Quick answers
Eating unripe tomatoes can cause digestive issues like stomach cramps, bloating, and diarrhea due to their high starch and acid content. The tomatine toxin in unripe tomatoes may also cause headaches, dizziness, and joint pain in some people. While generally safe in small amounts, eating too many green tomatoes regularly is not recommended. Ripe red tomatoes are healthier and tastier.
What are unripe tomatoes?
Tomatoes go through various stages of ripeness. An unripe tomato is one that has not yet fully ripened on the vine and turned red. Unripe tomatoes are green in color because the chlorophyll in the tomato has not yet been replaced by the red lycopene pigment.
Some common types of unripe tomatoes are:
- Green tomatoes – These are tomatoes picked prematurely while still green and have not been allowed to ripen fully on the vine.
- Breaker tomatoes – These show the first signs of ripening with some pinkish-red streaks on the blossom end but are still mostly green.
- Turning tomatoes – In these, the green color has lightened and about half or more of the surface shows pinkish-red color.
Ripe tomatoes have vivid red color with a more even color distribution, softer flesh, more sweetness, and complex flavor. Unripe tomatoes lack the texture, sugar content, and full flavor of ripe tomatoes and have a bitter, sour, grassy taste instead.
Why are some tomatoes sold unripe?
Although ripe tomatoes taste better, unripe green tomatoes are often picked and sold because:
- They are less perishable and have a longer shelf life than ripe tomatoes.
- Ripe tomatoes are fragile and get damaged easily during transportation.
- Unripe tomatoes ripen during storage and transportation if stored at room temperature.
- Ripe tomatoes must be used quickly before they spoil but unripe ones can ripen slowly on the counter.
For these reasons, tomatoes are often harvested prematurely to prolong storage life and reduce food waste. Although not as tasty, unripe tomatoes are still edible and safe to eat.
Nutrition content
| Nutrient | Unripe tomato | Ripe tomato |
|---|---|---|
| Water | 93% | 94% |
| Protein | 1.0g | 0.9g |
| Fiber | 1.2g | 1.5g |
| Sugar | 2.5g | 3.9g |
| Lycopene | 0.7mg | 2.6mg |
| Potassium | 237mg | 292mg |
While unripe green tomatoes have a similar nutrient profile to ripe red ones, they are lower in beneficial lycopene levels. Lycopene is a bright red carotenoid pigment and antioxidant found abundantly in ripe red tomatoes. Unripe green tomatoes contain far less lycopene as the pathways for its synthesis are not fully active until ripening is complete.
Are unripe tomatoes safe to eat?
Unripe green tomatoes are generally safe to eat in small to moderate quantities, especially when cooked. However, eating too many raw green tomatoes can cause digestive problems in some people due to the following compounds:
- Tomatine – This is a glycoalkaloid with pesticidal properties found in tomatoes. Levels are highest in unripe green tomatoes and reduce as they ripen. Ingesting too much tomatine can cause headaches, dizziness, and joint pain in sensitive individuals.
- Solanine – Another toxin compound related to tomatine that impacts nerve impulses. Unripe tomatoes have higher solanine levels that may cause gastrointestinal and neurological side effects if excessively consumed.
- Oxalic acid – Found at higher concentrations in unripe tomatoes. May interfere with mineral absorption and cause kidney stones when eaten in large amounts.
- Malic acid – Unripe green tomatoes are high in malic acid, which adds to their sour flavor. It may cause stomach discomfort when eaten raw in excess.
Cooking helps break down these compounds making unripe tomatoes safer to eat. The small amounts present in an occasional green tomato are not harmful to most people. However, anyone with gastrointestinal sensitivities may want to avoid large raw green tomatoes.
Side effects of eating unripe tomatoes
For most people, eating a few unripe tomatoes occasionally does not cause side effects. However, ingesting very high quantities can sometimes lead to:
- Stomach pain, cramps, bloating
- Nausea, vomiting, diarrhea
- Gas, intestinal irritation
- Headaches, dizziness (due to tomatine)
- Muscle and joint aches (due to solanine)
In general, cooked green tomatoes are safer than raw ones. The high acid and starch content of unripe tomatoes may irritate the digestive tract when eaten raw. Cooking helps break down the toxins.
Those already prone to gastrointestinal problems like irritable bowel syndrome may face greater discomfort from excess unripe tomatoes due to their fiber, acid, and compounds like oxalates. The starchiness can also feed gut bacteria leading to excess gas.
The tomatine and solanine compounds may cause neurological symptoms like headaches or dizziness in those sensitive to nightshade alkaloids when consumed in very high amounts. Joint pain is also possible.
As tomatoes ripen, the starch converts to sugar, acid levels reduce, and the alkaloids degrade making ripe red tomatoes easier to tolerate and digest.
Benefits of ripe versus unripe tomatoes
Ripe red tomatoes offer more health benefits and enjoyable eating experience due to:
- Higher lycopene levels – The red pigment lycopene is a powerful antioxidant. Unripe green tomatoes contain far less lycopene.
- More umami flavor – Ripe tomatoes have higher levels of glutamic acid that enhances their umami or savory richness.
- Increased sweetness – As tomatoes ripen, starch turns into sugars making ripe tomatoes naturally sweeter.
- Lower acidity – Ripe red tomatoes cause less gastric irritation because their malic acid content reduces significantly upon ripening.
- Better texture – Ripe tomatoes have softer flesh that is more pleasant to eat compared to the firmness of unripe fruit.
- Reduced toxicity – As tomatoes ripen, alkaloids like tomatine and solanine degrade making ripe tomatoes safer.
Overall ripe tomatoes have a more enjoyable taste, texture, nutrition profile, and better digestibility than their unripe versions. Allowing tomatoes to fully ripen results in a healthier, tastier fruit.
Tips for ripening tomatoes
If you end up with some unripe tomatoes, here are some tips to ripen them at home:
- Store unripe tomatoes at room temperature away from direct sunlight. Around 65-75 ̊F is ideal.
- Place tomatoes in a paper bag or wrapped in newspaper to trap ethylene gas that promotes ripening.
- Add a banana or apple to the bag. Fruits like bananas give off ethylene to speed up ripening.
- Keep checking daily for color change from green to red. Discard any tomatoes that mold instead of ripening.
- Gently squeeze to check for softness that indicates ripening. Ripe tomatoes feel yielding to gentle pressure.
- Eat tomatoes once fully red and soft. Refrigerate ripe ones to slow further ripening.
- Speed up ripening by moving tomatoes temporarily to a warmer spot for a day or two once color starts changing.
With some patience and proper storage, green tomatoes can ripen for a better eating experience. Use both vision and touch to assess ripeness before consuming.
How to eat unripe green tomatoes
While it’s best to allow tomatoes time to fully ripen, here are some safe ways to make use of unripe tomatoes:
- Fry green tomatoes – Sliced green tomatoes dipped in batter then fried makes for delicious fried green tomatoes.
- Pickle green tomatoes – Unripe tomatoes are often pickled intact or in slices to make green tomato relish.
- Cook in soups and stews – Dicing and cooking green tomatoes reduces toxicity for using in recipes like gumbo.
- Make chutney – Blend cooked green tomatoes with seasonings like onion, garlic, vinegar, and sugar for a tangy chutney.
- Substitute in salsa – Chopped unripe tomatoes can be combined with regular ripe tomatoes for a twist on salsa.
- Use in baked goods – Shredded green tomatoes work well in zucchini bread, muffins, tarts, and other baked recipes.
Cooking helps minimize digestibility issues with unripe tomatoes. When using in raw preparations, moderation is key.
Avoid eating large quantities of raw green tomatoes. If making salad with them, balance with ripe tomatoes and limit intake if you face discomfort.
Potential risks for sensitive groups
Although green tomatoes are not highly toxic, some higher risk groups may be more vulnerable to side effects from excess unripe tomatoes.
- Those with gastrointestinal conditions – People with IBS, IBD, GERD may face more discomfort due to the higher fiber, acid, and compounds.
- Individuals prone to kidney stones – The higher oxalates in green tomatoes risks stone formation in those with kidney problems.
- People on blood-thinning medication – Green tomatoes contain vitamin K that can interfere with anticoagulant medication effects.
- Pregnant women – It’s recommended to avoid excess green tomatoes as a precaution though any risks are unconfirmed.
- Children – Tomato plant parts and unripe fruit contain higher alkaloid levels and may affect children more severely.
Those vulnerable to the effects of unripe tomatoes due to medical conditions or age should consume cooked forms and limit quantity. When in doubt, avoid unripe tomatoes altogether to be safe.
Unripe versus rotten tomatoes
It’s important not to confuse unripe with rotten tomatoes. Here’s how to tell:
- Unripe tomatoes are firm, green, and sour but not unpleasant smelling if fresh.
- Rotten tomatoes are very mushy, wrinkled, damaged and emit a foul unpleasant odor.
- Unripe tomatoes may ripen further to red. Rotten tomatoes will deteriorate and mold without ripening.
- Unripe tomatoes can be eaten cooked. Moldy rotten tomatoes should be discarded.
- Check for damage, leaks, sunken soft spots that signal rot rather than simple unripeness.
Only use unripe green tomatoes that are still fresh and intact. Discard diseased, damaged, leaky tomatoes or those emitting a smelly fermented odor. These are decayed and unsafe to eat even when cooked well.
Conclusion
Eating the occasional green tomato is generally harmless, especially if cooked. However, consuming very high amounts of raw unripe tomatoes regularly may cause digestive and other issues in sensitive individuals due to the higher starch, acid, and compounds. Allowing tomatoes time to fully ripen results in a tastier, healthier fruit with lower acidity and fewer anti-nutrients. While green tomatoes can be used in moderation in cooked preparations, most people should avoid eating too many raw. Those vulnerable to nightshades, stomach discomfort, or on blood thinners should be especially cautious with unripe tomatoes. When in doubt, play it safe by keeping intake low and cooking green tomatoes for maximal digestion benefits.
