Storage of Fresh Yam (Dioscorea alata L.) under Controlled Conditions

Abstract

Freshly harvested "Florido" yam tubers (a highly desirable variety of the species D. alata) were subjected to a temperature of around 32° C. (90° F.) and a relative humidity of 90 percent. Wounded tissues were suberized in about 4 days. This curing may be accomplished either in controlled environmental rooms or under tropical prevailing ambient conditions. The formation of the cork tissue during suberization protects tubers from infection by microorganisms if stored under reduced temperatures. Cured and uncured tubers were stored in a properly ventilated Forma Scientific room at 16° C. ± 1° (59° to 62.9° F.), and a relative humidity of 70 percent. Uncured samples suffered high losses due to physiological breakdown as well as markedly higher weight losses than similarly handled cured ones which showed no signs of internal decay during the storage period. Cured tubers kept under conditions noted above, at temperatures below those prevailing in tropical areas, had the dormant period lengthened by 4 additional months. High-quality tubers can be provided by this means for the fresh market and for processing during the off-season. Although the yam tubers hardened slightly during storage, weight losses were kept at a fairly low level and the palatability of the tubers remained very high, as determined by sensory evaluation.