For a project, I am trying to figure out if it is possible to determine the acidification of milk without probing, touching, destroying or opening the sample, thus leaving the sample inside the plastic, transparent sample container. I am fairly experienced with machine vision and sensors, but not even a little in biology. I read somewhere that "Milk spoils when bacteria convert the lactose into glucose and galactose, producing lactic acid." I was wondering if there is any way of detecting any of these changes using a special camera or special lighting. Any advice or help will be much appreciated.