Bitter Cucumbers: Eat or Throw Away?

(Dan Tri) - Cucumber is a nutritious food, containing lots of water, vitamins and minerals, but the bitter taste is not a "natural spice" but a warning sign from the plant's own defense mechanism.

Cucumber has long been considered a cool, crunchy, sweet, cooling vegetable with an affordable price.

However, sometimes consumers encounter bitter fruits, many people still keep the habit of throwing away the top or continue eating because they think "bitterness is due to the variety".

Bitter taste in cucumber

Cucumber has long been considered a refreshing, crunchy, sweet, cooling vegetable with an affordable price (Photo: Getty).

According to botanical studies, the bitter taste in cucumbers comes from cucurbitacin - a group of triterpenoid compounds produced by cucurbitaceae plants (including cucumbers, pumpkins, squash, bitter melons, etc.) to defend themselves against insects, pests and adverse environmental factors.

Normally, the cucurbitacin content in ripe fruit is very low, not enough to be detected by taste. However, when the plant is subjected to growth stress such as high temperature, drought, harsh light, poor soil or using unstable varieties, the synthesis of cucurbitacin can increase dramatically.

At this time, the compound will spread from the leaves and stems to the fruit, especially accumulating at the top of the stem or flower head, creating a distinct bitter taste.

An analysis in the Journal of Agricultural and Food Chemistry showed that when cucurbitacin concentrations exceed 30ppm, some people may experience gastrointestinal symptoms after just 30 minutes: nausea, abdominal pain, vomiting.

At higher levels, this compound can be toxic to the liver and kidneys. Cucurbitacin is heat-stable and does not decompose when boiled, grilled, fried or pickled. Therefore, if the original ingredient is bitter, no amount of cooking will completely eliminate the risk.

Lessons from cucurbitacin poisoning cases

Cucurbitacin poisoning has been reported in many countries in cases of eating bitter-tasting pumpkin and zucchini.

In the Czech Republic in 2024, a healthy woman suffered severe abdominal pain, vomiting, and diarrhea after eating bread made from homegrown, very bitter zucchini.

Tests confirmed that cucurbitacin was the cause. Dr. Babeta Čápková (Tomas Bata Hospital) said that the bitter taste was the only signal that the compound was at a dangerous level.

Although poisoning is rare, severe cases can lead to low blood pressure, dehydration...

In 2018, two women in France suffered from vomiting and diarrhea after eating bitter pumpkin soup. A few weeks later, they developed hair loss – a rare symptom thought to be related to cucurbitacin toxicity.

Medical experts warn that “toxic squash syndrome” is rare but can occur if users are subjective about the bitter taste.

How to recognize and advice from experts

The safest thing to do when encountering a bitter cucumber is to throw it away, even if it tastes only slightly bitter, says Veronica Tegen, a board member for Midwest Fruit Explorers. Simply cutting off the top is not safe because cucurbitacin can be unevenly distributed throughout the fruit.

To minimize the risk, Ms. Tegen recommends choosing less bitter melon varieties, while ensuring cool growing conditions, adequate water, and avoiding periods of intense heat or prolonged drought.

Additionally, some folk remedies such as rubbing the cut end with the stem to create a white foam – where cucurbitacin is concentrated – can help reduce the bitterness but do not completely eliminate the risk in fruits with high levels.

Observing the appearance is also helpful: good fruit usually has a moderate dark green color, shiny skin, soft and sparse spines, and a slightly curved natural shape, while bitter fruit can have a dark color, wrinkled skin, and loss of moisture.

Source: https://dantri.com.vn/khoa-hoc/dua-chuot-bi-dang-an-hay-bo-20250815082814124.htm