很多人有生吃蔬菜的习惯,但是有细心的消费者发现。用白色的餐巾纸擦拭葱叶,纸上会出现蓝色痕迹。这究竟是怎么回事呢?经“专家”鉴定,这种蓝色痕迹是一种叫硫酸铜的化学药剂,很可能是商贩在运输途中用来防腐保鲜的,而且用过硫酸铜的菜也会显得更绿。这种情况在不少果蔬上都存在,比如芹菜、韭菜、菠菜、苹果、葡萄等。 Many people have the habit of eating raw vegetables, but attentive consumers find. Scratch the onions with a white napkin and blue marks appear on the paper. This is what is going on? By “expert ” identification, this blue trace is a chemical called copper sulfate, is likely to be used by traders in transit preservative preservation, and the use of copper sulfate The dish also looks greener. This situation exists in many fruits and vegetables, such as celery, leeks, spinach, apples, grapes and so on.