Structural changes of meat protein of chicken sausages with various levels of salt and phosphate and their effects on in vitro digestion

Abstract

SummaryThe objectives of this study were to evaluate protein oxidation and in vitro digestibility of chicken sausages with various salt/phosphate combinations. Hydrophobicity increased when protein was cooked and denatured (P < 0.05). Protein oxidation was increased based on levels of SH, S‐S and carbonyl groups during the cooking process (P < 0.05). Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS‐PAGE) revealed that the intensity of myosin heavy chain band was decreased while biopolymer band was denser when sausages were cooked. Sausages with 1.8% salt and 0.3% phosphate (S1P1) showed the lowest digestibility and maintained a flat and compact structure, unlike other treatments during the gastrointestinal digestive stage. SDS‐PAGE of digested chicken sausages showed that protein bands were degraded into small bands followed by gradual disappearance. In conclusion, cooking process can lead to protein denaturation and oxidation, regardless of levels of salt and phosphate added. In addition, adding salt and phosphate can significantly affect the digestibility of meat products.