How to evaluate quality and composition of an essential oil? And how to be sure that it is really a natural product? Only chemical and chemical-physical analysis can provide reliable informations. In Renolab’s laboratory, by gas chromatography (GC) and mass spectrometry (MS) it is possible to identify the individual components; to detect if two or more oils of similar composition have been mixed; if terpenes have been removed; if an oil has been rectified. It is also possible to reveal traces of solvents or mineral oils. Contact us for information or to request a quote.
Microencapsulation of essential oils is a very attractive technique for the formulation of products in cosmetics and personal care. It allows to overcome the chemical instability and susceptibility to degradation of the essential oils. It is mainly the consumer’s demand to push new cosmetics formulated with natural ingredients and nutraceuticals as an alternative to the chemical substances.
Microencapsulation was introduced for the first time in 1930, but the large-scale application dates back to 1950. Today it is still evolving and it is used in various industrial sectors: food, textile, pharmaceutical, cosmetic, agrochemical.
Different techniques are used for the microencapsulation depending on the active substance, the release properties, the application field and the regulations. However, they can be attributed to three main categories, as a review explains:
– Chemical processes eg. interfacial and in situ polymerization;
– Physicochemical processes eg. coacervation (one of the oldest and most widely used methods) and emulsion with solvent evaporation/extraction;
– Physical-mechanical processes eg. air suspension, pan coating, spray drying, spray chilling, spray cooling and fluid bed coating.
Among the various microencapsulation techniques of essential oils, the spray drying has a strong potential for large-scale development: it is simple, fast and flexible. It is suitable for volatile materials thanks to the short contact time in the dryer. It has low production costs too.
For the other methods, here are some of the conclusions of the review:
– Interfacial polymerization: fast, but not easy to control;
– In situ polymerization: it uses many organic solvents and one of the known issues is the residual formaldehyde in the microparticles;
– Coacervation: high efficacy in the control of particle size, but very expensive. The most common problem is the aggregation of the microcapsules;
– Emulsification: produces smaller droplets, but with low efficiency;
– Fluid bed spray: low operating costs, but a very long time.
According to the study, the knowledge about the biological activity of essential oils microencapsulated must be broaden to ensure safe use in the field of cosmetics and to modulate the release of active substances.