Bioactivity and Sensory Evaluation of Portuguese essential oils obtained from logging residues and thinnings
394
Presented by: Helena Ribeiro
Landscaping of Eucalyptus globulus, Pinus pinaster, Pinus pinea and Cryptomeria japonica forest provide logging residues that can be used to extract essential oils (EOs). The evaluation of EOs bioactivity obtained from biomass wastes resulting from Portuguese forest maintenance, and in a context of sustainability, was the aim of this work. In addition, the sensory evaluation (odor) of E. globulus, P. pinaster, P. pinea and C. japonica EOs in skin care emulsions was performed.
Local producers supplied eleven EOs from E. globulus, P. pinaster, P. pinea and C. japonica. Using gas chromatography and gas chromatography ‑ mass spectrometry, the EOs were chemically characterized as previously described [1]. The antioxidant activity of these EOs was evaluated using 2,2’-diphenyl-1-picrylhydrazyl (DPPH) assay [2]. The minimum inhibitory concentration (MIC) was assessed by the microdilution method for five reference strains, namely Staphylococcus aureus ATCC 6538, Pseudomonas aeruginosa ATCC 9027, Bacillus subtilis ATCC 6633, Escherichia coli ATCC 8739, and Candida albicans ATCC 10231.
A sensory double-blind evaluation was performed in 100 volunteers, from 18 to 60 years old of both genders. The protocol was approved by the local Ethical Committee (nº 1_2022) and respected the Helsinki Declaration and Good Clinical Practice studies on cosmetic products. All participants gave their informed consent. A structured questionnaire was used to collect data about the perception and applicability’s of different emulsions, and they were encoded with different colors (pink, blue, green, orange and lilac). Emulsions were prepared with 0.5% EO of selected samples.
Two P. pinaster EOs were dominated by α-pinene (37-45%), and one showed similar amounts of α‑pinene and β-pinene (27% and 28%, respectively). P. pinea EO was dominated by limonene (73%), and α-pinene (26%) was the main component of C. japonica EO.
C. japonica EO showed the highest antioxidant activity, whereas one of the E. globulus EO samples showed the lowest. Eucalyptus EOs showed the greatest efficacy against the selected strains while C. japonica EO had no antimicrobial activity against these strains.
The bioactivity of all EOs samples is related to their composition. C. japonica EO antioxidant activity is probably due to the presence of appreciable amounts of sabinene, β‑myrcene, and γ-terpinene. P. pinea EO presented similar efficacy against B. subtilis ATCC 6633 as two of E. globulus EOs, may be related to 1,8-cineole content, which shows antimicrobial properties.
The C. japonica emulsion odor was chosen by 60% of the volunteers as the most pleasant odor, followed by the P. pinaster emulsion with 53%. Moreover, C. japonica emulsion was the best in improving the sense of well-being. Overall, 19% of the volunteers selected C. japonica and P. pinaster emulsions as their favorite.
These results can be related EOs chemical composition. P. pinaster EOs were dominated by α-pinene and β-pinene that are referred as showing a fresh and earthy scent. P. pinea EO presented high limonene content (73%), which evokes citrus fruits aroma. α-Pinene (26%), with unmistakable fresh and earthy scent, was the main component of C. japonica EO. In addition, E. globulus EOs presented 1,8-cineole, which shows a camphor-like odor.
It is possible to conclude from these results that EO’s studied have relevant antioxidant activity and promising antimicrobial activity, which can be a key benefit justified by their promising skin health properties. These natural-based EOs address the demand for sustainable and responsibly sourced odor accepted by consumers.
1] A Neves, J Marto, A Duarte, LM Gonçalves, P Pinto, AC Figueiredo, HM Ribeiro. Flavour Fragr. J. 32 (2017) 392-402.
[2] AK Mishra, N Sahu, A Mishra, AK Ghosh, S Jha, P Chattopadhyay. Pharmacogn. J. 2 (2010) 25-28.
Acknowledgments: Funded by the Fundação para a Ciência e Tecnologia, to CESAM UIDP/50017/2020+UIDB/50017/2020+LA/P/0094/2020, UIDB/04138/2020 and UIDP/04138/2020 to iMed.ULisboa, CEECINST/00145/2018 to J.Marto.
Local producers supplied eleven EOs from E. globulus, P. pinaster, P. pinea and C. japonica. Using gas chromatography and gas chromatography ‑ mass spectrometry, the EOs were chemically characterized as previously described [1]. The antioxidant activity of these EOs was evaluated using 2,2’-diphenyl-1-picrylhydrazyl (DPPH) assay [2]. The minimum inhibitory concentration (MIC) was assessed by the microdilution method for five reference strains, namely Staphylococcus aureus ATCC 6538, Pseudomonas aeruginosa ATCC 9027, Bacillus subtilis ATCC 6633, Escherichia coli ATCC 8739, and Candida albicans ATCC 10231.
A sensory double-blind evaluation was performed in 100 volunteers, from 18 to 60 years old of both genders. The protocol was approved by the local Ethical Committee (nº 1_2022) and respected the Helsinki Declaration and Good Clinical Practice studies on cosmetic products. All participants gave their informed consent. A structured questionnaire was used to collect data about the perception and applicability’s of different emulsions, and they were encoded with different colors (pink, blue, green, orange and lilac). Emulsions were prepared with 0.5% EO of selected samples.
Two P. pinaster EOs were dominated by α-pinene (37-45%), and one showed similar amounts of α‑pinene and β-pinene (27% and 28%, respectively). P. pinea EO was dominated by limonene (73%), and α-pinene (26%) was the main component of C. japonica EO.
C. japonica EO showed the highest antioxidant activity, whereas one of the E. globulus EO samples showed the lowest. Eucalyptus EOs showed the greatest efficacy against the selected strains while C. japonica EO had no antimicrobial activity against these strains.
The bioactivity of all EOs samples is related to their composition. C. japonica EO antioxidant activity is probably due to the presence of appreciable amounts of sabinene, β‑myrcene, and γ-terpinene. P. pinea EO presented similar efficacy against B. subtilis ATCC 6633 as two of E. globulus EOs, may be related to 1,8-cineole content, which shows antimicrobial properties.
The C. japonica emulsion odor was chosen by 60% of the volunteers as the most pleasant odor, followed by the P. pinaster emulsion with 53%. Moreover, C. japonica emulsion was the best in improving the sense of well-being. Overall, 19% of the volunteers selected C. japonica and P. pinaster emulsions as their favorite.
These results can be related EOs chemical composition. P. pinaster EOs were dominated by α-pinene and β-pinene that are referred as showing a fresh and earthy scent. P. pinea EO presented high limonene content (73%), which evokes citrus fruits aroma. α-Pinene (26%), with unmistakable fresh and earthy scent, was the main component of C. japonica EO. In addition, E. globulus EOs presented 1,8-cineole, which shows a camphor-like odor.
It is possible to conclude from these results that EO’s studied have relevant antioxidant activity and promising antimicrobial activity, which can be a key benefit justified by their promising skin health properties. These natural-based EOs address the demand for sustainable and responsibly sourced odor accepted by consumers.
1] A Neves, J Marto, A Duarte, LM Gonçalves, P Pinto, AC Figueiredo, HM Ribeiro. Flavour Fragr. J. 32 (2017) 392-402.
[2] AK Mishra, N Sahu, A Mishra, AK Ghosh, S Jha, P Chattopadhyay. Pharmacogn. J. 2 (2010) 25-28.
Acknowledgments: Funded by the Fundação para a Ciência e Tecnologia, to CESAM UIDP/50017/2020+UIDB/50017/2020+LA/P/0094/2020, UIDB/04138/2020 and UIDP/04138/2020 to iMed.ULisboa, CEECINST/00145/2018 to J.Marto.