Carrot Volatile Terpene Metabolism: Terpene Diversity and Biosynthetic Genes

Abstract

Carrot is considered one of the leading horticultural crops in the world in terms of its nutritional value, health benefits, and unique flavor based on its high content of carotenoids and volatile aroma compounds. Terpenes such as monoterpenes and sesquiterpenes represent some of the predominant volatile compounds that contribute to carrot aroma and flavor. Variation of terpene composition based on genotypic differences or environmental factors has significant effects on taste perception by consumers and, therefore, is a critical quality attribute for carrot breeders and growers. Surprisingly, little is known about the biosynthesis of volatile terpenes in carrots and the various enzymes involved in their formation. In this chapter, we provide an overview of volatile terpene sampling and terpene diversity in different D. carota genotypes. Facilitated by the recent elucidation of the carrot genome, we further describe and discuss latest findings of the function of genes and enzymes in the terpene synthase family involved in the biosynthesis of carrot terpene volatiles.