Comment by gus_massa

I tried to take a look. They have to match a refraction index of lipids of 1.43-1.53. A sugar solution from 0% to 80% has an index of 1.33 to 1.44 so it's too low. And 80% solution of sugar is a lot, they are using a 5% solution of tartrazine (that is also a lot, but a smaller lot).