Relationship of I<inf>AD</inf> index to internal quality attributes of apples treated with 1-methylcyclopropene and stored in air or controlled atmospheres
Citation
Toivonen, P.M.A., Hampson, C.R. (2014). Relationship of IAD index to internal quality attributes of apples treated with 1-methylcyclopropene and stored in air or controlled atmospheres. Postharvest Biology and Technology, [online] 91 90-95. http://dx.doi.org/10.1016/j.postharvbio.2013.12.024
Abstract
The research was conducted to evaluate the relationship between IAD index (index of absorption difference between 670 and 720nm) values and internal quality attributes of apples treated with 1-methylcyclopropene (1-MCP) and stored in air and controlled atmospheres (CA). Apples of '8S6923' (Aurora Golden Gala™), 'Fuji' and 'Royal Gala' were tested. The results with Aurora Golden Gala™ show that IAD index values were maintained at higher levels if the fruit were stored in CA and that 1-MCP had no significant effect on retaining at-harvest values. The IAD values correlated with chlorophyll a content in the peel (R2=0.95, P<0.0001), but not with chlorophyll b content, internal ethylene levels, firmness or titratable acidity. 'Royal Gala' apples showed a similar response to Aurora Golden Gala™ apples, showing no correlation between IAD index values and internal quality attributes of those apples when treated with 1-MCP and/or CA. In contrast, 'Fuji' apples showed a relationship between IAD index value changes and internal ethylene concentrations (R2=0.67, P<0.05) and titratable acidity changes (R2=0.89, P<0.01), but not firmness. These results suggest that when 1-MCP and/or CA are applied to apples after harvest, that IAD index values do not consistently correlate to any internal quality attributes other than peel chlorophyll a content. © 2014.