Turnip (Brassica rapa ssp. rapa) is an important vegetable crop producing phenolic compounds. Phenolic compounds are a large group of phytochemicals widespread in the plant kingdom.
Phenolic compounds are characterized by having at least one aromatic ring with one or more hydroxyl groups attached. Phenolics are produced in plants as secondary metabolites via the shikimic acid pathway. Phenylalanine ammonialyase is the key enzyme catalyzing the biosynthesis of phenolics from the aromatic amino acid phenylalanine.
Depending on their structure they can be classified into simple phenols, phenolic acids, hydroxycinnamic acid derivatives and flavonoids. The phenolic compounds and organic acids are considered to regulate enzymes and the cell cycle, and are responsible for the organoleptic characteristics. Colored flavonoids, anthocyanins are the most important group of plant pigments due to their antioxidant activity and other useful biological characteristics.
Flavonoids are another major type of compounds in turnip, and are always present as glycosides. Flavonoids and phenolics with high free radical scavenging activity should be corresponding to the antioxidant effects. Flavonoids may reduce the potential risk of cardiovascular, cancer and inflammatory ailments in humans.
Sinapic, ferulic and caffeic acids, kaempferol 3-O-sophoroside-7-O sophoroside, kaempferol 3,7-O-diglucoside, isorhamnetin 3,7-O-diglucoside, kaempferol 3 O-(feruloyl/caffeoyl)-sophoroside-7-O-glucoside, kaempferol 3-O-sophoroside, 1,20 disinapoyl-2-feruloyl gentiobiose, kaempferol 3-O-sophoro-side-7-O-glucoside, 3-p coumaroylquinic, 1,2-disin-apoylgentiobiose, isorhamnetin 3-O-glucoside and kaempferol 3-O-glucoside are the phenolic compounds found in the stem, leaves and flower buds of the turnip.
Phenolic compounds in turnip
