When searching for science-based recipes, I came across this recipe for vegan mayonnaise. Traditional mayonnaise is made by blending eggs and oil. Eggs contain lecithin, an emulsifier that helps to stabilize the mixture of water and oil. Emulsifiers can change the mixture physically, by adding viscosity to liquids, and chemically, by binding to a hydrophobic and a hydrophilic molecule. This vegan mayonnaise, however, is made not with eggs, but aquafaba (liquid from a can of chickpeas). Essentially, the aquafaba has plenty of protein and starch to act as an emulsifier. However, the aquafaba is less stable than eggs, as it only has physical emulsion properties. The solution is to add some of the actual chickpeas to prevent separation of the oil and water. Overall, this seems like a good alternative to mayo for those who are avoiding eggs, but I am not sure how it stands up against traditional mayo.
Image from Serious Eats