Influence and correction of temperature on optical measurement for fat and protein contents in a complex food model system

The influence of temperature on optical measurements has been studied for determining fat and protein contents in complex food systems. A model system consisting of mixtures of fat, protein, water and emulsion was developed to create an imitation of complex food systems. The changes in optical properties of the system from 25 °C to 40 °C were measured in the wavelength from 1100 nm to 1670 nm. Irregular changes as a whole were founded and therefore a statistical method was needed to correct the temperature effect. A method called global robust temperature calibration model is proposed and the correction effect was validated. The results indicated that it can significantly reduce the temperature effect on optical measurement.