PhenolsPhenols, the aromatic compounds with hydroxyl groups are widespread in plant kingdom. They occur in all parts of the plants. Phenols are said to offer resistance to diseases and pests in plants. Grains containing high amount of polyphenols are resistant to bird attack. Phenols include an array of compounds like tannins, flavonols etc. Total phenol estimation can be carried out with the Folin-Ciocalteau reagent.Principle Phenols react with phosphomolybdic acid in Folin-Ciocalteau reagent in alkaline medium and produce blue colored complex (molybdenum blue). Materials» 80% Ethanol» Folin-Ciocalteau Reagent » Na2CO3,20% » Standard (100mg Catechol in 100mL Water) Dilute 10 times for a working standard. Procedure
CalculationFrom the standard curve find out the concentration of phenols in the test sample and express as mg phenols/100g material.Notes 1. If any white precipitate is observed on boiling, the color may be developed at room temperature for 60 min. 2. Express the results in terms of catechol or any other phenol equivalents used as standard. References 1. Malick, C P and Singh, M B (1980) In: Plant Enzymology and Histo Enzymology Kalyani Publishers New Delhi p 286. |