Orange Serum Agar is a selective culture medium used in food and beverage microbiology for the isolation and enumeration of lactic acid bacteria and other microorganisms from citrus products, fruit juices, and carbonated beverages. The addition of orange serum supplies essential vitamins, amino acids, and growth factors that support the cultivation of fastidious organisms in acidic environments. It is particularly useful for detecting microbial contamination in processed fruit products and soft drinks, aiding in quality control and safety assessments.