A non-destructive method of testing of fruits and vegetables for post-harvest quality (firmness, texture, aroma and color) using fluorescence intensity of the skin or leaves is described. A low intensity red light source (10) is used to irradiate the skin or leaves of fruits or vegetables...http://www.google.com/patents/US5822068?utm_source=gb-gplus-sharePatent US5822068 - Non-destructive method and apparatus for detection of fruit and vegetable quality 
