ジャガイモのクッキング進行中におけるクッキング速度に関する研究

これまでにジャガイモを例として、クッキング速度に関する多くの研究が行われてきているが、速度パラメータの値が異なってきている。前報(張ほか, 1993)では、クッキング率を求めるレオロジー特性の測定法の進いなどによる影響があると考えられる結果を得た。本研究では、ジャガイモの加熱湯中のクッキングにおけるクッキング速度の測定を、前報で示した定速貫通法を用いて、加熱温度下と冷却後温度下とで行って比較検討した。クッキング進行中におけるクッキング進度が測定温度を変えると異なってくると考えられる結果を得た。

In previous papers, the cooking rate parameters of potatoes were differed. It this paper, we were measured the cooking ratios of potato by using the constant velocity penetration method under the hot condition of cooked samples and the cooled condition.

The values of cooking ratio of the samples during the cooking process were differed to the measuring temperature. The cooking-rate equation obtained under the hot condition was as follows:
dx/dθ=A・exp[—E/ (Rg・T)] (1-x)^n
A=6.398 x 10^8 min-1, E=7.50 x 10^3 cal/g-mol, n=1
where, x[—]: cooking ratio, θ[min]: cooking time, T[°K]: cooking temperature, Rg=1.987 cal/(g-mol・°K). The value of activation energy obtained was lower than the value of 1.50 x 10^4 cal/g-mol obtained in previous paper which measured the cooking ratio under the cooled condition. We can consider that the softening behavior of potatoes occured by the cooking phenomena and the measuring temperature changes, and conclue that the softening behavior occured for the samples of high measuring temperature method during the uncooked temperature.