Di phenyl residues in florida grapefruit citrus paradisi and oranges citrus sinensis following actual and simulated long export shipments
Wardowski, W.F.; Ting, S.V.; Smoot, J.J.; Davis, P.L.; Craig, J.O.
Journal of the American Society for Horticultural Science 104(4): 440-443
The long voyage of Florida [USA] grapefruit (C. paradisi Macf.) to Japan and extended marketing periods on arrival were associated with a problem with excess diphenyl (biphenyl) residues. Japanese food additive regulations necessitated reliance on the vapor-phase fungistat diphenyl, for which residues in the fruit increase with time after packing. Residues in some shipments unexpectedly exceeded the Japanese tolerance of 70 ppm. Experiments designed to identify the effect of various factors on diphenyl residues are reported. The amount of diphenyl, temperature before refrigerated transit and exposure time, especially before refrigeration, affected diphenyl residues. Air filtration had little effect. Very early season grapefruit (harvest started before legal maturity) in Aug. and Sept. 1978 absorbed excessive diphenyl residues. Excessive absorption of diphenyl by grapefruit is apparently characteristic of very early fruit.