不同山藥(Dioscorea alate L.)品系塊莖之貯藏研究

Abstract

The effect of temperature on the tuber storage life and quality of three Yam lines was investigated. Experimental results indicated that for the two white-flesh genotypes, Tainung No. 1 and Brazilian Yam, stored at 14℃ in netted bags, tuber sprouting occurred at 14-23 weeks after storage, or 5-6 weeks later as compared with the storage treatment of 17℃. The rotting rate could reach 33% if storage at 14℃ was prolonged to 34 weeks. For the red-flesh genotype 70R-01, no sprouting was recorded when stored at 14℃, however, severe chilling injury occurred after 27 weeks in storage, When storage temperature was elevated to 17℃, both Tainung No.1 and Brazilian Yam remained unsprouted after 25 weeks. Tubers of the line 70R-01 could also be stored for 26 weeks without significant decrease in quality and economic value although a 10% sprouting rate was observed between 11 and 18 weeks in storage. All the three genotypes showed sprouting between the 4th and 9th weeks if stored at room temperature, with marked decrease in economic value at the 13th week. It is therefore recommended that the appropriate storage temperature for the three Yam genotypes is 17℃. The weight lose percentage of stored tubers was lower at 14 or 17℃ than that at room temperature. The weight loss percentages were 26.6 and 27.5%, respectively, for Tainung No. 1 and Brazilian yam after 26 weeks in storage at 17℃. The value was 37.1% for 70R-01 due to its thinner skin as compared to the other two genotypes. After 26 weeks of storage at 17℃, decreases in contents of water and starch in tubers of Tainung No.1 were, respectively, 12.25 and 4.07%. Brazilian yam had higher contents of water and crude protein than Tainung No.1 after storage under the same condition. For tubers of the two white-flesh genotypes, storage for 26 weeks at 17℃ resulte1 in higher viscosity while the meat color remained unchanged. In conclusion, both the storage life and quality of yam tubers could be maintained at 17℃. It is therefore suggested as an ideal storage method for commercial purpose.