1-Methylcyclopropene (1-MCP) inhibits the action of ethylene and, therefore, it has the unique ability to maintain quality and extend the shelf-life of many fresh fruit and vegetables. The postharvest gaseous application of 1-MCP has been shown to improve many physiological characteristics of apples, such as reduced ethylene production and respiration, enhanced fruit firmness and acidity retention, and reduced peel greasiness and various physiological disorders (Blankenship and Dole, 2003; DeEll et al., 2007; Fan et al., 1999a, 1999b; Watkins, 2006).
1-MCP affects the incidence of storage disorders in a variety of ways, depending on apple cultivar and storage regime. Superficial scald is generally reduced by 1-MCP (DeEll et al., 2002; Fan et al., 1999b; Moran, 2006; Rupasinghe et al., 2000; Watkins et al., 2000), as is peel greasiness (Fan et al., 1999b; Watkins and Nock, 2005) and senescent breakdown (DeLong et al., 2004; Watkins et al., 2000). There is often no effect of 1-MCP on internal browning in ‘Empire’ apples (DeEll et al., 2007; Fawbush et al., 2008; Watkins and Nock, 2005). Core browning is reduced by 1-MCP in ‘McIntosh’ apples held in air storage at 0.5 °C (Watkins et al., 2000), but is increased in ‘Delicious’ apples stored long-term in controlled atmosphere (CA) (DeEll et al., 2007). 1-MCP also increases susceptibility to external CO2 injury in ‘Empire’ and McIntosh' apples (DeEll et al., 2003; Fawbush et al., 2008). Watkins (2007) recently reviewed the effect of 1-MCP on the development of physiological storage disorders in horticultural crops.
There are many factors that can influence the response of apples to 1-MCP. Each cultivar tends to behave differently and responses often vary with storage conditions (Bai et al., 2005; DeEll et al., 2005a; Fan et al., 1999a, 1999b; Watkins et al., 2000). 1-MCP treatment temperature is important when application is less than 9 h (DeEll et al., 2002), whereas temperature has little effect in the case of 24-h treatments (Watkins and Nock, 2005). A dose response of 1-MCP has been found in some cultivars but not in others (Watkins et al., 2000). Application delays of up to 8 d can have no effect on 1-MCP efficacy or it can markedly reduce it (Watkins and Nock, 2005).
The commercial formulation of 1-MCP for use on food is SmartFreshSM (AgroFresh, Spring House, PA). Application in the United States is at a concentration of 1000 ppb 1-MCP, whereas in United Kingdom it is 625 ppb. Due to the diverse responses of apples to 1-MCP, these concentrations could result in different effects under various conditions. The objectives of this work were to investigate the effects of 1-MCP concentration (1000 vs. 625 ppb) and treatment delays after harvest (3, 7, and 10 d) on the ripening and incidence of storage disorders in ‘McIntosh’ apples from three harvest times. Apples were stored in air at 0 °C to 1 °C for 3 and 6 months, as well as in CA storage at 3 °C for 6 and 9 months.
Bai, J., Baldwin, E.A., Goodner, K.L., Mattheis, J.P. & Brecht, J.K. 2005 Response of four apple cultivars to 1-methylcyclopropene treatment and controlled atmosphere storage HortScience 40 1534 1538
DeEll, J.R., Ayres, J.T. & Murr, D.P. 2007 1-Methylcyclopropene influences ‘Empire’ and ‘Delicious’ apple quality during long-term commercial storage HortTechnology 17 46 51
DeEll, J.R., Murr, D.P., Porteous, M.D. & Rupasinghe, V.R. 2002 Influence of temperature and duration of 1-methylcyclopropene (1-MCP) treatment on apple quality Postharvest Biol. Technol. 24 349 353
DeEll, J.R., Murr, D.P., Wiley, L. & Porteous, M.D. 2003 1-Methylcyclopropene (1-MCP) increases CO2 injury in apples Acta Hort. 600 277 280
DeEll, J.R., Murr, D.P., Wiley, L. & Mueller, R. 2005a Interactions of 1-MCP and low oxygen CA storage on apple quality Acta Hort. 682 941 948
DeEll, J.R., Murr, D.P., Mueller, R., Wiley, L. & Porteous, M.D. 2005b Influence of 1-methylcyclopropene (1-MCP), diphenylamine (DPA), and CO2 concentration during storage on ‘Empire’ apple quality Postharvest Biol. Technol. 38 1 8
DeLong, J.M., Prange, R.K. & Harrison, P.A. 2004 The influence of 1-methylcyclopropene on ‘Cortland’ and ‘McIntosh’ apple quality following long-term storage HortScience 39 1062 1065
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Fan, X., Mattheis, J.P. & Blankenship, S. 1999b Development of apple superficial scald, soft scald, core flush, and greasiness is 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 (1-MCP) in the ‘Empire’ apple Postharvest Biol. Technol. 48 92 98
Meheriuk, M., Prange, R.K., Lidster, P.D. & Porritt, S.W. 1994 Postharvest disorders of apples and pears Agr. Agri-Food Canada Publ. 1737/E
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Rupasinghe, H.P.V., Murr, D.P., Paliyath, G. & Skog, L. 2000 Inhibitory effect of 1-MCP on ripening and superficial scald development in ‘McIntosh’ and ‘Delicious’ apples J. Hort. Sci. Biotechnol. 75 271 276
Watkins, C.B. 2007 The effect of 1-MCP on the development of physiological storage disorders in horticultural crops Stewart Postharvest Rev. 2 11
Watkins, C.B. & Nock, J.F. 2005 Effects of delays between harvest and 1-methylcyclopropene treatment, and temperature during treatment, on ripening of air-stored and controlled-atmosphere-stored apples HortScience 40 2096 2101
Watkins, C.B., Nock, J.F. & Whitaker, B.D. 2000 Responses of early, mid and late season apple cultivars to postharvest application of 1-methylcyclopropene (1-MCP) under air and controlled atmosphere storage conditions Postharvest Biol. Technol. 19 17 32
Watkins, C.B., Silsby, K.J. & Goffinet, M.C. 1997 Controlled atmosphere and antioxidant effects on external CO2 injury of ‘Empire’ apples HortScience 32 1242 1246