| 摘要 |
PURPOSE:To prepare a high-quality water-soluble gelatin, by adding water to gelatin, heating the hydrated gelatin thus obtained with a microwave oven to effect rapid melting and drying of the gelatin, and freezing and crushing the dried gelatin. CONSTITUTION:Gelatin on the market is slowly hydrated and swollen by mixing with 20-50wt% of water at 0-20 deg.C, and stirring with a stirrer, etc. To prevent the cohesion of gelatin partices and to facilitate the hydration operation, it is preferable to cool the gelatin to be hydrated and add a small amount of starch to the system. The hydrated gelatin is placed in a shallow tray and heated with a microwave heater. The heating conditions are controlled usually to complete the drying of the gelatin within 1-10 minutes. The hydrated gelatin melts and collapses rapidly upon heating, and is gradually foamed and dried to obtain a solidified matter containing uniformly dispersed bubbles. The heating is stopped usually when the water-content of the gelatin reaches 5-8%, and the gelatin is cooled rapidly to -50--60 deg.C. After maintaining at the temperature for 20-30 minutes, it is pulverized to obtain the objective high-quality water-soluble gelatin. The powder thus prepared contains >=85% of fine component which passes through a 200 mesh sieve. |
