Developing an optical backscatter method for determining casein micelle particle size in heated milk.

Area of Science:

• Food Science
• Dairy Technology
• Physical Chemistry

Background:

• Milk processing involves factors like heat and pH that alter key components like casein micelles.
• Physicochemical changes influence protein-protein interactions and particle size, detectable via light scattering.
• Inline monitoring offers potential for real-time process control in dairy production.

Purpose of the Study:

• To investigate the potential of light backscatter measurements for monitoring casein micelle particle size.
• To develop predictive models for casein micelle particle size based on heat treatment and pH.
• To assess the feasibility of using simple, low-cost optical sensors for dairy process control.

Main Methods:

• Measured casein micelle particle size and near-infrared light backscatter spectra in milk samples.
• Applied varying heat treatments (80-90°C) and pH levels (6.3-7.1).
• Utilized a simple optical backscatter sensor (200-1100 nm) to collect light intensity data.

Main Results:

• Developed prediction models correlating light backscatter spectra with casein micelle particle size.
• Models incorporating an exponential factor with a ratio of specific wavebands showed improved accuracy (R² of 0.993).
• Achieved a prediction error (SEP) of 2.36 nm for casein micelle particle size.

Conclusions:

• Inline light backscatter measurements show significant promise for monitoring whey protein denaturation and casein micelle particle size.
• This technique offers a cost-effective and efficient method for real-time quality control in milk processing.
• The developed models can aid in optimizing heat treatment and pH conditions for dairy products.