Changes in Physicochemical and Sensory Characteristics of Dandelion (Taraxacum officinale) Leaves by Roasting Treatment

덖음처리에 의한 민들레 잎의 이화학적 및 관능적 특성 변화

  • Published : 2007.10.31

Abstract

To establish the roasting conditions of dandelion leaves for the manufacture of processed foods such as beverages and tea, we investigated the physicochemical and sensory characteristics of dandelion leaves and their hot water extracts by roasting treatment. As the number of roasting times increased, the free sugar content of the roasted dandelion leaves decreased, and in particular, free amino acid and total polyphenol content decreased greatly after only 1 roasting treatment. The amino nitrogen and total polyphenol contents of the roasted dandelion leaf hot water extracts also decreased greatly, and their L-, a-, and b-values showed much lower values than those of the raw leaf extracts. However, a greater amount of reducing sugars was extracted in the roasted leaves than in the raw leaves, suggesting that the roasting process allows for easier extraction of the compounds in dandelion leaves. Five sensory characteristics, including astringent taste, bitter taste, peen flavor, burnt taste, and sweet odor, were deduced through quantitative descriptive analysis of the hot water extracts. Among them, astringent taste, bitter taste, and green flavor showed significant differences between roasting treatments. The sensory evaluation results show that as the number of roasting times increased, the palatability of the hot water extracts increased greatly, in terms of color and taste.

Keywords

dandelion leaves;roasting;physicochemical properties;sensory characteristics

References

  1. Kang MJ, Kim KS. Current trends of research and biological activities of dandelion. Food Ind. Nutr. 6: 60-67 (2001)
  2. Han SH, Hwang JK, Park SN, Lee KH, Ko KI, Kim KS, Kim KH. Potential effect of solvent fractions of Taraxacum mongolicum H. on protection of gastric mucosa. Korean J. Food Sci. Technol. 37: 84-89 (2005)
  3. Shin SR. Studies on the nutritional components of dandelion (Taraxacum officinale). Korean J. Postharv. Sci. Technol. 6: 495- 499 (1999)
  4. Park JH, Kim YO, Jung JM, Seo JB. Effect of quality of panfired green tea at different pan-firing conditions. J. Bio-Environ. Control 15: 90-95 (2006)
  5. Sharma V, Gulati A, Ravindranath SD. Extractability of tea catechins as a function of manufacture procedure and temperature of infusion. Food Chem. 93: 141-148 (2005) https://doi.org/10.1016/j.foodchem.2004.10.016
  6. Sahlin E, Savage GP, Lister CE. Investigation of the antioxidant properties of tomatoes after processing. J. Food Compos. Anal. 17: 635-647 (2004) https://doi.org/10.1016/j.jfca.2003.10.003
  7. Yang KS, Jeon CM. Effect of Taraxacum coreanum Nakai on low density lipoprotein oxidation. Korean J. Pharmacogn. 27: 267-273 (1996)
  8. Cho SY, Park JY, Oh YJ, Jang JY, Park EM, Kim MJ, Kim KS. Effect of dandelion leaf extracts on lipid metabolism in rats fed high cholesterol diet. J. Korean Soc. Food Sci. Nutr. 29: 676-682 (2000)
  9. Takasaki M, Konoshima T, Tokuda H, Masuda K, Arai Y. Anticarcinogenic of Taraxacum plant. II. Biol. Pharm. Bull. 22: 606- 610 (1999) https://doi.org/10.1248/bpb.22.606
  10. Crozier A, Lean MEJ, McDonald MS, Black C. Quantitative analysis of the flavonoid content of commercial tomatoes, onion, lettuce, and celery. J. Agr. Food Chem. 45: 590-595 (1997) https://doi.org/10.1021/jf960339y
  11. Kim TJ. Our Flower, 100 Species. 9th ed. Hyunamsa, Seoul, Korea. pp. 2-5 (1994)
  12. Lee YT, Seog HM. Changes in physicochemical characteristics of immature barley kernels during roasting. Korean J. Food Sci. Technol. 26: 336-342 (1994)
  13. Takasaki M, Konoshima T, Tokuda H, Masuda K, Arai Y. Anticarcinogenic of Taraxacum plant. I. Biol. Pharm. Bull. 22: 602- 605 (1999) https://doi.org/10.1248/bpb.22.602
  14. Seog HM. The effects of the roasting temperature on the formation of volatile compounds in the malted naked barley. PhD thesis. Chung-Ang University, Seoul, Korea (1987)
  15. Ismail A, Marjan ZM, Foong CW. Total antioxidant activity and phenolic content in selected vegetables. Food Chem. 87: 581-586 (2004) https://doi.org/10.1016/j.foodchem.2004.01.010
  16. Singleton V, Rossi J. Colorimetry of total phenolics with phosphomolybdic- phosphotungstic acid reagents. Am. J. Enol. Viticult. 16: 144-158 (1965)
  17. Kang MJ, Shin SR, Kim KS. Antioxidative and free radical scavenging activity of water extract from dandelion (Taraxacum officinale). Korean J. Food Preserv. 9: 253-259 (2002)
  18. Kim KH, Chun HJ, Han YS. Screening of antimicrobial activity of the dandelion (Taraxacum platycarpum) extract. Korean J. Soc. Food Sci. 14: 114-118 (1998)
  19. Cristina JK, Brandes WB. Determination of sucrose, glucose, and fructose by liquid chromatography. J. Agr. Food Chem. 22: 709- 715 (1974)
  20. Kang MJ, Seo YH, Kim JB, Shin SR, Kim KS. The chemical composition of Taraxacum officinale consumed in Korea. Korean J. Soc. Food Sci. 16: 182-187 (2000)
  21. Ohmori K, Nakamura S, Watanabe T. Changes in color of a tea leaf steamed under different steaming condition. J. Tea Res. 63: 24-29, 78-80 (1986)