Calcium-induced skim milk gels using different calcium salts

Area of Science:

• Food Science
• Dairy Chemistry
• Physical Chemistry

Background:

• Milk proteins and calcium interactions are crucial for dairy product texture.
• Understanding how different calcium salts affect milk's physical and rheological properties is essential for product development.

Purpose of the Study:

• To investigate the impact of various soluble calcium salts on skim milk's physico-chemical and rheological characteristics.
• To determine how different calcium salts influence casein solubility, calcium distribution, and gelation properties.

Main Methods:

• Heating skim milk with different soluble calcium salts (calcium chloride, lactate, gluconate, lactobionate).
• Analyzing changes in casein and calcium content in milk serum and sediment.
• Measuring calcium ion activity (a_Ca²⁺) and gel firmness (G') of milk gels.

Main Results:

• Heating milk with calcium salts decreased serum casein and increased sediment calcium and serum calcium.
• The required calcium salt amount for gelation and final gel firmness (G') varied significantly by salt type.
• Calcium ion activity followed the order: calcium chloride > calcium lactate > calcium gluconate > calcium lactobionate, mirroring the order of final G'.

Conclusions:

• Different calcium salts exhibit varying effects on milk gelation due to differences in association constants and complex formation.
• Calcium ion activity is a key factor influencing the gelation properties of milk.
• The choice of calcium salt can be optimized to control the texture and firmness of milk-based gels.