Aroma of some plants cultivated in Lithuania : composition, processing and release

In this study, some factors affecting the aroma of some plants of the families Umbelliferae and Asteraceae were evaluated. The composition of the aromas is influenced by several factors: plant family, harvesting time, anatomical part of plant, method used to isolate volatiles, cultivar, fertilisers used for the growing of plant, cultivation site. The yield of caraway fruits varies over a wide range depending on fertiliser content, cultivation area and the cultivar itself. The trends for the accumulation of essential oils differ between the families in yield and composition. Seeds and flowers of lovage ( Umbelliferae ) possess the highest yields of oil. In the leaves of lovage seasonal changes are less significant than in the stems. In leaves and flowers of costmary ( Asteraceae ) the highest oil content is obtained before full flowering, while their stems possess only negligible amount of volatiles. Various anatomical parts of lovage showed differences in flavour release measured by the dynamic headspace method. The effluents from a gas chromatography column were characterised by a sniffing panel, which attributed descriptors to the recognised constituents.

Liquid essential oils can be processed by emulsification and encapsulation with milk proteins. Stability of essential oil-in-water emulsions can be improved either by adding soybean phosphatidylcholine and/or by increasing its protein concentration. Adsorption of the protein from the aqueous phase at the oil/water interface was studied by applying ellipsometry. Essential oil of caraway was encapsulated by milk derivatives either alone or combined with carbohydrates. Partial replacement of whey protein concentrate increases the retention of volatiles during spray drying and enhances the protective properties of solidified capsules against oxidation and the release of volatiles during the timed period. The structural features of spray- dried capsules indicated that good physical protection is provided to the caraway essential oil.