You were given three samples containing lipids and have been tasked to add Br2 solution until a color change is observed. Sample A required 5 mL of bromine before a visible color change. Sample B changed color almost immediately. Sample C required 12 mL while sample D needed 3 mL for a color change to be observed. Rank the samples in order of increasing degree of unsaturation and explain why.
Explain the two ways in which oil-based food products can be preserved.