Disappearance of Residual Chlorine and Formation of Chloroform in Vegetables Treated with Sodium Hypochlorite

Abstract

We studied the disappearance of residual chlorine and the formation and behavior of chloroform (CHCl3) in vegetables treated with sodium hypochlorite (NaClO).Soybean sprouts and cabbages were treated with NaClO solutions of various concentrations, and residual chlorine and formation of CHCl3 in the samples were determined. It was found that both residual chlorine and CHCl3 increased with an increase in NaClO concentration. However, CHCl3 formation was less in the cabbages than in the soybean sprouts. The soybean sprouts and cabbages treated with NaClO solution were then kept in glass containers and changes which took place with the passage of time in the residual chlorine and CHCl3 were studied. When stored at lower temperatures, the loss of residual chlorine was less and CHCl3 increased, while chlorine remained. When the soybean sprouts were immersed in NaClO solutions and maintained at different temperatures, CHCl3 formation was less when the treatment temperature was lower. For treatment of vegetables with NaClO solution, low temperature treatment is therefore preferable.