Lettuce Turning Red or Pink: The reasons and what you can do

Lettuce Turning Red

Lettuce leaves are beginning to turn pink or scarlet. Regarding the causes of this color change, you must be concerned. In addition, you might wonder if you can consume red or pink lettuce. Let’s investigate.

There are primarily two causes for lettuce turning red or pink. Exposure to ethylene gas is the first, while exposure to high temperatures is the second. It also becomes red or pink when it doesn’t get enough water, for another reason. This state is possible till the plant’s demise and fall.

There is a great deal to learn about it. To learn more about why lettuce becomes pink and whether eating pink lettuce is safe, keep reading this article.

Why Does Lettuce Turn Pink

The initial causes of lettuce turning pink include oxidation and exposure to ethylene gas. Ethylene gas comes in touch with lettuce. The lettuce becomes pink as a result of this exposure.

The surface discoloration is the other justification.

The oxidation of phenolic chemicals to quinones, which are then further oxidized to form colorful compounds, is commonly blamed for the surface discoloration of leafy vegetables.

Polyphenols are substances that are naturally present in foods that come from plants, including fruits, vegetables, tea, dark chocolate, wine, herbs, and spices.

The quantity and type of polyphenols in food are influenced by the food’s origin, maturity, and farming practices, transportation methods, storage conditions, and preparation methods.

In supermarkets, lettuce is preserved in airtight bags with higher quantities of nitrogen and carbon dioxide than the air outside. The high oxygen levels in the surroundings are made available to the lettuce when the packaging is opened.

The rate of oxidation increases with an increase in oxygen flow. As a result, air is crucial in the process that turns lettuce pink.

Therefore, improper handling during storage and packaging accelerates the oxidation process and adds to the pinking of the lettuce.

Exposure to high temperatures is the second factor in lettuce turning pink.

Lettuce overmatures more quickly when the temperature is high. This damages its green color in some way. Always keep lettuce in colder locations.

They lose their flavor and freshness if they are stored in heated environments. turning it pink as a result.

These are the two main factors that cause lettuce to change from green to pink.

What Affects the Pink Color In Lettuce

The causes listed below help to influence the pink hue of lettuce:


The intensity of the lettuce’s pink color is influenced by the light. The plant’s reaction to the light’s chemical stimulation intensifies it.

The reaction between the molecules of carotenoid and chlorophyll results in the pink hue.


One of the primary elements that can impact lettuce’s color is water. Your lettuce will absorb some water as you wash it, making it lighter in color.

On the other hand, if you wash your lettuce in vinegar or lemon juice, it will turn a darker color.


Bruising, trauma, and rough treatment can all cause phenol production. If lettuce is handled roughly, these color-changing chemicals can still be produced even at low temperatures in cold storage.

The pink tint of the lettuce might vary depending on how it is handled. It will turn brown more frequently the more tearing and damage there is.

Because of its flavorful, crunchy texture, and vast range of colors found in different kinds, lettuce is frequently used in numerous meals and salads.

However, if you don’t handle your lettuce carefully, it could turn brown or lose its fresh flavor. This is due to the possibility of enzymes coming into touch with oxygen when lettuce is bruised or ripped, which results in the leaves turning brown.

To avoid this, don’t handle your fresh food with any needless roughness or abrupt motions.


As lettuce ages, its color may change. The veins of the leaves may develop red and turn a darker shade of green.

This is so that the plant can create the green pigment chlorophyll and the yellow-to-pink carotenoids.

More carotenoids and less chlorophyll are generated as the plant ages.

How crunchy lettuce is also depends on how mature it is. Compared to older, more crunchy leaves, younger leaves are softer and more sensitive.


The lettuce’s color is impacted by the storage conditions.

  • The leaves will turn a pale green tint when kept in a cool, dark location.
  • The leaves will turn a darker green if you keep it in a light, room-temperature storage area.
  • It will start to become pink if you put it somewhere warm.

In addition to this, lettuce flavor can also be impacted by storage conditions.

Does the Lettuce Turn Pink Before or After Harvesting

When lettuce turns pink, it is impossible to identify if this is before or after harvesting.

The dying leaves and stems of lettuce plants release the plant hormone ethylene, which is what causes the color shift.

It need not occur after or before harvesting and can occur at any step of the growing process. However, following harvesting is definitely one time when lettuce will become pink.

This is due to the fact that processing procedures like washing, trimming, and cutting can turn lettuce leaves brown when they are exposed to air. Because of its distinctive pink discoloration, this lettuce is known as “pink rib.”

Why do Only the Outside Leaves Turn Pink or Brown

Several factors might induce a change in the color of the leaves. The fluctuating amount of chlorophyll on the leaves is one of the most frequent causes.

Plants are green because of chlorophyll, but when it decomposes, certain leaves may turn brown or red while other leaves retain their green color.

Since different types and concentrations of chlorophyll break down at various speeds, some outdoor leaves turn brown or pink while others stay green.

Due to their greater exposure to the effects of oxygen, the lettuce head’s outermost leaves will eventually turn brown.

The oxygen gas depletes when it reacts with the outer leaves, and the interaction is less pronounced with the inner portions of the lettuce head.

But let’s say the lettuce is divided into two pieces or the leaves are removed. In that instance, as the remaining lettuce is exposed, the likelihood of all the leaves or the interior becoming brown is considerably increased.

Lettuce that Commonly Turns Pink

Iceberg and romaine lettuce are the varieties that turn pink the most frequently.

When we hear the phrase “lettuce that frequently turns pink,” we frequently picture iceberg lettuce. Crisp and crispy, the pale green leaves of this lettuce kind are often the least expensive variety seen in grocery shops.

Romaine lettuce can, however, also turn pink or crimson. Iceberg lettuce is cheaper, while romaine is more expensive and has a more delicate flavor.

The plant’s leaves change color due to a process known as photo-oxidation, a natural chemical response to oxygen and light exposure.

The greens can be stored in an airtight container and kept away from light to avoid the harmless color change.

Is it Safe to Eat Lettuce When it Turns Pink?

One such food that people frequently eat is lettuce. It typically has a crisp texture and is green.

Since this item may multiply quickly, it is either consumed raw or in salads. Cooking lettuce is preferred by some people because they feel the nutrients will be more readily available to the body. Lettuce can be consumed raw or cooked.

There has been a chemical reaction that has turned the lettuce from green to pink. It’s not because of bacteria, fungi, or other microbes.

Plant substances referred to as polyphenols provide a number of health advantages. Consuming polyphenols consistently is known to improve digestion, cognitive health, and protect against heart disease, type 2 diabetes, and even some malignancies, therefore pink rib lettuce is safe to eat.

Even in storage, the lettuce will eventually go bad as it ages and develop a slimy layer that smells awful.

Toss out any lettuce that has gone bad, is wilted, slimy, or has beyond its expiration date since eating anything that has gone bad can make you sick.

When lettuce turns pink, make sure that the following things are true:

– Has the lettuce begun to wilt? If the answer is yes, it shouldn’t be consumed because it has been left out too long and could be contaminated with bacteria.

– Does the lettuce have any mold on it? If so, avoid eating it since this indicates the growth of fungi.

You can determine if it is okay to eat lettuce or not by asking similar questions.

Why Does Lettuce Turn Brown

With time, oxidation’s impacts cause the pink discoloration in lettuce to turn brown.

The majority of fruits and vegetables contain polyphenol oxidase (PPO), which controls the enzymatic browning of fresh horticulture products after bruising, cutting, or other cell injuries.

The impact of discoloration on leafy greens like lettuce and its variants can be reduced with sealed packaging.

The outer leaves’ phenols won’t be reacted with by the atmosphere’s invasive oxygen if the lettuce is sealed.

The lettuce was exposed to the air, which is one of the reasons it turned brown. This is because oxygen and the chlorophyll in the leaves interact, oxidizing the leaves.

Polyphenol oxidase, a naturally occurring enzyme in all plants, is another factor causing lettuce to turn brown.

The enzyme causes a chemical reaction that results in the production of the brown pigment termed melanin when it interacts with phenols and minerals in the plant.

The Takeaway

Thus, it is acceptable to say that twisting lettuce is not bad. However, you should consume pink lettuce as soon as you can since otherwise, it will rot and become unfit for consumption.

Only a chemical reaction may cause lettuce to turn pink, and this reaction is primarily brought on by two conditions: first, exposure to ethylene gas, and second, a high ambient temperature.

The pink lettuce is not a cause for concern other from that. As long as the lettuce is clean and free of slime or mold, it is safe to eat.