Many nutritionists say that it is possible for vendors to use additives to push back the freshness expiration dates on foods as well as improve color and texture in everything from fruits and vegetables to grain products, fish, and meats. Copper sulfate, for example, can be added to green vegetables to keep them looking fresh.
許多營養師表示，業者為了增加食材的保存期限、色澤、口感等，不論蔬果、麵食、魚肉，都可能攙入不當添加物。