Plant metabolites and nutritional quality of vegetables

Vegetables are an important part of the human diet and a major source of biologically active substances such as vitabmins, dietary fiber, antioxidants, and cholesterol-lowering compounds. Despite a large amount of information on this topic, the nutritional compounds was discovered by trial and error. By the turn of the century, the application of chromatography, mass spectrometry, infrared spectrometry, and nuclear magnetic resonance metabolites have been elucidated in plants, and it is predicted tha the final number will exceed 200000. Most of them have unknown function. Metabolities such as carbohydrates, organic and amino acids, vitamins, hormones, flavonoids, phenolics, and glucosinolates are essential for plant growth, development, stress adaption, and defense. Besides the importance for the plant itself, such metabolites determine the nutritional quality of food, color, lating, and cholesterol-lowering properties. This review is focused on major plant metabolites that characterize the nutritional quality of vegetables, and methods of their analysis.