In this book, the authors present topical research in the study of the synthesis, properties and applications of citric acid. Some of the topics discussed include fungal and yeast production of citric acid; mitochondrial production and applications in food and pharmaceutical industries; synthesis of the CuO/CeO2 catalytic system by polymerisation with citric acid; citric acid as a useful tool in artificial enamel formation and regeneration; the impact of citrate on glycolysis in brain tumours and applications of citrus fruits and their extracts for detection of food poisoning caused by bacteria.