October 16, 2017
Apples are privy to a number of types of diseases, so they are treated with an array of fungicides and bactericides (in addition to insecticides). Organic or naturally produced apples are the rage right now as part of a $40 billion a year spending spree on “all natural” foods in the US as of 2015. What can be wrong with a desire to eat healthful produce?
Biological systems are often more complex than you might think, and apples are no exception. The general public tends to overlook the natural toxins that are rife in the world. People are generally surprised to find out that a leading cause of cancer in the world is a group of fungal toxins called aflatoxins.
And aflatoxins are only one type of toxin produced by fungi. These organisms produce a great diversity of chemicals that are toxic to humans and livestock. They are known as “mycotoxins” – from the Greek words for “fungus” and “poison.”
Apples that have fallen from a tree, are stored improperly, or suffer from insect or bird damage frequently contain a mycotoxin known as patulin. Exactly how bad this toxin is for you is under debate, but it is known to be genotoxic, and there are fears that exposure could lead to cancer.
The US Food and Drug Administration (FDA), the European Union (EU), and the World Health Organization (WHO) all regulate the amount of patulin that commercial apples or apple-derived products such as jellies or jams can contain.
The FDA takes patulin so seriously that its regulations entitled “Juice Hazard Analysis” list the compound under the “chemical hazards” designation for juice along with toxins such as lead and tin.
Since children are particularly vulnerable to toxins, the maximal concentration of patulin allowed in products marketed to children is even lower than that for adults.
How does patulin end up in apples, you might ask? Fungi are the culprits. In particular, a type known as Penicillium. If that name seems vaguely familiar to you, this is the type of fungus that Alexander Fleming famously observed inhibiting bacteria in his lab that yielded the breakthrough antibiotic penicillin.
Since fungicides inhibit the growth of fungi, judicious applications of these chemicals are one way to prevent this fungus from growing on apples. Another is to ensure that the apples are kept in optimal postharvest storage conditions. Apples do not contain patulin unless they have been infected with particular types of fungi.
Risk-assessment is a very complicated endeavor, but you can make an intellectual argument that apples that contain trace amounts of fungicide are much better for you than those that contain a nasty fungal toxin such as patulin.
There is data to back up this view. One study found that 0.9% of the children who drank organic apple juice had levels of patulin in their body that exceeded the federal limit on this toxin. While that is admittedly a low percentage, given the number of children who drink organic apple juice, it adds up to a lot of children being exposed to this compound.
Some people think that chemicals are something foreign and not found in natural food. Nothing could be further from the truth. In fact, plants make hundreds of thousands of different types of secondary chemicals – that is in addition to the ones they need for their basic survival functions such as photosynthesis.
This view really came into the spotlight when the FDA tried a third time to come up with a definition for “natural” to be able to properly label food. The FDA invited the public to weigh in on what they thought the definition should be, and 1,772 responses had to do with “chemicals.” While many of these comments concerned added chemicals, other comments were such as “Natural should mean without chemicals.”
That is terribly ironic when you consider the number of chemicals in an apple.
A 2009 study identified 266 volatile compounds that have been isolated from apples.
The study included only volatile compounds that are airborne and excluded chemicals that remain in the apple which do not enter the air.
Therefore, a healthful all-natural apple is full of chemicals. That is a good thing for us, since many of these compounds provide the nutrients and taste that make apples such a joy to eat.
One way to keep apples healthy and avoid producing ones contaminated with patulin (which many companies screen for) is to use the right kind of fungicides to control the Pencillium and other types of fungi that can grow on apples during growth and storage.
With the susceptibility of apples to an array of fungal and bacterial pathogens, you may need help choosing the right fungicide for your particular orchard. Let Charkit’s seasoned agricultural professionals help you select the proper mix of compounds to fight back the microbes that plague apples and can make them so unhealthy.