Table of contents
Sun-dried tomatoes or dried tomatoes (Solanum lycopersicum) have a distinctive, intense flavor. They are used raw or cooked, especially in Mediterranean dishes. Organic?
Culinary uses of dried tomatoes
Sun-dried (or dried) tomatoes taste intensely fruity-sweet and 'umami'. These can be found dry-packed, in brine or pickled in oil. Depending on the type of use, you can soak sun-dried tomatoes in salt before processing and rinse off the excess salt. The sun-dried tomatoes preserved in oil can be eaten directly (e.g., as antipasti) or processed.
Can you eat sun-dried tomatoes raw? Sun-dried tomatoes are suitable both for eating raw and for use in cooked dishes. But whether they can really be considered raw food is difficult to judge. If necessary, ask your health food store or your trusted shop whether the drying temperature was maintained below 40 °C. Sun-dried tomatoes may have experienced higher drying temperatures.
Popular uses include salads (e.g., rocket and baby spinach with figs, Mediterranean pasta salad), sandwiches, omelettes or vegan piadinas. Sun-dried tomatoes are also great as a snack - they make a wonderful combination with dried fruits and nuts. They add splashes of color to Mediterranean dishes such as risotto, pasta, pizza and bruschetta and are also excellent for flavoring bread and rolls. Other recommended recipes are pesto rosso made with sun-dried tomatoes and sun-dried tomato tart with zucchini hummus.
How to prepare sun-dried tomatoes
If you have too many fresh, ripe tomatoes, you can make sun-dried tomatoes (without salt) with them. They are traditionally dried in the sun in Mediterranean countries (hence the name sun-dried). You can also use a dehydrator to make dried tomatoes in raw food quality (ready after 10-12 hours at approx. 42 °C).
Sun-dried tomatoes are made in the oven without a dehydrator. Temperatures below 50 °C are usually difficult to regulate here, which is why these dried tomatoes are no longer considered raw. To do this, wash 2-3 kg of ripe tomatoes (“San Marzano” or “Pozzano” tomatoes), cut open one long side and unfold. If the tomatoes are of other shapes, cut in half and remove soft spots and larger stalks. Place the tomato halves close together, skin side down, on a wire rack (oven rack). Optionally season the halves with dried herbs (e.g., basil, thyme). Allow to air dry for a few hours, turning the tomatoes occasionally. Put the partially dried tomatoes in the oven (circulating air) preheated to approx. 80 °C (no longer raw!) and dry for approx. 7 hours, depending on the size and water content of the tomatoes. At lower temperatures (approx. 50 °C) you have to allow more time. Stick a thin stick in the door or open the oven door in between so that the moisture can escape. When the tomato halves are leathery to rubbery in texture and are not damp or crumbly, they are done drying.
If necessary, you can salt the tomato halves and get dried tomatoes with salt.
Vegan recipe for Chickpea Salad with Sun-dried Tomatoes
Ingredients (for 2 people): 480 g cooked chickpeas (e.g., from a can), 180 g dried tomatoes (organic), 1 red sweet pepper, 1 red onion, 6 sprigs of parsley, ½ lemon, 1 clove of garlic, 4 tablespoons of rapeseed oil, 1 dash of agave syrup, 1 pinch of ground cumin, some (salt and) pepper.
Procedure: Cut the sun-dried tomatoes into pieces. Wash the sweet peppers and also cut into pieces. Peel and dice the onions. Rinse the parsley, shake dry and roughly chop. Place the cooked chickpeas, sundried tomatoes, sweet peppers, onion and parsley in a bowl and mix. For the dressing, squeeze out half the lemon, peel the garlic clove and squeeze the lemon juice with a garlic press. Add oil and agave syrup and mix well. Season with cumin and pepper to taste. Little or no salt is needed because dried tomatoes have a certain salt content. Pour the dressing over the vegan chickpea salad, mix well and serve.
To find vegan recipes with sun-dried tomatoes follow the reference: "Recipes that have the most of this ingredient".
| Not only vegans and vegetarians should read this: A Vegan Diet Can Be Unhealthy. Nutrition Mistakes. |
Purchasing - storage
You can buy sun-dried tomatoes in the larger branches of most supermarket chains including Walmart, Costco, Whole Foods Market, Target, Albertsons and Safeway (United States); Asda, Sainsbury’s, Tesco, Morrisons, Aldi, Lidl, and Holland & Barret (Great Britain); Metro, Extra Foods, Real Canadian Superstore and Goodness Me (Canada); and Coles, Woolworths, and Harris Farm (Australia). Organic supermarkets also sell sun-dried tomatoes in organic quality. In many places, however, sun-dried tomatoes can only be found in oil. Good places to go for sun-dried organic tomatoes without oil are health food stores and delicatessens.
Storage tips
Sun-dried tomatoes will keep for several months in airtight containers stored in a cool, dry place. If you dried your own tomato halves, it is advisable to put some rice in a tea bag in the container so that it can absorb any residual moisture.
Ingredients - nutritional values - calories
Tomatoes (dried) contain 258 kcal per 100 g, which come primarily from carbohydrates (56 g/100g, of which 38 g are sugar). The water content is only around 15 % instead of 95 %, i.e., ⅙ of fresh tomatoes. 100 g tomatoes (dried) contain 14 g proteins. The fat content is rather low at 3 g/100g.
100 g of dried tomatoes cover 41.8 % of the daily sugar requirement. The sugar content is comparable to that of dried plums (38 g/100g) and dried peaches (42 g/100g). The salt content is 272 mg/100g (11.3 % of the daily requirement). In comparison, dried tomato with salt has almost 10 times the amount of table salt (2001 mg/100g).1
Do dried tomatoes contain potassium? Sun-dried tomatoes contain 3427 mg/100g potassium which covers 171 % of the daily requirement. Dried herbs such as dill (3308 mg/100g) and tarragon (3020 mg/100g) have a similar amount - but much less is used. Even more potassium is present in kombu seaweed (6100 mg/100g).1
Dried tomatoes have 1.8 mg manganese per 100 g (92 % of the daily requirement). Roasted peanuts (1.8 g/100g) and sprouted wheat (1.9 g/100g) have comparable amounts. At 8.8 g/100g, raw pine nuts contain almost 5 times the manganese.1
100 g of dried tomatoes contain 62 % of the daily iron requirement. Dried tomatoes contain 9.1 mg/100g iron which can be compared with that of dried pumpkin seeds (8.8 mg/100g) and dried porcini mushrooms (8.4 mg/100g). Even more iron is found in dried herbs such as thyme (124 mg/100g) and basil (90 mg/100g); again remember to only use small amounts of each.1
Do dried tomatoes contain vitamins? Dried tomatoes are rich in niacin (9 mg/100g; 57 % of the daily requirement) and vitamin K (43 µg/100g; 57 % of the daily requirement). Vitamin C and thiamine are also preserved relatively well with gentle drying.1,4,5
Do tomatoes contain glutamate? Dried tomatoes contain about 5 % monosodium glutamate, which accounts for their umami taste.
You can find the total ingredients of sun-dried tomatoes, the coverage of the daily requirement and comparison values with other ingredients in our nutrient tables above.
Health effects
Are sun-dried tomatoes healthy? How healthy are dried tomatoes? Both the vitamin C content and water content are reduced by drying. Therefore, 100 g of dried tomatoes are richer in vitamin C than 100 g of fresh tomatoes. Dehydrated tomatoes also have higher levels of carotenoids, lycopene and phenolic compounds, as well as increased antioxidant activity (after 90 and 180 days of storage).3 They can thus prevent damage to cells caused by free radicals.
A 2015 study compared the levels of phenols and ascorbic acid (vitamin C) and antioxidant capacity of fresh and dried tomatoes. The study found significant losses in all measured variables for all thermally dried samples. However, there were statistically significant differences among the methods of thermal drying, and with freeze dried tomatoes. Freeze-dried tomatoes showed better levels of the variables and antioxidant properties.4
However, a 2020 study examining the effects of different drying temperatures (and thus drying times) on chemical and bioactive parameters of dried tomatoes concluded that tomatoes dried at a higher temperature (60 °C, 360 min) effectively preserve certain bioactive components (phenols, antioxidant activity in general, flavonoids) after drying and during the storage period. This also applies to lycopene, but not to vitamin C. The vitamin C content decreases steadily during drying in proportion to the rise in temperature (40, 50 and 60 °C).5
For more information on the health aspects, read the Tomato (raw) article.
Dangers - intolerances - side effects
A 2019 study examined fresh and dried tomato products from markets and packhouses in the Puglia region of southern Italy for Alternaria toxins (mycotoxins, mold toxins). Overall, dried tomatoes showed a higher level of contamination than fresh ones. A connection with the use of sodium chloride in the drying process could not be determined.2
Are sun-dried tomatoes in oil healthy? Sun-dried tomatoes preserved in oil have a higher calorie content compared to dried tomatoes without oil. These are therefore not suitable for losing weight.
Ecological footprint - animal welfare
As with fresh tomatoes, the ecological footprint of dried tomatoes depends on the cultivation method and the region of cultivation, in addition to the drying method. For example, the production of tomatoes from a heated greenhouse produces almost 10 times more greenhouse gas emissions than regional tomatoes grown outdoors.8 Tomatoes are usually dried by industrial processes, or, ideally, by solar heat. In order to keep the emissions as low as possible, it is best to look for regional, sun-dried tomatoes from organic cultivation when shopping. With this cultivation method, no chemical fertilizers or pesticides are used, which play a major role in conventional agriculture.
There are reports of sun-dried tomatoes being sold with labels suggesting Italian origin, but the small print then says Turkey as the country of origin and Greece as country of production.11 So please always read. The origin of dried tomatoes should be stated on the product.
The amount of water needed to produce 1 kg of dried tomatoes is very high at 4276 liters compared to fresh tomatoes (214 liters) or tomato paste (855 liters).9 To minimize the use of fossil fuels, solar greenhouse dryers are used. In addition, research is being conducted to optimize the sun drying process by pre-treating the tomatoes (e.g. blanching) to reduce the heat required for drying.10
Worldwide occurrence - cultivation
The history of drying food for preservation dates back to 20,000 B.C. Evidence shows that cultures in the Middle East and the Orient have been drying food for preservation since 12,000 B.C. Food was actively dried in the hot sun. By the end of the 18th century the French successfully developed a drying device to dry fruit and vegetables at controlled temperatures. The French sliced the fruit and vegetables, dried them with hot air (40 °C), pressed them and then sealed them with tin foil (aluminum foil). Mechanical drying began around the turn of the century to replace natural sun drying. Towards the end of the second world war, mechanical drying experienced a rapid upswing and methods such as cupboard, tray or tunnel drying were used; drum drying came later. This was followed by developments such as spray drying, fluidized bed drying, vacuum drying and freeze drying.6
The origin, cultivation and harvest of tomatoes are described in the article on fresh tomatoes.
Industrial production
Most dryers used in the food industry are convective, which means that they use hot air to both supply heat to evaporate the water and remove the evaporated moisture from the product. This is by far the most commonly used drying method on an industrial scale, as it is simple and easy to use and (for the time being) has relatively low investment costs, although it has poor energy efficiency.6
Additional information
Industrial processing of tomatoes produces a lot of waste consisting of skins, seeds, fibrous parts and pulp residues. The disposal of tomato waste is a global problem, both ecologically and economically. Recycling or reusing these by-products can reduce processing costs. Although these wastes have no commercial value, they are a rich source of nutrients and biologically active compounds. Tomato skins have been shown to be a richer source of lycopene and polyphenolic compounds than the pulp. Tomato seeds have been shown to contain approximately 20% nutritional quality oil, as well as carotenoids, proteins, polyphenols, phytosterols, minerals and fiber.7
Alternate names
Sun-dried tomatoes are also known as dried tomatoes.
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