Fruit can contain naturally-occurring chemicals, such as rutin and glycine, as well as artificial chemicals like ethephon chloroethyl phosphonic acid and calcium carbide.
From a biological perspective, the main function of fruit is to protect and disperse the seeds of flowering plants. Since most fruits are edible, the animals that eat them help propagate the seeds of fruit-bearing plants by spreading them through digestion. Agriculturally, edible fruits are harvested and eaten for their sweet fleshy parts. Many are eaten raw, but some may be processed into other products such as jams, juice extracts, and pies.
During the growing and cultivation process, fruits absorb and process various types of chemicals. Most of these are essential nutrients while a few are incidental chemicals from the environment.
In this post:
What chemicals are naturally found in fresh fruits?
The naturally-occurring chemicals found in fresh fruits serve both aesthetic and functional purposes. They’re responsible for the attractive colour, palatable taste, and sweet scent of fruit, for example. Alongside these aesthetic roles, natural chemicals have functional purposes that include structural support, enzymatic activities, and protection.
Here’s a brief overview of some of the chemicals found naturally in fresh fruits.
1. Rutin
Rutin is a plant pigment found in certain fruits and vegetables. It’s abundant in buckwheat, Japanese pagoda trees, and eucalyptus, but it’s also found in citrus fruits and berries. Rutin is classified as a citrus flavonoid glycoside. One of the best natural antioxidants, it has various physiological functions in humans and other species.
2. Glycine
Glycine is an important amino acid that serves as a precursor to other macromolecules, especially proteins. It’s the simplest stable amino acid and has the chemical formula NH₂‐CH₂‐COOH. 
3. Beta-caryophyllene
Beta-caryophyllene, otherwise known as β-Caryophyllene, is an oily, pale yellow liquid. Its bicyclic molecular structure (classified as sesquiterpene bicyclic) gives it an odour that’s somewhere between cloves and turpentine. The compound is one of the essential oils found in cannabis plants, flowers, fruits, and herbs. 
Artificial chemicals used on fruits
As agricultural products, fruits need to be harvested and processed. Artificial chemicals are primarily used on fruits to:
- Help with preservation and extend shelf life
- Enhance the colour
- Improve the taste
- Trigger the ripening process
You can learn more about the chemicals used in the agricultural industry here.
Here are some examples of artificial chemicals that are commonly used on fruits.
1. Ethephon chloroethyl phosphonic acid
Ethephon is a chemical that’s used as a plant growth regulator. It regulates growth by stimulating the release of ethylene. It also triggers a series of enzymatic activities as well as mineral absorption, particularly in grapevines. Ethephon is often used in the cultivation of coffee, tobacco, rice, and cotton.
2. Calcium carbide
Calcium carbide (CaC₂) is another chemical commonly used for ripening fruit. Otherwise known as calcium acetylide, it’s also used industrially to manufacture acetylene.
3. Ascorbic acid
Ascorbic acid, or vitamin C, occurs naturally in many types of fruits, particularly citrus fruits. It can also be artificially added to other fruits to prevent oxidation, thereby preserving the natural colour.
How dangerous are the chemicals found on fruit?
The most dangerous chemicals found in fruits are those contained in the pesticides and fertilisers that are added to the crops. Some of these chemicals can cause poisoning when they accumulate in the cells, while others have even been linked to cancer in the long term. 
Here are some examples of fruits that typically contain dangerous chemicals:
- Strawberries – some strawberries contain carbendazim, which is a type of fungicide. Carbendazim can disrupt hormone function and damage the male reproductive system. Bifenthrin, an insecticide with potentially carcinogenic effects, is also found on some strawberries.
- Apples – some apple harvests contain diphenylamine, which is a precursor to carcinogenic nitrosamines.
- Peaches – these may contain the pesticide fludioxonil and the neurotoxin phosmet.
- Pears – pyrimethanil, a possible hormone disruptor, is found in pears. The fruit may also contain the carcinogen o-Phenylphenol.
- Grapes – the pesticide imidacloprid is often found in grapes, along with carcinogenic chemicals like boscalid, which is a byproduct of pesticides.
How to clean fruits using chemicals
Fruits that are harvested for selling or processing into other products can easily be cleaned using water and mild detergents. This can be done on an industrial scale or by using one of the following methods: 
1. Salt water bath
An aqueous solution of sodium chloride (table salt) is an effective way of removing and killing bacteria. It also has the added benefit of extending the shelf life of fruit.
2. Bicarbonate soda
Washing fruits with sodium bicarbonate soda is a good way to neutralise any harmful acidic chemicals and kill microorganisms that are present on the surface.
3. Soak in vinegar
Vinegar, also known as acetic acid, is a mild acid that can neutralise some of the basic and potentially harmful chemicals found on the surface of fruits. It’s also known for its antiseptic properties. 
Summary
There are various types of organic and inorganic chemicals found in fruits. Chemicals such as rutin, glycine and beta-caryophyllene occur naturally, while others like ethephon chloroethyl phosphonic acid and calcium carbide are added artificially. Fruit that’s been treated with pesticides and fertilisers should be cleaned thoroughly to ensure potentially harmful chemicals are removed from the surface.
