Gw. Cheng et Ch. Crisosto, DEVELOPMENT OF DARK SKIN DISCOLORATION ON PEACH AND NECTARINE FRUIT IN RESPONSE TO EXOGENOUS CONTAMINATIONS, Journal of the American Society for Horticultural Science, 119(3), 1994, pp. 529-533
Dark skin discoloration development on peach and nectarine cultivars w
as investigated in response to exogenous pH and metallic ions. The inf
luence of skin abrasion and washing in combination with exogenous cont
aminants was studied in a factorial design experiment by using skin di
scs. Only abraded skin discs with and without washing developed discol
oration after being exposed to high pH and different metallic ion conc
entrations. Among the metallic ion contaminants studied (Fe, Al, Cu, S
n, Zn, and Na), iron was the most effective in causing dark skin disco
loration at physiological pH (3.5). Iron concentrations greater-than-o
r-equal-to 10 ppm induced dark discoloration on abraded fruit skin. Da
rk discoloration development produced by exposing the skin tissue to p
H levels >6 was reversible, whereas the dark discoloration induced by
iron and aluminum remained stable.