Molecular Distillation of Lavender Supercritical Extracts: Physicochemical and Antimicrobial Characterization of Feedstocks and Assessment of Distillates Enriched with Oxygenated Fragrance Components

Abstract

Lavandula angustifolia is one of the most widely cultivated non-food crops used in the production of essential oil; it is used in perfumery, aromatherapy, pharmaceutical preparations, and food ingredients. In this study, supercritical fluid extraction (SFE) and molecular distillation (MD) were combined, primarily to enrich scCO2 extracts with lavender oxygenated monoterpenes, avoiding thermal degradation, hydrolysis, and solvent contamination, and maintaining the natural characteristics of the obtained oils. Molecular distillation was developed for the first time for the extraction of crucial lavender fragrance ingredients, i.e., from two scCO2 extracts obtained from dry flower stems of lavender cultivated in Poland and Bulgaria. The best results for high-quality distillates were obtained at 85 °C (EVT) and confirmed that linalyl acetate content increased from 51.54 mg/g (initial Bulgarian lavender extract, L-Bg-E) and 89.53 mg/g (initial Polish lavender extract, L-Pl-E) to 118.41 and 185.42 mg/g, respectively, corresponding to increases of 2.3 and 2.1 times in both distillate streams, respectively. The distillates, light oils, and extracts from lavender were also evaluated for their antimicrobial properties by determining the minimum inhibitory concentration (MIC) by the broth microdilution method. Generally, Gram-positive bacteria and Candida spp. were more sensitive to all distilled fractions and extracts than Escherichia coli (Gram-negative bacteria).

Chemical composition of essential oil extracted from lavender growing in Kastamonu, Türkiye

“…Lavandulyl acetate has generally been noted to be active against Gram-positive bacteria and yeasts and may have a bactericidal or bacteriostatic effect depending on the type of bacteria. It is also in high demand in cosmetics and perfumery (Dębczak et al, 2022). In our study, the amount of lavandulyl acetate was determined to be 6.11% (Table 1).…”

“…In our study, the amount of lavandulyl acetate was determined to be 6.11% (Table 1). In another study, Polish and Bulgarian lavenders were examined, and the amounts of lavandulyl acetate were determined to be 5.17% and 3.02%, respectively (Dębczak et al, 2022). In a study comparing two Czech lavender varieties, the average amount of lavandulyl acetate was found to be 8.62% in Krajová' lavender and 8.88% in Beta lavender (Dušková et al, 2016).…”

“…The amount of α-terpineol in lavender essential oil grown in Afyon, Eskişehir, Isparta, and Uşak regions was determined to be 0.48%, 0.45%, 2.96%, and 3.30%, respectively (Katar et al, 2020). In a study examining Polish and Bulgarian lavender, α-terpineol was detected only in Polish lavender, and its amount was 0.31% (Dębczak et al, 2022). In another study, the amount of α-terpineol was found to be 1.03% (Marincaş and Feher, 2018).…”

“…In a study examining Polish and Bulgarian lavender, trans-βocimene was detected only in Polish lavender, and its amount was 0.26%. (Dębczak et al, 2022).…”

Solid‐phase extraction based on PDMS/ionic liquid sponge followed by gas chromatography–mass spectrometry for rapid and sensitive determination of volatile components in lavender

“…5,6 Essential oils are complex mixtures of volatile compounds with non-polar or weak polarities that are usually present in low concentrations and vary greatly in the amount of each ingredient. 7 Therefore, to improve the precision and accuracy of the analytical technique, it is necessary to adopt appropriate processing techniques to preconcentrate volatile components and reduce the interference of complex plant matrices before gas chromatography-mass spectrometry (GC-MS) analysis. 8 Traditional processing techniques, such as hydrodistillation, steam distillation and solvent extraction, have been applied to extract volatile components from aromatic plants.…”