References

1. 임종환, 김선재, 정병춘, 이준설. 1997. 자색고구마로부터 천연식용색소의 추출 및 색소의 이용성에 관한 연구, 농촌진흥청 보고서. pp. 69
2. 우원식. 2001. 천연물화학연구법. 서울대학교출판부 pp. 109-112
3. 한국식품공업협회. 1994. 식품공전. pp. 643-678
4. Ahu, Y. S., J. S. Lee, B. C. Jeong, M. N. Chung and M. H. Lee. 2005. A new sweetpotato cultivar for food with storage root and culinary vegetable with purple petiole 'hayanmi'. Korean J. Breed 37(1) : 67-68
5. Anon. 1985. Composition of edible fiber in sweet potato tips. Avrdc progess Report. pp. 310-313
6. AOAC. 1984. Official Methods Analysis 14thed. Association of official analytical chemists. Washington D.C.
7. Aurea, M. A., B. Fatima and J. Colette. 1997. Nutritional quality of sweet potato greens from greenhouse plants. J. Food Compo. Analy 10 : 246-253 https://doi.org/10.1006/jfca.1997.0538
8. AVRDC. 1985. Composition of edible tiber in sweetpotato tips. In Asian vegetable research and development center progress report. Shanhua. Taiwan. pp. 313-314
9. Bradbury, J. H., R. E. Beatty, K. Bradshaw, B. Hammer, W. D. Holloway, W. Jealous, J. Lau, T. Nguyen and U. Singh. 1985a. Chemistry and nutritive value of tropical root crops in the south pacific. Proc. Nutr. Soc 10: 185-188
10. Candish, J. K., L. Gourley and H. P. Lee. 1987. Dietary fiber and starch contents of some Southeast Asian vegatables. J. Agric. Food Chem 35: 319-321 https://doi.org/10.1021/jf00075a008
11. Cheng, H. H. 1978. Protein content and amino acid composition in tubers and stems and leaves of sweet potato cultivars in Taiwan, Chinese. J. Agric. Res. China 27(4) : 291-295
12. Fumitaka, H. and K. Hiromichi. 1984. Antioxidative components of sweet potatoes. J. Nutr. Sci. Vitaminol 30 : 37-46 https://doi.org/10.3177/jnsv.30.37
13. Hammett, L. K., C. H. Miller, W. H. Swallow, and C. Harden. 1984. Influence of N source. N rate and K rate on the yield mineral concentration of sweet potato. J. Am. Soc. Hort. Sci 109(3) : 294-298
14. Hagerman, A. E., K. M. Riedl, G. A. Jones, K N. Sovik, N. T. Ritchard, P. W. Hartzfeld and T. L. Riechel. 1998. High molecular weight plant polyphenolics (tannins) as biological antioxidants. J. Agric. Food Chem 46: 1887-1892 https://doi.org/10.1021/jf970975b
15. Huang, A. S., L. Tanudjaja and D. Lum. 1999. Content of alpha, beta-carotene and dietary fiber in 18 sweetpotato varieties grown in Hawaii. J. Food Compo. Analy 12: 147-151 https://doi.org/10.1006/jfca.1999.0819
16. Kim, H. B., S. L. Kim and J. Y. Moon. 2002. Quantification and varietal variation of anthocyanin pigment in mulberry fruits. Korean J. Breed 34(3) : 207-211
17. Konczak-Islam, I., M. Yoshimoto, D. X. Hon, N. Terahara and O. Yamakawa. 2003. Potential chemopreventive properties of anthocyanin- rich aqueous extracts from in vitro produced tissue of sweetpotato(ipomoea batatas L.). J. Agric. Food Chem 51 : 5916-5922 https://doi.org/10.1021/jf030066o
18. Lee, J. S., Y. S. Ahh, M. N. Chung, H. S. Kim, B. C. Jeong and J.K. Bang. 2007. Varieties for sweetpotato tips production as a vegetable. Korean J. Breed 39(2) : 224-231
19. Makoto, Y., O. Shigenori, S. Kazuo, S. Terumi and Y. Osamu. 2001. Effect of harvest times on the vitamin contents of sweetpotato leaves. Sweetpotato research front. pp.56-63
20. Menezes, D. M., M. M. Rego, A. Nobre and C. A. Meneguelli. 1976. Effect of harvest time on the sugar and protein content of sweet potatoes. Portuguese. Pes. Agropec. Bras. Agron. 11(2) : 49-52
21. Oyenuga, V. A. 1968. Nigerian foods and feeding stuffs. Ibadan University Press. Ibadan. Nigeria. pp. 124-129
22. Pace, R. D., T. E. Sibiya, B. R. Phills and G. G. Dull. 1985. Ca, Fe and Zn content of Jewel sweet potato greens as affected by harvesting practices. J. Food Sci 50(4): 940-941 https://doi.org/10.1111/j.1365-2621.1985.tb12984.x
23. Palmer, J. 1973. Determination of organic acids in foods by liquide chromatography. J. Agr. Food Chem. 21(5) : 903-907 https://doi.org/10.1021/jf60189a019
24. Purcell, A. E., H. E. Swaisgood and D. T. Pope. 1972. Protein and amino acid content of sweet potato cultivars. J. Am. Soc. Hort. Sci. 97( 1) : 30-33
25. Riichirch, O., I. Kihara and T. Akio. 2000. Anthocyanins food color with health benefits kenpakusha Co. Ltd. Japan. pp. 45-50
26. Sauthier, C., K. Dieng, C. Flament, C. Doucet, J. P. Suguet and D. Lemonnier. 1983. Effects of whey protein. casein, soyabean and sunflower proteins on the serum, tissue and faecal steroids in rats. J. Mutr 49: 313-319
27. Scott, L. E. and J. C. Bouwkamp. 1974. Seasonal mineral accumulation by the sweet potato. J. Am. Soc. Hort. Sci 9(3) : 233-235
28. Shahidul-Islam, M., M. Yoshimoto and O. Yamakawa. 2003. Distribution and physiological functions of caffeoylquinic acid derivatives in leaves of sweetpotato genotypes. J. Food Sci. 68 : 111-116 https://doi.org/10.1111/j.1365-2621.2003.tb14124.x
29. Simonne, A. H., S. J. Kays, P. E. Koehler and R. R. Eitenmiller. 1993. Assessment of $\beta$-carotene content in sweetpotato breeding lines in relation to dietary requirements. J. Food Compo. Analy 6(4) : 336-345 https://doi.org/10.1006/jfca.1993.1037
30. Takayo, M., and J.A. Ruth. 1988. Isolation of 1-O-trans-p-couma-royl-$\beta$- D-glucopyranose from sweet potato roots and examination of its role in chlorogenic acid biosynthesis. Plant cell physiol. 29(7) : 1221-1226
31. Villareal, R. L., S. K. Lin, L. S. Chang and S. H. Lai. 1979a. Use of sweet potato(Ipomoea batatas) leaf tips as vegetables. I. Evaluation of morphological traits. Exptl 256: 368-371
32. Wimalasiri, P. and R.B.H. Wills. 1983. Simaltaneous analysis of ascorbic acid and dehydroascorbic acid in fruit and vegetables by high performance liquid chromatography. J. chromato. Agric 15(2) : 113-116
33. Woolfe, J. A. 1992. Sweet potato. Cambridage University Press. New York. USA