Recovery and Characterization of Enzymatic Protein Hydrolyzates and Fat from Chicken Skin

Abstract

AbstractChicken skin is a valuable source of proteins and fat. In this work, the efficacy of five commercial proteases (Alcalase, Protamex, Pancreatic trypsin, Neutrase, and Flavourzyme) was evaluated in enzymatic recovery of fat and protein hydrolyzates from chicken skin. The highest (49.19%) and lowest (8.92%) degrees of hydrolysis (DH) of protein were obtained using Alcalase and Flavourzyme, respectively. Protein hydrolyzates obtained using Flavourzyme showed the highest water‐holding capacity (WHC), oil‐holding capacity (OHC), and emulsifying activity index (EAI). The highest foaming capacity was observed in the hydrolyzate produced using Alcalase, Protamex, or Trypsin treatments. Hydrolysis using Protamex or Trypsin resulted in the highest fat yield (34.48–35.85%). Fatty‐acid composition, iodine value, unsaponifiable matter, and the amount of iron in chicken‐skin fats were not affected by the enzyme's type. The phosphorus content of chicken‐skin fat was in the range of 5.6–10.8 ppm, the lowest obtained by Flavourzyme. The oxidative stability index of the enzymatically extracted fat was in the range of 0.98–1.51 h at 110 °C. In conclusion, the enzyme type had a significant effect on some physicochemical properties of fat and protein hydrolyzates.