Volatile response of four apple varieties with different coatings during marketing at room temperature.
Five experimental coatings with different resistance to gas exchange were used with freshly harvested and 20-week commercially stored apples of Delicious, Fuji, Braeburn, and Granny Smith varieties. The coated or noncoated apples were held at 20 degrees C for up to 4 weeks. The gas partial pressures inside the fruits with the various coatings ranged from 1 to 25 kPa CO(2) and from 20 to 1 kPa O(2). Volatile evaporation rates were measured, as also were the volatiles compositions in the fruit. The coatings with intermediate gas resistance (carnauba-shellac mixture and candelilla) gave intermediate values of CO(2) and O(2) in the internal atmosphere in Delicious, Fuji, and Braeburn apples and the highest concentrations of butyl acetate and 2-methylbutyl acetate in the fruits. The coatings with the highest gas resistance (shellac and shellac-protein) caused high internal CO(2) and low O(2), resulting in 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 evaporated from fruits compared to esters, this attributed to their high Henry's law coefficients.
Bai
Jinhe
J
Citrus and Subtropical Products Laboratory, US Department of Agriculture, 600 Avenue S, NW, Winter Haven, Florida 33881, USA.
Hagenmaier
Robert D
RD
Baldwin
Elizabeth A
EA
D000085:Acetates / Q000032:analysis; D002245:Carbon Dioxide / Q000032:analysis; D004952:Esters / Q000032:analysis; D000431:Ethanol / Q000032:analysis; D005503:Food Additives; D005519:Food Preservation; D005638:Fruit / Q000737:chemistry*; D027845:Malus / Q000737:chemistry*; D010100:Oxygen / Q000032:analysis; D010313:Partial Pressure; D012116:Resins, Plant; D013045:Species Specificity; D013696:Temperature; D014835:Volatilization; D014885:Waxes
D000085:Acetates; D004952:Esters; D005503:Food Additives; D012116:Resins, Plant; D014885:Waxes; D002245:Carbon Dioxide; D000431:Ethanol; C006848:butyl acetate; C003934:shellac; C026344:carnauba wax; D010100:Oxygen