Factors Affecting Imazalil and Thiabendazole Uptake and Persistence in Citrus Fruits Following Dip Treatments

• Published in: Journal of agricultural and food chemistry 1999-08, Vol.47 (8), p.3352-3354
• Main Authors: Cabras, Paolo, Schirra, Mario, Pirisi, Filippo M, Garau, Vincenzo L, Angioni, Alberto
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Biological Transport; Citrus - metabolism; Drug Residues - pharmacokinetics; Food Handling; Food industries; Food toxicology; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; Fungicides, Industrial - pharmacokinetics; General aspects; Handling, storage, packaging, transport; Imidazoles - pharmacokinetics; Thiabendazole - pharmacokinetics; Time Factors
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf990106h

The effect of concentration, temperature, and length of treatment with imazalil (IMZ) and thiabendazole (TBZ) was studied with application to citrus fruit. The amount of residues retained by fruit after “home” washing was also monitored. IMZ uptake in citrus fruit was related to treatment duration, whereas TBZ residues was not. Residues of IMZ or TBZ fungicides were significantly correlated with dip temperature (r = 0.943 for IMZ; r = 0.911 for TBZ). Treatment at 50 °C produced a deposition ∼8 and ∼2.5 times higher than when treatments were carried out at 20 °C in IMZ and TBZ, respectively. No significant differences in terms of IMZ deposition were detected after treatments carried out alone or in combination. Uptake of the two fungicides was associated with their physicochemical characteristics as well as different formulation types. IMZ residues showed a great persistence during storage when applied separately, and >83% of active ingredient was present after 9 weeks of storage. IMZ residues increased with dip length, doubling when dip time increased from 0.5 to 3 min. In contrast, TBZ residues did not change with the different dip times. Following postharvest dip treatments of citrus fruit at 20 or 50 °C, home washing removed ∼50% of the IMZ and ∼90% of the TBZ. Keywords: Citrus; postharvest; heat treatments; imazalil; thiabendazole; residues