Extending the storage life of fresh cranberries (Vaccinium macrocarpon Ait.) requires an optimum storage environment to minimize decay and physiological breakdown (PB). To assess the effects of relative humidity (RH) and temperature on storage life, cranberry fruit from four bogs were stored over calcium nitrate, sodium chloride, or potassium nitrate salts, which maintained RH at 75%, 88%, and 98%, respectively. Containers at each RH were held at 0, 3, 5, 7, or 10 °C and fruit quality was evaluated monthly for 6 months. Both decay and PB increased with increasing RH in storage. After 6 months, 32%, 38%, and 54% of fruit were decayed and 28%, 31%, and 36% developed PB when stored in 75%, 88%, and 98% RH, respectively. The effects of RH continued to be apparent after fruit were removed from storage, graded, and held for 7 days at 20 °C. The decay of graded fruit after 4 months of storage in 75%, 88%, or 98% RH was 10%, 13%, and 31%, respectively, while PB was 12%, 12%, and 17%, respectively. Fresh weight loss decreased as RH increased averaging 1.9%, 1.4%, and 0.7% per month for storage in 75%, 88%, and 98% RH, respectively. Fruit firmness was not affected by RH. Storage temperature had little effect on decay. However, PB was greatest in fruit stored at 10 °C, encompassing 55% of fruit after 5 months of storage. When graded fruit were held an additional 7 days at 20 °C, decay and PB were greater in fruit previously stored at 0 or 3 °C than at 5, 7, or 10 °C. Fresh weight loss increased as storage temperature increased, averaging 0.8%, 1.0%, 1.3%, 1.7%, and 1.9% per month at 0, 3, 5, 7, and 10 °C, respectively. Fruit firmness decreased during storage, but was not affected by storage temperature. To maximize storage and shelf life, cranberry fruit should be stored in a RH of about 75% at 5 °C.
Charles F. Forney, Stephanie Bishop, Michele Elliot, and Vivian Agar
Barbara J. Daniels-Lake, Robert K. Prange, Stephanie D. Bishop, and Kimberly Hiltz
The fry color of potatoes (Solanum tuberosum L.) stored for processing remains an important quality characteristic that can be affected by many factors, including ethylene gas from various sources and the interaction of very low concentrations of ethylene gas (less than 1 μL·L−1) and accumulated CO2. Because previous studies show that pretreatment with 1-methylcyclopropene (1-MCP) can substantially reduce fry color darkening attributable to applied ethylene, we hypothesized that 1-MCP could also reduce fry color darkening attributable to the interaction of ethylene and CO2. Trials were conducted over two storage seasons, using ‘Russet Burbank’ tubers, either untreated or treated with 0.5 μL·L−1 ethylene gas ± 2 kPa CO2 and ± 1-MCP. Tubers exposed to ethylene gas had darker fry color than untreated tubers, whereas the fry color of tubers exposed to ethylene plus CO2 was darker still. However, the fry color of tubers pretreated with 1-MCP was as light as that of the untreated tubers. This provides a potential new tool for the potato industry to manage potato fry color of stored processing potatoes.