By law, sodium dehydroacetate (a preservative) can only be added to four types of dairy products such as cheese and butter, but it's also routinely added to bread, fen yuan (flour balls), and taro products to increase softness and improve flavor.
而原本只能合法添加在乳酪、奶油等 4 種乳製品的「去水醋酸鈉」（一種防腐劑），卻經常被添加在麵包、粉圓、芋頭，以讓產品鬆軟又 Q。