Well, scientists at Tianjin University of Science and Technology say they have developed a handheld tester that can detect pathogenic bacteria and excessive drug or pesticide residue.
The kit, which contains more than 60 strips of indicator paper - one for almost every contaminant listed by the State - works in a matter of minutes, said Wang Shuo, director of the college's biotech laboratory.
For example, users simply dip the right strip into milk, and if two bars on the paper turn purple, it contains melamine.