Ethylene gas (H2C=CH2) is a harmless odorless, colorless, gas that is produced from both natural and man-made sources, and that has a profound effect on the freshness of produce.
As is so often the case, the effects of ethylene gas on produce was discovered by accident. For years, lemon growers had stored newly harvested green lemons in sheds kept warm by kerosene heaters until they turned yellow and ripened enough to deliver to market. When new electric heating systems were installed, the lemons no longer turned yellow on time. Investigation soon found that the critical factor in the ripening process was the ethylene gas given off by the burning kerosene in the heaters.
In fact, it was discovered that fruits and vegetables actually produce ethylene as they ripen. Experts think that the ethylene gas acts as a signal to the other plants to synchronize and coordinate ripening, thus maximizing the appeal of the plant to their seed disseminators (e.g. birds) and assuring the dispersal of their seeds. Scientists have since studied the effects of ethylene gas on produce and found that the effects are widespread. Other plant tissues can produce this gas as well. Even after harvest, fruits, vegetables and flowers are still alive, continuing their biochemical processes, including ripening and the generation of ethylene gas. Bruising or cutting some fruits and vegetables can even cause them to increase their ethylene gas production. For more information please see this Wikipedia’s history of ethylene in plant biology.
Since the discovery of the relationship between ethylene gas and the ripening process over two decades ago, industry has developed technology to manage the amount of ethylene gas in order to accelerate or slow down ripening and spoilage. Commercial warehouses, ships and trucks are nearly all fitted either with ethylene absorption technology or ethylene generation machines.
However, when you buy fruits and vegetables and bring them home they sit on your counter or in your refrigerator where ethylene gas accumulates and accelerates the ripening process. You perhaps live in one of the numerous households that experts say throw away over $600 worth of produce per household each year due to accelerated spoilage from ethylene gas.
Bluapple® has been developed in partnership with leading industry experts in order to bring industry technology to your home, save you money and benefit the environment. Bluapple® has been thoroughly tested. You can click HERE to download a copy of the latest independent test results!
Ethylene gas (CH) is removed via an oxidation reaction wherein ethylene gas is changed to manganese oxide, water and carbon dioxide. For all you chemists out there, the balanced chemical reaction is as follows:
1. 3CH2CH2 + 2NaMnO4 + H2O = 2MnO2 + 3CH3CHO + 2NaOH
2. 3CH3CHO + 2NaMnO4 + H2O = 3CH3COOH + 2MnO2 + 2NaOH
3. 3CH3COOH + 8NaMnO4 = 6CO2 + 8MnO2 + 8NaOH + 2H2O
Combining chemical equations 1-3, we get:
4. 3CH2CH2 + 12NaMnO4 = 12MnO2 + 12NaOH + 6CO2
Even if the reaction does not go all the way through to the carbon dioxide-producing step, many of the intermediate products formed either become irreversibly bound to the media or act as reactants themselves. Such is the case of the sodium hydroxide (NaOH) formed in equation 1 and 2. The NaOH will react with the acetic acid formed in equation 2 to produce the sodium acetate salt (NaCOOCH3) through a simple acid-base neutralization reaction. This is shown below.
5. CH3COOH + NaOH = NaCOCH3 + H2O
Combining equations 1, 2, and 5 we get:
6. 3CH2CH2 + 4NaMnO4 = 3NaCOOCH3 + 4MnO2 + NaOH + H2O
Some plastic bag makers claim that their bags absorb ethylene gas. Though we have seen instances where some manufacturers have blended ethylene gas absorbent material into the plastic resin, the amount of absorbent material is necessarily extremely tiny. Because micro-pore plastic bags create a more balanced humidity environment inside the bag they do offer more protection than nothing, but the truth is that actually absorbing and neutralizing ethylene gas from the entire storage space is a better solution. The Bluapple® ethylene gas removal solution is comprehensive, cheaper, more effective, and does not add plastic bags to landfills. A recent analysis by Consumer Reports reports disappointing results from so-called “green” bag products.
Bluapple® is designed to absorb ethylene gas from the typical home refrigerator for three months, however you may want to check the potency of the granules yourself. Heavy produce users may need to change their packet more often, while light produce users may see the potency of Bluapple® lasting well over three months.
If you wish to check potency here’s how to do it.
Bluapple® packet contains small granules of the active ingredient. Using a scissors, snip open a corner of the packet. When fresh and fully potent, the granules are purplish in color and when crushed the granules are a white/purple. As ethylene gas is absorbed and oxidized the granules slowly turn completely brown inside and out (in other words, they “rust”). Packets with completely brown granules have used up their ethylene gas absorption potential and should be replaced. If the packets still have potency-life remaining, continue to use them even if you have used them for three months already! You can cover the packet corner you have cut off with a small piece of cellophane tape to seal the packet.
You can check the potency by crushing and examining the granules from time to time as needed!
Bluapple® will aggressively absorb ethylene gas from any environment it is placed in and will help protect produce in a fruit bowl or any non-refrigerated area. It works best if it is used in a closed environment where it can vacuum all the ethylene molecules from the entire space.
Obviously the product cannot effectively absorb ethylene gas from “room” size areas, particularly if combustion is present (such as with the use of natural gas stoves) but it will help extend the life of produce in fruit bowls. Note that using Bluapple® around combustion can reduce the potency dramatically as the amount of ethylene gas produced by combustion activities is substantially greater than the ethylene released from produce.
Remember that Bluapple® will not care what the source of ethylene gas is and will do its best to absorb all it can!
Bananas and avocados are some of the trickier produce items to manage. You want them to stay fresh and last a long time, but at the same time you also want them to be ripe when you are ready to eat them. Unfortunately, when they are finally ready and fully ripe, they are entering a phase where there is a cascade effect at play in terms of the ripening process and the ability to control ripening is limited. For example, fully yellow or spotted-yellow bananas are ripe to a point where it will be impossible to slow the ripening process much. The same is true of soft, black-looking avocados.
To preserve avocados for a long time it is necessary to keep them cold and protected by Bluapple®. Store them in the fridge. When you want them to ripen take them out and put them on the counter and let them ripen as desired. Once they have achieved the ripeness you desire, put them BACK in the fridge with Bluapple®. Again, you are not going to have weeks and weeks to use these, but you should be able to keep them pretty well for the better part of a week.
For bananas we recommend you put your green bananas in a paper bag with Bluapple® and take OUT two or three bananas that you want to ripen quickly and keep these on the counter. In a few days you can take out a few more bananas to begin to ripen. If you stage your use in this way you will get excellent usage from your bananas and rarely have to throw any out.
Growers from as far away as Argentina and Thailand successfully harvest produce, transport it for great distances over land and in ocean freighters using refrigerated containers, and then it is warehoused and transported in the U.S.to your local store produce department in excellent condition. This amazing feat can only be accomplished using the three essential elements to successful produce storage – and all three are vital!
Temperature. You will want the temperature to remain about 38-48 degrees at all times. Keep produce in the refrigerator crispers unless you are planning on deliberately ripening the produce items or if you want to use them immediately. With some produce items like avocados, you may want to keep them on the counter until they are ripe, but then return them to cold storage in order to keep them from continuing to ripen to spoilage.
Ethylene gas control. Nearly all shipping containers use Bluapple technology to absorb ethylene gas during shipment, and you should use this same technology at home too! Bluapple® is designed to protect your entire storage space from ethylene gas.
Humidity. Ideal humidity can neither be too dry or too wet. Most plastic bags do not breathe and end up keeping produce too wet from condensation. Micro-pore bags are available but not necessary. We recommend poking a few dozen holes in your standard plastic bags with a fork in order to keep produce humid, but not dripping. Sometimes with items like broccoli, a damp paper towel in the plastic bag can act as a humidity buffer, adding moisture if necessary and absorbing it if there is too much.
Remember, neglecting even one the essential elements can ruin successful produce storage. For example, if your produce is kept cool, and ethylene gas is controlled with Bluapple®, but condensation forms inside your plastic storage bags . . . well, we all have had the experience of opening up a bag of soggy onions or cauliflower. Similarly, poor temperature control or absent ethylene gas control will also sabotage successful produce storage efforts.
Well it certainly is the obvious case that the necessary essential element of Bluapple® is the packet of active ingredient, and we certainly have heard of people who merely buy the One Year Refill Kit.
However, Bluapple® itself does some important things that are not insignificant. First, Bluapple® allows for airflow all around the packet and prevents produce from piling on top of the packet and smothering it. Second, Bluapple® protects the packet from condensation or moisture in the refrigerator because if the packet were to get completely wet the efficacy would be significantly degraded. Also, the sodium permanganate is a deep purple color, and a wet packet can actually stain clothing. Third, it’s cute. It continually reminds you when you look in the refrigerator that produce freshness management is an ongoing, necessary activity if you are serious about saving money and maximizing the quality of your fresh food investment.
Considering the hundreds of dollars saved every year we certainly think that the using Bluapple® to contain the active ingredient packet is well worth it!
I ACCIDENTALLY DID MY LAUNDRY WITH A BLUAPPLE IN THE MACHINE AND IT HAS STAINED THE CLOTHES. ANY IDEAS ON HOW TO GET STAINS OUT?
Sodium permanganate is the active ingredient in Bluapple® and it can leave a very difficult purple stain. This is, of course, one reason that we advertise not to open the packets. Here are some things that can work.
1. Try a mild acidic solution such as vinegar or lemon juice.
2. Use sodium metabisulfite to remove sodium permanganate stains from all surfaces. This is a preservative found in most grocery stores in the canning supply section.
NO, you do not need to open the packets. The packet itself is permeable to ethylene gas and it is NOT NECESSARY to tear open the packets. To use or replace a packet, merely place Bluapple® on a sturdy table with the center seam touching the table and oriented vertically, then place your palm on Bluapple® and push down firmly. Bluapple® will split open along its seam, and once opened, you can remove the used packet and replace it with a new packet. Remember to use the contents of your used packet as fertilizer for house plants and gardens.
If you have accidentally opened the packet, you can put the tiny Bluapple® granules back in the packet and reseal with some cellophane tape. Remember Bluapple® granules are non-toxic and cannot hurt you, but the purple color of the granules can leave stubborn, purple if the granules get wet.