. Lancet 342:1007-1011.
9. Jeon, S.M., J.Y. Lee, H.W. Kim, Y.M. Lee, H.H. Jang, K.A. Hwang, H.R. Kim, and D.S. Park. 2012. Antioxidant activity of extracts and fractions from Aster scaber. J. Korean Soc. Food Sci. Nutr. 41: 1197-1204.
10. Ji, E.J., K.M. Yoo, J.B. Park, and I.K. Hwang. 2008. Preparation of citron peel tea containing yuza (Citrus Junos Seib. ex Tanaka) and its antioxidant characteristics. Kor. J. Food Cookery Sci. 24:460-465.
11. Kim, I.W., D.H. Shin, and U. Choi. 1999. Isolation of antioxidative components from the bark of Rhus verniciflua STOKES screened from some Chinese medicinal plants. Kor. J. Food Sci. Technol. 31:855-863.
12. Kim, Y.C., K.S. Koh, and J.S. Koh. 2001. Changes of flavonoids in the peel of Jeju native citrus fruits during maturation. Kor. J. Food Sci. Biotechnol. 10:483- 487.
13. Kim Y.D., W.J. Ko, K.S. Koh, Y.J. Jeon, and S.H. Kim. 2009. Composition of flavonoids and antioxidative activity from juice of Jeju native citrus fruits during maturation. Kor. J. Nutr. 42:278-290.
14. Lee, S.L., C.S. Seo, J.H. Kim, and H.K. Shin. 2011. Contents of poncirin and naringin in fruit of Poncirus trifoliata according to different harvesting times and locations for two years. Kor. J. Pharmacogn. 42:138-143.
15. Rhyu, M.R., E.Y. Kim, I.Y. Bae, and Y.K. Park. 2002. Contents of naringin, hesperidin and neohesperidin in premature Korean citrus fruits. Kor. J. Food Sci. Technol. 34:132-135.
16. Shin, J.H., S.J. Lee, J.K. Seo, E.W. Cheon, and N.J. Sung. 2008. Antioxidant activity of hot-water extract from yuza (Citrus junos Sieb. ex Tanaka) peel. J. Life sci. 18:1745-1751.
17. Shin, J.H., S.J. Lee, M.J. Kang, S.M. Yang, and N.J. Sung. 2009. Biological activities of yuza grown in different areas. J. Kor. Soc. Food Sci. Nutr. 38:1485-1491.
18. Singleton, V.L. and J.A. Rossi, Jr. 1965. Colorimetry of total phenolics with phosphomolybdic-phosphostungstic acid reagents. Am. J. Enol. Viticul. 16:144-158.
19. Sohn, J.S. and M.K. Kim. 1998. Effect of hesperidin and naringin on antioxidative capacity in the rat. Kor. J. Nutr. Soc. 31: 687-696.
20. Treutter, D. 2010. Managing phenol contents in crop plants by phytochemical farming and breeding-visions and constraints. Int. J. Mol. Sci. 11:807-857.
21. Vinson, J.A., X. Su, L. Zubik, and P. Bose. 2001. Phenol antioxidant quantity and quality in foods: Fruits. J. Agric. Food Chem. 49:5315-5321.
22. Wang, Y.C., Y.C. Chuang, and H.W. Hsu. 2008. The flavonoid, carotenoid and pectin content in peels of citrus cultivated in Taiwan. Food Chem. 106:277-284.
23. Woo, D.H. 2000. Stabilization to sunlight of natural coloring matter by soluble methyl-hesperidin. Kor. J. Food Sci. Technol. 32:50-55.
24. Yang, H.S. and J.B. Eun. 2011. Fermentation and sensory characteristics of Korean traditional fermented liquor (Makgeolli) added with citron (Citrus junos SIEB. ex TANAKA) juice. Kor. J. Food Sci. Technol. 43:438-445.
25. Yang, J.W., I.S. Choi, J.H. Lee, C.W. Cho, and S.S. Kim. 2012. Change of physicochemical properties and hesperidin contents of Jeju processing citrus fruits with the harvest date. Kor. J. Food Preserv. 19:652-658.
26. Yoo, K.M. and I.K. Hwang. 2004. In vitro effect of yuza (Citrus junos SIEB ex TANAKA) extracts on proliferation of human prostate cancer cells and antioxidant activity. Kor. J. Food Sci. Technol. 36:339-344