Cooking Enhances the Antioxidant Properties of Polyphosphates

ABSTRACT: Raw and cooked brook trout muscle (BTM) samples were treated with phosphates and other antioxidants. Sodium tripolyphosphate (STPP), added before or after cooking, significantly reduces the formation of thiobarbituric acid-reactive substances (TBARS) only in cooked BTM. Fish processed during rigor mortis had higher TBARS. The effect of different types of phosphates depended also on cooking BTM. When copper was added to accelerate oxidation, only EDTA completely prevented TBARS formation. Sodium citrate (SCit) was more concentration-dependent and slightly less efficient than STPP. Higher levels of orthophosphates were found in raw BTM. Because cooking enhanced the antioxidant activity of STPP, SCit, and EDTA, the results suggest that phosphates are good chelators, provided cooking has eliminated phosphatase hydrolysis.