Essential oil extracts from Teucrium flavum L. subsp. flavum contained a high proportion of the apple-like flavour (Z,E)-alpha-farnesene, in addition to a range of other compounds, according to findings published in the Journal of the Science of Food and Agriculture.
The plant species is already interesting the food industry, said the researchers, because many are already used in the preparation of flavoured wines and beers, herbal teas, and liqueurs.
The study is said to be the first report of the fruit-like aroma of Teucrium flavum L. subsp flavum.
“The particular fruit-like aroma of the plant confirms the usefulness of the species as natural flavouring agent in wines, beers, bitters and liqueurs, and suggests also other applications, mainly as aroma and taste enhancer in food processing,” wrote the researchers from the University of Camerino.
The whiff of opportunity
Filippo Maggi and his co-workers used hydrodistillation (HD) and headspace solid-phase micro-extraction (HS-SPME) technique to extract and analyse the compounds from various parts of the plant, including different parts of a single flower.
According to their findings, a total of 102 components were identified, with sesquiterpenes hydrocarbons representing the major fraction, accounting for almost 50 per cent. The main component was identified as (Z,E)-alpha-farnesene, which is known to have an apple-like aroma.
“The major volatile (Z,E)-alpha-farnesene is one of the two naturally occurring stereoisomers of alpha-farnesene, an acyclic sesquiterpene hydrocarbon that was found in the coating of apples, and other pomoidea fruits,” explained the researchers.
“The two stereoisomers are responsible for the characteristic green apple odour. They have been detected in apple distillates where are responsible for an important ‘apple-like quality’ scent and, generally, for a ‘fresh floral terpenyl topnote’.
“They are used also for enhancing the aroma or taste of foodstuffs, chewing gums, medicinal products and toothpastes,” they added.
From apples to mushrooms
Maggi and his co-workers also identified 1-octen-3-ol as a major contributing aroma compound. This is well-known as a mushroom aromatic compound, and also reported to be an aroma component in several food products and beverages, they said.
“The major contribution to the aroma of the plant was given by flowers, while their fragrance seemed to depend mainly on the volatiles emitted from sepals of calyx, which included the majority of compounds detected in the whole flower (47 out of 54, and 65 out of 68 in dry and fresh samples, respectively),” report the researchers.
“However, the corolla was the major source of some volatile compounds, such as linalool and 1-octen-3-ol,” they concluded.
Source: Journal of the Science of Food and Agriculture
Published online ahead of print, doi: 10.1002/jsfa.3757
“Comparison of the characterisation of the fruit-like aroma of Teucrium flavum L. subsp flavum by hydrodistillation and solid-phase micro-extraction”
Authors: F. Maggi, T. Bilek, G. Cristalli, F. Papa, G. Sagratini, S. Vittori