Peanuts (Arachis hypogaea) are one of the most popular leguminous plants that originated in the Andean Cordilleras of South America, and they were spread all over the world in the Middle Ages. There are mainly four different cultivars of Virginia, Runner, Spanish, and Valencia. Peanuts contain lipids, protein, and carbohydrates as the major components as well as small amounts of pigment, aroma components, etc. In this book, Chapter One discusses the aroma active components in roasted peanuts. Chapter Two reviews the scientific research literature on the texture (both sensory and instrumental) of peanuts and peanut butter. Chapter Three thoroughly studies the biochemical properties of major peanut allergens. Chapter Four evaluates the quality and productivity of high oleic acid peanut cultivars. Chapter Five focuses on bioactive fatty acids and triacylglycerols found in cultivars and wild peanut species, underlying the importance of wild peanut species.