Determination of total phenolic content, total flavonoid content and FRAP in culinary herbs in relation to harvest time

Abstract

In this study there were evaluated total phenolic and flavonoid contents, and ferric reducing antioxidant power (FRAP) of 3 herbs species, that are commonly used in fresh stage (summer savory – Satureja hortensis L., marjoram – Majorana hortensis M. and thyme – Thymus vulgaris L.) in dependence on time of harvest. The total flavonoid content ranged from 2.36 to 4.10 g of catechin equivalents (CE).100g−1 of dry weight (dw) of plant material. The highest average total flavonoids content was ascertained in aerial part of summer savory colected in first harvest (4.10 g CE.100g−1 dw) and the lowest in aerial part of summer savory collected in third harvest (2.36 g CE.100g−1 dw). The highest total flavonoid content was measured by all tested species in plant material harvested in first time of harvest. The highest total phenolic content was estimated in plant material of marjoram harvested in the second time of harvest (6.74 g gallic acid equivalents (GAE).100g−1 dw) and the lowest in aerial part of summer savory harvested in the third time of harvest (4.16 g GAE .100g−1 dw). Ferric reducing antioxidant power (FRAP) ranged from 1,13 (summer savory, harvest No. 3) to 1.91 g GAE .100g−1 dw (thyme, harvest No. 1). The best results of total flavonoid content, total phenolic content and FRAP were obtained by marjoram. Among harvest times there were the highest contents of measured compound mainly by the samples collected in the first time of harvest.

Keywords

• total phenolic content
• total flavonoid content
• FRAP
• summer savory
• marjoram
• thyme