Studies on the storage stability of white beet sugar depending on its quality

Storage stability of white beet sugar is an important factor determining the sugar quality. Due to color formation during storage the sugar color can exceed the quality criteria of the European council directive 2001/111/EC for white sugar. It is not possible to predict the color formation tendency of a white sugar lot at the time of its production. Also the source and the mechanism of color formation during storage are unknown. Color formation in general can be caused by several factors, which can be divided into external influences such as humidity and temperature during storage and internal causes such as contents of ash, polyphenols, mono- and oligosaccharides, and amino compounds. In this work, the effect of the above mentioned factors and the nature of the formed colorants were analyzed. Studies on the color distribution in sugar crystals were carried out and the nonsucrose compounds in the surface film were determined. The syrup film on the crystal surface contains the same compounds and in similar contents as thick juice. A correlation between the changes in the amino acid and monosaccharide content and the color formation was established, which shows that the Maillard reaction is responsible for the color development during storage of sugar.