In addition to the changes in double bond position, there are isomerizations from cis to trans and 90% of the peroxides formed may be in the trans configuration (25).

The decomposition of hydroperoxides has been described (29). It involves decomposition to alkoxy and hydroxy aldehydes, which are in great part responsible for the oxidized flavor of fats. They are powerful flavor compounds with very low flavor thresholds. For example, 2,4-decadienal has a flavor threshold of less than one part per billion.

Trace metals, especially copper, and to a lesser extent iron, will catalyze fat oxidation; metal deactivators, such as citric acid, can be used to counteract the effect of metals.

Antioxidants may be present naturally or added to fats and oils. Many foods contain natural antioxidants; the tocopherols are the most important of these. They are present in greater amounts in vegetable oils than in animal fats, which may explain the greater stability of the former. Antioxidants react with free radicals, thereby terminating the chain reaction. The synthetic antioxidants are phenolic compounds and limited in number. The four most widely used are BHA (butylated hydroxy anisole), BHT (butylated hydroxy toluene), PG (propyl gallate), and TBHQ (tertiary butyl hydroquinone). BHT is volatile with steam, which makes it less suitable for use in frying oils and baked products. Nonvolatile antioxidants are said to have carry-through properties for these applications.

Sleeping Sanctuary

Sleeping Sanctuary

Salvation For The Sleep Deprived The Ultimate Guide To Sleeping, Napping, Resting And  Restoring Your Energy. Of the many things that we do just instinctively and do not give much  of a thought to, sleep is probably the most prominent one. Most of us sleep only because we have to. We sleep because we cannot stay awake all 24 hours in the day.

Get My Free Ebook

Post a comment