Blueberries and other fruits are quite prone to fungi such as gray mold, whereas sunflowers are resistant to them. With that fact in mind, scientists have now used an extract from waste sunflower stems to keep such fruits from molding.
For some time now, sunflowers have been known for their resistance to many plant diseases. And while their seeds and oil have numerous uses, the stems of harvested plants are typically just discarded.
Led by Xiao-Dong Luo and Yun Zhao, scientists from the Chinese Academy of Sciences recently set out to see if those stems might be a source of anti-fungal compounds that could be applied to harvested fruits. When extracts from such stems were obtained and analyzed, they were found to contain 17 different types of chemical compounds called diterpenoids. Four of these were previously unknown to science.
When tested on Botrytis cinerea fungus, four of the 17 diterpenoids (including two of the new ones) destroyed the plasma membrane of the fungus. This caused its cells to leak, and kept it from forming into what we know as gray mold.
The scientists proceeded to apply a nontoxic sunflower extract solution to a batch of blueberries, after which they dried those berries and then injected them with Botrytis cinerea spores. Over a six-day period, instead of all becoming moldy as they otherwise would have, 42.9% of the blueberries did not. That figure should rise as more research is conducted.
A paper on the study was recently published in the Journal of Agricultural and Food Chemistry.
Source: American Chemical Society