Sauces are liquid or semi-liquid mixtures that can be sweet, sour, spicy, or savory, and are used to enhance the flavor, color, and nutritional value of foods. There are six original "mother sauces" that form the foundation for other continental sauces: bechamel (a white sauce made with milk and roux), veloute (made with stock and roux), espagnole (made with stock, meat, and vegetables), tomato, hollandaise (an emulsion of egg yolks and butter), and mayonnaise (an emulsion of oil, egg yolks, and acid). These mother sauces were categorized by Marie Antonie Care