Effects of sulphur dioxide and chlorine dioxide treatments on quality of 'Sultana Seedless' table grapes in storage

摘要

Sulphur dioxide fumigation is one of the most important factors that determine sto nihility of table grapes. Despite its beneficial effects, there is a risk of having sulphite residues in grapes. In this study, the effects of sulphur dioxide (SO2) pads and chlorine dioxide (CIO2) generators on storability of table grapes 'Sultana Seedless' packed in modified atmosphere packages (MAP) was investigated. Grape samples were subjected to 6 different treatments as a) MAPI, b) MAP1+C102, c) MAP2, d) MAP2+C102, e) MAP2+S02 and f) Polyethylene (PE)+S02 (commercial) after pre-cooling and packages sealed with plastic clips. Grapes in all treatments were stored at -0.5°C and 90% relative humidity for 3 months. SO2 concentrations of grapes in MAP's and PE packages were determined as 0.53 and 8.30 ppm, respectively. Decay rates increased significantly (26%) in CIO2 treatment after 3 months of storage. Sensory evaluation scores also decreased due to increases in stem browning and decrease in texture. CIO2 treated grapes lost their marketability due to high decay development and loss of sensory properties after 3 months. Effects of different treatments on color, berry removal force, berry firmness and chemical attributes of table grapes were similar. The resultsshowed that table grapes could be successfully stored up to 2 months with C102 generators and 3 months with SO2 pads.