Flower power: In agriculture, large quantities of apple blossoms are regularly produced as a waste product. But these remnants could prove useful, researchers have discovered. If the flowers are fermented, an extract is created that contains hundreds of previously unknown useful active ingredients. Among other things, apple blossom extract is harmful to fungi. The brew could therefore be used in the future to remove unpleasant fungi in the production of food, cosmetics or medicine in a cheap and natural way.
Apple blossoms are not only beautiful to look at, but also a previously unused by-product of apple production. Farmers intentionally remove around 93 percent of the flowers so that not too many flowers are fertilized at the same time. This allows the trees to put their energy into growing initially fewer but larger apples and, in the long term, produce more apples than without thinning out the inflorescences.
Hundreds of new active ingredients discovered
Two microbiologists have now examined whether the excess apple blossoms that have previously ended up in the trash can be put to good use. To do this, Stefano Tonini and Ali Tlais Alabiden from the Free University of Bozen-Bolzano fermented the apple blossoms in three different ways: using the microorganisms already present on the flowers, with specifically added bacteria or with yeast. After fermentation, the researchers concentrated the fermentation product into a liquid extract and examined the properties of the substances contained in the brews. They compared these with the non-fermented flowers.
It turned out that the fermented apple blossom extracts contain a high number of short amino acid chains, so-called bioactive peptides, which have antioxidant and antifungal properties. This means that they are harmful to fungi and inhibit their growth. The extracts from the two fermentations, to which bacteria or yeast had been added in a controlled manner, were particularly effective in this regard.
“After fermentation, we were able to identify a total of 1,797 new peptides: a very high number,” explains Tonini. “These short amino acid chains have never been examined before and must be characterized in order to understand which of them have an antifungal and antioxidant effect.” So far, it is unclear which of the newly discovered substances in the apple blossom extracts are specifically responsible for the antifungal effect are. It is also possible that their effects complement or reinforce each other, as the biologists explain.
Natural aids for industry
These results suggest that the previously unused apple blossoms have considerable potential. The fermentation products from apple blossoms could in future be used in the pharmaceutical, cosmetics and food industries to combat unpleasant or dangerous fungi. For example, the flower extracts could help to extend the shelf life of some foods. In the cosmetics industry, the substances obtained from apple blossoms could be a cheap and natural alternative to the anti-fungal active ingredients previously used and possibly even improve cosmetic products, as the team reports.
Source: Free University of Bozen