Abstract: In students’ nutrishing meal and fast food, potato is the most commonly used. The bowing and nourishment loss about potato before cooking still are not solved. The paper studied the trend of starch and VC variety and the best processing conditions in potato before cooking. The results showed that the longer time of soaking takes and the higher soaking temperature is, the more nourishment material of potato loses, but the effect of the feed ratio is insignificant. The effect of pH to VC is more significant, but as to the starch is insignificant. The best conditions are: 0.5% NaCl, soaking temperature 20 ℃, soaking time less than 15 minutes, the feed ratio 3:1 and optimum pH5. It can prevent browning of potato , and the nourishment in potato lose less.

Key words: potato, Vitamin C, soaking, browning, starch