Phenolic compounds: Main class of secondary metabolites in plant

Plant phenolic and polyphenolic compounds, are defined as compounds possessing one or more aromatic rings bearing hydroxyl substituent(s), and are the secondary metabolites of phenylalanine and to a lesser extent tyrosine in plants.

Phenolic compounds mostly present in various types of foods of plant origin. Natural antioxidants have been extensively found in fruits and vegetables, seeds of many fruits, cereals, berries, wine, tea, olive oil, and aromatic plants. The content of phenolic compounds in foods may change during processing and storage as mediated by light and temperature.

There is now considerable evidence that wine phenolics, particularly resveratrol, inhibit low-density lipoprotein oxidation and reduce platelet aggregation, two major parameters implicated in atherothrombogenesis. This provides a possible explanation for the cardio protective action of wine.

Phenolic compounds such as cafeic acid, chlorogenic, p-coumaric and ferulic are present in parts of plants that are used as spices. The antimicrobial activity of these and other acids as hydroxycinnamic and cinnamic may retard microbial invasion as well as fruit and vegetable putrefaction.

Apart from being naturally present in the raw materials used for foods, phenolic compounds are also added to certain foods and beverages as colorants or as antioxidants. Phenolic compounds have also been successfully employed as the processing aid for texture modification of fish mince and surimi.

The potential value of phenolic compounds as biopreservatives is considered for the safe extension of perishable products shelf life and these substances can be used to delay or inhibit the oxidation and growth of microorganisms. However, in food applications, the phenolic compounds could be influenced by food components, processing and storage.
Phenolic compounds: Main class of secondary metabolites in plant