Type A and B bovine milks: Heat stability is driven by different physicochemical parameters

Area of Science:

• Dairy science
• Food processing
• Animal science

Background:

• Milk's physicochemical properties are crucial for processing.
• Heat stability is a key functional trait of milk.
• Understanding composition-functionality relationships is vital for the dairy industry.

Purpose of the Study:

• To investigate the relationships between milk composition and heat stability.
• To determine factors influencing heat stability in different milk types.
• To assess seasonal variations in milk type and their impact on heat stability.

Main Methods:

• Analysis of individual milk samples from 24 dairy cows over three seasonal periods.
• Classification of milk into type A or B based on heat coagulation time versus pH profiles.
• Application of best subsets regression to identify predictors of heat stability for each milk type.

Main Results:

• Milk type classification (A or B) changed seasonally for 50% of cows.
• Urea concentration was a significant predictor for both milk types.
• Type A milk heat stability was influenced by osmotic pressure and milk solids.
• Type B milk heat stability was predicted by casein micelle size and ionic calcium.

Conclusions:

• Milk type and its influencing factors can vary significantly over a lactation season.
• Optimizing milk heat stability requires different strategies depending on milk type (A or B).
• These findings have implications for dairy processing and quality control.