M. Schirra et al., EFFECT OF HEATED SOLUTIONS ON DECAY CONTROL AND RESIDUES OF IMAZALIL IN LEMONS, Journal of agricultural and food chemistry, 45(10), 1997, pp. 4127-4130
Freshly harvested lemons [(Citrus limon (L.) Burm)] were dipped 3 min
in water with and without imazalil (IMZ) at 50, 100, and 200 ppm at 50
degrees C and at 1000 ppm IMZ at 20 degrees C. Following treatments f
ruit were kept at 9 degrees C and 90%-95% relative humidity (RH) for 1
3 weeks and an additional week at 21 degrees C and ca. 75% RH, to simu
late a marketing period (SMP). No decay control was observed with frui
t dipped in water at 50 degrees C. In contrast, IMZ treatments provide
d 90%-96% control of Penicillium rots during cold storage and SMP. Fun
gi other than Penicillium spp. were also found in all samples as diffe
rences among treatments were negligible. IMZ treatment caused some ext
ernal damage to the fruit (peel browning), and the percentage of damag
ed fruit was related to the amount of active ingredient (AI) present i
n it. Dipping in 200 or 1000 ppm IMZ promoted off-flavor development a
fter 10 weeks of storage, and fruit were judged to be unacceptable for
consumption after 13 weeks of cold storage. After 1000 ppm IMZ dippin
g at 20 degrees C, residue concentration in fruit was 8.20 ppm; this v
alue doubled that found in a previous investigation on lemons treated
with comparable IMZ levels. Residue concentrations in fruit after trea
tment at 50 degrees C was strictly related to the amount of fungicide
employed. After 13 weeks Al residues in fruit decreased to average ca.
35% of the initial values. During the 1 week SMP, residue levels decr
eased by a further ca. 25%. It was concluded that it is possible to ac
hieve significant control of decay in lemons during longterm storage b
y dipping fruit in 50 ppm IMZ mixtures at 50 degrees C. Such treatment
should be advised to remarkably reduce potential pollution in the env
ironment due to packinghouse wastewater disposal.