Contaminants endogenous primary

Hydrocarbons are common components of many foods often occurring as constituents of essential oils and food hpids. They are either natural components of food raw materials and foods (primary substances) or form during food processing and storage by enzymatic and chemical reactions as secondary substances (e.g. as lipid oxidation products and degradation products of carotenoids). Some hydrocarbons may be present in food as endogenous or exogenous contaminants (e.g. polycychc aromatic hydrocarbons). 

In principle, the circumstances under which the primary (exogenous) or secondary (endogenous) organic and inorganic contaminants get into the human food chain may be summarised in the following points ... 

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