Oranges, tangerines, and lemons are wonderful sources of vitamins. Whether in a fruit salad, as a snack for small children or freshly squeezed – citrus fruits taste wonderfully fruity and refreshing in all variations.
Insects threaten oranges, tangerines, and lemons
Growing oranges, tangerines, and lemons are not child’s play. Citrus mealybugs, leaf miners, Mediterranean fruit flies, Australian mealybugs, common spider mites, red scales, whiteflies, and of course the aphids – they all (and many more) have a preferred target in the Orange & Co. growing regions: citrus trees.
Citrus fruits are often sprayed
All of these harmful insects infest leaves, flowers, young shoots, and not infrequently the ripening fruits. The more of these insects that congregate in an orange or tangerine orchard, the smaller the harvest. Yes, there is even a threat of total crop failure. Understandable when citrus growers reach for their sprayers at the first sign of insect infestation.
Since, of course, not all insects appear at the same time of year, spraying is carried out several times over the course of the year and with different chemicals.
Ladybugs as helpers in orange and tangerine cultivation
However, even in conventionally managed plantations, it is known that nothing is more effective against the Australian cotton scale, for example than a healthy ladybird population.
The ladybird comes flying over long distances when it scents the Australian scale insect. Ladybugs only need a month to permanently rid an infested citrus orchard of this species of lice.
And just as the ladybug can keep the scale insect under control, almost every harmful insect has one or more natural enemies: small sciatica eats the whitefly, a gall midge eats the spider mite and certain parasitic wasps have specialized in the citrus mealybug. But just like the ladybug, they also need a few weeks to settle and do their job.
Sprays also kill beneficial insects
But not every farmer has the nerve to wait a month to see if enough ladybirds, gall midges, and parasitic wasps arrive. And if there are other harmful insects to be seen, they are sprayed.
Then, of course, not only the target insects die, but also the ladybug, which reacts particularly sensitively to chemicals, and many other beneficial insects as well.
Now the crop is completely dependent on chemical protection as the biological balance is destroyed. Spraying is now being used more and more frequently in order to prevent crop losses and not endanger one’s own existence.
Spray against weeds, fungi, and premature fruit fall
But chemicals are not only used against insects but also against weeds, various fungal diseases, and even (in the weeks before harvest) premature fruit dropping.
The latter is done with a mostly synthetic growth regulator, which exerts a hormonal effect on the citrus tree so that it can no longer shed its ripe fruit (otherwise it would get bruises), but has to wait for the harvest team.
How to color green citrus fruits
When the fruits are finally well-formed and spotless in their crates, the days of chemical baths for oranges, tangerines, etc. are far from over.
If the temperature was still too high at the time of harvest, then citrus fruits are harvested green. In this particular case, the color does not have much to do with the degree of ripeness, but actually only with the lack of a cold period.
For this reason, green citrus fruits are often seen on the markets in tropical countries, but they are perfectly ripe and therefore taste wonderfully juicy, sweet, and aromatic.
Oranges and mandarins from the Mediterranean region, however, are only harvested green if they are very early varieties. By November at the latest, it will also be autumnally cool in Spain and Italy. If the temperatures at night drop to 10 to 12 degrees, the fruit will turn the well-known orange color within a few days.
Green citrus fruits, ie when the cold period is a long time coming, must first be “dyed” into the desired orange. This takes place in so-called ripening chambers, in which the fruit is exposed to a gas known as ethylene. Ethylene ensures that the fruit turns a nice orange or, in the case of lemons, a nice yellow.
Fortunately, ethylene is not a problematic chemical, but a plant hormone that is produced by a great many fruits themselves.
Post Harvest Chemicals
Substances used to preserve the fruit are significantly less harmless. Some of these chemicals are designed to protect oranges, tangerines, and lemons from spoilage from mold and rot during their storage and shipping periods. Others are designed to prevent dehydration.
And precisely because these substances are so harmless, the labels on the fruit crates or fruit nets must also state that the citrus fruits have been treated. You can choose from imazalil, biphenyl (E230), orthophenylphenol (E231), sodium orthophenylphenol (E232), or thiabendazole.
If the latter was sprayed onto the fruit, this must also appear on the label. Thus, only the specific mention of thiabendazole is required by law. If, on the other hand, the other chemicals were used, the label usually only says “preserved”.
The fungicide imazalil is considered carcinogenic
Imazalil is manufactured worldwide. It is a fungicide, i.e. an agent against mold and fungal infestation. In animal studies, the chemical had caused liver and thyroid tumors and had negative effects on development and reproductive capacity.
In some cases, there was also a drop in blood pressure, coordination disorders, and tremors. In addition, the substance is considered to be toxic to fish and harmful to the environment.
According to statistics provided by the United States, Environmental Protection Agency (EPA) and the United States Department of Agriculture (USDA) Pesticide Data Program (PDP), the 45-pound (20 kg) child weight limit of citrus fruit treated with Imazalil that is safe to eat is a precautionary measure at only 400 g, which would be equivalent to about 6 small tangerines.
In adults, the tolerance level for toxins of this type is higher, so that – according to the American authorities – one can eat 630 grams of treated citrus fruit without succumbing to poisoning.
Orthophenylphenol – From food additive to pesticide
Two other agents used to treat oranges, tangerines, and other citrus fruits are orthophenylphenol and sodium orthophenylphenol. Both are approved as food additives or preservatives for food – hence the E numbers.
But that is about to change. The substances are probably too dangerous and should in the future belong to the category of pesticides, where the chemicals really fit much better.
Like many other chemical pesticides, these two substances are highly toxic to water and the environment. In animal experiments, they triggered bladder cancer and can also cause nausea and vomiting in humans, even in small amounts. Skin-sensitive people should also not let the substances or fruits treated with them get on their skin.
Thiabendazole – The wormer on the tangerine
Thiabendazole is arguably the most commonly used citrus preservative. When not sprayed on orange or tangerine peels, it is used as an anthelmintic, which means wormer.
However, it is not only used in wormers for animals but also, for example, when people bring migratory larvae home from vacations in tropical regions. Wandering larvae eat visible passages under the skin – mostly on the legs, arms, or buttocks.
Thiabendazole can also damage the liver and disrupt bile function, of course depending on the dose consumed.
A drug may be very helpful in an emergency. And with a wandering larva in your butt, you are happy to take some risks in terms of side effects. However, it is doubtful whether one would want to incorporate a wormer with every tangerine.
Grow on oranges and lemons
Luckily, preserved fruit is easy to spot even if the label weren’t there. They are extremely shiny.
However, they don’t shine because of the preserving chemicals, but because of the wax in which the fruit has been dipped so that it does not dry out so quickly and can be stored for months if necessary.
However, there are few citrus fruits that are only waxed but not treated with chemicals. This is because the chemicals are already mixed into the wax.
Either natural or synthetic waxes are used. Of course, they are, if they z. B. consist of shellac (E904), a substance from the lacquer scale insect. Carnauba wax (E903) is also a natural wax. It is made from the leaves of the Carnauba palm.
Synthetic waxes include those based on paraffin (E905) or the so-called polyethylene wax oxidates (E914).
Neither natural nor artificial waxes were originally intended for consumption. Damage caused by the waxes is not known, however, since they are usually excreted unchanged. Nevertheless, waxed fruits are declared with the note “Waxed”.
Cross-contamination via packing lines is possible
However, citrus fruits contain not only those chemicals with which they were knowingly sprayed or treated, but also completely different ones.
In a study by the German Fruit Trade Association and the University of Hohenheim in 2010, it was found that so-called cross-contamination can easily occur on packing lines.
Heavily contaminated fruit leaves chemical residues on the packing line, which are then absorbed by the following fruit, which may be less contaminated. Cross-contamination via reusable boxes is also conceivable.
Toxic residues in oranges, tangerines & other citrus fruits
With all the chemicals used before and after the harvest, it should come as no surprise that residue analyses found 80 active ingredients in pesticides – as was the case, for example, in investigations by the Bavarian State Office for Health and Food Safety in 2010.
At that time, 94 samples of citrus fruits from the wholesale and retail trade were examined. Among them were 80 conventional fruit samples and 14 organic samples.
While half of the organic fruit was completely residue-free and the other half only showed traces of chemicals, all 80 conventional samples contained clear residues of toxic sprays and preservatives – and not just residues from one substance, but from several at the same time.
Even half of all conventional fruit contained five to seven different chemicals and another 20 percent even eight or more residues. A Grecian orange was the top performer with a toxic cocktail of 12 different chemicals.
The above-mentioned 80 spray agents could be detected 464 times in this way. The limit values were only exceeded in 4 percent of the cases, which could possibly also indicate that the limit values were set much too high. However, the Bavarian State Office described conventionally produced oranges, tangerines, and lemons as “rather heavily contaminated” fruits.
How practical it is that the crates or netlabels at least state whether the fruit was treated after it was harvested. These are usually fruits that have been sprayed extensively before harvest, while organic oranges, organic tangerines, etc. are hardly ever treated after harvest – and if they are, then only with natural waxes, which of course are also declared got to.
However, most organic citrus fruits have a matt surface and are therefore untreated.
Treated citrus peels are inedible!
The specific declaration of treated fruit should in any case prevent the skin from being used for baking or cooking recipes.
Treated citrus peels should also not necessarily end up in the compost, as they would otherwise enrich the soil with chemicals, which is exactly what you want to avoid in natural gardening.
It would be ideal to scrub the fruit thoroughly in hot or at least lukewarm water before peeling. But even then it will not be possible to completely remove the residues. After peeling the fruit, you should always wash your hands thoroughly (and also tell children to do the same) before you start eating.
Unfortunately, chemicals that you had on your fingers get onto the peeled fruit even during the peeling process.
Tangerines and clementines, which are usually eaten straight from the hand and which children like to take to kindergarten or school, should therefore never be bought in conventional, i.e. treated quality, but always in organic quality.
Likewise, fruits whose skins you want to use must be organic.
Because why take the chemical risk when there are wonderful tangerines and oranges in the organic food trade that not only remain untreated after harvesting but also ripen beforehand without chemicals and instead with the help of ladybugs & co?