Design of experiment for a sustainable extraction of phenolic compounds from pomegranate peels and proof of antioxidant and antimicrobial properties

• Published in: Sustainable chemistry and pharmacy 2024-12, Vol.42, p.101860, Article 101860
• Main Authors: Santana, Robertta J.R., Batista, Thigna de C., Valença, Camilla A.S., Zielińska, Aleksandra, Severino, Patrícia, Souto, Eliana B., Marques, Maria N., Cardoso, Juliana C.
• Format: Article
• Language: English
• Subjects: Hydrolysable tannins; Punica granatum; Responsible production; Sustainable extraction
• ISSN: 2352-5541; 2352-5541
• DOI: 10.1016/j.scp.2024.101860

The aim of this work was to develop a sustainable and highly efficient method to obtain an aqueous extract from pomegranate peels, with a high content of phenolic compounds. Several parameters (i.e., extraction time and temperature, acidity of the extracting solution and purification step using ethyl acetate) were studied considering their influence on the yield, content of chemical markers, antioxidant and antimicrobial efficiency of extracts. Extracts obtained at room temperature and using water as the extraction solvent showed the highest content of chemical markers and resulted in low energy consumption with the avoidance of organic solvents in the purification step. Such extracts showed intermediate antioxidant activity with a half-maximal inhibitory concentration (IC50) of 208.26 μg/mL for the crude extract and IC50 = 292.26 μg/mL for the purified extract. Extracts rich in ellagic acid and gallic acid, obtained in distilled water and at room temperature, showed antimicrobial activity against Gram-positive and Gram-negative strains. In conclusion, the extraction of active phenolic substances from pomegranate peel can be carried out in a single step (without purification) and under conditions that involve lower operational costs and are more sustainable (room temperature, water solvent). Such conditions favour an industrial scale production, with high yield and the possibility to customize the type of extraction to the desired usage. [Display omitted] •A sustainable method to obtain phenolic compounds-rich aqueous extract from pomegranate is described.•One single step of low cost and low temperature was developed using water as solvent.•Antioxidant properties were kept for crude extract obtained under milder conditions.•Pomegranate extracts have strong activity against Staphylococcus strains due to formation of an antifilm by gallic acid.