Use of the product of mean intensity ratio (PMIR) technique for discriminant analysis of lycopene-rich vegetable juice using a portable NIR-excited Raman spectrometer

•Lycopene content discriminant analysis with a portable Raman spectrometer was tested.•Near-infrared Raman spectrometry accurately yielded the lycopene content of juice.•An index capable of effectively indicating lycopene-rich substances was developed.•The same methods can be applied to intact fruits and to analyze other ingredients.