Food Additives: Importance, Classification, and Adverse Reactions in Humans. -- Natural Antioxidants -- Natural Antimicrobials -- Natural Colorants -- Natural Sweeteners -- Vegetal and Microbial Sources of Natural Additives and their Food Applications -- Utilization of Saccharomyces cerevisiae as a Source of Natural Food Additives -- Preservation of Natural Food Additives -- Effect of Thermal Treatments on the Properties of Natural Food Additives -- Effect of Nonthermal Treatments on the Properties of Natural Food Additives -- Toxicological Aspects of Natural Food Additives -- Consumer Attitudes Toward Natural Food Additives -- Regulation of Natural Food Additives.