While Skittles don't include white in their line-up, Dr. Johnson-Arbor theorizes that titanium dioxide is used to help contain all the other beautiful colors.

Titanium dioxide is used in the production of paper and textiles to improve whiteness, brightness, opacity and durability. It’s often used in fabrics, yarns, paper and other fibers.

1. Using roasting and leaching method. The reaction equation is as follows:

In a study published in the journal Toxicology, researchers examined the effects of exposing human colon cancer cell line (HTC116) titanium dioxide food additives in vitro. “In the absence of cytotoxicity, E171 was accumulated in the cells after 24 hours of exposure, increasing granularity and reactive oxygen species, inducing alterations in the molecular pattern of nucleic acids and lipids, and causing nuclei enlargement, DNA damage and tubulin depolymerization,” the scientists wrote. Researchers removed the additive from the culture, then examined the results 48 hours later. They found, “The removal of E171 was unable to revert the alterations found after 24 h of exposure in colon cells. In conclusion, exposure to E171 causes alterations that cannot be reverted after 48 h if E171 is removed from colon cells.”