Effects of processing techniques on propargite residues in orange juice and its by-products

The objective of this study was to evaluate the effects of commercial processing techniques on propargite residues in orange juice and its by-products. In order to assess the persistence during juice processing, the field trials were carried out by spraying with the solution of 5-fold the concentration of the maximum recommended dosages. Propargite residues were determined by Gas Chromatography-tandem Mass Spectrometry based on QuEChERS extraction. The results indicated that the propargite was mainly distributed in orange peels, and the residual level in orange pulps was less than 5% compared to the raw materials. Propargite residues could be partially removed by washing, and the reduction was 32.5%. The residual levels in squeezed juice, filtrated juice, NFC juice and concentrated juice were 1.98%, 1.95%, 1.73%, and 1.37% of the raw material, respectively, and the processing factors of NFC juice and concentrated juice were 0.0173 and 0.0137, respectively. But the residues were enriched in pomace and orange essential oil, and the concentrated factors were 1.2822 and 18.4947, respectively. The research can provide a basis for optimization of processing technology as well as the dietary exposure assessment of propargite residues.