Nature of the Olefines produced by Apples

SINCE Gane1 identified ethylene as a volatile product of ripening apples, other workers2–4 have demonstrated its production by other fruits, leaves and the fungus Penicillium digitatum. The identification by conversion to ethylene dibromide and then to the crystalline substance NN′-diphenylethylene-diamine established ethylene as the predominant olefine, but did not specifically exclude higher homologues the derivatives of which could be lost during crystallization of the main product. As the volatile emanations of apples include a series of acids and alcohols with one to six carbon atoms5–7, the absence of a corresponding series in the olefines cannot be accepted without rigorous proof.