Need for a Working-Factor in Evaluating Freezing Point Results on Raw Milk Samples ¹

Area of Science:

• Dairy Science
• Food Safety
• Analytical Chemistry

Background:

• The accepted legal standard for detecting water adulteration in milk is -0.525°H.
• Previous research indicated this standard may allow for up to 3% added water in average dairy farm milk samples.
• Concerns exist regarding the effectiveness of current standards in preventing milk adulteration.

Purpose of the Study:

• To evaluate the effectiveness of the current legal upper base for detecting water adulteration in milk.
• To investigate the potential for naturally occurring milk samples to fall above the legal standard.
• To propose a more practical 'working factor' for the dairy industry to address milk adulteration.

Main Methods:

• Analysis of milk samples with unknown purity (assessing for added water).
• Comparison of results against the established legal standard of -0.525°H.
• Statistical evaluation of naturally occurring milk sample variations.

Main Results:

• The study confirmed the potential for the current legal standard to permit added water in milk.
• A significant percentage of naturally occurring milk samples may fall within levels that suggest adulteration under the current standard.
• The findings suggest the existing standard is not sufficiently protective against milk adulteration.

Conclusions:

• The current legal upper base of -0.525°H for detecting water adulterated milk is potentially inadequate.
• A lower, practical 'working factor' is recommended for the dairy industry to effectively combat milk adulteration.
• Implementing a revised standard could enhance milk quality and protect consumers and producers.