Happy (belated) Turkey Day, foodie friends! Hope everyone had a wonderful Thanksgiving. The hubs and I had a great time hosting family for dinner this year (my countertops are still crammed with breads and sweets, even after I’ve pawned plates of it off on willing takers)! Anybody else still reheating leftover turkey? Have you noticed a slight “off” flavor developing in the turkey meat? Well…get out the gravy, friends. You’ve got some WOF going on.
“Warmed-over flavor,” (WOF) refers to the development of off-flavors in leftover turkey after a few days of refrigerated storage. Turkey meat is high in polyunsaturated fatty acids, which makes it susceptible to lipid oxidation and the subsequent off-flavor (and off-aroma) characteristic of WOF.
A reaction occurs when turkey is cooked – the meat tissue is disrupted and phospholipids release. When exposed to light, singlet oxygen is generated from triplet oxygen and myoglobin (a photosensitizer in turkey meat). The highly reactive singlet oxygen attacks bonds of unsaturated fatty acids in the phospholipids, producing hydroperoxides. Metal catalysts, like iron, found in muscle foods (like…ahem… turkey) speed the reaction along. Hydroperoxides are unstable, and readily decompose into acids, aldehydes, and keytones which produce off-flavors often described as “rancid,” “stale,” or “cardboard-like.” These off-flavors develop under refrigeration temps, and are amplified after re-heating.
If you find WOF development occurring in your kitchen, you can imagine the effect on an industrial scale. Several commercial pre-cooked meat products on the market call for reheating by the consumer. Products like these require food manufacturers to find solutions that fight the quality imperfections brought on by WOF development. In addition to utilizing reliable packaging (materials with low oxygen permeability), many manufacturers turn to antioxidants or nitrites which retards the onset of off-flavor/aroma. So, now you know why you may see additives like BHT (butylated hydroxytolulene), ascorbyl palmitate, tocopherols, and nitrite on the labels of meat products – a mystery no more!
WOF development occurs in other types of meat as well – chicken, beef, lamb, etc. However, due to the higher levels of unsaturated fatty acids, poultry meat (especially turkey) is more susceptible to lipid oxidation and off flavor development.
A Food Science tid-bite: Want to reduce the WOF susceptibility in your turkey at home? Natural antioxidants such as rosemary, black pepper, and ingredients high in citric acid (like lemons) are known to have a positive effect on WOF development.Source: Genevieve L. Christen, ed and J. Scott Smith, ed. Food Chemistry: Principles and Applications. Science Technology System, 2000 Source: Casimir C. Akoh, ed and David B. Min, ed. Food lipids: chemistry, nutrition, and biotechnology. Taylor & Francis Group, LLC, 2008