How do they make things appear in color white like paper, flour, mayonaise, chalk, whipped cream, etc?

They use white pigments that both reflects and/or transmits almost all, usually more than 90% or so, of all the wavelengths of light falling on it. Common ones are


silica[SiO2], chalk[calcium carbonate[CaCO3], Titania [titanium dioxide, TiO2], Zirconia[Zirconium dioxide, ZrO2], baryta[barium sulfate,BaSO4], gypsum[calcium sulfate, CaSO4], powdered glass, zinc oxide[ZnO] and zinc sulfide[ZnS]. Probably the most common in modern paints are silica and titanium dioxide the first because it is inexpensive.How do they make things appear in color white like paper, flour, mayonaise, chalk, whipped cream, etc?
They do NOT add pigments to those products as the other person answered. You can look at the list of ingredients on mayonnaise, flour or milk , if you want.





The substances you mention above are white for the same reason snow is white or most powders are white. They are mixtures of two substances that never fully dissolve into one another. Almost every smooth surface is at least a little reflective. These substances have many many surfaces in them, and that makes them white because all these surfaces work together to reflect all the colors.





For example, the surface of water is somewhat reflective. You can see the sun bounce off a lake or puddle. Still most of the light goes through into the lake. If you want the water to reflect most of the light you need to turn the single surface of still water into many surfaces. You do this by churning or mixing up the water with air. Foam or white water rapids are examples of water that has a lot of air mixed with it and so has so many reflective surfaces it becomes white. Ice is clear but if you grind it up into tiny crystals like snow it becomes white.





Mayonnaise is essentially a mixture of, oil and water. The billions of oil droplets in the water make innumerable reflective surfaces.





Wheat is primarily starch with some protein, it is tan and somewhat translucent. When you grind it into flour it becomes a lighter color because of reflective surfaces. Paper is made of many fine cellulose fibers and crystals that form reflective surfaces, but like flour it needs to be bleached to destroy substances that would absorb some of the light.





Whip cream is like foam, except it is a mixture of air with butterfat. The butter fat bubbles are the reflective surfaces.





Chalk is essential what you get when you grind up crystals of calcium carbonate, calcium sulfate and zirconia.





You can take almost any clear substance and grind it up to make a white powder. Glass, plastic, gems, rock candy, etc...How do they make things appear in color white like paper, flour, mayonaise, chalk, whipped cream, etc?
BRP and irene.de are both right. The compounds you have named are either naturally white or bleached white, and in some cases the manufacturer does add oxide pigments to enhance the whiteness.





The main thing I wanted to add is about UV brighteners. They use these in things like paper to make it look whiter by adding a dye that fluoresces making the item look brighter and therefore whiter. Most clothing detergent contains these to make your clothing appear whiter
paper and flour are bleached even though flour is naturally white or only slightly yellowish, chalk is naturally white and Whipped cream and Mayonaise are naturally white.


Whipped cream is naturally white because cream is white, and beating air into it just makes it look whiter.


Mayonaise is an emulsion of oil in water and the light refraction off the suspended oil droplets makes it look white.