POTATO STORAGE IN TAIWAN

In Taiwan commercial storage of potatoes (CV Kennebec, Wu-Foon, Cardinal) at 2°C, 85% RH can supply the fresh market all year round. However reducing sugar and total sugar which accumulate in the tubers will reduce the processing quality of potatoes.

Reconditioning of tubers from cold stores at ambient temperature (20–30°C) was undertaken for up to 6 wk. The sugar content decreased most rapidly at 25°C for Kennebec and 20°C for Cardinal. Treating tubers with sprout inhibitor CIPC during reconditioning can control the problem of sprouting. The optimum dosage of CIPC are: 1,000 ppm at 20°C, 1–3,000 ppm at 25°C and 3,000 ppm at 30°C. CIPC residuals in all tubers are below the standard limit. It was found that the higher the reconditioning temperature, the more the solanine contents in the tubers.

When newly harvested potatoes pretreated with CIPC (300–500 ppm) and stored at 10°C, 80% RH, sprouting was inhibited effectively. The quality of potatoes retained well and reducing sugar remained in a low level for up to 8 months. MENA was found ineffective. Gamma irradiation of potatoes at 0.175–0.20 KGy, 0.10–0.125 KGy and 0.125 KGy for Cardinal, Kennebec and Wu-Foon respectively was found effective to control the sprouting of tubers stored at 10°C, 80% RH for 9 months. Rapid increase of sugar content was found after storage for 7 months.