| Objective To explore the migration regularity and the reduction and control technology of pesticide residues in citrus during canning. Methods Weizhang, a Satsuma variety, was used as the research object to do the simulation test of the entire canning process. The high-risk pesticide residues were treated by soaking the whole fruit. The design dose was 1 mg/L, 10 mg/L, 100 mg/L. Through the selection of methods and process parameters, sampling analysis and risk assessment were conducted on various processing stages such as cleaning, blanching, peeling, segment membrane removal, rinsing and sterilization in canning. Results It is proved that pesticides of citrus mainly remain in the peel. Ozone and ultrasonic treatment are more effective than running water cleaning. The effects of blanching and acid and alkali treatment on pesticide degradation are better with the increase of time and temperature. In the segment membrane removal tests, the residue of carbendazim decreased by 67.12% on average with the acid-treatment, and decreased by 46.98% with the alkali-treated. The best technical system for reducing pesticide residues in canned citrus has been determined: After washing the entire fruit with running water for 10 min and combined with ozone or ultrasonic cleaning, blanching at 95℃ for 2 min. Peel and split within 15min. Soak for 40 min with 0.15% HCl in 25℃ and 0.05% NaOH for 5 min, Rinsing with running water for 1 h and sterilize after canning. Conclusion The degradation effect of each process on pesticide residues was ascertained. The migration law of pesticide residues was clarified. The key control points of canning were determined and a set of perfect and effective reduction technologies have been formed. |
