Research on the Color Stability of Edible Ink-jet Ink

Edible ink-jet ink is environmental friendly and all of its materials reach the food sanitation standards, so it can be directly printed on the surface of food, medicine and packaging in the way of non-contact ink-jet printing. Due to the acid and alkaline of food surface are different, and the food may experience low or high temperatures and long time exposure in the preserved process, so the stability of the ink is of vital important. Edible ink-jet ink has been prepared through choosing reasonable materials. And then, the performances of the ink such as viscosity, surface tension and pH value have been tested. Finally, the best formula of ink has been determined by evaluating the influence of the ink performances to the ink-jet printing quality. We prepared ink sample based on the best formula and stored it in normal temperature environment which is closed to outside, and evaluated the stability of the ink performance through regularly checking its performance; we evaluated the stability of the ink color under different PH value through adding a little acid-base regulator in it; we also evaluated the stability of the ink color to temperature and light through putting the coating sample in the environment with alternate high and low temperature and in the environment with strong light. The result shows that the stability of the ink is fine, and it can be preserved a month at least without any food preservative. The pH value, temperature and light have no influence to the ink color. So it has a favorable color performance and can be printed on the surface of food.