Isoelectric Point of Meat Proteins

Low net charge reduces repulsion between protein structures, allowing them to pack more closely and leaving less space for immobilised water. Meat therefore tends to show lower water-holding capacity near this region.

Meat contains many proteins with different isoelectric points. The commonly discussed muscle-protein region is an approximation used to explain behaviour, not a single exact pH for every protein or product.

After slaughter, glycolysis lowers pH while muscle structure changes through rigor. The relationship between final pH, temperature and the isoelectric region helps explain PSE, DFD and normal technological meat quality.

Salt, phosphates, mechanical action and protein extraction alter ionic conditions and spacing. Functional meat systems can therefore bind water differently from an untreated piece at the same measured pH.

Use the concept to explain drip, water retention, binding and yield. It should not be turned into a universal shelf-life, fermentation or food-safety threshold.