Abstract
The accumulation curves of phenol in the flesh of apples were measured at $5^{\circ}C$, $25^{\circ}C$ and $40^{\circ}C$ when they were exposed to phenol vapor, The effective diffusivities of phenol at the rind and flesh were determined by comparing its experimentally obtained accumulation curves with simulated ones. The simulation was carried out by the non-steady state diffusion rate equation. The diffusion model assumed the consecutive diffusion of phenol at the rind and flesh of apples. The detection time of phenol in the flesh of apples was shortened with increasing temperature, and it accumulated amount also increased rapidly. The estimated effective diffusivity of phenol at the rind of apples increased with temperature as like $1.1{\times}10^{-13}\;m^2/s$ at $5^{\circ}C$, $1.4{\times}10^{-13}\;m^2/s$ at $25^{\circ}C$ and $2.2{\times}10^{-13}\;m^2/s$ at $40^{\circ}C$, but those at the flesh of apples were invariant as $1.5{\times}10^{-10}\;m^2/s$ at this temperature range. The effect of temperature on the diffusivity of phenol was small, but the increase of the vapor pressure of phenol with temperature accelerated the penetration of phenol at the rind, resulting in the rapid accumulation at the flesh of apple.
페놀 증기에 노출된 사과에서 페놀의 축적량 곡선을 $5^{\circ}C$, $25^{\circ}C$, $40^{\circ}C$에서 측정하였다. 과피와 과육에서 페놀의 연계 확산을 비정상상태 확산 속도식으로 모사한 축적량 곡선을 실험 결과와 비교하여, 과피와 과육에서 페놀의 유효확산계수를 추정하였다. 노출온도가 높아지면 사과 내 페놀이 검출되는 시기가 빨라지고, 페놀의 축적량이 빠르게 증가하였다. 사과가 부패되지 않은 범위에서 얻은 축적량 곡선에서 추정한 유효확산계수는 과피에서는 $5^{\circ}C$에서 $1.1\times10^{-13}\;m^2/s$, $25^{\circ}C$에서 $1.4\times10^{-13}\;m^2/s$, $40^{\circ}C$에서 $2.2\times10^{-13}\;m^2/s$로 노출온도에 따가 유효확산계수가 커졌으나, 과육에서는 $1.5\times10^{-10}\;m^2$로 일정하였다. 온도가 확산 속도에 미치는 영향은 작으나, 온도가 높아지면 페놀의 증기압이 커져서 과피에서 페놀의 이동이 빨라지므로 사과 내에 페놀이 빠르게 축적되었다.