Effect of washing treatments on pesticide residues and antioxidant compounds in Yuja (Citrus junos Sieb ex Tanaka)

Abstract

This study investigated the removal efficiency of pesticide residues and microorganisms, and changes of the amount of antioxidant compounds on yuja (Citrus junos Sieb ex Tanaka) by various washing methods. The washing methods were mechanical washing (MW), mechanical washing after soaking in SAcEW, strong acidic electrolyzed water (SAcEW+MW), and soaking detergent solution (DW), with a tap water washing (TW) as the control. After treatment of MW and SAcEW+MW, the microbial count were 3.71 and 2.66 log CFU/g, respectively. Compared with the TW treatment (5.77 log CFU /g), MW and SAcEW+MW treatments showed a higher reduction. As a result of pesticide residue, the SAcEW+MW removed 70.5–98.1% and was the most effective, regardless of the pesticides. Antioxdant activities, as measured by DPPH radical, ranged from 20.36 to 21.27% and there was no significant difference from the washing methods. The results of this study demonstrated that the SAcEW+MW was the most effective method for removing residual pesticides without affecting the quality of the yuja.