Action of Crude Amylolytic Enzymes Extracted from Sweet Potatoes and Amylolytic Enzymes on the Sweet Potato Starches

고구마 전분에 대한 고구마 조효소와 전분분해 효소의 작용에 관하여

  • Shin, Mal-Shick (Department of Food Science and Nutrition, Chonnam National University) ;
  • Ahn, Seung-Yo (Department of Food and Nutrition, Seoul National University)
  • 신말식 (전남대학교 식품영양학과) ;
  • 안승요 (서울대학교 식품영양학과)
  • Published : 1986.12.01


The action of crude amylolytic enzymes extracted from Wonki and Chunmi sweet potatoes, ${\alpha}-amylase$, and ${\beta}-amylase$ on the sweet potato starches from Wonki (dry type) and Chunmi (moist type) were studied. The activity of crude amylolytic enzyme extracted from Wonki was higher than that extracted from Chunmi. The content of reducing sugar released from the reaction between crude amylolytic enzyme and Chunmi starch preheated at $70^{\circ}C$ was higher, but that preheated at $95^{\circ}C$ was lower than that from Wonki starch preheated at the same temperature. The activites of ${\alpha}-amylase$ and ${\beta}-amylase$ on the Wonki starch were higher than those of the Chunmi starch at the same conditions. Iodine affinity of amylolytic enzyme-treated starch was decreased and enzyme treated starch granule shape was found with porous structure having inner layers. X-ray diffraction patterns of amylolytic enzyme-treated starches were the Ca type like the intact starches and relative crystallinity was decreased.