What must juices from fruits and vegetables undergo before being served?

Juices from fruits and vegetables must undergo pasteurization before being served to ensure they are safe for consumption. Pasteurization is a heat treatment process that kills harmful microorganisms, including bacteria, viruses, and parasites, that can cause foodborne illnesses. This process is crucial because raw juices can be contaminated with pathogens that may not be visible or have any effect on the taste or smell of the product. By pasteurizing juices, the risk of foodborne illness is significantly reduced, making them safer for consumers.

While carbonation, fermentation, and refrigeration play roles in food production and preservation, they do not focus on eliminating harmful pathogens in juices. Carbonation involves dissolving carbon dioxide in liquids, fermentation is a metabolic process that converts sugars to acids, gases, or alcohol, and refrigeration slows down microbial growth but does not eliminate pathogens. Therefore, pasteurization is the essential step for ensuring the safety of juices before they are served.