Cucumbers not straight or curly are not only a problem with cucumbers but they may cause other vegetables such as tomatoes, peppers, eggplants and even melons to turn yellow. They have been known to affect many fruits including apples, pears and peaches. These cucurbitacins are toxic to humans and animals. Most commonly these toxins occur in the form of aflatoxins (produced by mold) which are produced by certain types of fungi. Other forms of toxicity include damage to enzymes that break down proteins, and damage to the liver.
The symptoms vary from person to person depending upon their genetic makeup, diet, health status and environmental factors such as stress levels. Symptoms usually appear within a few days after eating contaminated produce.
Symptoms can range from mild to severe and may last up to several weeks. If you do get exposed to this type of toxic chemical it is essential that you seek emergency medical treatment right away. Call your physician immediately and in the mean time drink lots of fluids and eat lightly. Try to avoid eating any more vegetables (especially fruits) until you receive medical attention.
Moldy fruits and vegetables that are not eaten should be discarded in a sealed plastic bag and then placed in a covered trash can outside well away from animals and children. Moldy seeds should be double bagged and placed in the trash outside.
Carefully clean all surfaces and tools used during the preparation of the vegetables. Dishes and pots can be cleaned with a mold killer.
Another toxin called Citrinin is produced by a group of certain species of Penicillium (Blue Green Molds). These molds produce this toxin as well as other molds within this group.
These are slightly different than other molds such as a types of aspergillus, which are more likely to attack when there is excess moisture and high temperatures. Molds need these conditions in order to thrive.
Symptoms from this mold are similar to aflatoxin and range from nausea, vomiting and diarrhea to more serious conditions such as liver and kidney damage. These types of molds can be destroyed by thorough cooking.
Symptoms of food poisoning include nausea, vomiting, stomach cramps, diarrhea, headaches and dizziness. These will develop within a few hours of eating the food (sometimes within minutes).
These symptoms usually last a few days and can vary in their severity.
Green Moldy Tomatoes
This type of mold is common on tomatoes. The mold often grows in cooler temperatures and is encouraged by high humidity levels, rainfall and by the use of water on the plants.
Tomatoes that have been damaged (carts, bruises and insect damage) will also be more likely to encourage fungal growth. Moisture on the tomato encourages mold growth.
The good news is mold on tomatoes is not a food safety issue. You can easily cut off the area of mold and around it and still enjoy eating the rest of the tomato.
The bad news is many people have an aversion to eating foods with any sign of mold on it and they may discard the whole fruit. Unfortunately mold on fruits and vegetables does not always have a visible sign.
There are two types of molds that often grow on tomatoes: gray fuzzy mold and black spots with green fuzzy mold. Either type can be toxic, although green fuzzy mold is more toxic.
Tomatoes that are discolored but not mushy are more likely to be toxic than completely rotten ones. Green fuzzy mold has toxins that may affect the gastrointestinal tract, causing nausea, vomiting and diarrhea. It may also affect the nervous system causing headaches, confusion and dizziness. In severe cases it may cause paralysis and even death.
Tomatoes with gray fuzzy mold are less likely to be toxic than green fuzzy mold but they can still cause nausea, vomiting and diarrhea as well as headaches, dizziness and confusion.
Some of the toxins in these molds damage the liver. The symptoms may not appear for several days and can last up to a week or longer.
Fatigue and jaundice may also occur.
Tomatoes with black spots and green fuzzy mold (which looks like green pin mold on bread, often with black centers) should be thrown out immediately.
Lettuce with Blackened Areas
Several different types of molds produce black or dark green spots on lettuce. A few of these type produce aflatoxins, which are among the most toxic substances known.
Symptoms of a very high level of exposure to aflatoxins include loss of appetite, abdominal pain, diarrhea, nausea and vomiting. These can be followed by liver damage and even death in some cases.
Many molds growing on vegetables are not toxic but since the symptoms are so similar it is hard to tell unless you do testing in a lab. Even when they are not toxic the molds will foul the taste and appearance of the vegetable and should always be thrown out.
To prevent mold growth on cut lettuce, either eat it promptly or store in the refrigerator in an airtight container (such as a sealed plastic bag). If you wash and drain the lettuce in the fridge put it back in the same container.
Always keep it cold.
The first line of defense when handling any potentially hazardous food is common sense and good hygiene. The next line of defense is to refrigerate perishable foods when possible.
When in Doubt, Throw it Out!
If you’re not sure whether a food is contaminated or has gone bad, always throw it out. Most moldy foods should be discarded.
It is difficult to eat around mold on larger foods such as cantaloupes, watermelons and even bread so you have to decide whether the area with mold on it is worth cutting around or not.
For example, one small area on a watermelon might have mold around the stem area. If you cut around the mold and eat the watermelon the rest of it should be safe.
Any mold elsewhere on the watermelon should always be discarded.
If you cut around the moldy area on a slice of bread and eat the rest of it, you’re taking a chance that the rest of the bread is not contaminated so it’s better to just throw it out.
If you’ve sliced strawberries for your cereal and you see a few that have a tiny spot of mold on them, they’re fine to eat since the rest of the berry is good. If the mold is larger than a pinhead or if the mold is on the skin then you should discard that whole berry.
If there’s more than just a few berries with mold on them then you should throw them all out.
The “Rule of Thumb” for mold on soft cheeses (like Brie or Camembert) is to slice off the area of the rind that has mold on it and the area of the cheese that comes up to that mold. This is called “pasting.” The rest of the rind and the rest of the cheese should be safe.
Hard cheeses (like cheddar, swiss or colby) should be discarded if they have any mold on them at all.
Hard salamis and dry-cured country hams are safe if they have mold on them. However, soft cooked hams (like the kind you buy in a plastic container at the super market) should never be eaten when they have mold on them.
Sources & references used in this article:
Nutritional disorders in glasshouse tomatoes, cucumbers and lettuce by JR Van Eysinga, KW Smilde – 1981 – edepot.wur.nl
Induction of male flowering in gynoecious cucumbers (Cucumis sativus L.) by silver ions by APM Den Nijs, DL Visser – Euphytica, 1980 – Springer
Curls of Green by Ø Hammer – The Perfect Shape, 2016 – Springer
Growing cucumbers for pickling by JH Beattie – 1930 – books.google.com
Value, market preferences and trade of beche-de-mer from Pacific Island sea cucumbers by SW Purcell – PloS one, 2014 – journals.plos.org
Inheritance of resistance to anthracnose and target leaf spot in cucumbers by Z Abul-Hayja, PH Williams, CE Peterson – Plant Dis Rep, 1978 – books.google.com
Making healthy plant-based eating easy! by CG Rogue, AG Story – veggie-quest.com
Toxicity of ethylene glycol vapors to cucumbers by TW Tibbitts, B Peterson – HortScience, 1999 – journals.ashs.org