The characteristics of extracts and precipitates after extraction at different water temperature (25, 50, 75, 95oC), ethanol ratio (25, 50, 75, 100%), and extraction method (stir, soak, autoclave) of yam powder and raw yam were investigated. The total polyphenol content was the highest in the 50% ethanol extract of yam powder. The DPPH radical scavenging activity was the highest in the 75% ethanol extraction and the crude saponin content was the highest in the 95oC water extraction. Tyrosinase inhibitory activity was the highest in 95oC water extraction, low concentration of ethanol extraction, and autoclave extraction. The peak viscosity, trough, and final viscosity of the precipitates increased after ethanol extraction, whereas decreased after the 95oC water extraction and the autoclave, indicating the destruction of starch granules. This was confirmed by observing the starch granules broken using the SEM. The significance of this study was to investigate the possibility of the use of yam resources as a material, processing product development, skin beauty functional food and cosmetic material.

Abstract
 서 론
 재료 및 방법
 결과 및 고찰
 요 약
 References

• 김재용(한국식품연구원 가공공정연구단) | Jae-Yong Kim (Food Processing Research Center, Korean Food Research Institute)
• 금준석(한국식품연구원 가공공정연구단) | Jun-Seok Kum (Food Processing Research Center, Korean Food Research Institute)
• 박종대(한국식품연구원 가공공정연구단) | Jong-Dae Park (Food Processing Research Center, Korean Food Research Institute)
• 성정민(한국식품연구원 가공공정연구단) | Jung-Min Sung (Food Processing Research Center, Korean Food Research Institute)
• 최윤상(한국식품연구원 가공공정연구단) | Yun-Sang Choi (Food Processing Research Center, Korean Food Research Institute)
• 최현욱(한국식품연구원 가공공정연구단) | Hyun-Wook Choi (Food Processing Research Center, Korean Food Research Institute) Corresponding author