Effect of sulphur forms on colour and residue of sulphur during the storage at drying grapes by sulphur

¹ Hazelnut Research Institute, 28200 Giresun, Turkey
² Ege University Department of Horticulture, 35100 Izmir, Turkey

Abstract

Turkey is the world leader in the manufacture and export of seedless raisins. Requirement of golden bleached raisins is increasing in food Industry of especially cake, bread and pastry year by year. In this research, the lowest residual value and the practical realization of such production was intended to determine by drying grapes with application of sulphur. In this case, sulphur residue and colour situations were determined during 12-mounth-storage according to sulphur forms. In this study sulphur studies were applied by Vitis Vinifera cv. “Sultani Çekirdeksiz” with Na₂S₂O₅, which is liquid source of sulphur and SO₂, which is gas source of sulphur. SO₂ application were studied during 3, 6 and 8 hours and liquid form of sulphur is Na₂S₂O₅ that was used during by 10, 20 and 30 minutes. Applications were prepared with 3 replicates which contain 20 kg fresh grape in each replicate. In conclusion, changes in dried grape have been identified in point of colour (chroma and hue) and the sulphur content was determined according to sulphur forms in packing. Gas form of sulphur (SO₂) which was applied 3 hours, gave the best result during 12-mounth-storage for colour and sulphur residue.