misflavour

noun

Amer·:   misflavor
Plural:   misflavours (UK)  /  misflavors (US)

Wrong or undesirably altered taste or smell of something, especially food;  unpleasant aftertaste;  unexpected or unmatching savour.

Examples: 

We should better not go into mentioning the hideous so-called refrigerator misflavour of over-aged long-frozen food.  Our guests and we undoubtedly deserve a yummier and health-friendly treat.  (Source: J∙ Okram - Mayonnaise Stew  ●  Cooking Recipe.)