回転粘度計による熱帯産澱粉糊液の流動特性  [in Japanese] Flow Behaviors of Tropical Starch Pastes as Measured by a Rotational Viscometer  [in Japanese]

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Abstract

熱帯産澱粉4種すなわち食用カンナ,アロールート,キャッサバ,サゴの澱粉と対照として馬鈴薯とトウモロコシの澱粉を選び,2,3,4%の澱粉糊液につき,ずり速度流動化流動,チキソトロピー,降伏値,流動の見かけの活性化エネルギーを測定した. 各澱粉糊液は非ニュートン流動を示した.流動曲線につき,10s<SUP>-1</SUP>から300s<SUP>-1</SUP>の範囲で直線が得られたのでベキ則を適応し,流動方程式τ=Kγ<SUP>n</SUP>を求め,粘性定数(K)および流動性指数(n)を求めた. キャッサバとサゴの各濃度の澱粉糊液および4%アロールート澱粉糊液の流動性指数(n)は,20~60℃に比べて10℃ の値が極端に小さく馬鈴薯澱粉糊液に近い性質を示し,食用カンナと2,3%アロールート澱粉糊液は,温度依存性が小さく,トウモロコシ澱粉糊液に近い性質を示した.流動性指数(n)と分子特性の関係は,10℃ で値が小さく20~60℃ で大きくなる馬鈴薯に代表されるタイプのnはアミロースとアミロペクチンの分子量が両方とも大きい傾向であり,10~60℃ まで変化が少ないトウモロコシに代表されるnを示すものは,アミロースとアミロペクチンの分子量が両方とも小さい傾向がみられた.サゴはこの傾向に一致しなかった. チキソトロピー性はキャッサバ,食用カンナ,サゴ,4%アロールート糊液に10~60℃ まで認められ,キャッサバ,サゴが大きく,食用カンナは中位,アロールートは最小であった.10℃ でチキソトロピー性が大きい馬鈴薯とキャッサバはアミロースとアミロペクチンの分子量が両方とも大きい傾向で,食用カンナ,アロールート,トウモロコシは,チキソトロピー性は中位から最小であるが,これらはアミロースとアミロペクチンの分子量は両方とも中位から最小の傾向が認められた.サゴはこの傾向と一致しなかった. 降伏応力は4%アロールート澱粉糊液の10,20℃と3,4%トウモロコシ澱粉糊液の10~60℃ に認められた. 流動の見かけの活性化エネルギーは,6種の澱粉の2,3,4%糊液について,約8.5~17kJmol<SUP>-1</SUP>の範囲であった.

The flow behaviors (i.e., shear thinning flow, thixotropy, yield value and apparent activation energy) of tropical starch pastes were studied by a rotational viscometer using potato and corn starches as controls. Each flow curve could be described by a power-law equation: τ=K γ<SUP>n</SUP>, and viscosity index (K) and flow behavior index (n) were calculated. The n of cassava and sago pastes and arrowroot paste at 4% was similar to that of potato starch pastes. On the other hand, the n of edible canna pastes and arrowroot at 2 and 3% was similar to that of corn starch pastes. Starches, the n of which was represented by that of potato starch paste, consisted of both amylose and amylopectin with relatively large molecular weights. On the other hand, starches, the n of which was represented by that of corn starch paste, consisted of both amylose and amylopectin with relatively small molecular weights. Thixotropy was found with edible canna, cassava and sago pastes and 4% arrowroot paste between 10 and 60°C. Potato and cassava starch pastes, which consisted of both amylose and amylopectin with relatively large molecular weights, showed large thixotropy. Edible canna, arrowroot and corn starch pastes, which consisted of amylose and amylopectin with a combination of small and intermediate molecular weights, showed relatively small thixotopy. Sago starch was out of course with n and thixotropy. Yield values were found with 4% arrowroot starch paste at 10 and 20°C and corn starch pastes at 3 and 4% from 10 to 60°C. The apparent activation energy ranged between 8.5 and 17 kJ mol<SUP>-1</SUP> for the six varieties of starches.

Journal

  • Journal of Applied Glycoscience

    Journal of Applied Glycoscience 45(2), 107-115, 1998-06-30

    The Japanese Society of Applied Glycoscience

References:  30

Cited by:  1

Codes

  • NII Article ID (NAID)
    10008257858
  • NII NACSIS-CAT ID (NCID)
    AN10453916
  • Text Lang
    JPN
  • Article Type
    Journal Article
  • ISSN
    13403494
  • NDL Article ID
    4505299
  • NDL Source Classification
    ZP24(科学技術--化学・化学工業--糖・澱粉)
  • NDL Call No.
    Z17-15
  • Data Source
    CJP  CJPref  NDL  J-STAGE  JASI 
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