Chemical stability of antioxidant-washed beef heart surimi during frozen storage

Beef heart surimi was prepared in the presence or absence of propyl gallate and blended with or without cryoprotectants (sucrose, sorbitol). Samples were stored at -15, -29, and -70 degrees C for 0.2, 2, 4, 12, 26 and 52 wk to observe oxidative changes in lipids (TBARS and dienes) and proteins (sulfhydryl, carbonyl, surface hydrophobicity, and myosin ATPase). Lipid and protein oxidation was minimal al -70 degrees C. The freeze-thaw process caused lipid and protein oxidation in control samples at -15 and -29 degrees C. Oxidation increased rapidly after 4 wk. Propyl gallate inhibited lipid oxidation but was ineffective against protein changes. After 12 wk, cryoprotectants promoted lipid and protein oxidation in the absence of propyl gallate.