Influence of Phosphate-Induced pH Modification on Moisture Retention and Yield Characteristics of Porcine Muscle Systems

Water retention is a critical quality attribute in comminuted meat products, directly affecting product yield, texture, and consumer acceptability. The present study investigated the role of phosphate-based ingredients in modifying the physicochemical properties of porcine muscle systems and their subsequent effects on moisture retention during thermal processing.

Model systems were prepared from fresh pork loin with the incorporation of 20% water and selected functional ingredients. Formulations contained sodium chloride (1.5%) combined with sodium diphosphate, sodium tripolyphosphate, or phosphate mixtures (0.05%). Physicochemical properties were assessed through pH determination, water-binding capacity (WBC), and cooking loss measurements following heat treatment to an internal temperature of 72°C.

Phosphate supplementation significantly altered the reaction environment of the meat matrix. The highest pH value recorded was 6.24, representing a substantial increase compared with untreated samples. This shift away from the isoelectric region of major myofibrillar proteins promoted greater electrostatic repulsion between protein filaments, increasing their ability to immobilize water. Among the tested formulations, systems containing sodium tripolyphosphate in combination with sodium chloride exhibited the most pronounced technological improvements. Water-binding capacity reached 96.47% of total moisture, while cooking losses decreased to 13.19%. These effects are associated with enhanced protein solubilization and structural swelling of the myofibrillar network, facilitating the formation of a stable gel matrix during heating.

The findings demonstrate that phosphate-assisted pH adjustment is an effective strategy for improving moisture retention and processing yield in porcine muscle systems. Sodium tripolyphosphate, particularly when applied together with sodium chloride, showed the greatest potential for enhancing the functional properties of meat emulsions intended for further processing.