SOLUBILIZATION AND RHEOLOGICAL BEHAVIOR OF RAISIN SUSPENSIONS

Solubilization of raisins is the first step in the production of raki or similar anise flavoured spirits. It is a two-phase process. Components in direct contact with water dissolve at a constant rate in the first phase. The rates of the first phase and final amounts of the solubilized components increase with temperature and stirring rate and decrease with particle size and volume of dissolving water. In the second phase of the solubilization phenomena, the driving force was the deviation of the solubilized solids contents from the finally attainable value. A loose net-like structure was established in this phase; therefore, the mass transfer rates were not affected by the actual size of the particles

POLYESTER FILM STRIPS COATED WITH PHOTOGRAPHIC GELATIN CONTAINING IMMOBILIZED INVERTASE

Invertase was immobilized into photographic gelatin by chemical crosslinking with formaldehyde and chromium (III) acetate. Polyester film strips were coated with invertase-gelatin mixture which increased durability during consecutive immersions into reaction media. The effect of gelatin, crosslinker and enzyme concentrations on activity were studied. Enzyme leakages from immobilized invertase film strips were controlled by washing with EDTA solutions. The activities of washing solutions were measured spectrophotometrically to determine unbounded enzyme concentration. Effect of use number on activity was also determined. Percent activity of immobilized invertase was lower than that of free enzyme. The activity however retained even after 10 washings (170 minutes) followed by 9 use in 18 weeks