Each ingredient in a recipe has a purpose. Substitution of one ingredient for another may alter the taste, color, moisture content or texture of the result. However, there are many situations where a handy substituion will help complete a product, in spite of a pantry outage, uplift the result or just plain taste better.

"Not only can substitution save the day when you lack an ingredient called for in a recipe, but it also enables you to make a recipe better for you. That's helpful whether you are trying to improve your overall eating pattern or are cooking for a specific health condition.
Although you may hesitate to change a recipe for fear of ruining it, remember that recipes are simply instructions for combining and processing a group of ingredients. "Recipes are crafted by people who simply had ideas about what ingredients may work together, but there’s no reason you can't change them," says Helen Rasmussen, PhD, RD, an instructor at Tufts' Friedman School and a senior research dietitian in the Metabolic Research Unit at the HNRCA. "You've probably found that even some published recipes don’t taste quite right when you first make them, so you make notes and tweak them next time to get a better result." Substituting ingredients to improve healthfulness of recipes works the same way."

Tufts University