Phytonutrients, also called phytochemicals, cover a broad range of chemically and physiologically diverse, low molecular weight, secondary metabolites. These natural products (NPs) are often non-essential food components which are found in vegetables and fruits, but they are also found in spices and traditional ingredients. Whether as food, spices, traditional ingredients or medicinal plants, a large number of NPs are consumed by individuals in their normal, everyday lives. All of these compounds have the potential to provide either beneficial or toxic effects. These compounds exhibit a wide range of physiochemical properties and need specific analytical methods for their profiling, identification and quantification in their original matrices or in body fluids.