Sunflower extracts, like other plant extracts, may include antibacterial chemicals. These qualities could be used to preserve fruits such as blueberries by limiting the growth of fungi and other microbes.
It’s depressing to open a clamshell of berries and find them covered in fuzzy mold. And it’s not a minor issue. Gray mold and other fungi that cause fruit to rot generate substantial economic losses and food waste. Researchers report in the Journal of Agricultural and Food Chemistry of the American Chemical Society that chemicals from sunflower crop waste prevented rotting in blueberries. They believe that the food industry could benefit from using these natural substances to defend against postharvest illnesses.
Sunflowers are grown all over the world for their seeds and oil, but the flower stalks, known as receptacles, are often considered a waste product. Noticing that this crop is exceptionally resistant to numerous plant diseases, its receptacles might contain chemical elements responsible for this protective function.
Xiao-Dong Luo
Sunflowers are grown all over the world for their seeds and oil, but the flower stalks, known as receptacles, are often considered a waste product. Noticing that this crop is exceptionally resistant to numerous plant diseases, Xiao-Dong Luo, Yun Zhao, and colleagues began to study whether its receptacles might contain chemical elements responsible for this protective function.
They also wanted to know if these chemicals may be used to protect fruit from fungal plant infections without the toxicity and resistance associated with chemical fungicides.
Sunflower extracts contain various compounds, including polyphenols and antioxidants, which may have antimicrobial properties. These properties could potentially help in inhibiting the growth of fungi and other microorganisms. However, the specific use of sunflower extract for preserving blueberries would depend on the findings of scientific studies and the development of practical applications.
The researchers used methanol and ethyl acetate to prepare extracts from sunflower stems. They then isolated and identified the components in these extracts, focusing on diterpenoids, which are known to have biological activity. They found 17 diterpenoids, including four previously unknown compounds.
The majority of the diterpenoids were effective against gray mold. Four of the chemicals, including two newly found ones, were efficient at destroying the plasma membrane of this fungus, causing its cells to leak and preventing it from forming biofilms. In another experiment, the researchers quickly soaked blueberries with receptacle extracts, then dried the fruits and injected them with mold spores.
Over the course of six days, the receptacle extracts preserved about half of the berries from mold growth. The researchers believe that sunflower stem extracts could be employed as a natural biocontrol agent to prevent postharvest illness in fruit.
