Changes in Texture during the Boiling Process of Potatoes

감자의 증자중(蒸煮中) 텍스쳐의 변화(變化)

The texture changes of potato of the variety ‘Namjack’ were determined as a function of temperature and boiling time by a puncture test with Universal Testing Machine. Apart from texture measurement, heat penetration test and sensory evaluation were carried out. Textural softening during cocking could be expressed by the puncture work and was followed first order kinetics. The Z-value for texture changes was $19.9^{\circ}C$. The cook value in equivalent minutes at $100^{\circ}C$ to get a boiled potatoes was 7 min. Mechanically the boiled product could be regarded as cooked when the final puncture work reduced to the equilibrium value, approximately 6/100 of the initial value.

남작 품종의 감자를 열탕 중에서 증자하면서 열침투 특성과 텍스쳐의 변화를 증자온도 및 시간의 함수로 측정하였다. 열침투 특성값 $f_b$는 무게(w)에 대하여 $f_b=7.051+0.128w(g)$의 관계가 성립되었으며 $j_b=1.66$이였다. 증자에 의한 감자텍스쳐의 변화는 1차 속도식을 나타내었으며 텍스쳐 변화의 Z값은 약 $20^{\circ}C$였다. 관능적으로 평가한 증자완료점에서의 C값은 7 min이였으며 이점은 텍스쳐의 변화가 평형에 도달하는 점과 거의 일치하였다.