Alternative Ultrasound-Assisted Method for the Extraction of the Bioactive Compounds Present in Myrtle (Myrtus communis L.)

Abstract

The bioactive compounds in myrtle berries, such as phenolic compounds and anthocyanins, have shown a potentially positive effect on human health. Efficient extraction methods are to be used to obtain maximum amounts of such beneficial compounds from myrtle. For that reason, this study evaluates the effectiveness of a rapid ultrasound-assisted method (UAE) to extract anthocyanins and phenolic compounds from myrtle berries. The influence of solvent composition, as well as pH, temperature, ultrasound amplitude, cycle and solvent-sample ratio on the total phenolic compounds and anthocyanins content in the extracts obtained were evaluated. The response variables were optimized by means of a Box-Behnken design. It was found that the double interaction of the methanol composition and the cycle, the interaction between methanol composition and temperature, and the interaction between the cycle and solvent-sample ratio were the most influential variables on the extraction of total phenolic compounds (92.8% methanol in water, 0.2 s of cycle, 60 °C and 10:0.5 mL:g). The methanol composition and the interaction between methanol composition and pH were the most influential variables on the extraction of anthocyanins (74.1% methanol in water at pH 7). The methods that have been developed presented high repeatability and intermediate precision (RSD < 5%) and the bioactive compounds show a high recovery with short extraction times. Both methods were used to analyze the composition of the bioactive compounds in myrtle berries collected from different locations in the province of Cadiz (Spain). The results obtained by UAE were compared to those achieved in a previous study where microwave-assisted extraction (MAE) methods were employed. Similar extraction yields were obtained for phenolic compounds and anthocyanins by MAE and UAE under optimal conditions. However, UAE presents the advantage of using milder conditions for the extraction of anthocyanins from myrtle, which makes of this a more suitable method for the extraction of these degradable compounds.

Ultrasound-Assisted Extraction of Two Types of Antioxidant Compounds (TPC and TA) from Black Chokeberry (Aronia melanocarpa L.): Optimization of the Individual and Simultaneous Extraction Methods

“…This technique has many advantages, since it decreases extraction and processing times, reduces energy and solvent consumption, and improves extraction performance. In addition, it is an easy, flexible, versatile and low-cost technique [15,16], as it has already been proven with other fruits such as grapes [17] or myrtle berries [18].…”

Extraction of Anthocyanins and Total Phenolic Compounds from Açai (Euterpe oleracea Mart.) Using an Experimental Design Methodology. Part 2: Ultrasound-Assisted Extraction

“…The variables chosen for the optimization were: Solvent of extraction (25%-75% methanol in H 2 O), the extraction temperature (10-70 • C), the amplitude (30%-70% of the maximum amplitude −200 W), the cycle (0.2-0.7 s), the pH of the extraction solvent (2-7), and the amount of sample (g):volume of the extraction solvent (mL) ratio (0.5:10-0.5:20). Methanol was used as the extraction solvent, due to the very good extractant qualities for this type of compound, such as its small size (easy penetration capacity), low density, and polarity related to the polarity of the studied compounds [38,41,42,44].…”

“…Furthermore, the extraction efficiency can be increased by using a greater range of temperatures, since the number of bubbles formed in the cavitation phenomenon increases [39,40]. UAE has been earlier applied to extract bioactive compounds from different matrices, such as myrtle, [41], black chokeberry [42], perlette grapes [43], sesame [44], etc. Additionally, this technique is easy to use and cheaper than other extraction techniques.…”

Extraction of Anthocyanins and Total Phenolic Compounds from Açai (Euterpe oleracea Mart.) Using an Experimental Design Methodology. Part 1: Pressurized Liquid Extraction

“…Phenolic constituents are generally associated with health-promoting properties and the prevention of several degenerative diseases. Some studies have demonstrated their relation to antioxidant and anticancer properties in general [33][34][35]. The main phenolic compounds that could be found in açai are protocatechuic acid, epicatechin, benzoic acid, caffeic acid, chlorogenic acid, ferulic acid, syringic acid, vanillic acid, p-coumaric acid, orientin, isoorientin, vitexin, and procyanidins, amongst others [10,24].…”