Food-grade lubricating grease and method for preparing same

A method for preparing food-grade lubricating grease, wherein the food-grade lubricating grease comprises the following components in percentage by mass:

• 75% to 85% of food-grade white oil, 6% to 16% of stearic acid, 2.0% to 3.0% of benzoic acid, 5% to 8.7% of aluminum isopropoxide, 1.0% to 1.5% of water and 1.0% to 7.0% of nano-PTFE;
• and the method comprises the following steps:
• (1) mixing the food-grade white oil and the aluminum isopropoxide with the benzoic acid, and performing heating to completely dissolve the mixture to obtain a dissolved mixture;
• (2) adding the stearic acid into the dissolved mixture in step (1), and dissolving the stearic acid through stirring to obtain a corresponding product system A;
• (3) adding water into the product system A obtained in step (2) for saponification, performing dewatering after the saponification is completed, then, adding a second portion of the food-grade white oil, and raising the temperature for refining to obtain a product system B;
• (4) adding a third portion of the food-grade white oil into the product system B obtained in step (3) after temperature raising refining, and performing grinding after cooling to obtain food-grade lubricating grease base grease;
• and
• (5) mixing the food-grade lubricating grease base grease obtained in step (4) with food-grade nano-PTFE through stirring, and then, performing ultrasonic treatment and grinding to obtain the food-grade lubricating grease.