Effects of some salts on the shelf life of Shahrood Sorkh-e-Fakhri table grapes stored in cold storage

In this study, some preservative solutions were used as an alternative to sulphur fumigation. For this purpose, sodium metabisulfite, calcium chloride, sodium acetate, and sodium carbonate solutions at concentrations of 0.5, 1 and 2 percent were applied. Grapes (Sorkh-e-Fakhri var.) were dipped in different concentrations of each solution for 2 minutes. After dipping, the surface water of grapes was dried by natural air blowing and then, put in conventional baskets and stored at 0.5-1°C at 85-95% RH for 6 months. The percentage of moldiness, soluble solids, reducing sugar, acidity, and pH of the samples were determined after 2, 4, and 6 months of storage. The results of this study showed that the effect of type of preservative used and the storage time, on the percentage of moldiness and pH and acidity of all samples were significant at 1% level. Sodium metabisulfite had the highest inhibitory effect on mold growth. Calcium chloride had the greatest effect on moisture retention. In addition, the highest pH was observed in samples immersed in sodium carbonate solution. In the case of interactions, the effect of type of preservative and storage time on moldiness, moisture content, brix, sugar content, and acidity, and also the type of preservative and its concentration on moldiness and acidity of samples were significant. According to the obtained results, it was shown that the grapes could be stored for 6 months by dipping them in 0.5% sodium metabisulfite for 2 minutes before cold storage.