Effect of Water Activity on the Physicochemical Properties of Sweet Potato Starch during Storage

저장 중 수분활성이 고구마 전분의 이화학적 특성에 미치는 영향

  • Baek, Man-Hee (Department of Food and Nutrition, Chonnam National University) ;
  • Shin, Mal-Shick (Department of Food and Nutrition, Chonnam National University)
  • 백만희 (전남대학교 식품영양학과) ;
  • 신말식 (전남대학교 식품영양학과)
  • Published : 1995.08.31

Abstract

Effect of water activity $(0.32{\sim}0.89)$ on the physicochemical properties of sweet potato starch during the storage for 5, 15 and 30 days at $40^{\circ}C$ was investigated. Shapes and sizes of starch granules were not changed. X-ray diffraction patterns of the starches appeared equally Ca-crystal structure. Sorption isotherm with storage day was sigmoidal. A slight loss of iodine affinity, increase in water binding capacity, and decrease in swelling power at $80^{\circ}C$ occurred as water activities increased. Viscosity pattern under Brabender Amylogram was not significantly changed with water activity, but initial pasting temperature decreased as water activity increased. The viscosity at $50^{\circ}C$, consistency and setback were increased with increasing storage day and water activity.

저장 중에 수분활성이 전분의 이화학적 성질에 미치는 영향을 알아보기 위해 수분활성도(0.32, 0.48, 0.75, 0.89)로 조절된 데시케이터에 고구마 전분을 넣고 $40^{\circ}C$ 항온기에서 5, 15, 30일간 저장한 다음 이화학적 특성을 비교하였다. 입자의 모양이나 형태는 변화가 없었고, 결정형은 Ca형으로 변하지 않았다. 수분활성이 높을수록, 저장기간이 길어질수록 수분함량과 물결합능력은 증가하였고, 요오드 친화력과 $80^{\circ}C$에서의 팽윤력은 감소하였다. 아밀로그라프에 의한 호화 양상은 저장 15일에는 뚜렷한 차이를 보이지 않았으나, 저장 30일에는 수분활성이 높을수록 $50^{\circ}C$ 냉각점도, consistency와 setback이 증가하였다.

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