Indoxylsulfate in milk.

Area of Science:

• Food Chemistry
• Analytical Chemistry
• Dairy Science

Background:

• Indoxylsulfate is a metabolite found in milk.
• Understanding indoxylsulfate variability is crucial for dairy quality control.

Purpose of the Study:

• To quantify indoxylsulfate in various milk products.
• To investigate factors affecting indoxylsulfate concentration in milk.
• To explore the analytical potential of indoxylsulfate determination.

Main Methods:

• Analysis of indoxylsulfate in individual and pooled milk samples.
• Assessment of indoxylsulfate levels in dried skimmed milk over one year.
• Evaluation of processing effects (fermentation, heat treatment) on indoxylsulfate.
• Correlation analysis with blood-serum indoxylsulfate and milk urea content.

Main Results:

• Indoxylsulfate concentrations in milk varied widely (25.4–111 µg/l).
• Regional, seasonal, and feeding factors influenced indoxylsulfate levels.
• Fermentation reduced indoxylsulfate; heat treatment had no effect.
• Positive correlations were observed between milk and serum indoxylsulfate (r=0.752) and milk urea (r=0.61).

Conclusions:

• Milk indoxylsulfate content is influenced by diet and processing.
• Indoxylsulfate levels in milk correlate with blood levels.
• Further research is warranted for using indoxylsulfate to detect adulteration (sweet whey) and differentiate milk species.