The protein content of pure milk of 5 yuan is not as high as that of protein of 7 yuan. In addition, the milk of 5 yuan is a little astringent, and the milk of 7 yuan may be better and smoother, so people who like to drink pure milk can drink it.

The difference between storage temperature and storage time, 5 pieces of plastic packaging must be refrigerated or it will rot easily, and 7 yuan cartons can be stored at room temperature for one month.

I think 7 yuan is thicker and has higher nutritional value, while 5 yuan has lower nutritional content.