Effects of γ-Glutamylated Hydrolysates from Porcine Hemoglobin and Meat on Kokumi Enhancement and Oxidative Stability of Emulsion-Type Sausages

Valorization of slaughtering side streams is considered as an important research topic. To investigate the sensory and antioxidant effects of modified hydrolysates on sausages, protein hydrolysates from porcine hemoglobin and meat treated by gamma-glutamyltranspeptidase (GGT) were incorporated into emulsion-type pork sausages at 2% and 4% concentrations. Sensory evaluation as well as analysis of textural properties and thiobarbituric acid-reactive substances (TBARS) were carried out. The sensory results showed that addition of hydrolysates and gamma-glutamylated hydrolysates from both raw materials enhanced the kokumi sensation and overall flavor intensity of fresh sausages. Furthermore, compared with the corresponding hydrolysates, gamma-glutamylated hydrolysates from hemoglobin showed a stronger effect on taste enhancement. During chilled storage, gamma-glutamylated hydrolysates from both raw materials contributed to the higher hardness and slower lipid peroxidation of sausages. These results showed the kokumi-enhancing and antioxidant potential of gamma-glutamylated hydrolysates, indicating that they might be used as valuable functional protein ingredients in foods.