Bland strawberries? Pesticides may be to blame

Have you ever bitten into a plump, red strawberry, only to find it bland and watery? According to a study in ACS’s Journal of Agricultural and Food Chemistry, certain pesticides may be responsible. The study found that two common strawberry fungicides can impact cellular mechanisms, leading to subdued flavour and sweetness in berries, as well as lower nutritional value.

In any produce, the flavour profile is a result of its taste and smell, with sweetness often arising from the amount of dissolved glucose or fructose and its aroma coming from volatile compounds, such as esters and terpenes. Many fruits are also full of nutrients such as vitamin C, folic acid and antioxidants.

Fungicides are designed to disrupt the cellular processes of detrimental fungi and might accidentally interfere with these processes in crops, inhibiting the production of flavour and nutritional compounds. Researchers investigated how two common pesticides used on strawberries — boscalid (BOS) and difenoconazole (DIF) — affect specific molecular pathways in berries.

The researchers grew three groups of strawberries in identical conditions, applying BOS or DIF to two of the groups when the berries were still green. After treatment, the full grown berries were identical in size and colour to those grown without pesticide, but under the surface, a number of chemical changes were found in the treated strawberries:

• 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 a closer look, the researchers found 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 a blind taste test, people consistently preferred the untreated strawberries. According to the researchers, this work will guide farmers in the usage of pesticides.

Image credit: iStock.com/Jasmina007