Large quantities of acetic acid are added to food products as a preservative. But to offset the sour taste, it is necessary to add one of three additives: sodium DL-malate, trisodium citrate, or sodium phosphate. Inevitably, then, one additive is used to offset the effects of another.
為了防腐，食品添加了許多乙酸；而為了緩衝酸味，又必須加入蘋果酸鈉、檸檬酸鈉、磷酸鹽等 6 樣添加物，因此「複方使用」、一物緩衝一物，就成了食品添加物不可避免的宿命，更增加了消費者的肝腎重擔。