Food preservation

Lemon or Lime as a Preservative (Complete Guide)

Lemon or lime can be used as a traditional preservative to improve the quality and shelf-life of a number of perishable goods.

You can use lime or lemon juice as a preservative to prevent fruits like apples, bananas, avocados from turning brown. You can also soak fruits before dehydrating them, in lemon juice and water so they last a little bit longer. Lemon juice may be also used in canning tomatoes.

In this article, we will discuss this issue in more detail. We will talk about whether lime and lemon preserve food. We’ll discuss how they might work as preservatives and give some examples of foods that could be preserved with these things.

Do Lime or Lemon Preserve Food?

Both lime and lemon can be used to preserve food to a degree. However, it is important to recognize that these fruits can vary quite significantly in their ability to do so.

When lemon or lime juice is added to foods or drinks, the acid they contain helps in inhibiting the growth of bacteria. Adding acidic substances also reducing the ability oxygen molecules have to interact with the molecules on the surface of the food. The slow down in the chemical reactions means that food will age or brown less quickly. Reducing oxidation also means that the food can retain more healthy vitamins.

However, the degree to which lime or lemon can be beneficial in food preservation varies because these fruits can vary significantly in their acidity levels. This can vary depending on the variety of lemon or lime, the age, size, and maturity of the fruits, and a number of other factors.

How Do Lime or Lemon Work as Preservatives?

As mentioned above, lemon juice and lime juice work as natural preservatives because of their acidic nature. Both lemons and limes contain both ascorbic and citric acids. And both of these have antibacterial and antioxidant properties. While standardized juices with specific acidity levels are recommended for long term preservation and canning, juice squeezed from the fresh fruits can also be used to prevent fresh fruits and vegetables from browning.

Which Foods Can Be Preserved With Lemon or Lime?

So, we’ve already covered the fact that lemon and lime can be useful preservatives for a range of foods – especially lemon juice with a standardized pH level. But which foods can benefit from the addition of one of these natural preservatives? Let’s look at a few examples:

Can Lemon Stop Apple or Other Fresh Fruits Going Brown?

Adding lemon juice to cut slices of apples, bananas, or other fruits can stop them from turning brown on exposure to the air. This will make sure that they remain looking good until you want to eat them, with very little impact on the flavor of the fruit. They will remain edible in a lunchbox kept at room temperature until you are ready to eat them. But more than this, adding the citrus juice will also give them two or three extra days of shelf life in your fridge.

Can You Use Lemon or Lime Juice to Make Smoothies and Home-made Juices Last Longer?

When you buy fruit juices or smoothies from the store, these often contain substances that have been added to prolong their shelf life. If you make your own juices or smoothies at home, they will tend to go bad much more quickly than commercial varieties. To prevent this from happening, you can add some lemon juice to slow down the chemical aging processes and keep bacteria at bay. In addition to giving your juices or smoothies a little extra time in your fridge, adding citrus juices can also add some fresh and zesty flavor to your recipes – plus extra boosts of vitamins too. 

Can You Use Lemon or Lime Juice to Make Dried Fruit Last Longer?

Lemon or lime juice can also be used to improve the quality and shelf life of dried fruits. Before dehydrating fruits, soak them for ten minutes in a mixture made up of 50% water, 50% lemon juice. Again, this will prevent browning and will also mean that your dehydrated fruits should last a little longer than dried fruits that were not treated in this way. 

Does Lime Preserve Guacamole?

Just as lemon juice and other citrus juices will stop apples, bananas, etc., from turning brown, so these can be used to prevent the browning of avocados or any avocado-based dish (like guacamole, for example). When you add lime juice to your guacamole, it not only improves the flavor, it also stops it from changing color and means that it will last a couple of days longer in your fridge.

Can Lemon be Used To Preserve Cakes and Baked Goods?

Since lemons contain citric acid, in theory, this means that they may serve to keep cakes and other baked goods fresher for a little longer. Citric acid is commonly used commercially as a preservative in baked goods.

However, the citric acid that is used commercially usually does not come from citrus fruit. Rather, it is created from a mold through fermentation (often using molasses and corn starch). Because this is artificially made and is a powder, the concentration and properties are different from those of fresh lemon juice. 

So while lemon juice may help cakes stay fresher a little longer, it is not hugely reliable as a preservative because there are so many unknowns. The citric acid content can vary, and there is a lot to consider with regard to how adding lemon will change the chemical balance of the cake batter (and the flavor and rise of baked goods). Citric acid from a natural source like lemons will also decompose at high temperatures, so the temperature at which goods are baked will also have a bearing. 

What Foods Can’t Be Preserved With Lime or Lemon?

It is important to recognize that while lemon and lime juice can be beneficial in improving the quality and shelf life of fresh fruits and vegetables short term – they are not sufficient as a preservative to protect fresh produce over longer-term storage.

The best way to preserve fresh produce that is not being frozen is to follow proper canning advice to can, according to tried and tested scientific recipes. Lime or lemon juice can, however, be used in addition to canning processes. And can aid in improving the quality, appearance, taste, and longevity of properly canned goods. 

We’ll look at this in a little more depth shortly. But before we get onto that, it is important to recognize that there are certain foods that cannot ever be preserved with lime or lemon. Vegetarian ingredients can often benefit from the addition of lime or lemon juice. But these substances are not strong enough to preserve any meats. Preserving meats and animal-derived products always involve very careful thought and consideration.

How Are Lime or Lemon Juice Used in Canning?

In order to properly preserve fresh produce over the longer term, it is important to follow the canning process. Lemon and lime juice can be used in canning to add flavor and reducing browning. Mostly, however, it is used to augment the natural acidity of certain foods that are being canned.

Canning acids are used to create an environment where bad bacteria will not grow. Lemon and lime juices are both examples of canning acids. And they are used in a wide range of canning recipes – most commonly and notably those involving tomatoes.

Canning Acids and Their pH

Apple Cider Vinegar3.1
White Vinegar (Distilled)2.4- 3.4
Fresh Oranges3.3-4.3
Fresh Lemon Juice2.0-2.6 *
Fresh Lime Juice2.0-2.35

* Note, however, as mentioned above, that there are a number of factors that can lead to variations in the pH and acidity content of fresh citrus fruits. The average acidity content of fresh lemons is about 5%, but some are far less acidic.

Meyer lemons and Key limes are different and weaker, and so it is generally recommended that these are not used in most canning recipes. However, there are certain lab-tested recipes where these can be used. Again, always follow canning instructions from a reputable source, and follow them to the letter to make sure that nothing goes wrong. 

Therefore, if you are trying to preserve food using lemon juice (rather than just trying to stop food from browning in the shorter term), then it is best to use commercially bottled juice.

Commercially bottled lemon juice will have a uniform pH. Unlike lemon of lime juice that you have freshly squeezed yourself from the fruit, it will not vary widely in its acidity level. This means that it will have a much more consistent effect, and so you can depend upon it to preserve food more effectively over the longer term. 

Using bottled lemon juice is similar to using vinegar, and it is used in preserves in a similar way. The fresh juice, however, cannot be used with such reliability if you are planning on using it in canning or any other form of longer-term food preservation. 

This is why most canning recipes call for bottled juice rather than fresh juice. Erring on the side of caution means that there should not be any nasty surprises, and food safety can be maintained. If a canning recipe calls for bottled lemon or lime juice, you should not use fresh. However, if the recipe calls for fresh juice, then this is what you can use.

One exception where fresh lemons might be used in canning is where they are not being relied upon for their acidity. If the acidity comes from elsewhere, you might just be adding lemon juice to a canning recipe to balance the sweetness in a jam or jelly, for example. In these cases, fresh lemon juice may be preferable in taste and is perfectly safe and sensible to use. 

Can You Use Bottled Lemon or Lime Juice Instead of Vinegars in Canning Recipes?

Since lemon and lime juice has a more acidic pH than vinegar, you can safely substitute vinegar with lemon or lime juice in a recipe. However, it is important to note that you cannot substitute lemon or lime juice for vinegar, nor for other less acidic citrus juices (like orange juice) as these have less acidity and so may not provide the requisite acidity levels for food safety. 

Can You Substitute Citric Acid for Lemon or Lime Juice in Canning Recipes?

Unfortunately, though they are uniform in pH and acidity levels, commercial lemon and lime juice contain sulfites. Some people have sulfite sensitivity or allergies. Citric acid can potentially be substituted in appropriate ratios in such scenarios, or you can consider canning recipes that can cope with having canning acids with lower acidity, so fresh juices or vinegar could be used. 

Some great canning recipes using fresh lime juices for canning salsas, for example, can be found in Ball’s 2016 canning book. 

Why Is pH Important in Canning?

PH and acidity are important in canning because dangerous pathogens such as Botulinum toxins can survive or grow in some foods at certain levels of acidity. The FDA recommends that naturally acidic foods such as fruit/ jams and jellies and acidified foods (such as pickles and salsa) have safe pH levels before canning. A pH of 4.6 or below is needed in order to achieve safe canning without the use of pressure processing. Lemon and lime juice are used to achieve these levels in a range of recipes. 

Here is a table of pH levels for different tomato varieties canned with and without lemon juice:

      Tomato Variety

Tomato VarietyTomato pHPH of salsa with lemon juicePH of Salsa without lemon juice
Bush Celebrity4.934.154.75
First Prize54.34.87
Dr Carolyn5.014.24.72
Health Kick5.044.144.88
Super Italian Paste5.064.234.85
Vita Gold5.094.094.84
Super Marzano5.24.25

The table above shows tomatoes grown in Williston, N.D. Approx. 100g of raw tomato pulp was used in pH measurement, and 139g of cooked salsa was used in pH measurement. 

To ensure the safe canning of tomatoes, it is typically recommended that 2 tbsp of bottled lemon juice or half a teaspoon of citric acid are added per quart. (Or 1 tbsp/ ¼ tsp per pint jar.)

As you can see, salsa canned without lemon juice for these tomatoes in the table above did not bring pH down below the recommended level.

Sugar can be added to offset the acidic flavor if desired.

As you can see from the above, lemon juice and lime juice can make a big difference to food safety in canning. And as you have learned in this article, they can also be used as short term preservatives in a number of different applications.

Understanding natural preservatives and their strengths and limitations is very important. It can help you avoid any common canning issues and make sure your food is not wasted but stays in good condition and looking and tasting good for as long as possible.

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