Occasional occurrence of a superficial skin injury associated with CA storage can cause severe commercial loss in the `Empire' cultivar in the northeast. To develop industry strategies to prevent losses due to the disorder, we have examined a number of factors related to its occurrence. 1) Fruit from six orchards were stored with 2% or 5% CO2 (with 2% O2) at 0.5 or 3°C for 6 or 9 months. Orchard variation in susceptibility was high. Preharvest factors such as maturity or mineral levels in the fruit did not account for these differences. Incidence of the disorder was much higher at 5% than at 2% CO2. However, temperature did not affect the extent of injury. 2) Exposure of fruit stored at 2% CO2/2% O2 to 5% CO2 at 4-week intervals from harvest until 20 weeks indicated that fruit were most susceptible to injury between 0 and 8 weeks. 3) A postharvest treatment with diphenylamine (DPA) prevented occurrence of the disorder, ethanol reduced it, but ascorbic acid had little effect. 4) Fruit were held at storage temperatures for up to 10 days before exposure to either 2% or 5% CO2. Injury was highest in fruit exposed one day after harvest and negligible when exposed after 10 days. Collectively the results indicate that rapid CA can aggravate the disorder if care is not taken to maintain low CO2 concentrations in the storage atmosphere but that use of DPA for control of superficial scald will prevent its occurrence.
Christopher B. Watkins and Kenneth J. Silsby
Fanjaniaina Razafimbelo, Jacqueline F. Nock and Chris B. Watkins
The ethylene inhibitor, 1 methylcyclopropene (1-MCP), is used extensively in New York to maintain quality of the `Empire' apple cultivar through the marketing chain. However, the cultivar is susceptible to external CO2 injury, a physiological disorder that develops predominantly on the unblushed area of the apple skin. Injury is expressed as tan colored, smooth, water-soaked areas that become irregularly shaped, rough, depressed and wrinkled. The disorder usually occurs during controlled atmosphere (CA) storage. 1-MCP may increase susceptibility of fruit to external CO2 injury. Three experiments have been carried out to investigate postharvest manipulations that may attenuate the effects of 1-MCP on external CO2 injury of `Empire' apple. 1) The effect of CO2 concentration (1%, 2.5%, and 5%) and time of exposure to 2.5% and 5% CO2 during CA storage. 2) Delaying exposure of fruit to 5% CO2 after harvest to up to 14 d. 3) Using lower concentrations of diphenylamine (DPA), an antioxidant that is known to eliminate susceptibility at normal rates. The results show that higher external CO2 injury levels are associated with higher CO2 concentrations, but that 1-MCP does not increase the exposure period of susceptibility to injury during CA storage. Susceptibility to CO2injury is decreased markedly by delaying application of CA storage in untreated fruit. In contrast, high susceptibility to injury is maintained in 1-MCP-treated fruit as long as 14 days after harvest. DPA eliminated injury in 1-MCP-treated fruit, even at 250 ppm, 25% of commercial rates used for superficial scald control. Our data show that 1-MCP increases susceptibility of `Empire' apples to external CO2 injury and special care is therefore required to avoid fruit losses. Nonchemical means may reduce losses, but the only technology that has been shown to eliminate risk of injury is DPA treatment.
George D. Nanos and F. Gordon Mitchell
`High-temperature controlled-atmosphere (high CO2/low O2) conditioning was investigated as a possible treatment to delay the incidence of internal breakdown of peaches and nectarines (Prunus persica L. Batsch) during subsequent cold storage. Maintaining an atmosphere of 5% to 15% CO2 added to air or to 1% to 5% O2 while conditioning peaches for 2 days at 20C partially prevented fruit ripening (compared to fruit conditioned in air), as measured by flesh softening and loss of green pigment, while no off-flavors were detected. Conditioning of peaches at 20C for 4 days in air or in air + 20% CO2 was detrimental to fruit quality, as indicated by flesh softening or detection of off-flavors.
J. Pablo Fernández-Trujillo, Jacqueline F. Nock and Christopher B. Watkins
`Cortland' and `Law Rome' apples [Malus sylvestris (L.) Mill var. domestica (Borkh.) Mansf.] were either nontreated or treated with the inhibitor of superficial scald development, DPA, and exposed to air or CO2 (40 or 45 kPa) in air at 2 °C for up to 12 days. Fruit exposed to air or 45 kPa CO2 were sampled during treatment, and peel and flesh samples taken for fermentation product and organic acid analyses. After treatment, fruit were air stored for up to 6 months at 0.5 °C for evaluation of disorder incidence. `Cortland' apples were most susceptible to external CO2 injury and `Law Rome' to internal CO2 injury. DPA treatment markedly reduced incidence of both external and internal injury. Fermentation products increased in peel and flesh of both cultivars with increasing exposure to CO2, but the extent of the increase was cultivar dependant. Acetaldehyde concentrations were about 10 times higher in peel and flesh of `Law Rome' than that of `Cortland' apples. Ethanol concentrations in the flesh were similar in both cultivars, but were about twice as high in `Cortland' than in `Law Rome' peels. Neither acetaldehyde nor ethanol concentrations were affected consistently by DPA treatment. Succinate concentrations, often regarded as the compound responsible for CO2 injury, increased with CO2 treatment, but were not affected by DPA application. Citramalate concentrations were reduced by CO2 treatment in `Law Rome' peel, but other acids were not consistently affected by CO2. Results indicate that acetaldehyde, ethanol or succinic acid accumulation are not directly responsible for CO2 injury in apples. Chemical name used: diphenylamine (DPA).
Rachel S. Leisso, Ines Hanrahan, James P. Mattheis and David R. Rudell
-tree development and storage in atmospheres conducive to internal browning development Postharvest Biol. Technol. 61 95 102 Fernández-Trujillo, J.P. Nock, J.F. Watkins, C.B. 2001 Superficial scald, carbon dioxide injury, and changes of fermentation products and
Jennifer R. DeEll, Robert K. Prange and Dennis P. Murr
Chlorophyll fluorescence was evaluated as a rapid and nondestructive technique to detect low-O2 or high-CO2 stress in apples (Malus domestica Borkh.) during storage. `Marshall' McIntosh apples were held for 5, 10, 15, 20, or 25 days at 3C in 1) standard O2 (2.5% to 3%) and low CO2 (<1%), 2) low O2 (1% to 1.5%) and low CO2 (<1%), 3) standard O2 (2.5% to 3%) and standard CO2 (4% to 4.5%), or 4) standard O2 (2.5% to 3%) and high CO2 (11% to 12%). Only 10% of the apples had skin discoloration after 5 days in 1% to 1.5% O2; 80% developed skin discoloration after 20 days in low O2. Small desiccated cavities in the cortex, associated with CO2 injury, developed in 10% of the apples after 20 days in 11% to 12% CO2. Five days in 1% to 1.5% O2 or 11% to 12% CO2 caused variable fluorescence (Fv) of apple fruit to decrease compared to those held in standard atmospheres. Additional exposure did not significantly affect Fv in either the low-O2 (1% to 1.5%) or high-CO2 (11% to 12%) treatment. Our results suggest that chlorophyll fluorescence techniques can detect low-O2 and high-CO2 stress in apples before the development of associated disorders.
Christopher B. Watkins and Jacqueline F. Nock
reduced by MCP J. Agr. Food Chem. 47 3063 3068 Fawbush, F. Nock, J.F. Watkins, C.B. 2008 External carbon dioxide injury and 1-methylcyclopropene Postharvest Biol. Technol. 48 92 98 Ferguson, I.B. Watkins, C.B. 1989 Bitter pit in apple fruit Hort. Rev. 11
James P. Mattheis
Disorders of carbohydrate metabolism of apples (watercore, internal breakdown, low temperature and carbon dioxide injuries) Bot. Rev. 35 168 194 Kupferman, E. 2003 Controlled atmosphere storage of apples and pears Acta Hort
Jennifer DeEll and Behrouz Ehsani-Moghaddam
. Food Chem. 47 3063 3068 Fawbush, F. Nock, J.F. Watkins, C.B. 2008 External carbon dioxide injury and 1-methylcyclopropene (1-MCP) in the ‘Empire’ apple Postharvest Biol. Technol. 48 92 98 Jung, S.K. Watkins, C.B. 2011 Involvement of ethylene in browning
Elena de Castro, Bill Biasi, Elizabeth Mitcham, Stuart Tustin, David Tanner and Jennifer Jobling
‘Cox's Orange Pippin’ apple fruit J. Amer. Soc. Hort. Sci. 117 373 376 Fernández-Trujillo, J.P. Nock, J.F. Watkins, C.B. 2001 Superficial scald, carbon dioxide injury, and changes of fermentation products