Information on apple and other fruit wax and why it's important

Had a conversation today with @39thparallel regarding Apples and certain properties of each one. Discussing specifically the fact that Arkansas Black is more greasy than many of the others. This is the part where many people are saying so what does that mean and why bring it up?

" That’s because the fruit is coated with a layer of natural wax that protects it from drying out and helps to prevent fungi from getting a foothold . The wax is a mixture of up to fifty different compounds, most of which fall into the chemical category known as esters."

That’s interesting information as we know the Arkansas black is a long storing apple. Consider this is not something discussed a lot but it’s very relevant to our bigger plan to grow certain fruits for certain properties such as long storage. @39thparallel grows lots of different apples so I don’t miss a chance to ask when i observe something different.

This tells us something else new “That oily film you often get in store bought apples can be either a food grade wax that’s added, or it could be a sign that the apples are overly mature.” So apples wax increases in storage.

“Apples are covered by waxy-cuticle layers that protect against the environment and minimizing water loss. Basically, as the apple matures, the ethylene given off creates greasy esters, melting the waxy layer and separating it. It makes the surface of the apple look and feel greasy. If we can slow ethylene maturation down, the fruit in storage might not develop greasiness.”

So you might ask do other apples have more wax as well or is it just Arkansas black? Jonagold and Cortland also are high in wax and there are others.

" Certain apple (Malus domestica Borkh.) cultivars develop a greasy surface when overripe and the wax changes are considered to be responsible for this disorder, but the contributing wax composition for skin greasiness remains unclear. Cuticular wax composition and wax morphologies of three cultivars were analyzed during storage at 20 °C. ‘Jonagold’ rapidly became greasy over a 20 d storage period but ‘Red Delicious’ did not. ‘Cripps Pink’ showed a slower greasiness development than ‘Jonagold’ over 70 d of storage. Alkanes, principally nonacosane, and fatty alcohols, principally nonacosan-10-ol contributed to the formation of the three-dimensional structure of waxes. Accumulation of more fluid wax constituents, which consist mainly of linoleate and oleate esters of (E,E)-farnesol and short-chain alcohols (C3-C5), led to the solid-liquid phase change of waxes, ultimately causing the greasy feeling on ‘Jonagold’ and ‘Cripps Pink’ apples. Compared with ‘Jonagold’, the increase of liquid fractions in ‘Red Delicious’ was much smaller and the wax crystals remained intact after the same storage period. The intact farnesyl esters were profiled for the first time using GC–MS. The results for ‘Cripps Pink’ suggest that the increase in solid fractions (alkanes and fatty alcohols) may lessen the effects of the fluid fractions on greasiness by maintaining wax structure. Finally, a hypothesis is proposed for ester production associated with greasiness development. "

It’s not just apples most fruit has a waxy coating Why fruits like pears, grapes, tomatoes, and apples have waxy coatings? | Britannica

It’s true that grocery stores have known for many years adding wax makes the fruit look more appealing and last longer


I have many varieties of apple in refrigeration and I’ve never even thought about waxiness as an issue that affects enjoyment or storage. It doesn’t affect my eating enjoyment at all, but I do like the shininess of my Ark Blacks.

The crucial issue to me is texture- that an apple sustain its crunch and even that doesn’t seem to depend on waxiness. Goldrush is my best storage apple and I suppose its lack of wax is why it can become wrinkled so soon if stored in an evaporative environment. Store apples in refrigeration devoid of defrost and you overcome a lot of that problem as do plastic bags with a small amount of perforation.


In the case of Arkansas black it impacts storage in a good way as we know they really store a long time. We don’t think of apples storing longer because of wax but it seems true enough. Never realized before they got more greasy the longer I kept them in storage. It changes how I will buy and grow some fruit.


I’ve noticed that greasiness on some apples as they age but didn’t know what to make of it. It probably won’t change my habits much.


Maybe it’s the greasiness or maybe the good storageability is the result of being a real hard apple to begin with, which is an even more common trait of good storing apples. How about a little of both?


@marknmt @alan

What I find interesting is that they use artifical wax on the other apples to increase their shelf life. That may change the way I think of storage. If we can wax apples and get another month of storage out of fruit it might be a game changer.


Thanks for sharing this Clark, and thanks for spurring the discussion @39thparallel. This is something I hadn’t even considered for my fruit growing, and now I’m wondering if I should be trying to tweak a wax formula like the one @Barkslip or @39thparallel uses for their scion/graft preparation. A thinner mix than what they both use would make sense, and obviously you would want it to be food safe wax (beeswax would likely make sense?). Would you even want to wax certain fruit to extend its ripening period? I’m thinking about pears, persimmon, stone fruit etc. Basically any other bigger fruits.



Yes ofcourse your referring to their bench grafts or scion wood they wax to allow them to heal over from the graft without being dried out. They do not wax their fruit but it has natural wax. The French dip the stems of certain winter pears in wax to keep the pear from drying out. The commercial fruit growers clearly have known for years wax buys them additional shelf life to fruit. 3 or 4 weeks extra weeks life for your fruits is huge. I’m just bringing attention to this as I think we are missing the picture on some things. A tree sprayed with wax eg. Dormant oil spray fights many pests on fruit trees, fruit waxed fight drying out or spoilage, bench grafts waxed are much more likely to succeed. I use parafilm a wax grafting tape for my grafts. Bringing this up because it needed attention drawn to the subject. Since Arkansas black and other long keeping winter apples are more greasy I think we need to take notes on whats going on here. This thread will help in addition for fruit storage What's too cold to store apples, 30-32F? . Make special note on comice and anjou in this pdf document fs147.pdf (26.5 KB) as they require refrigeration or mass amounts of fruits ripening that are releasing enough gas to ripen. Take a look at these Passe Crassane pears and note the stems
Passe Crassane Pears Information and Facts
Large commercial farmers already know the benefits of wax as a preserving tool
Watch this video


Shelf life? This has as much or more to do about appearance than eating quality. What I’m interested in is texture- does a waxy surface influence texture or only dehydration?

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I’m not sure your question is easy to answer how do we quantify that without doing the research ourselves? My suspicion is it’s about dehydration and appearance only. Texture of the fruit ofcourse is influenced as the fruit begins to break down towards the end of it’s shelf life. We know some texture related issues are in how the fruit was grown. Some apples have water core which impact storage. We might want to research this further. We know this is a bit of a stretch but listen to these women’s beauty secrets because 2 of them are cold ice water and sunflower oil. Ironically cold temperature and natural wax in fruit are two things that keep fruit looking good as well. If it’s any consolation another tip was eating fruits , vegetables, wheat grass.

This would be the more technical answer about apples and how they naturally progress from crisp and snappy to dry and mealy over time The Science of Apples - Article - FineCooking
" Apples rank among the world’s most popular fruits. Not only are they delicious eaten out of hand, but they’re also a crisp addition to salads, a star in autumn pies, and a sweet complement to savory meat dishes. Here’s how to choose the right apple for what you’re making and how to keep it tasting its best.

What makes an apple crisp and juicy?
The cells of apples are filled with flavorful juices composed of water, sugar, acids, and aromatic esters (compounds made of one acid and one alcohol molecule). The spaces between the cells are filled with air, which accounts for as much as 25% of the volume of a ripe apple (that’s why apples float). In a ripe apple, the cells bulge with juice, which stretches the cell walls and compresses the air between the cells. When you take a bite, the cell walls break (hence the crispness), and the juice bursts out. At the same time, the trapped air is released, transporting the apple’s aromatic esters up the back of your throat to the olfactory membranes in your nose, and you taste the distinctive flavor of that particular apple. Apples that contain less air aren’t as flavorful, crisp, or juicy, but they’re better for cooking.

What makes an apple sweet or tart?
All apples have a balance of sugars and acids, but the balance changes by variety. Granny Smith apples are high in acid and lean in sugar, for example, and Fujis are decidedly sweet with a subtle acidity. Regardless of the varietal differences, the sweet-sour balance of any apple evolves during storage. Apples are climacteric, which means they contain starch that converts to sugar after harvest. In addition, malic acid, the primary acid in apples, is consumed by the fruit once picked and is used for energy over time in storage. This means that all apples are at peak tartness right after picking and gradually become sweeter the longer they’re stored.

How do you a tell a good apple from a bad one?
As an apple ripens, its cells fill with water, and green chlorophyll in the skin breaks down, revealing deeper green, yellow, red, and pink colors underneath. When picking apples from the tree or the market bin, look for brightly colored fruit that feels plump, firm, and somewhat heavy. This heaviness indicates maximum water retention and juiciness.

After harvest, apples continue to ripen due to ethylene, a vaporous hormone produced by the fruit. With continued exposure to ethylene, apples become increasingly soft, shrunken, and lighter in weight. Hemicelluloses and pectic substances that hold water in the apples’ cells (and keep the cells separate) eventually break down, causing moisture to escape and the apple skin to wrinkle. Overripe apples will appear shrunken and wrinkled, and feel soft when pressed. They may also taste dry and mealy due to lack of water and desegregation of the plant’s tissues as the hemicelluloses and pectic substances weaken.

Can one bad apple spoil the whole bunch?
Yes. Jostling and impact injuries can bruise an apple, leaving behind soft brown spots that are easily attacked by the fungus Penicillium expansum. Known as blue mold or soft rot, P. expansum rapidly spreads from one bad apple to those nearby, particularly in warm, humid conditions, which encourage mold growth.

What’s the best way to store apples?
Properly stored apples will taste crisp and juicy months aft er harvest. To minimize bruising and untimely rotting, apples should be handled gently and kept separate during and aft er harvest; that’s why produce distributors ship apples in soft trays with individual cradles.

For the longest storage, keep apples in the refrigerator produce drawer to slow their natural ripening processes and discourage mold growth. If your fridge has drawers with adjustable humidity, set the apple drawer to about 85% humidity, which helps keep apples from drying out prematurely.

How do I keep apples from browning?
Browning in fruit is caused by exposure to oxygen. Bruised or cut apples release enzymes from the damaged cells that mix with phenols, the fruit’s aromatic compounds, and react with oxygen to form new molecules that appear brown in color.

So how do you keep cut apples nice and white in, say, a fresh apple salad? There are a few options. The easiest way is to slow the enzymes’ activity with acid and cold temperatures. To do this, put cut apples in a bowl of cold acidulated water (add 1?4 cup lemon juice, 2 tsp. vinegar, or 500mg crushed vitamin C tablets to every 4 cups cold water). To avoid the mild acidic flavor imparted by this method, you can simply keep cut apples submerged in plain cold water to shield them from oxygen; however, the lack of added acid will cause enzyme activity to increase more rapidly when the apples are removed from the water. You can also toss cut apples in sugar or syrup to shield the cut surfaces from oxygen-this method works well for sweet fruit salads. Finally, you can deactivate enzymes by dipping cut apples in boiling water for at least 1 minute. This blanching method soft ens the fruit slightly, but is a good choice if you want the apple to stay white without an acid or an oxygen-shielding solution.

What makes an apple good for cooking?
In general, apples that are high in acid, such as Granny Smith and Braeburn, hold up best during cooking. Acids enhance our perception of other fl avors, and because heat tends to dissipate aromatic molecules, cooked dishes made with high-acid apples retain more fl avor. In addition, acids are necessary to strengthen pectin (the “glue” that holds fruit cells together), which helps apple slices keep their shape in pies and crisps. Apple varieties with less air, like Rome Beauty and Braeburn, are best for baking whole because theywon’t collapse as their water evaporates, their juices concentrate, and their cells contract. Although any apple can be used for making applesauce, those with less air, like McIntosh, make creamy smooth applesauce, while crisp, tart apples, like Granny Smith, make chunkier, looser sauce.

We are also trying to prevent penicillium


I’ll go there- I wonder if some form of waxing could extend the shelf life of pawpaws. I’d imagine you would want to choose only the thickest skin varieties, and you remove the skin regardless so the wax would have minimal impact on the eating experience. What say you @JustPeachy @TrilobaTracker would you guys be interested in trying an experiment this year?

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We can look to how commercial growers hold apple texture- they limit oxygen in CA Storage. I do the same thing by keeping apples tightly packed in a refrigerator I seldom open- taking out a lot of apples for less oxygen starved storage elsewhere (a refrigerator I frequently open). It is also possible to store apples in the ground within a garbage pail to limit oxygen.

Ethylene is released by the fruit via respiration. Much of modern food storage is accomplished by removing oxygen within packaging.


No. Because, there are multiple ways for spoilage to occur. With regards to pawpaws, the problem is the high fat, moisture content, and the enzymatic activity. Rancidification has multiple pathways, and for pawpaws, oxygen exclusion doesn’t really anything because you still have other thing occurring inside the pawpaw. Temperature is more of a significant concern with pawpaws than other fruits.

Waxing was really more for preventing desiccation and related spoilage. If you look at the fruits and vegetables being waxed, it’s a replacement for existing wax that was removed during processing.

Pawpaws have their own natural wax. We don’t process pawpaws in the way we do apples, where they are washed, so there is no replacement step required.

If we compare to say mangos, papayas, avocados, other high water content or high fat fruits, the difference is that pawpaws do not get picked under ripe and undergo artificial ripening.

Apples as much variation there is with say a desert apple vs a storage apple, you can still leave a tree ripened waxed desert apple on the counter top for 36 hours, ship it cross country, and have it perfectly edible. The same goes for a mango, papaya, or avocado. You cannot do this with a pawpaw. The waxing enhances the inherent storage properties of the fruit. It cannot serve to induce a storage property that didn’t already exist.

You could encase the pawpaw in lucite, and I’m pretty sure spoilage time frame would still be the same. The enzymatic activity in the pawpaws is still occurring.


@JustPeachy @TrilobaTracker @disc4tw

Yes pawpaw are much like banana if you want to ship them its got to be green. The big difference is pawpaw don’t taste well when picked green and the lack of market reflects that. Pawpaw have to be shipped carefully even if they are going only a short difference Pawpaw in Kansas - it's a lot of work but can be done!

Took pictures of these pawpaw when I picked them and you can see some bruising. Note the very soft flesh you can see in the photo.


Restricting oxygen is to limit metabolism. Stored fruits have their own metabolism and keeping oxygen from them slows it down. Having a waxy surface does this to some extent, but also limits moisture evaporation.

On a different note, I deliberately stored some apples from Walmart for about 2 months. The improvement in flavor was amazing. This is variety dependent.


I remember way back in organic chemistry lab when we tried to identify compounds by their characteristics and the chemical reactions we put them through. Everyone loved when we had an ester to work with. They were fruity and aromatic and wonderful. Special enough to remember it 40 years later.

Thanks for this post. Lots of good info here.

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Really nice deep orange flesh. Mine don’t get that color even when soft on the tree. More yellow-greenish. I bet yours taste better than mine.

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For Greasy apples
Does this Link help It is a rosaceae data base
Note I didn’t fill out anything except grease (medium _10)
(for extremely greasy no results so do not waste your time searching on the data base except not sure yet what _10 _ 20 means If you know what please inform me, and others )

I know of this site, but not breeding (or buying apples so I have no Incentive to waste my time browsing it)
when I do I plan to use it looks to give good results …
(although if you browse around you will see a tutorial video
out of curiosity couldn’t figure the gene thing to do on the you tube video it didn’t work for me , but may for you , but other then that, and I have no Idea how to use the genes myself ctaa taaa etc it looks to be a good resource)

(I searched by traits )
(remember to reset database search each time easy to use finding grease
using the computers key board hold ctrl and f
(type in grease in find box or other word)mac uses window key
(wikipedia word ctrl for examples on using the ctrl button) ( ie ctrl B is bold)
(one of the results out of over a dozen ----
Note does not let me save link with all varieties on one page )