The concept of optothermal window (OW) detection was used for the first time to assess the color of several products (juice, purée, paste) derived from thermally processed tomatoes. Unlike traditional techniques that operate either in the reflectance or transmission mode, the method proposed here actually relies on indirect measurement of absorbance in optically opaque and scattering samples. Very good correlation between the magnitude of the OW signal and the color-related parameters [colorimetric index L* and tomato paste index (TPI)] was observed.
- optothermal window
- lycopene content