The Use of Biopolymers as a Natural Matrix for Incorporation of Essential Oils of Medicinal Plants

Roxana Gheorghita Puscaselu; Andrei Lobiuc; Ioan Ovidiu Sirbu; Mihai Covasa

doi:10.3390/gels8110756

The Use of Biopolymers as a Natural Matrix for Incorporation of Essential Oils of Medicinal Plants

Gels. 2022 Nov 21;8(11):756. doi: 10.3390/gels8110756.

Authors

Roxana Gheorghita Puscaselu^{1

2}, Andrei Lobiuc², Ioan Ovidiu Sirbu^{1

3}, Mihai Covasa^{2

4}

Affiliations

¹ Department of Biochemistry, Victor Babeş University of Medicine and Pharmacy, 300041 Timisoara, Romania.
² Department of Medicine and Biomedical Sciences, College of Medicine and Biological Science, University of Suceava, 720229 Suceava, Romania.
³ Center for Complex Network Science, Victor Babes University of Medicine and Pharmacy, 300041 Timisoara, Romania.
⁴ Department of Basic Medical Sciences, College of Osteopathic Medicine, Western University of Health Sciences, Pomona, CA 91766, USA.

Abstract

The benefits of using biopolymers for the development of films and coatings are well known. The enrichment of these material properties through various natural additions has led to their applicability in various fields. Essential oils, which are well-known for their beneficial properties, are widely used as encapsulating agents in films based on biopolymers. In this study, we developed biopolymer-based films and tested their properties following the addition of 7.5% and 15% (w/v) essential oils of lemon, orange, grapefruit, cinnamon, clove, chamomile, ginger, eucalyptus or mint. The samples were tested immediately after development and after one year of storage in order to examine possible long-term property changes. All films showed reductions in mass, thickness and microstructure, as well as mechanical properties. The most considerable variations in physical properties were observed in the 7.5% lemon oil sample and the 15% grapefruit oil sample, with the largest reductions in mass (23.13%), thickness (from 109.67 µm to 81.67 µm) and density (from 0.75 g/cm³ to 0.43 g/cm³). However, the microstructure of the sample was considerably improved. Although the addition of lemon essential oil prevented the reduction in mass during the storage period, it favored the degradation of the microstructure and the loss of elasticity (from 16.7% to 1.51% for the sample with 7.5% lemon EO and from 18.28% to 1.91% for the sample with 15% lemon EO). Although the addition of essential oils of mint and ginger resulted in films with a more homogeneous microstructure, the increase in concentration favored the appearance of pores and modifications of color parameters. With the exception of films with added orange, cinnamon and clove EOs, the antioxidant capacity of the films decreased during storage. The most obvious variations were identified in the samples with lemon, mint and clove EOs. The most unstable samples were those with added ginger (95.01%), lemon (92%) and mint (90.22%).

Keywords: biopolymers; chamomile; cinnamon; citrus; clove; eucalyptus; ginger; mint.

Grants and funding

This work was supported by a grant of the Romanian Ministry of Research, Innovation and Digitization, CNCS/CCCDI–UEFISCDI, project number PN-III-P1-1.1-PD-2019-0793, within PNCDI III.