Affiliation:
1. University of Allahabad, India
Abstract
Phytochemicals include a heterogeneous class of compounds (polyphenols, carotenoids, tocopherols, phytosterols, and organosulfur compounds) with different chemical structures (hydrophilic or lipophilic), distribution in nature (specific or ubiquitous), range of concentrations both in foods and in the human body, possible site of action, effectiveness against oxidative species, specificity, and biological action. Factors such as food source, chemical interactions, other biomolecules present in the food, restricted release of compounds from plant matrix, the solubility in gastrointestinal fluid, the permeability across intestinal epithelial cells, enzymatic and chemical reactions occurring within the gastrointestinal tract, drastically affect the bioavailability of these bioactive compounds. The chapter will present the essential aspects of bioavailability and bio accessibility of phytochemicals, factors limiting the oral bioavailability, as well as the new delivery approaches that have potential and can be explored to enhance the bioavailability of phytochemicals.