EFFECT OF LIPID OXIDATION ON THE FUNCTIONAL AND NUTRITIONAL PROPERTIES OF WASHED CHICKEN MYOFIBRILS STORED AT DIFFERENT WATER ACTIVITIES

Effects of water activity (aw) on the functional and nutritional properties of freeze-dried chicken breast myofibrils during storage at 20 °C were investigated. Control myofibrils and myofibrils with 0.6 μmol of added methyl linoleate (ML)/g of protein were stored for 21 days at aw's between 0.11 and 0.85. Control and ML treatments were 67% and 34% soluble, respectively, after freeze-drying. Monolayer values determined from moisture sorption isotherms in the control and ML treatment were 6.5 and 9.1 g of H2O/g of fat-free solids, respectively. Lipid oxidation was lowest in myofibrils stored at relative humidities near the monolayer value. Protein solubility decreased more rapidly during storage at high aw's. Solubility and gel strength were lower in ML treatments than in controls stored at the same aw. Protein digestibility and quality were not influenced by treatment or storage time. © 1990, American Chemical Society. All rights reserved.