What is the main acid in lemon juice?

The main acid in lemon juice is citric acid. Citric acid is a weak organic acid that is found in citrus fruits, such as lemons, oranges, and grapefruits. It is also found in other fruits and vegetables, such as strawberries, pineapples, and tomatoes. Citric acid has a sour taste and is used as a flavoring agent in food and beverages. It is also used as a preservative and as a chelating agent.