我在二楼就说了这个原理你这个说法很无厘头。
还有楼上奇葩的幻想喷一氧化碳的。
这段话让你们学习学习。选自usda
6. Why is pre-packaged ground beef red on the outside and sometimes grayish-brown on the inside?
These color differences do not indicate that the meat is spoiled or old. As discussed earlier, fresh cut meat is purplish in color. Oxygen from the air reacts with meat pigments to form a bright red color which is usually seen on the surface of ground beef purchased in the supermarket. The interior of the meat may be grayish-brown due to the lack of oxygen penetrating below the surface.
但是大部分都不信。。。
因为再国内看到的都是暴露在空气里很久的肉。。。所以觉得只有红的肉才是新鲜的。。。
其实红的部分是不那么新鲜的。。。。。