Residue Level of Imazalil Fungicide in Lemons following Prestorage Dip Treatment at 20 and 50 °C

• Published in: Journal of agricultural and food chemistry Vol. 44; no. 9; pp. 2865 - 2869
• Main Authors: Schirra, Mario, Cabras, Paolo, Angioni, Alberto, Melis, Marinella
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 18.09.1996
• Subjects: Biological and medical sciences; Food industries; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; Imidazole derivatives; Heat treatment; Fruit; Soaking; Chemical treatment; Citrus fruit; Postharvest; Food preservation; Shelf life; Lemon; Fungicide
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf9508256

Commercially mature Di Massa lemons [Citrus limon (L.) Burm.] were submerged for 3 min in water at room temperature (20 °C) or in hot water (50 °C) with or without imazalil (IMZ) fungicide solution at concentrations ranging from 250 to 1500 ppm. They were then stored at 9 °C for 13 weeks plus 1 additional week at 20 °C to simulate shelf life. After simulated shelf life, rot percentage was 28.9% in fruit submerged in water at 20 °C and 15.0% in fruit treated with hot water, a decrease of about 50%. IMZ applied at 20 °C was highly effective in suppressing rot development. The fungicide provided complete control of decay at a concentration of 1500 ppm. When applied in combination with hot water, the complete control of decay was achieved at 250 ppm. The residual level of IMZ in lemons dipped at 20 °C was related to the amount of fungicide used in postharvest treatment. The mean values (on a whole fruit basis) ranged from 1.47 to 5.05 ppm when used at 250 or 1500 ppm, respectively. The combination of IMZ and hot water produced a residue level 4.59-fold higher compared to corresponding treatments performed at room temperature. It was concluded that IMZ solution applied at 50 °C greatly reduces the dose of fungicide needed to control postharvest decay of citrus fruit when the treatment is applied at room temperature and offers environmentally interesting prospects owing to the smaller amounts of pesticide in citrus packinghouse wastewater following treatment. Keywords: Citrus limon; postharvest; heat treatments; imazalil