ABSTRACT
ABSTRACT Propolis also known as "bee glue or bee resin" is a resinous mixture of bee saliva or bee wax and exudate from tree trunks and flowers, produced by honeybees. The composition of propolis varies depending on the vegetation the bees can access. It is therefore expected that propolis obtained from various localities may have different chemical profiles. In this study, the headspace volatiles of propolis (n = 39) collected from various locations in South Africa (Gauteng, Northern Cape and Western Cape Provinces) were explored for the first time using GCxGC-ToF-MS. Several GCxGC parameters were optimised including; incubation time, temperature and modulation period. Multivariate data analysis techniques (principal component and hierarchical cluster analyses) were applied on the GCxGC-ToF-MS data to investigate trends and clustering patterns within propolis samples. The results demonstrated that headspace volatiles of propolis varied between locations. The volatile profiles were dominated by monoterpenes such as α-pinene (1.2-46.5%), β-pinene (2.0-21.8%), dihydrosabinene (trace-17.8%), limonene (trace-11.6%), p-cymene (0.1-5.3%), 1,8-cineole (0.1-11.0%), 2,7-dimethyl-3-octen-5-yne (trace-11.7%), E-β-ocimene (trace-17.8%), octanal (trace-12.9%), styrene (trace-13.5%) and α-thujene (trace-11.0%). Principal component analysis revealed chemical variation within propolis from the various locations. The heatmap of the averages revealed dehydrosabinene, isopropentyltoluene, p-cymene, acetophenone and α-thujene as chemical markers for the Northern Cape propolis, while λ-terpinene, propanoic acid, furfural, 2-methoxy benzyl alcohol and hexanoic acid methylester were filtered out as markers for Gauteng propolis. The propolis samples originating from the Western Cape Province were dominated by prenal, cinnamaldehyde styrene, 1,8-cineole, decanal, prenyl acetate and butanoic acid. Using GCxGC-ToF-MS in combination with chemometrics, it was possible to profile headspace volatile constituents of propolis and further identify marker compounds that differentiate propolis from various provinces in South Africa.
ABSTRACT
ABSTRACT Recently there has been a renewed impetus in the search for novel ingredients to be used in the cosmetic industry and Baobab (Adansonia digitata L., Malvaceae) seed oil has received high interest. In this study, a commercial Baobab seed oil sample was characterised (fatty acid content) using GCxGC-ToF-MS and a pilot study on the safety and efficacy of the seed oil was performed. The safety and efficacy of Baobab seed oil after topical application was determined using healthy adult female caucasian participants (n = 20). A 2× magnifying lamp was used for visual analysis, while for monitoring and evaluation of the irritancy level, transepidermal water loss (TEWL) and hydration level of the skin, Chromameter®, Aquaflux® and Corneometer® instruments, respectively, were used. In addition, Aquaflux® and Corneometer® instruments were used to assess occlusive effects. Thirteen methyl esters were identified using GCxGC-ToF-MS. The major fatty acids included 36.0% linoleic acid, 25.1% oleic acid and 28.8% palmitic acid with 10.1% constituting trace fatty acids. The irritancy of sodium lauryl sulphate (SLS) in the patch test differed significantly compared to both de-ionised water (p < 0.001) and Baobab seed oil (p < 0.001) but the difference between the irritancy of Baobab seed oil and de-ionised water was not significant (p = 0.850). The moisture efficacy test indicated a reduced TEWL (p = 0.048) and an improved capacitance moisture retention (p < 0.001) for all the test products (Baobab oil, liquid paraffin, Vaseline® intensive care lotion and Vaseline®). The occlusivity wipe-off test indicated an increased moisture hydration (p < 0.001) and decreased TEWL particularly when Baobab oil was applied. Baobab possesses hydrating, moisturising and occlusive properties when topically applied to the skin. Baobab seed oil could be a valuable functional ingredient for cosmeceutical applications.