Limes can turn yellow when they become overripe, and lemons are green when they are underripe. So you can be forgiven for thinking they are the same fruit.
In actuality, while they come from the same family of citrus fruits, they are not the same fruit at different stages of life.
Lemons turn from green to yellow as the chlorophyll in the rind is replaced with anthocyanin as they ripen.
Limes will turn a yellow color too when they are fully ripened, but they are often picked when under-ripe and green. This is because they are easier to transport and will last longer in stores if they are less ripe when picked and shipped.
The scientific name for lemons is Citrus limon whereas the lime’s is Citrus aurantifolia. This shows that they are both descended from a common ancestor, but are not in fact the same species.
Where do they grow?
Limes need a warmer temperature to grow and are often grown in tropical and subtropical climates.
Brazil and Mexico produce around 40% of the globe’s Persian and West Indian lime supply. They are also grown commercially in Israel, Vietnam, Guatemala, and other South American countries.
Lemons are hardier and can be found growing in moderate climates around the globe. The largest exporters of lemons are Brazil, Argentina, Mexico, India, and China.
In the US, the USDA gives areas of land plant hardiness zones depending on the climate. Lemons are grown in American zones 9-11.
What do they taste like?
Limes are more bitter, whereas lemons are sourer.
The taste of limes is often described as tart and acidic, with a slight hint of sweetness.
Lemons tend to be sour and mouth-puckering, but add a very refreshing sense to whatever you are using them in.
What do they look like?
Limes tend to be smaller than lemons, and are often much more rounded. They usually only reach between 1 and 2 inches in diameter. They have an intense green rind.
It is not only the fruit that is smaller, but lime trees tend to be shorter too. They are fairly slim and have small leaves on the branches.
Lemons are larger and more oval, about 2 to 4 inches in diameter. Lemons are a deep, rich yellow in color when they are ripe.
Lemon trees can grow to become enormous, reaching heights of around 20 feet. They have broader branches and much bigger, more oblong leaves.
How many variations are there?
There are 20 different varieties of limes, ranging from Australian dessert limes to the more common key limes.
The most widely available lime species in the United States are known as the Tahitian or Persian lime, and the Mexican or Key lime.
There are around 25 different variations of lemon species, but the three most common ones are Eureka, Lisbon, and Meyer.
Lisbon lemons have a big ‘nipple’ that stands out on one end of the fruit. Eureka lemons have a much smaller and less pronounced nipple. The rind is also variable between the types.
Meyer lemons have a thin rind, Lisbon lemons have a smooth rind and Eureka lemons have a less even surface.
What are the origins?
In 2011, a group of researchers from China looked into the origins of various citrus fruits. They traced the DNA patterns of hybrid citrus fruits backward to find the species they originated from.
According to their research, lemons are derived from male citrons and female sour oranges. Sour oranges are also a hybrid species, meaning that lemons have a 3-way mix of genetic roots. Sour oranges are a hybrid between pomelos and mandarin oranges.
Key limes are a hybrid between female micranthas and male citrons. Persian limes are a 4-way hybrid as an offspring of key limes and lemons. This means that they have DNA that can be traced to citrons, mandarin oranges, pomelos, and micranthas.
This ancestral link can be used to explain why the two different species of citrus fruits share common traits.
What are the nutritional profiles?
Lemon (1 fruit ~ 108g)
Lime (1 fruit ~ 67g)
Fat is used in the body as a method of storing excess energy to be used as a fuel source later. You need a moderate amount of fat in your diet to remain healthy. It is used to help your body digest fat soluble vitamins such as A, D, and E.
Carbohydrates provide your body with the most readily available source of energy. If you do not consume enough, this can cause fatigue, nausea, lethargy, and many other issues.
Carbohydrate sources often come with a bucketload of important nutrients. If your intake of carbohydrates is too low, this can potentially cause knock-on effects for other requirements.
Sugar is part of the carbohydrate umbrella and is needed in your diet as an energy source. To keep your intake at a healthy level, you should only allow sugars to make up around 5% of your daily calorie intake.
Too little glucose and your body will enter a state of ketosis as your body breaks down fat into energy.
Fiber is needed to help your digestive system. Too little fiber and you may become constipated which can lead to a whole host of health issues. It also helps to keep you full and ensure your blood cholesterol levels remain stable.
Protein is one of the main building blocks of your body. It is required to create many different tissues in the body and is vital to good health.
There are at least 10,000 different proteins involved in the creation and maintenance of the human body.
In terms of micronutrient profiles, this is how the 2 fruits compare.
Lemon (1 fruit ~ 108g)
Lime (1 fruit ~ 67g)
Both fruits contain a decent amount of Vitamin C for their size, but on all of these micronutrients, the lemon far outperforms the lime.
Vitamin A is important for eyesight, immunity, and fertility. Neither fruit is a good source of this and it will need to be supplemented by the rest of your diet.
Vitamin C prevents you from getting scurvy, and limes used to be given to British sailors suffering from it. This is where their nickname ‘Limeys’ came from. This is because of the large quantities of Vitamin C that are contained within the lime.
It is equally possible that they were given lemons too, as, at this point in time, there was not much distinction between the 2 species.
It helps to keep your body in good overall health and is important to ensure you are not deficient in it. Vitamin C is also used to protect against cell damage and to help with iron absorption.
It is also vital to the formation of collagen in the body, a substance that helps to heal wounds.
Vitamin B6 is used to assist with the transportation of oxygen around the body via your red blood cells. It is vital to the production of hemoglobin and is very important to include in your diet.
Calcium helps your bones grow strong and not break easily. It also helps with the clotting of your blood, contraction of muscles, and the beating of your heart.
Iron is vital to make red blood cells in the body. These are the cells that transport oxygen around the body and keep all of your muscles in working condition.
If you have a prolonged deficiency in iron, you can develop anemia which can be very impactful on your day to day life.
Magnesium regulates nerve and muscle function within the body, as well as blood pressure and blood sugar levels. It is a vital micronutrient to create DNA and proteins.
Copper is also used in the creation of red blood cells. Studies suggest that having a diet rich in copper can help to prevent the development of osteoporosis and cardiovascular diseases.
Limes have the most citric acid of any of the citrus fruits. Roughly 8% of the fruit’s weight is citric acid, compared to 5% of a lemon.
When you compare a liter of lime and lemon juice, lemon slightly has the edge in citric acid content. Per liter of lemon juice, there is on average 48g of citric acid, whereas for lime juice this is more commonly around 45.8g.
Both fruits have taken the culinary world by storm. Many recipes use either of their juices and rinds to add some sourness and acidity to a dish.
Lemon is slightly milder and can be used to add a hit of refreshment to any dish! Desserts, such as lemon meringue pie or tarte au citron are beautiful dishes that showcase the lemon’s tangy flavor.
It is commonly added to fish and vegetables to lift the dish.
Lime is commonly used in Mexican, Thai, and Vietnamese dishes. A hugely popular dessert made with limes is Key Lime Pie, a staple American favorite. It is also a common ingredient in ceviches, summer drinks, salsa, and fruit salad.
Both fruits have been made into essential oils to use for both medical and cosmetic goals. They are also commonly used as scents in cleaning products due to their refreshing smell.
There have been many studies done into the health benefits of citrus fruits. In 2014, a study was conducted into the effects of citric acid on oxidative stress in the brains and livers of lipopolysaccharide treated mice.
This study showed a clear link between the consumption of citric acid and an anti-inflammatory response in the brain and liver.
A 2015 study by a team of Chinese researchers proved that citrus fruits have numerous beneficial health impacts. These include anti-inflammatory, antioxidant, and anti-cancer effects.
They can also offer neuroprotective and cardiovascular health benefits. These cardiovascular benefits are due to the flavonoid content, and kaffir lime has even been studied to be used in conjunction with chemotherapy to protect the patient’s heart.
Lemons have a lower GI (glycemic index) than limes, meaning that your blood glucose concentration is reduced. This is because the acidity causes your body to digest starches more slowly.
It has not been tested with limes, however, the hypothesis states that it would have a similar effect. Sweet limes may potentially be used to control diabetes mellitus (Type 1) due to their hypoglycemic effects on the body.
The acidity of lemons and limes means that ingesting an excessive amount can lead to GERD (gastroesophageal reflux disease) and heartburn. This is exacerbated by consuming excess acidity on an empty stomach.
Dentists are not huge fans of citrus, as the acid can eat away at tooth enamel. This can cause your teeth to yellow, become more sensitive, and develop cavities. To reduce the risks of this happening, you can water down the juice or drink it through a straw.
Limonene, a component found in citrus fruits, is a mild irritant to human skin and eyes. If you have a limonene allergy, you can develop contact dermatitis if you touch citrus fruits.