Use 1 tablespoon lemon juice or 1/5 teaspoon citric acid for every pound of tomatoes.A little added salt (less than half a teaspoon) will also ensure better conservation.

• 每磅的蕃茄加入1大汤匙柠檬汁、1/5茶匙柠檬酸，或加入一点的盐(约一半茶匙)也可以保存的不错。