In previous papers, we have studied the cooking-rate equations for the hot-water dipped cooking and the microwave cooking of potatoes. The values of the rate parameters in the cooking-rate equations were differed. In this paper, we were measured the cooking ratio and the temperarure in the inner part of potato dipped in hot water. The cooking-rate equation obtained was as follows:
dx/dθ=A•exp (-E/Rg•T) (1-x)n
A=4.912 x 10^8 min-1, E= 1.500 x 10^4 cal/g-mol, n=1.0
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 2.96 x 10^4 cal/g-mol obtained for the hot-water dipped cooking of potato slice which used the impact-penetration method, and very similar the value of 1.82 x10^4 cal/g-mol obtained for the microwave cooking of cylindrical potato which used the constant velocity penetration method.