Effect of Storage Temperature on Shoot and Root Elongation in the Okinawan Traditional Vegetable Shima-Rakkyo

Abstract

　We determined the optimal storage temperature of shima-rakkyo, which is the rakkyo (Allium chinense) blanched. We found that the freezing point of shima-rakkyo was －1.8℃ and the respiration rate increased at 10℃. It was inferred that the suitable storage temperature for shima-rakkyo is in the range of －1.8℃ up to 10℃. We stored shima-rakkyo at 0, 2, and 5℃ for 6 months and investigated shoot elongation, percentage of rooted bulbs, taste, sugar content and pyruvic acid content, every two months. The shoot elongation and rooting of shima-rakkyo were inhibited as the temperature decreased. The taste of shima-rakkyo also tended to be better with the decrease in temperature. When stored at 0℃ for 6 months, shoot and root elongation was suppressed and the taste was preserved. We therefore concluded that the optimal storage temperature for shima-rakkyo is 0℃.