India, Oct. 12 -- University of Queensland researchers have developed a nanoprobe that changes colour to indicate how much vitamin C is in fresh produce and juice.

Dr Run Zhangfrom UQ'sAustralian Institute for Bioengineering and Nanotechnology(AIBN) said the technology could be added directly to food and juice samples or applied to paper testing strips that, when touched to cut or intact produce, changed colour to indicate the concentration of vitamin C.

Vitamin C - also known as ascorbic acid - is a critical antioxidant in most fruits and vegetables and can vary significantly depending on the length of journey from the farm to fridge.

"Things like exposure to heat, oxygen, and light all accelerate vitamin C degradation, as does the qu...