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ID 30163
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title alternative
A Non-destructive and Continuous Measurement of Gelatinization of Rice in Rice Cooking Process
creator
NDC
Domestic arts and sciences
abstract
アルミニウム製の鍋と蓋に2枚の電極板としての機能を持たせ, 炊飯過程における米-水系試料の誘電特性の変化を低周波領域で測定し, 以下の結果を得た.

(1) 炊飯過程における電気容量の変化は, 加熱開始5分後から急激に増加し, 沸騰が始まる7分付近でピークを示し, 11分以降は加熱前の水準に戻った. 電気容量の増加が始まった時点の試料温度は米デンプンの糊化開始温度とほぼ一致していた.

(2) DSCによる米の糊化度の変化は, 沸騰直前から急激に糊化が始まり, 加熱開始7分後に50%のデンプンが糊化し, その後糊化速度が緩やかに減少して行く傾向を示した.

(3) 実測した電気容量と誘電正接から誘電体損を求め, これを時間で積分し新たな糊化度を定義したところ, DSC測定により得られた糊化度と良好に一致した.

(4) 以上の結果より, 誘電特性を利用した炊飯過程の米の糊化度の非破壊・連続測定の可能性が示唆された.
abstract
A non-destructive and continuous method to measure gelatinization of rice samples in a rice-water system during rice cooking process was examined. An aluminum pot and a lid of a rice cooker were used as two electrode plates, and changes in dielectric properties (capacitance : C, and dielectric dissipation factor : tan δ) of the samples in the rice cooking process were measured by a capacitance meter. Differential scanning calorimetry (DSC) was used to measure gelatinization enthalpy and to determine the degree of gelatinization. Dielectric loss was calculated from the dielectric properties, which changed as the rice cooking process proceeded. Thus, we defined the degree of gelatinization as the value obtained by integrating the dielectric loss with respect to time. The degree of gelatinization based on the dielectric properties was consistent with that based on the DSC. We concluded that the degree of gelatinization in the rice cooking process can be non-destructively and continuously determined by measuring the dielectric properties.
journal title
日本食品科学工学会誌
volume
Volume 49
issue
Issue 6
start page
416
end page
421
date of issued
2002-06-15
publisher
日本食品科学工学会
issn
1341-027X
ncid
language
jpn
nii type
Journal Article
HU type
Journal Articles
DCMI type
text
format
application/pdf
text version
publisher
relation url
department
Graduate School of Biosphere Science