Improves food structure as a non-nutritive filler and thickener. In the baked food, the micro-crystalline cellulose is used to replace part of the flour, and when the substitution amount is not more than 50% of the flour, the baked food can be kept the same as the original taste. Microcrystalline cellulose and protein are encapsulated in casein and used as a fat substitute in cheese, cheesecake, and mayonnaise to reduce fat in liquid foods.