柠檬酸

例句：

1. 1. This lemonade is made with real lemon juice and a touch of citric acid.
   这款柠檬水是用真正的柠檬汁和一点柠檬酸制成的。
2. 2. Citric acid helps to preserve the freshness of fruits and vegetables.
   柠檬酸有助于保持水果和蔬菜的新鲜度。
3. 3. The acidity of the lemon juice can be adjusted by adding more or less citric acid.
   可以通过添加更多或更少的柠檬酸来调整柠檬汁的酸性。