Static and varied magnetic fields effects on shrinkage and sprouting characteristics of stored potatoes

The effects of static and varying magnetic fields (MF) on shrinkage and sprouting characteristics of stored potatoes were studied. Static MF was produced by the use of direct current (DC), while alternating current (AC) produced varying MF. Intensities of DC MF were set at 0.5, 1.0, 1.5, and 2.0 mT and those of AC MF set at 0.2, 0.4, 0.6 and 0.8 mT. The exposure time of DC MF on potatoes was held at 10, 20, 40, 60, and 120 s, while the exposure time of AC MF was 10, 20, 40, 80, and 160 s. Potatoes were then stored in a dark room, with light intensity and temperature of 0 lm/m(2) and 14 +/- 2 degrees C, respectively, for 8 weeks after which they were examined. Weight reduction was significantly (P < 0.05) lower in potatoes that were subjected to both DC and AC MF than in the untreated tubers. However, it is the DC MF of 2.0 mT that resulted in low acceptable weight loss of less than 10%. Fewer numbers of sprouts per tuber were observed in potatoes that were exposed to DC MF of 0.5, 1.0, and 2.0 mT for 60 s or AC MF of 0.4, 0.6, and 0.8 mT for 80 s, respectively. Our results provide important insights on the applicability of static and varying magnetic fields on reduction of postharvest losses in potatoes.