Study of Measurement of Protein Content Based on Laser Light Scattering Technology

The objectives of this study were to investigate the measurement methodology of the protein content in skimmed milk by laser light scattering(LLS). There was a definition that the ratio of the scattering light( at 90°scattering angles, relative to the incident beam direction) intensity to the transmitted light intensity, which was called scattered transmitted ratio(STR). Using the STR theory, we constructed a sensing system to measure the protein content. The sensing system contains a laser beam of 658nm wavelength, sample reservoir and two photodiodes which measure the scattered light and transmitted light respectively. Through data analysis, the relationship model was established between the protein content and the STR. Comparing with Kjeldahl determination of nitrogen, the STR method described in this study can also accurately measure the protein content.