Antioxidants and Antibacterial Activities of Bioactive Compounds of Clove (Syzygium aromaticum) and Thyme (Tymus vulgaris) Extracts.

El-Refai, A. A.; Sharaf, A. M.; Azzaz, N. A. E.; El-Dengawy, M. M.

doi:10.21608/jfds.2020.118367

Antioxidants and Antibacterial Activities of Bioactive Compounds of Clove (Syzygium aromaticum) and Thyme (Tymus vulgaris) Extracts.

Document Type : Original Article

Authors

¹ Food Industries Dept., Fac. of Agric., Mansoura Univ., Egypt.

² Food Industries Dept., Fac. of Agric., Damietta University, Egypt.

³ Agricultural Chemistry Dept., Fac. of Agric., Damietta University, Egypt.

10.21608/jfds.2020.118367

Abstract

Recently, there is an increasing attention in finding antioxidant phytochemicals natural to avoid the effects of synthetic antioxidants and antimicrobialcompounds. In this study, two herbs namely clove buds (Syzygium aromaticum) and thyme leaves (Tymus vulgaris), were used to extract the bioactive compounds. The chemical composition of clove buds and thyme leaves was determined. Ethanolic and aqueous extractions were carried out to obtain biological active compounds. Ethanolic clove-powdered buds extracts had the highest total phenolic compounds (TPC) (372.21 mg GAE/g extract) while, essential oil extract of thyme-powdered leaves was (158.83 mg GAE/g extract). Total flavonoids compounds (TFC) of ethanolic clove-powdered buds extract was (177.15 mg QE/g extract) but aqueous extract of thyme-whole leaves was (126.50 mg QE/g extract). The reducing power of thyme-powdered leaves was (1.022) comparable with vitamin C (8.911) meanwhile, clove- powdered buds extract was (1.031). Free radical scavenging capacity of clove-whole buds was (IC
₅₀
; 2.75 µg/mL) and thyme-whole leaves extracts had (IC
₅₀
; 2.86 µg/mL) comparable with ascorbic acid (IC
₅₀
; 6.75 µg/mL). The antibacterial of all used herbs extracts against Escherichia coli, bacillus cereus and Staphylococcus aureus. Were studied. On Escherichia coli, thyme-powdered leaves essential oil had (19.75mm inhibition zone) while, clove-whole buds ethanolic extract was (14.5 mm inhibition zone). Thyme-whole leaves essential oil was (24.5 mm inhibition zone) against Staphylococcus aureus, but clove-whole buds essential oil extract was (12.25 mm inhibition zone). Aqueous extract obtained from thyme-powdered leaves was (14.5mm inhibition zone) While, clove-powdered buds ethanolic extract was (13.5 mm inhibition zone) against bacillus cereus.