The consumption of functional foods is growing in the health and wellness communities because of their range of potent nutrients and health advantages, such as the ability to shield against illnesses, stop vitamin deficiencies, and encourage healthy growth and development. This new volume discusses the nutritional and health benefits of functional foods. The volume first looks at the functional activities of plants and their derivatives, discussing microgreens as functional foods as well as functional foods for certain populations, including those involved in sports and the elderly. The volume includes chapters on antiviral activities of functional foods for first helping to reduce the risk of contracting COVID-19 as well as combating the disease once contracted. Several chapters detail the beneficial antidiabetic activities of plants, looking particularly at mushrooms and guava. Probiotics as functional foods for human health is investigated as well, discussing the role of probiotics in gut microflora, probiotics as dietary supplements, various extraction methods, and more. Finally, the volume addresses the quality aspects of functional foods, providing an overview of foodborne pathogens and food-related microorganisms. This volume will aid experts working in food science and technology, agricultural science, food safety, and Ayurveda around the world. It will be of interest and use to professional food scientists, nutritionists and dieticians, academicians researching food engineering problems, and graduate-level students in related fields.