Adding piquancy to food is a way of making it more flavorful and interesting. Zesting is a technique used to add flavor to food by grating the outer layer of citrus fruits such as lemons, limes, and oranges. This layer contains essential oils that give the food a zesty flavor. Spicing is another way to add flavor to food, usually by adding herbs and spices such as cinnamon, nutmeg, and cumin.