Is Cutting Away the Moldy Part of Fruit Really Safe?

By Tahani Elghazaly
Published September 16, 2026

Latest news on WhatsApp أجدد الأخبار على واتساب

When part of a fruit or vegetable becomes moldy, many people simply cut away the affected area and eat the rest. But experts warn that this may not always be safe, because some toxins produced by fungi can spread into parts of the food that still look completely normal.

A recent study published in the journal Food Microbiology examined how fungal toxins can spread inside tomatoes infected with Alternaria alternata, a common fungus that can affect tomatoes after harvest.

Researchers found that several types of mycotoxins could develop as the moldy area became larger. More importantly, some of these toxins were not limited to the visibly spoiled section of the tomato. They were detected in surrounding tissue that appeared unaffected.

One compound, tenuazonic acid, was found to spread farther through the fruit than some of the other toxins examined.

The size of the moldy area also mattered. When the affected area was relatively small, toxin spread was more limited. However, as the mold expanded, researchers found that contamination could extend much farther through the tomato.

This means that simply removing the visible mold may not always remove the potential risk.

Food safety guidance also distinguishes between soft and firm foods. Soft fruits and vegetables have a high moisture content, allowing mold and associated contamination to penetrate below the surface. For this reason, food safety authorities generally recommend discarding soft produce when mold appears.

Some firm, dense foods may be treated differently because mold has greater difficulty penetrating deeply into them. In certain cases, a generous section around and beneath the affected area can be removed.

Experts also warn that some mycotoxins are resistant to heat, meaning cooking or baking does not necessarily eliminate them.

Proper storage can help reduce the problem. Refrigeration can slow fungal growth and toxin production in many perishable foods.

The practical lesson is simple: the part of a fruit that looks healthy may not always be completely unaffected when mold is present, particularly in soft, high-moisture produce.