Technical Abstract: The purpose of this investigation was to evaluate the rate of deterioration of lycopene in watermelon tissue during frozen storage since little is known about the stability of watermelon tissue lycopene under cold storage conditions. Heart tissue from each of nine individual watermelons was stored at -20C or -80C as either small chunks or puree and periodically sampled over a year's time. Initial freeze-thaw experiments indicated that a small percentage of lycopene, ~4-6%, degraded during an initial freeze-thaw. Analyses of the samples showed a loss of ~ 30-40% lycopene over a year's storage at -20oC and a loss of ~ 5-10% over the same period at -80C. Watermelon tissue is equally-- or slightly more stable stored as a puree rather than chunks. The kinetic data were best fitted by application of two simultaneous, first order decay processes. HPLC analysis of the samples after a year's storage suggested that b-carotene was more stable to storage at -20C than was lycopene.