Ultrasound-assisted extraction of polyphenols from Thymus serpyllum and its antioxidant activity

Aleksandra Jovanovic,Branko Bugarski,Gordana Zdunic,Katarina Savikin,Dejan Pljevljakusic,Verica Djordjevic

doi:10.2298/hemind150629044j

Aleksandra Jovanovic, Branko Bugarski + Show 4 more

Open Access

https://doi.org/10.2298/hemind150629044j

Copy DOI

Abstract

The present study was designed to establish and optimize a method for extracting natural bioactive compounds from Thymus serpyllum which possess antioxidant, antimicrobial, antispasmotic and stimulant properties. Ultrasound-assisted extraction (UAE) is a well-established method in the processing of plant material, particularly for extraction of bioactive substances such as polyphenols. The influential factors including extraction time (3, 7 and 10 minutes), solid:solvent ratio (1:10, 1:20 and 1:30) and particle size (0.3, 0.7 and 1.5 mm), have been studied to optimize the extraction process, while using 30% ethanol as an extraction medium and amplitude set to 65%. The yield of UAE was expressed via total phenol content and antioxidant activity of the obtained extracts. The optimum process paremeters were found to be: extraction time, 3 min; solid:solvent ratio, 1:30; particle size, 0.3 mm. Under these conditions, the yield of total polyphenols was raised up to 23.03 mg/L GA and the highest antioxidant activity was recorded (10.32 mmol/mg Trolox and IC50 3.00 mg/ml).

Highlights

The present study was designed to establish and optimize a method for extracting natural bioactive compounds from Thymus serpyllum which possess antioxidant, antimicrobial, antispasmodic and stimulant properties
In order to study the effects of different extraction conditions of ultrasound-assisted extraction, three different particle size (0.3, 0.7 and 1.5 mm) were tested in this study in combination with different extraction time (3, 7 and 10 min) and solid:solvent ratio (1:10, 1:20 and 1:30)
The lowest total polyphenols content was detected in extracts obtained with a particle size of 1.5 mm and at solid:solvent ratio 1:10, after 3 and 10 min of the extraction (12.07–12.10 mg/L GAE)

Summary

Introduction

The present study was designed to establish and optimize a method for extracting natural bioactive compounds from Thymus serpyllum which possess antioxidant, antimicrobial, antispasmodic and stimulant properties. The optimum process parameters were found to be: extraction time, 3 min; solid:solvent ratio, 1:30; particle size, 0.3 mm Under these conditions, the yield of total polyphenols was raised up to 23.03 mg/L GA and the highest antioxidant activity was recorded (10.32 mmol/mg Trolox and IC50 of 3.00 mg/ml). Well-known as wild thyme is perennial, herbaceous plant of genus Thymus and possesses aromatic, antiseptic, analgesic, diuretic, diaphoretic, carminative, antioxidant, spasmolytic, anti-inflammatory and stimulant properties. It has been used in mouth washes and gargles and against cough and cold because of antimicrobial activities of its extracts [4]. Extraction efficiency was expressed via total polyphenols content (Folin–Ciocalteu method) and antioxidant activity (ABTS and DPPH methods) of the obtained extracts

Methods

Results

Discussion

Conclusion