Multi-Reflectance-Spectroscopy, Part I: Theory and Calculations Using Simulated Milk Samples.

Area of Science:

• Optical physics
• Spectroscopy
• Materials science

Background:

• Optical methods are effective for analyzing suspensions and emulsions.
• Accurate monitoring of constituents requires precise measurement of optical properties.

Purpose of the Study:

• Introduce a novel multi-wavelength, multi-reflectance spectroscopic (MRS) technique.
• Derive analytical relations for MRS reflectance, absorption (μ_ABS), and scattering (μ_S) coefficients.
• Validate the MRS method using milk samples and compare with Mie theory and Monte Carlo simulations.

Main Methods:

• Developed MRS-Technology measuring reflectance from small and large sample volumes.
• Utilized Mie scattering theory to calculate μ_ABS and μ_S for virtual milk samples (UV-Vis-SWNIR range).
• Employed Monte Carlo (MC) simulations for numerical reflectance validation.
• Applied multilinear regression (MLR) to correlate reflectance with fat and protein content.

Main Results:

• Analytical MRS reflectance closely matched numerical MC results for low to medium absorption.
• Established correlations between reflectance at specific wavelengths and milk fat/protein volume fractions.
• Achieved acceptable root mean square error (RMSE) values for constituent quantification.

Conclusions:

• MRS-Technology offers a viable optical method for monitoring constituents in suspensions and emulsions.
• The technique demonstrates potential for accurate, non-invasive analysis of complex fluid compositions.
• Optimizing wavelength selection for small and large measuring volumes enhances quantification accuracy.