Abstract
Thymus vulgaris (thyme) is an aromatic plant and its essential oil has been applied as antimicrobial and antioxidant due to the presence of phenolic compounds. However, after steam distillation, the deodorized plant material is rejected, despite the possible presence of bioactive compounds. Ethanolic thyme waste extract revealed the presence of benzoic acid, 4-hydroxybenzoic acid, ferulic acid, caffeic acid, and sinapic acid. This waste thyme extract had the capacity for preventing the formation of primary and secondary lipid oxidation products in emulsions O/W (oil in water), constituted by diverse proportions of wheat and almond oils, without interfering with the viscosity parameters, for 10 weeks, at 37 °C. The increasing proportion of almond oil (≥50%) in the emulsion increases its resistance to oxidation, which is improved with the presence of an optimal concentration of tested thyme waste extract (0.02% and 0.04%). The waste thyme extract can, therefore, be used as an antioxidant either in food or pharmaceutical emulsions O/W, replacing the synthetic antioxidants.
Highlights
In spite of emulsions O/W being largely used in food, pharmaceutical, cosmetic industries, and biomedical sciences [1], they are thermodynamically unstable, tending to breakdown through coalescence and aggregation of the dispersed oil phase, over time [2]
Thyme waste extract prevented the hydroperoxide formation and the accumulation of malondialdehyde in emulsions O/W, this was dependent on its concentration as well as on the ratio of wheat germ and almond oil at the oil phase
Thyme waste extract was only effective in the prevention of the accumulation of malondialdehyde when 100% almond oil was used; the presence of wheat germ hampered the antioxidant action of the thyme waste extract
Summary
In spite of emulsions O/W being largely used in food, pharmaceutical, cosmetic industries, and biomedical sciences [1], they are thermodynamically unstable, tending to breakdown through coalescence and aggregation of the dispersed oil phase, over time [2]. The formation of free radicals can be avoided or decreased by adding antioxidants [3]. Thyme (Thymus vulgaris L.) is a source of a variety of natural bioactive materials, it contains many flavonoids, like lutein, apigenin, naringenin, luteolin, and thymonin [6], beyond thymol and carvacrol in the volatile part of the plant [7]. These two phenolic compounds have been considered as good antioxidants [7]. The large production of essential oils originates waste that is usually poorly exploited
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
