Will Vinegar Keep Apples From Turning Brown?

Which liquid do you believe will keep the food from browning the most effectively? Why?

Materials

  • Wax paper or a baking sheet
  • tape for tagging
  • Marker or a pen
  • Tongs
  • Bowl
  • Knife
  • Citrus juice
  • Vinegar
  • soda crystals
  • Almond oil
  • Water
  • Saltwater
  • Potato
  • Apple
  • Banana
  • Avocado
  • Any further fluids you want to examine
  • any further produce you want to try
  • Camera (optional)

Procedure

  • Label each of the liquids you will test using the tape.
  • Put your labels on the wax paper or baking sheet. Your samples for observation will be placed here.
  • Each fruit or vegetable should be sliced into at least 1-cm-thick pieces. Make sure you have one additional slice of each food item as a control and as many as there are liquids to test. To assist you cut your samples, ask an adult. Why ought the food samples to be divided?
  • On the baking sheet or piece of paper, arrange a slice of each food item under the title “Control.” Why is having a control necessary?
  • Pour enough liquid into the bowl to completely cover each sample.
  • Use tongs to dip a slice of each fruit or vegetable you are testing into the liquid. Make sure to completely cover the slice! Before placing it on the baking sheet or wax paper with the proper label, let the excess liquid drain off.
  • Clean the basin again and continue until samples of each liquid have been produced.
  • Keep a journal of all your observations while noting the time. To record how the food ages over several hours, you can also take pictures.

Results

Food won’t soon turn brown if you use lemon juice, vinegar, or clear soda. Since these liquids are acidic, they will cause the food’s surface to have a lower pH. Although less effective than acids, olive oil will help stop food from browning. Food browning will also be slowed down by water and salt water.

Why?

Because it’s crucial to know how long it will take the food samples to turn brown without any liquid added, a control group must be used.

The skin of the food shields the interior “meat” of the fruit or vegetable from contamination and injury. The food typically spoils more quickly when a fruit or vegetable is dropped and the skin is punctured or broken. When fruits and some vegetables are chopped, the portion containing the oxygen-reactive enzyme is exposed, which is why the food turns brown. The meal has a large surface area on which the air can contact it. Brown fruits and vegetables generally still taste good, but they do not have a particularly appealing appearance.

Because they react with the oxygen that comes into contact with the sample’s surface, acids stop browning. The sample will turn brown once all of the acid (or whatever else is covering the surface) has interacted with oxygen, deteriorated, or washed off. In fact, the enzyme can even be denatured by stronger acids like lemon juice. This indicates that the enzyme’s initial function can no longer be carried out due to its environment.

What preventive measure is most effective against browning of apples?

The question of how to inhibit enzymatic browning subsequently becomes one of preventing browning. Numerous academic studies have looked into this in-depth; after all, the produce sector has a strong financial interest to find a solution given that the process results in an annual loss of up to 50% of some types of produce.

The majority of remedies involve some form of oxygen blocking, reversing the oxidation process, altering the pH of the surrounding environment, or stopping the reaction by exposing it to either extremely hot or extremely low temperatures.

On an industrial scale, ascorbic and citric acids are frequently utilized together to optimize the results of these techniques. For the home cook, however, who only wants to delay browning for a little while, that is not a viable option. You know, so that while they are on the cheese platter for your cocktail party, the apple slices don’t change the color of a murky sponge.

I’ve been experimenting with more realistic techniques to see which one performs best at home. I chose Red Delicious apples for my experiments because of their propensity to discolor very quickly. Since my results were the same with the apples as with the Bartlett pears, which aren’t shown in the picture, I repeated all of my experiments.

Here is a succinct summary: The easiest approach to stop sliced fruit from rotting is to soak it in a saltwater solution for 10 minutes (use 1/2 teaspoon of kosher salt per cup of water), then drain it and put it away until you’re ready to use it. Before serving, the faint salt flavor can be removed with tap water. The best thing is that browning is still significantly minimized even after rinsing.

Using Water, Lemon Juice, and Citric Acid to Prevent Apples From Browning

Submerging sliced fruit in plain water lowers the quantity of oxygen and air that can reach it, which is one of the simplest ways to stop browning. Many fruits float, so it’s helpful to either place a dry paper towel on top, which will push them under once it becomes wet, or to place them in zipper-lock bags with the air squeezed out. The latter is what I did because it makes the apple slices in the pictures easier to see.

Many people may advise you to add some lemon juice to the water first, which will acidify it. Lemon includes ascorbic acid, which not only lowers pH (as does the citric acid also present in lemons), but can also stop the oxidation reaction through a procedure referred to as reduction in chemistry. In my experiments, I used three tablespoons of fresh lemon juice per quart of water, which is roughly similar to the juice of an average lemon.

Later, I experimented with citric acid in two different (very strong) solutions and sprinkled dry crystals of it straight over the chopped apple surfaces. I did this just for fun. Although the acid contents in these samples were too high for the apples to be genuinely edible, it’s intriguing to see what higher acid concentrations can achieve.

You can immediately see that the citric acid is keeping the sliced surfaces ever so little whiter in this initial photo, which I’ve classified as zero in the timeline (though, technically, it took me a few minutes to bag it all up and arrange it on the table for the photograph to be taken). However, it’s important to note that the light source in the photographs was to the right, which meant that the samples nearest to it were illuminated more than those to the left. I couldn’t tell the difference between the plain water and lemon water samples with my unaided eye in the dimly lit room. Note the white tabletop below for comparison; it is a consistent shade of white but appears darker at left in the photographs.

After fifteen minutes, disparities are already more pronounced.

The untreated apples in the top row at left are yellowing, but it is not just the light source at the right that is to blame.

The basic apple slices show more pronounced browning at 30 minutes. The sample of ordinary water (in the bag on the far left) is holding its color better, but not as well as the samples of citric acid in the two bags on the right. The lemon water sample (second from left) is not significantly different from the plain water sample, but it is unquestionably more yellow than the samples that were treated with citric acid. Also take note of the little pink color that the citric acid solutions have since the apple skins’ colour was leached out of them.

The variations are more obvious after one hour has passed since the initial picture. The slices of plain apple and lemon apple with water are holding up better than the plain apple pieces exposed to the air, but they don’t look wonderful. At this time, if you bit into any of the water-soaked samples, the apples would be soggy and a little bit mushy.

Look at the picture up there. That is a picture of the same samples three hours and fifteen minutes later. In the bottom row, second from the left, the lemon-water sample has browner skin than the plain-water sample at this stage, which is consistent with the findings of scientific research I’ve read that found enhanced browning when the apple was exposed to decreased ascorbic acid concentrations. The skins, on the other hand, have taken on a neon aspect as even more pigments have been pulled out, while the citric acid samples appear almost bleached.

All of the samples were now almost inedible. Of course, the ones with citric acid were inedible right away (unless you like the idea of Sour Patch Kidstyle apple slices). The plain and lemon water apples, on the other hand, had browned to an unfavorable degree and were both soggy and unpleasant to eat. The apple flavor was subtly changed by the lemon water, which added a unique lemony note.

Later, I conducted a number of tests using much lower citric acid concentrations (one teaspoon per quart of water), which I found to be more tasty, but they didn’t prevent browning nearly as well. I was unable to locate a citric acid dose that was both effective at preventing browning and did not taste too acidic.

I also ran a test by just rubbing a cut lemon over an apple’s cut surface. I’ll summarize the findings now, but you can see a picture of it in the salt section below: Skip it since it overpowers the apple with a strong lemon flavor and barely slows browning.

My opinion is that soaking apples and pears in plain water for a very little period of time is a strategy that works well.

Less than 30 minutes, ideally less than 15, is what I’d estimate. If you wait much longer, your fruit will turn brown and lose texture. Avoid lemon water, which actually has the opposite effect of slowing browning while altering the flavor of the apple.

See how the apples change color over time in the time-lapse GIF below (much like Gertrude’s poem, which goes around and around like an apple).

Using Salt to Prevent Apples From Browning

Another molecule that might obstruct oxidation is sodium chloride, also known as regular table salt. I prepared a salt solution for my experiment by dissolving half a teaspoon of Diamond Crystal kosher salt in one cup of cold water. I then soaked apple and pear slices in the solution for 10 minutes. In addition to samples of chopped, untreated apples, I also drained the samples and allowed them to stand for two hours.

In the image above, the apple that has been submerged in saltwater is on the bottom right, while two examples of untreated apples are on the left. (My apple with lemon juice applied is on the right, while its untreated counterpart is on the left.)

As you can see, the saltwater apple held up the best against browning—even two hours later, when this picture was taken, it still had a fair white hue. One tester didn’t even detect the salt flavor on the apple’s surface, but it is there. The good news is that even after the apple has been chopped, a brief washing under cold running water totally removes any salt residue, giving you a fresh-tasting and -looking apple.

The good news is that the apple and pear slices still have a bright white color after being rinsed of the salt. This indicates that there won’t be any quality loss if you soak the fruit in the salt water for 10 minutes, rinse it, and pat it dry before putting it out on a cheese platter for at least a couple of hours. Bringing lunch for the kids? They’ll eat fruit for lunch that appears to have just been sliced, and they won’t whine about how salty it was when they get home!

The salted apple will eventually, gradually, after many hours, begin to deteriorate. That’s not a major problem for the majority of home cooks.

In the end, using salt was the approach that produced the best results while causing the least harm to the apple’s flavor and texture.

Cooking Apples to Prevent Browning

As you can see in the image above, using an excessive temperature can also be utilized to stop browning. The apple on the right was chopped and blanched in boiling water for two minutes before being drained and shocked in cold water. The browning reaction is entirely stopped by high heat. Sadly, it also significantly softens the apple and gives it a cooked flavor because you’ve already cooked it. It might be acceptable if you require the apple for baking, but otherwise this method is useless.

Continue using salt, and you won’t have to be concerned about browning any longer. Which gives you plenty of time to consider your apple’s shape repeatedly rather than its color.

Does vinegar aid with apple preservation?

Apple slices are prevented from browning and turning brown by the high acidity of pineapple juice or lemon and lime juice. You can either soak the apple slices in a bowl of pineapple juice or cold water that has been mixed with lemon or lime juice. The slices will retain some, but not an overwhelming amount, of the flavor of whatever you soak them in.

Sprite

Sprite or another lemon-lime drink can help keep apple slices from browning, while it’s not the healthiest choice (after all, it is soda). After soaking, drain and keep in an airtight container.

Cider vinegar

To 1 cup of water, add 1 tablespoon of cider vinegar. Apple slices should be soaked in the mixture for about five minutes, drained, and then placed in an airtight container.

Can you cut the apples in advance?

The issue is that apples begin to deteriorate as soon as they are cut. But I’ve discovered a quick, two-step process to keep them looking good. I’ve tried this approach a few times. The first time, I checked the apples after chopping them for a few days. They maintained their appearance throughout. This time, I gave them a full day of testing. Again, the approach was flawless.

The first step entails slicing the apples and soaking them in Sprite for two to three minutes. I pour the Sprite into a bowl, add the apples, then swirl to combine the Sprite with all apple surfaces.

I’ve dipped apples in lemon juice, however it does change the flavor little. Additionally, I’ve only ever given the apples a quick dip in lemon juice, so the anti-browning action isn’t as effective.

Additionally, I’ve heard of people who use salt water to prevent apple browning. But once more, that would change the way the apples tasted.

But Sprite works fantastically. The fruit’s flavor is unaffected by it in any discernible way. And since the apples may tolerate a soak for two to three minutes, browning is effectively delayed for a longer period of time.

The method’s second step is to drain the apples and place them in plastic bags with zip tops. Squeeze the bags to remove as much air as you can. Next, put the slices in the refrigerator.

The apples have been in the refrigerator for a few days now, and they haven’t browned. This is beneficial if you need to prepare for the party in advance. Although cutting apples isn’t difficult, it can take a long time if you have a lot to accomplish. It’s convenient to know you can prepare the apples in advance and they will still look good.

I also tested the apples after they were taken out of the fridge and allowed to come to room temperature on a dish. Here is how they seemed right after I set them out.

You can see that I tested three distinct kinds. Although Jonathan and Ida Red were naturally lighter than The Fuji, all three of them continued to look young 24 hours after the Sprite bath.

After 30 minutes, here they are:

No discernible modification. Additionally, I tested the slices on the counter for several hours, and I didn’t see any browning.

So, buy some Sprite and zip top bags if you want fresh slices to carry in a lunch or serve at a party. Don’t forget the dipping caramel sauce!