Storage Conditions Affect Quality of Raisins

Raisins had a moisture content of ca 14% and were stored over an 11 mo period. The initial SO 2 content was ca 640 ppm. Moisture content, water activity, color, browning, texture, SO 2 content, soluble sugars, acidity and pH were periodically determined. A substantial decrease in SO 2 content was observed, especially in samples stored at room temperature (20–25°C) which had higher browning indexes. No substantial changes were detected in water activity, acidity and pH. No sugaring was observed. Refrigerated samples (stored at 4 and 11°C) were of higher quality in comparison with nonrefrigerated samples. Both were suitable for consumption after storage.