Determination of polyphenols, antioxidant activity, and antimicrobial properties of Zhourat using different extraction conditions

Abstract

Zhourat is an herbal infusion popular in the Middle East consisting of a mixture of different plants. The aim of this study was to (1) to determine the best conditions to extract phenolic compounds from twelve plants and their combination (Rosa damascena (Wared Joury, Zer Wared), Viola odorata L., Matricaria chamomilla L., Althaaea officinalis Linn., Melissa officinalis, Elaeagnus angustifolia L., Foeniculum vulgare L., Pimpinella anisum L., Saccharum officinarum L., Prunus dulcis, andZea mays L.), and (2) to elucidate their bioactive potential (antioxidant and antimicrobial capacity). Different conditions were used for the extraction and the subsequent analysis was performed. Results showed that optimal extraction conditions vary greatly between different kind of plants. A mixture of 50% water/50% ethanol at 40°C appeared to be optimal to extract the antioxidant and antimicrobial compounds for the samples tested. The total phenolic content (TPC) ranged from 0.2 mg GAE/g and 11.4 mg GAE/g. Zer Wared and Wared extracts at 40 ˚C showed the highest free radical scavenging activity. For TPC and anti-radical properties, Zhourat blend extracts did not show any additional effect over individual plants, and results fell in mid-range. As for the antimicrobial effect, antibacterial properties varied among the different plants as well. No synergistic effects appeared for the Zhourat mixture as a whole; neither antimicrobial nor antioxidant tests showed added value in mixing twelve plants. Wared and Zer Wared seem to have the best antioxidant and antimicrobial properties, followed by the Zhourat mixture. The results suggested that the most available herbal infusions in Lebanon should better be consumed on their own, rather than in a Zhourat Mixture. The combination of herbal ingredients in Zhourat mixture mertits further inbestigation.