Enhancing the Extraction of Phenolic Compounds from Juniper Berries Using the Box-Behnken Design

Noureddine Elboughdiri; Djamel Ghernaout; Karim Kriaa; Bassem Jamoussi

doi:10.1021/acsomega.0c03396

Enhancing the Extraction of Phenolic Compounds from Juniper Berries Using the Box-Behnken Design

ACS Omega. 2020 Oct 21;5(43):27990-28000. doi: 10.1021/acsomega.0c03396. eCollection 2020 Nov 3.

Authors

Noureddine Elboughdiri^{1

2}, Djamel Ghernaout^{1

3}, Karim Kriaa^{4

2}, Bassem Jamoussi⁵

Affiliations

¹ Chemical Engineering Department, College of Engineering, University of Ha'il, P.O. Box 2440, Háil 81441, Saudi Arabia.
² Chemical Engineering Process Department, National School of Engineering Gabes, University of Gabes, Gabes 6011, Tunisia.
³ Chemical Engineering Department, Faculty of Engineering, University of Blida, P.O. Box 270, Blida 09000, Algeria.
⁴ College of Engineering, Al Imam Mohammad Ibn Saud Islamic University, P.O. Box 5701, Riyadh 11432, Saudi Arabia.
⁵ Department of Environmental Sciences, Faculty of Meteorology, Environment and Arid Land Agriculture, King Abdulaziz University, Jeddah 21589, Saudi Arabia.

Abstract

Juniper berry is an important medicinal plant used in pharmaceutical and petrochemical industries thanks to its strong antioxidant potential, which is attributed to the presence of phenolic compounds. In this study, four different solvents, namely, aqueous acetone, aqueous ethanol, aqueous NaOH, and water, were used in the extraction process with a view to optimize and determine the polyphenolic contents in the juniper berry using ultraviolet (UV) spectrophotometry. Many experiments were performed at different solvent concentrations, time, temperature, and liquid-solid ratio. The models to evaluate the effects and the optimum of these variables on the polyphenols extraction using the response surface methodology (RSM) were developed. The predicted values of the polyphenol content of juniper berry were thus highly correlated with costly measured values (SECV = 0.14 and R ² = 0.97), and the optimal conditions of extraction were determined for the different solvents. Following the numerical optimization, the maximum predicted polyphenol contents obtained under the optimum extraction conditions are as follows: 17.57% for 58 °C extraction temperature, 78.5 min extraction time, 60% acetone concentration, and 29.8 liquid-solid ratio for the aqueous ethanol extraction; 20.68% for 71.46 °C extraction temperature, 79.2 min extraction time, 21.9% ethanol concentration, and 26.4:1 liquid-solid ratio for the aqueous acetone extraction; 34.51% for 96.4 °C extraction temperature, 37.7 min extraction time, 1.48% NaOH concentration, and 15.2:1 liquid-solid ratio for the aqueous NaOH extraction; and 9.8% was obtained under the optimum extraction conditions of 69 °C extraction temperature, 126 min extraction time, and 23:1 liquid-solid ratio for the water extraction. The GC-MS analysis of the chemical composition of juniper Berry revealed 60 identified components that represent 97.43% of the sample. The predominant fraction was monoterpene representing 80.87% especially for α-pinene (39.12%), β-pinene (12. 68%), and myrcene (12.92%). In the other fraction of sesquiterpene representing 16.54%, the predominant components were β-caryophyllene (4.41%) and germacrene D (4.23%).