Document Type : Research Article
Effects of three different level of SO2 generating pads with 1gr kg ¹ concentration (one on top, half on top and half on bottom of the packaged grapes and without sulfur pad) Combined with two type of polyethylene bags (perforated and imperforated) during cold storage (135 day) on some traits of grape cv Qzl ouzum such as: weight loss (%), bleaching, fungal rot (%), rachis desiccation, berry shriving, pH, TSS, TA, taste and sulfite residue was studied. Result showed that SO2 generating pads treatment significantly decreased weight losses, rachis and berry shriving and decay rate. Whereas bleaching and off flavors of grapes were increased. Imperforated bag treatment significantly decreased weigh losses, bunch and berry shriving. Among all sulfur pads treatments, the highest and the lowest sulfur taste was measured in two sulfur pad treatment with imperforated bags and one sulfur pad with perforated bags, respectively. Results of sulfite residue measurement showed that the highest sulfite residue means were observed in one and two sulfur pad treatment with perforated bags, respectively, whereas in imperforated bags, sulfide residue was less than 10 ppm at both sulfur pad treatments.
Keywords: Grape; Storage life, SO2 generating pads, Sodium metabisulfite, Polyethylene bags and sulfite residue