| Abstract
| - Five experimental coatings with different resistance to gas exchange were used with freshly harvestedand 20-week commercially stored apples of Delicious, Fuji, Braeburn, and Granny Smith varieties.The coated or noncoated apples were held at 20 °C for up to 4 weeks. The gas partial pressuresinside the fruits with the various coatings ranged from 1 to 25 kPa CO2 and from 20 to 1 kPa O2.Volatile evaporation rates were measured, as also were the volatiles compositions in the fruit. Thecoatings with intermediate gas resistance (carnauba−shellac mixture and candelilla) gave intermediatevalues of CO2 and O2 in the internal atmosphere in Delicious, Fuji, and Braeburn apples and thehighest concentrations of butyl acetate and 2-methylbutyl acetate in the fruits. The coatings with thehighest gas resistance (shellac and shellac−protein) caused high internal CO2 and low O2, resultingin anaerobic fermentation in Braeburn and Granny Smith apples and relatively high amounts of low-molecular-weight ethyl esters trapped within the fruit. A small portion of the alcohols were evaporatedfrom fruits compared to esters, this attributed to their high Henry's law coefficients. Keywords: Apple; coating; volatile; ester; alcohol; internal gas; modified atmosphere; variety
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