A new study published in the American Chemical Society’s (ACS) Journal of Agricultural and Food Chemistry has found that certain pesticides could be to blame for bland strawberries.

The researchers say that two common strawberry fungicides can impact cellular mechanisms, in turn creating berries with “subdued flavour and sweetness”, as well as a lower nutritional value.

Fungicides are designed to “disrupt the cellular processes of detrimental fungi” according to the researchers, meaning they could accidentally interfere with these processes in crops, thus inhibiting production of these flavour and nutritional compounds.

Study lead, Jinling Diao along with colleagues, investigated how two common pesticides used on strawberries – boscalid (BOS) and difenoconazole (DIF) – affected specific molecular pathways in berries.

To carry out the study, the researchers grew three groups of strawberries (Fragaria x ananassa Duch) in identical conditions, applying BOS or DIF to two of the groups when the berries were still green. Even after treatment, the fully grown berries were reportedly identical in size and colour to those grown without pesticide. However, under the surface, the team found there to be a number of chemical changes caused by both of the fungicides.

Changes included:

• The levels of soluble sugars and nutrients, such as sucrose and vitamin C, were reduced.
• Sugars were converted into acids, further reducing sweetness.
• The amount of volatile compounds changed, subduing the berry’s taste and aroma.

In addition, the research team found that that BOS had a “direct effect” on the regulation of genes involved in cellular pathways related to producing sugars, volatile compounds, nutrients and amino acids.

In response to a blind taste test, test subjects consistently preferred the untreated strawberries. These results are something that the researchers say could be used to provide pesticide guidance for farmers.