Study of aromatic and medicinal plants as potential natural ingredients for the food industry

Considering the association of plants consumption and utilization with the treatment of some illnesses and diseases, several aromatic and medicinal plants have been used in traditional and contemporary medicine. This capacity has been proven scientifically and there are numerous studies describing their therapeutic properties in the treatment of inflammatory and cardiovascular disorders, diabetes, among other conditions [1] . The antioxidant and antimicrobial activities have already been studied in a wide variety of plants, which have been shown to contain bioactive molecules effective against pathogenic microorganisms and capable of removing reactive oxygen species formed in cells [2,3]. In this sense, ten aromatic and medicinal plants ( Eucalyptus globulus Labill., Olea europaea L., Melissa officinalis L., Origanum vulgare L., Glycyrrhiza glabra L., Arbutus unedo L., Matricaria recutita L., Thymus vulgaris L., Ocimum vulgare L., and Salvia officinalis L.) were selected to perform an initial screening for the exploration of natural ingredients with bioactive potential. The plant extracts were obtained after ethanolic extraction. The antioxidant activity was evaluated through two in vitro cell-based assays, namely the lipid peroxidation inhibition test (TBARS) and the oxidative hemolysis inhibition test (OxHLIA), and antimicrobial activity was tested by the broth microdilution method, against a panel of bacteria and fungi, selected according to their public health importance. These analyses presented very promising results, showing a high bioactive potential for all plant extracts. In the TBARS assay, E. globulus and O. vulgare stood out with lower EC 50 values, followed by T. vulgaris and S. officinalis . In turn, in the OxHLIA assay, for Δ t 60 min and Δ t 120 min, the excellent antioxidant capacity of S. officinalis and T. vulgaris was also evidenced, respectively. In addition, the evaluation of the antimicrobial activity highlighted the sample of G. glabra , both at the bacterial and fungal levels. Overall, it was possible to prove the great bioactive potential of the E. globulus , O. vulgare , S. officinalis , T. vulgaris and G. glabra extracts, and to highlight them as promising options for exploitation in the food industry.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support through national funds FCT/MCTES to CIMO (UIDB/00690/2020); national funding by FCT, P.I., through the institutional and individual scientific employment program-contract for L. Barros and J. Pinela’s (CEECIND/01011/2018) contracts, respectively; research contract of C. Caleja (Project AllNatt, POCI- 01-0145-FEDER 030463) and E. Pereira (Project Mobilizador Norte-01-0247-FEDER-024479: ValorNatural®); to FEDER-Interreg España-Portugal program for financial support through the project TRANSCoLAB 0612_TRANS_CO_LAB_2_P, ERDF, through the Incentive System to Research and Technological development, within the Portugal2020 Competitiveness and Internationalization Operational Program for the financial support to BIOMA(POCI_01_0247_FEDER_046112); ERDF through the Regional Operational Program North 2020, within the scope of Project GreenHealth (Norte-01-0145-FEDER-000042).