EVALUATION OF PHENOLIC COMPOUNDS CONTENT AND ANTIOXIDANT CAPACITY OF HERBS
 
More details
Hide details
 
Pol. J. Food Nutr. Sci. 2007;57(Special issue 4C):483–488
KEYWORDS:
ABSTRACT:
Research material constituted fresh herbs available in retail trade, i.e.: sweet basil (Ocimum basilicum L.), lemon balm (Melissa officinalis L.), marjoram - oregano (Origanum vulgare L.), rosemary (Rosmarinus officinalis L.) and thyme (Thymus vulgaris L.). Both whole herbs and their particular morphological parts (leaf, stalk, stem) were subjected to analyses. Polyphenolic compounds content was determined with the method of Singleton & Rossi and results were presented as GAE/g (Gallic Acid Equivalent). Antioxidant properties of the examined herbs were assayed with the spectrophotometric method with the use of ABTS cation radicals and expressed as TEAC/g (Trolox Equivalent Antioxidant Capacity). Total polyphenolics content and antioxidant capacity were determined with the extraction method using alcohol and water. Alcohol extraction influenced a considerably higher concentration of polyphenolic compounds and higher antioxidant capacity to a more favorable extent than water extraction. Antioxidant capacity of particular herbs and their morphological parts was closely correlated with the content of polyphenolic compounds. The highest concentration of polyphenols and simultaneously the highest antioxidant capacity were observed in herb leaves and whole plants, whilst the lowest – in stems and stalks. Among the examined fresh herbs, rosemary was characterised by the highest concentration of polyphenols, i.e. 35-45% of polyphenol compounds more than oregano and thyme, by about 58% more than lemon balm and about 80% more than sweet basil. When converted into dry matter, a significantly higher concentration of polyphenolic compounds and simultaneously the highest antioxidant capacity were typical of oregano and rosemary and then thyme and lemon balm, whereas the lowest one – of sweet basil.