"For the most part a shrewd manufacturer won't use propionic acid or sorbic acid as a preservative," says the anonymous specialist mentioned above. Many of the sausages on the market today claim to be preservative free. Why, then, don't they spoil when left out at room temperature for a few days?
「『高手』通常就不會拿丙酸或己二烯酸來防腐，」食品專家舉例，現在市面上許多香腸都號稱「不含防腐劑」，但為何室溫下一放幾天都不會壞呢？