A study of the migration of externally applied sucrose esters of fatty acids through the skins of banana, apple and pear fruits

Abstract

Abstract[14C]‐Labelled sucrose esters of fatty acids were prepared and included in a fruit coating which retarded ripening. The esters remained substantially intact on the surfaces of bananas, apples and pears during storage at 17 or 18°C for up to at least 30 days. The amounts of sucrose esters in the coatings applied to the surfaces of fruits were 250 mg m−2 for the banana, 681 mg m−2 for Cox's Orange Pippin apple, 617 mg m−2 for Conference pear and 362 mg m−2 for Comice pear. Analysis for radioactivity in the pulpy tissue of coated fruits stored for up to 41 days showed a low concentration of migrated label, which was difficult to distinguish from background. It was concluded that the concentrations of sucrose esters in the pulpy tissue were not more than 10 ng g−1 for banana, 350 ng g−1 for apple, 300 ng g−1 for Conference pear and 70 ng g−1 for Comice pear, and that the mode of action of sucrose esters in the retardation of ripening seems unlikely to be dependent upon their migration into the pulpy tissue.