Our study found that storage temperature, storage atmosphere and growing region interactively affect the probability of internal browning disorder in `McIntosh' apples (Malus domestica Borkh.). Higher incidence of internal browning occurred in apples stored for 6 months at 1 °C (34 °F) in controlled atmosphere (CA) with 2.5% O2 + 1.5% CO2 or in CA with 1.0% O2 + 0.5% CO2 than apples stored at 1 °C in air or stored at 3 °C (37 °F) in air or CA conditions. The magnitude of the incidence of internal browning varied among apples harvested from different growing regions. Apples from London, Ontario, Canada were less tolerant to these two storage conditions and therefore greater number of fruit developed internal browning than apples from other regions. In addition, apples from the London growing region and stored at 1 °C in CA with 1.0% O2 + 0.5% CO2 had greater probability of internal browning than apples stored at 1 °C in CA with 2.5% O2 + 1.5% CO2. However, there was no difference between these two CA storage conditions in causing internal browning among apples harvested from other three growing regions. Few apples showed internal browning when they were stored at 3 °C, no matter of what storage atmosphere was used. Therefore, internal browning disorder can be avoided or significantly reduced by storing apples at 3 instead of 1 °C, in these two CA conditions. Internal browning disorder will not be a risk if apples are stored in air at 1 or 3 °C.
Philip E. Hammer, S.F. Yang, M.S. Reid, and J.J. Marois
The effectiveness of fungistatic atmospheres for postharvest control of Botrytis cinerea Pers. infections on cut rose flowers (Rosa hybrids L.) was investigated. Storing cut `Sonia', `Royalty', and `Gold Rush' roses at 2.5C with 10% CO2 for 5 days, followed by 2 days of cold storage in air, reduced the number of B. cinerea lesions that developed on inoculated and noninoculated flower petals by 77% and 82%, respectively, compared to cold storage for 7 days in air. Higher CO2 concentrations and longer CO2 treatment times reduced disease severity further, but resulted in unacceptable leaf discoloration on some cultivars. No deleterious effects of CO2-enriched storage atmospheres on flower quality, weight gain, or vase life were observed. Storage at 2.5C for 7 days in 2 μl SO2/liter reduced B. cinerea infections on inoculated and noninoculated flowers by 53% and 43%, respectively. No deleterious effects on flower quality, weight gain, or vase life were observed. Higher SO2 levels reduced disease severity further, but caused bleaching of the petal margins and necrosis around leaf wounds.
Barbara J. Daniels-Lake and Robert K. Prange
attributes of processing tubers. It can be affected by various factors during the storage term. During long-term storage, the CO 2 concentration may increase considerably in the storage atmosphere. The major sources of CO 2 are tuber respiration and exhaust
Manish K. Bansal, George E. Boyhan, and Daniel D. MacLean
content. The objective of this study was to determine the influence of varieties, curing, storage atmosphere or fumigation, duration of storage, and poststorage time on marketability of Vidalia onions. Materials and methods This 2-year study evaluated
M. Darlene Mercer and Doyle A. Smittle
`Gemini II' cucumber (Cucumis sativus L.) fruits were stored for 2, 4, or 6 days at 5 and 6C in 1989 and for 5 days at SC or 10 days at 3C in 1990. Chilling injury (CI) symptoms were rated after 2 to 4 days at 25C. Cell wall polysaccharide concentrations in the peels and in injured and noninjured portions of the peels were determined only in 1990. High CO2 and low O2 delayed the onset of CI symptoms, but did not prevent symptom development. Chilling injury symptoms increased with longer exposure to chilling temperatures. Solubilization of cell wall polysaccharides was associated with development of CI symptoms. Variations in low methoxyl pectinates accounted for 70% of the variation in CI.
A method was devised for measuring the resistance to gaseous diffusion of bulky plant organs, such as apple (Malus domestica Borkh.) fruits, in which the skin is the major barrier to diffusion. An individual fruit was incubated in a sealed container in the presence of a measured concentration of ethane for a certain time (usually 20 min). The fruit was then transferred to another, similar container. The ethane concentration that diffused into the new container was measured after an equal time (usually 20 min). An expression relating resistance to the measured ethane concentrations was derived from Fick's First Law of diffusion. An estimate of the internal volume of the fruit, accessible to ethane, was also necessary. The method was tested on several fruits of various apple cultivars. Longer incubation periods are necessary for apples with high diffusive resistance.
Barbara L. Goulart, Philip E. Hammer, Kathleen B. Evensen, Wojciech Janisiewicz, and Fumiomi Takeda
The effects of preharvest applications of pyrrolnitrin (a biologically derived fungicide) on postharvest longevity of `Bristol' black raspberry (Rubus occidentals L.) and `Heritage' red raspberry [R. idaeus L. var. strigosus (Michx.) Maxim] were evaluated at two storage temperatures. Preharvest fungicide treatments were 200 mg pyrrolnitrin/liter, a standard fungicide treatment (captan + benomyl or iprodione) or a distilled water control applied 1 day before first harvest. Black raspberries were stored at 18 or 0 ± lC in air or 20% CO2. Red raspberries were stored at the same temperatures in air only. Pyrrolnitrin-treated berries often had less gray mold (Botrytis cinerea Pers. ex Fr.) in storage than the control but more than berries treated with the standard fungicides. Storage in a modified atmosphere of 20% CO2 greatly improved postharvest quality of black raspberries at both storage temperatures by reducing gray mold development. The combination of standard fungicide or pyrrolnitrin, high CO2, and low temperature resulted in more than 2 weeks of storage with less than 5% disease on black raspberries; however, discoloration limited marketability after≈ 8 days under these conditions. Chemical names used: 3-chloro-4-(2'-nitro-3'-chlorophenyl) -pyrrole (pyrrolnitrin); N-trichloromethylthio-4-cyclohexene-l12-dicarboximide (captan); methyl 1-(butylcarbamoyl) -2-benzimidazolecarbamate) (benomyl); 3-(3,5 -dichlorophenyl) -N-(l-methylethyl -2,4-dioxo-l-imi-dazolidinecarboxamide (Rovral, iprodione).
Nihad Alsmairat, Carolina Contreras, James Hancock, Pete Callow, and Randolph Beaudry
apparent weakening of the skin and/or cuticle of these two cultivars during air storage was not associated with higher rates of moisture loss. The relationship between storage atmosphere and skin and cuticle properties is, to our knowledge, unexplored in
Elena de Castro, William V. Biasi, and Elizabeth J. Mitcham
at 130 d of storage, ethylene concentration in the storage atmosphere decreased to less than 1 μL·L −1 ·kg −1 FW during the next 30 d (data not shown), indicating a ethylene production peak during storage in a CA at 0.5 ºC. When fruit stored in a CA
James P. Mattheis
Analysis Statistical analysis. The experiment was conducted using a completely random design. Assessment of fruit quality attributes and physiological disorders used 3 replications of 6 fruit each for each lot-treatment-storage atmosphere-storage duration