Solanum Lycopersicum
Tomato / Tomaat / Tomate / Tomate
When to buy // How to store // Impact // What's in it for you // Best way to prepare // Grow your own // Origin & History // Sources
When to buy
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Tomatoes are technically available year-round, thanks to imports and heated greenhouses. But the seasonal gap in flavour is unusually stark for this fruit specifically. In the Netherlands, outdoor-grown tomatoes typically run from July into October. Tomatoes can't survive frost, so outdoor planting doesn't start until mid-May, leaving a short window that heated greenhouse cultivation, the dominant method in Dutch tomato production, gets around entirely.
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Winter tomatoes are almost always heated-greenhouse or imported, and the flavour trade-off is real: tomato flavour comes from a delicate balance of sugars, acids, and over 400 volatile aroma compounds, a chemistry known to be disrupted by cold postharvest handling (source).
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On Ethylene
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Tomato is, quite literally, the model organism for how ethylene drives fruit ripening, most of what's known about the mechanism in fruit generally was first worked out in tomato.
Tomatoes follow an official USDA colour scale, moving through six defined stages: green, breaker (under 10% colour change), turning (10-30%), pink (30-60%), light red (60-90%), and red (over 90% coloured). Breaker is the turning point, both visually and biochemically. A green tomato produces almost no ethylene and barely responds if exposed to it, a dedicated "brake" gene keeps early ripening suppressed. That brake releases right around the breaker stage, triggering a self-amplifying ethylene burst. Once the burst starts, colour, softening, and flavour development all accelerate together. This stage is exploited commercially: Tomatoes are often picked mature green, before that ethylene burst, specifically to survive long-distance transport without bruising. They can be held at around 12.5°C for up to two weeks in that state before ripening is triggered artificially with ethylene gas closer to the point of sale (source). |
It works, colour develops on schedule, but it's also the most credible explanation for why supermarket tomatoes are so often accused of tasting like nothing: a tomato ripened on the vine develops its full mix of sugars, acids, and 400+ aroma compounds together, while one triggered into colour after the fact doesn't necessarily catch up on flavour at the same pace (source).
Nutrient content shifts dramatically during ripening, and lycopene leads the way: research shows that content climbs as much as 36% from green to fully red. With up to half of the final lycopene forming in the very last stretch, from red to deep red. Meaning a tomato picked at the first sign of red still has real development ahead of it. Vitamin C increases right up to full ripeness before a slight decline. Other antioxidants are less predictable: lutein is actually highest earlier, at the breaker stage, while beta-carotene and flavonoids peak somewhere in the pink-to-light-red middle ground, each compound has its own timeline rather than moving in lockstep (source and source). |
How to store
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Don't refrigerate ripe tomatoes, the resulting flavour loss is well-documented.
Production of flavour-associated volatiles is sensitive to temperatures below 12°C, and multiple independent studies confirm real, measurable loss: a PNAS study found no significant flavour volatile loss after 1 or 3 days of cold storage, but by 7 days in the cold, volatile content had dropped significantly in both cultivars tested, and even after a 3-day recovery at room temperature, volatiles remained significantly lower than on the day of harvest, which is damage that doesn't fully reverse. The exact tipping point between those two data points, 3 days and 7 days, hasn't been pinned down, but somewhere in that window is where real loss begins. A separate study pinned the mechanism down further: refrigerator temperatures around 4-6°C can cause severe alteration of the tomato aroma profile, while 12.5°C maintained noticeably better sensory quality than 10°C, suggesting there's a real threshold, not just "colder is always worse. A day or two in the fridge is unlikely to do much harm, based on the timeline above, but treat anything beyond that as a real trade-off. If you must refrigerate (travelling, surplus), bring tomatoes back to room temperature before eating, this recovers some but not all of the lost aroma. Keep tomatoes out of direct sunlight specifically, this is about heat and uncontrolled exposure degrading lycopene through oxidation (source). Interestingly, tightly controlled light treatments (UV-C, pulsed light) used in commercial research have actually been shown to boost lycopene content (source), but that's a specific technique, not something a sunny windowsill replicates. Ordinary daylight combined with heat works against lycopene, and will impact flavour and nutrient value of your tomato. |
A note on bruising
Tomatoes are considerably sensitive to mechanical damage, and it's a two-step process: the impact itself happens first, then the damaged tissue develops visible soft spots over the following 2-3 days, so bruising isn't always obvious right away. A drop test comparing three heights (20, 40, 60cm) found the highest drop height caused the most bruising and the sharpest drops in firmness, colour, and soluble solids after 48 hours, worse still when the bruised tomatoes were then stored at room temperature (22°C) rather than cooler. Bruising isn't just cosmetic here, it measurably degrades the tomato's key nutrient too. The same study found the highest-impact bruising significantly reduced lycopene and carotenoid content, alongside firmness and colour, particularly at the higher drop height and warmer storage temperature (source). A separate factor worth knowing: higher relative humidity and firmer fruit reduced bruise damage, while higher storage temperature and greater weight loss increased it, so a soft, dehydrated tomato bruises more easily than a firm, well-hydrated one. The practical takeaway: handle tomatoes gently, avoid stacking them deep, and if one does get knocked, use it soon rather than storing it, both the texture and the lycopene content take a hit that worsens with time and warmth. There's a popular trick worth mentioning: storing tomatoes stem-side down. The idea is that the small scar where the stem attaches is an entry point for moisture loss and mould, and turning it downward blocks that. The practical range: room temperature, out of direct sun, and use within a few days once ripe. If you need to slow ripening briefly, the least-bad cold option based on current research sits close to 12-12.5°C, cellar or unheated pantry territory, not a standard fridge. |
Historical storage
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Since tomatoes are watery, acidic, and don't keep long fresh, historical preservation focused almost entirely on transformation rather than storage. Turning the fruit into something shelf-stable before winter arrived. Drying, salting, and vinegar-based pickling were used long before mechanical refrigeration existed. Green, unripe tomatoes in particular were commonly pickled, the tartness of unripe fruit suited vinegar preservation well.
Canning became the tomato's defining preservation method once the technology existed. Nicolas Appert's early-19th-century breakthrough, sealing food in glass and heating it to kill microorganisms, was commercialised into tin cans by the 1810s. By the late 19th century, tomatoes specifically had become one of the most commonly canned vegetables. It was often easier to buy tinned tomatoes from a shop than to preserve them at home in glass jars, an early sign of how well-suited tomatoes were to industrial-scale preservation compared to home methods. |
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A specifically Italian tradition worth mentioning: sun-dried tomatoes preserved in olive oil. Farmers in southern Italy dried surplus tomatoes in the sun, then stored them in glass jars submerged in extra virgin olive oil. This both avoided waste from a short, glutted harvest season and helps enjoy tomatoes year-round.
It wasn't just a practical trick: a modern shelf-life study of this exact preparation found lycopene and other phytochemicals from the dried tomato actually enriched the surrounding olive oil over months of storage. And that keeping the jars in the dark protected the contents from degradation far better than light exposure did. |
Impact at a glance
Carbon footprint
This is the widest, most method-dependent range on this entire site, and the deciding factor isn't origin or season, it's whether the greenhouse is heated, and with what. A systematic review of 50 LCA studies found median emissions of 80 kg CO2-eq per tonne (0.08kg/kg) in open fields, 83 kg CO2-eq per tonne in unheated protected structures, and 1,709 kg CO2-eq per tonne (1.71kg/kg) in climate-controlled, heated greenhouses, more than 20 times higher. A separate Southern/Central European comparison found open-field tomatoes as low as 0.042kg CO2e/kg, with heated greenhouse scenarios elsewhere in the literature reaching as high as 10.1kg CO2e/kg. For open-field tomatoes, transportation to market is the largest single factor; for heated greenhouses, it's artificial heating. Weighting these by how tomatoes are actually traded internationally, roughly 60% of imported fresh tomatoes are greenhouse-grown, works out to an estimated 1.06kg CO2e per kg, closer to the heated-greenhouse end than the open-field end. This is a rough estimate based on a commercial market report rather than a peer-reviewed production split, and applies to internationally traded tomatoes specifically, not global production as a whole. The heating method matters more than heating itself. Greenhouses using renewable heat, wood pellets or geothermal, cut climate impact 3-5 times compared to fossil-fuel heating, down to roughly 0.4-0.7kg CO2e per kg, close to unheated greenhouse levels. The Netherlands already uses geothermal energy in commercial greenhouses for this reason, but it still supplies less than 10% of the sector's energy needs, so most Dutch greenhouse tomatoes today are still primarily gas-heated. (source) Taking that into account, renewables made up just 9.4% of Dutch greenhouse-sector energy in the most recent figures, the international weighted average barely shifts, from roughly 1.06 to 0.99kg CO2e per kg. The average itself isn't the real takeaway, though: a fossil-heated greenhouse tomato can carry a footprint 3-5 times higher than the same tomato grown in a renewably-heated one. How a greenhouse tomato was heated matters far more than how far it travelled to reach you. 
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Water use
Water footprints vary just as sharply by system and location. A study supplying the Sydney market found footprints of 5 to 53 litres per kg depending on production system and season, while a hyper-arid Israeli desert-greenhouse study found roughly 94 litres per kg. Interestingly, water and carbon footprints can trade off against each other: a system with a higher carbon footprint sometimes has a lower water footprint, and vice versa, meaning there's no single "most sustainable" tomato production method across every measure at once. Pesticide use Tomatoes sit in a genuine middle ground on EWG's 2026 guide, neither Dirty Dozen nor Clean Fifteen, alongside peppers, cucumbers, and citrus, carrying moderate rather than extreme residue levels. Within the EU, tomatoes are monitored on a rotating cycle, but seem to be moving in the wrong direction: EFSA's most recent comparison flagged tomatoes among the crops with rising exceedance rates, even as overall EU compliance stays above 96% (source). Food miles This is where the greenhouse-heating story from the carbon footprint section becomes directly relevant. The Netherlands is the world's second-largest tomato exporter after Mexico, with export volume regularly passing 1 million tonnes a year. Worth €2.1 billion in 2025, tomatoes are the single most valuable export product in the entire Dutch fruit and vegetable sector. Almost all of that is grown in heated greenhouses on roughly 1,900 hectares. Here's the twist: less than a tenth of what's grown stays in the Netherlands, the vast majority is exported, mainly to Germany (which sources roughly 48% of its tomatoes from Dutch greenhouses) and the UK (source). So a "local" Dutch tomato has often travelled a very short physical distance, but carries the heated-greenhouse carbon footprint discussed above, while a tomato imported from Spain or Morocco travelled further but was more likely grown in an unheated or open-field system with a much lower footprint per kilogram. Food miles and carbon footprint don't line up neatly here, and low distance doesn't necessarily mean low impact once heating enters the picture. Making an informed choice In winter, an imported field-grown tomato from Southern Europe often beats a Dutch greenhouse one on carbon footprint, since Dutch greenhouses are still mostly gas-heated in cold months. In summer, local wins again as heating demand drops. Look for signals of renewable heating (geothermal, residual heat) when you can, it cuts emissions 3-5x, more than the choice between local and imported ever will. |
What's in it for you
Nutrients
A medium tomato (about 123g) is roughly 94.5% water and genuinely low in calories, around 22 kcal, with about 4.8g carbohydrate, 1.5g fibre, and 1.1g protein, virtually no fat. Its standout nutrients are vitamin C, potassium, and folate, alongside a wide range of phytochemicals, lycopene chief among them. (source) At just 22 kcal, nutrient density looks pretty good, vitamin C, potassium, and folate punch well above the tomato's calorie weight. Fibre is genuinely low, 1.2-1.5g per 100g, and concentrates heavily in the skin, which holds an estimated 83% of the tomato's total flavonol content, so skin-on eating matters here too. (source) Protein is low too, under 1g per 100g, but not nutritionally empty: several essential amino acids are present, including leucine, lysine, and histidine, making up an estimated 40% of the tomato's total protein (source). There's no strong benchmark to say how this stacks up in quality, so treat it as present and varied rather than proven high-quality. |
Health benefitsTomatoes are best known for lycopene, the carotenoid responsible for their red colour and one of the most powerful antioxidants in the diet, Cornell research found it neutralises over 10 times more free radicals than vitamin E.
Heart health is backed by a systematic review of 25 cohort studies, which found higher lycopene intake or blood levels associated with 26% lower stroke risk, 14% lower cardiovascular disease risk, and 37% lower all-cause mortality, plausibly linked to lycopene's antioxidant effect on blood vessels and LDL oxidation. Skin health has direct experimental support too: a controlled human trial found a lycopene-rich tomato supplement blocked UV-induced stress markers in skin, and a separate trial found measurably less sun-related redness after 10 weeks of lycopene-rich tomato paste. |
Best way to prepare
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Counterintuitively, cooking increases lycopene availability rather than destroying it. The reason comes down to chemistry, not damage: lycopene naturally exists mostly in a stable, straight (all-trans) molecular shape that the body struggles to absorb well, and heat converts some of it into a bent (cis) shape that absorbs far more easily, like swapping a key that doesn't quite fit for one that does.
Fat makes the effect dramatically stronger, and this has been tested directly in human blood, not just in a lab dish. A controlled trial had participants eat tomatoes cooked with or without olive oil for five days. Those who ate tomatoes cooked in olive oil saw an 82% increase in trans-lycopene and a 40% increase in cis-lycopene in their blood plasma; the group eating tomatoes cooked without oil saw no significant change in trans-lycopene and only a 15% rise in cis-lycopene. Since lycopene is fat-soluble, oil doesn't just add calories, it's genuinely necessary for your body to absorb much of it at all. Cooking time and even other vegetables in the pan matter too. A study on tomato sauce found longer cooking time and olive oil both increased production of the more bioavailable bent isomers, and, unexpectedly, unblanched onion cooked alongside tomato and olive oil boosted the conversion further still, a compound released by the onion appears to help drive it (more in this study and this study). |
what also might be counterintuitive, is that store bought tomato paste is a better source of lycopene than a fresh tomato.
A controlled trial found tomato paste produced 2.5 times higher peak blood lycopene concentrations and 3.8 times higher total absorption over time than fresh tomatoes, despite containing the exact same lycopene isomer mix going in. This makes tomato paste the most valuable food source of bioavailable lycopene in humans of any commonly eaten tomato product. Fresh tomatoes still bring things paste can't fully replicate, vitamin C, texture, and fresh flavour compounds. So this isn't an argument for skipping fresh tomatoes altogether, just a reason not to think of paste as nutritionally inferior. 
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Grow your own
Planting & harvestingTomatoes come in two fundamentally different growth habits that determine almost everything else about how you grow them.
Determinate varieties are compact, stop growing at a set height, and ripen most of their fruit within a short 2-5 week window, useful for canning, but don't need staking. Indeterminate varieties keep growing, flowering, and fruiting continuously until frost kills them, often reaching 1.5-2.5m, and need staking, caging, or trellising throughout the season. Unlike most plants, tomatoes actually do better planted deep, burying part of the stem encourages extra root formation along the buried section, giving a stronger plant. |
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Space needed
Determinate varieties: roughly 45-75cm apart, with 1.2m between rows. Indeterminate varieties need more room, 45-90cm apart depending on support method (closer if staked, wider if left to sprawl), with rows at least 1.2-1.5m apart. Difficulty: moderate Tomatoes need consistent watering (uneven moisture causes cracking and blossom end rot), full sun (6-8 hours minimum for good flavour), and, for indeterminate types, ongoing pruning of side shoots ("suckers") to manage growth. They're also more disease-prone than other crops, avoid planting where potatoes, peppers, or eggplant grew in the previous two years, since they share the same nightshade-family diseases. Check out the growing guide by the RHS |
Origin & Botanical background
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The tomato, Solanum lycopersicum, belongs to the Solanaceae family, alongside potato, pepper, eggplant, and deadly nightshade, and shares some of its chemistry: the plant's leaves and stems contain meaningful levels of a toxin called tomatine and shouldn't be eaten.
The fruit itself starts out with the same compound while green, but tomatine drops roughly 100-fold as it ripens, leaving the red tomato you eat with almost none (source). The old myth that tomato seeds themselves are toxic and should be removed has no basis, they're perfectly safe and digestible. Tomato domestication was a genuine two-country affair: genomic research traces the lineage to wild, pea-sized Solanum pimpinellifolium, native to coastal Ecuador and Peru, which gave rise to an intermediate wild form, Solanum lycopersicum var. cerasiforme (source) That intermediate form spread north into Mesoamerica, where the actual domestication into the larger-fruited cultivated tomato is thought to have been completed by Mesoamerican peoples, with cultivation dating back to at least 700 CE, well before the Aztec Empire's height (source). |
From botanical curiosity to Italian staple
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Tomatoes reached Europe in the 1540s, arriving in Italy first via Spanish trade routes, but they weren't an instant culinary hit.
A detailed historical study tracing surviving 16th-century tomato specimens found they were grown mainly as ornamental curiosities for decades, viewed with suspicion partly due to their poisonous nightshade relatives. Now an italian staple, tomatoes only took off through the 18th and 19th centuries. This was driven by a mix of practical factors: Italy's climate suited the crop well, and its rise coincided with pasta's growing dominance in Italian cooking. Tomato sauce became, quite literally, the sauce pasta had been waiting for (source). Adoption also had a class dimension. Poorer households ate tomatoes well before the aristocracy did, partly because the wealthy's suspicion of the fruit as poisonous lingered longer. This suspicion was often (though not reliably) blamed on tin tableware reacting with the fruit's acidity, a popular explanation that persists without solid historical or medical documentation behind it. |
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The fruit/vegetable controversyBotanically, a tomato is unambiguously a fruit, it develops from the flower's ovary and carries seeds, exactly like cucumbers, peppers, and peas. But in 1893, the US Supreme Court ruled the opposite in Nix v. Hedden, a case brought by an importer trying to avoid a tariff that applied to vegetables but not fruit.
The Court didn't dispute the botany, Justice Horace Gray openly acknowledged tomatoes are "the fruit of a vine", but ruled that everyday language, not scientific classification, is what the law should follow: tomatoes are eaten with the main meal rather than as dessert. So in common speech they're vegetables, tariff or no tariff. The ruling still stands today, and sums up the whole debate neatly: it's a fruit by biology, a vegetable by legal and culinary convention, and both answers are correct depending on which question you're actually asking. |
Green grape to purple plum: tomato variaties
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Tomatoes are grouped by growth habit (determinate vs. indeterminate, above) and by fruit type: beefsteak (large, meaty slicers), plum/paste (San Marzano, Roma, favoured for sauce), cherry and grape (small, high sugar-to-acid ratio), and heirloom varieties, open-pollinated older cultivars prized for flavour and colour diversity over shelf life or uniformity.
The everyday round supermarket tomato belongs to its own category, "globe" tomatoes, not a single named variety but a type bred specifically for what commercial production demands: thick skin, uniform shape, and resistance to splitting and shipping damage. (source) It's a good example of a broader shift: tomato breeding has grown into a substantial global industry driven largely by demand for shelf life and uniform appearance. The trade-off is real and documented by the USDA: the same genetic mutations that extend shelf life by blocking ethylene synthesis consistently hurt flavour and nutritional value. So much so that most modern commercial varieties are now accepted to have lost both as a result. Even Haim Rabinowitch, the Israeli scientist behind the first commercially viable shelf-stable tomatoes in the 1970s-80s, later had to use genetic know-how specifically to reintroduce the flavour his own breeding programme had bred out. (source) |
Colour isn't just cosmetic.
Red tomatoes carry the most lycopene. Yellow and orange varieties trade it for different carotenoids, beta-carotene, prolycopene, usually with a milder, less acidic flavour. Green varieties that stay green when ripe (not unripe reds) top the charts for vitamin C and protein instead. Purple and black tomatoes are the real outlier: ordinary tomatoes contain no anthocyanins at all, these varieties were specifically bred to include them, the same antioxidant family found in blueberries, giving them measurably higher antioxidant capacity and slower ripening with better shelf life (source). Unlike lycopene, though, anthocyanins leach out when cooked, so raw is best if that's what you're after. (source) And loose tomatoes vs truss tomatoes? They're inherently the same (globe) variety. Tomatoes always grow in clusters, but breeders have since developed cultivars specifically selected for staying firmly on the vine, which is why most truss tomatoes today do come from their own, purpose-bred varieties. |
