Shoppers comparing salt
A plain tomato base leaves you to choose the other lunch ingredients. Compare tins using salt per 100g, then check the ingredients for added salt; a serving figure alone may reflect a different portion size.
Who is choosing tomatoes for a desk lunch?
People heating lunch at work
Check the exact tin’s heating instructions before planning a microwave lunch. ASDA Groceries instructs shoppers to transfer its Chopped Tomatoes 400g to a covered, vented microwaveable container and heat for two minutes at 900W.
Shoppers choosing a sauce texture
Smaller tomato pieces and a chunkier sauce suit different lunches. Mutti describes Polpa as finely chopped and suited to fast cooking; Napolina describes its standard chopped tomatoes as chunky. Compare their salt labels separately from those texture claims.
What matters when choosing a lower-salt tin?
Start with a like-for-like salt comparison, then decide which texture, heating method and leftover period will work for the lunch you plan to make.
| Priority | What to check | Your needs |
|---|---|---|
| Salt | Compare salt per 100g and read the ingredients for added salt. The NHS defines low salt for foods as 0.3g or less per 100g; a stated portion may be a different size from the one you use. | I want to compare tins on the same basis before adding other lunch ingredients. In the Food Standards Agency and Ipsos Northern Ireland’s 2024 survey of 611 people interviewed from 16 September to 23 November, 49% said they actively used traffic-light labelling when food shopping; its reported uses included checking salt, sugar and fat. That figure measures general label use, not tinned-tomato choices. |
| Texture | Check whether the tomatoes are finely chopped, standard chopped or whole plum tomatoes. Mutti describes Polpa as finely chopped for fast cooking, while Napolina describes its standard chopped tomatoes as chunky. | For a short lunch break, smaller pieces may fit the sauce I am making; for another dish, I may prefer distinct tomato pieces. Texture does not tell me the salt value. |
| Heating | Read the method and timings for the exact product and appliance. ASDA Groceries specifies a covered, vented microwaveable container and two minutes at 900W for its Chopped Tomatoes 400g; Tesco gives a three-to-four-minute hob method for its Italian Chopped Tomatoes 400g. | If I only have a microwave at work, I need instructions I can follow with a suitable container rather than assuming a hob method applies. |
| Leftovers | Check the pack size, decanting instructions and refrigerated use-within period. The cited Sainsbury’s chopped tomatoes specify two days after opening, while ASDA Groceries specifies four days for its chopped tomatoes. | Will I use the rest of an opened tin in time? A multi-pack also makes more sense if I expect to make tomato-based lunches regularly. |
Which desk-lunch mistakes are easy to avoid?
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Assuming an Italian or familiar brand has less salt
Origin and texture descriptions do not establish the salt content. ASDA Groceries declares 0.01g per 100g for its Chopped Tomatoes 400g; Mutti declares 0.30g per 100g for Polpa and lists added salt.
Compare the nutrition panels per 100g and read the ingredients before deciding which texture you prefer.
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Comparing different serving sizes
A half-can figure describes that stated portion, not necessarily the amount going into your lunch. The NHS notes that labels give nutrition information per 100g and may also give it per portion.
Use per-100g values to compare tins, then check the figure for the amount you expect to eat.
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Keeping leftovers in the opened tin
The cited ASDA, Sainsbury’s and M&S products instruct shoppers to move unused tomatoes to a non-metallic container and refrigerate them. Their stated use-within periods differ.
Decant leftovers and follow the storage period on the exact tin; note when you opened it if you plan another lunch.
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Planning lunch around a tin of plain tomatoes alone
The cited plain chopped tomatoes are tomato bases rather than prepared lunches, so the other ingredients and any seasoning remain part of the plan.
Decide what you will combine with the tomatoes and check those ingredients’ labels too if salt is your reason for comparing tins.
How do these tomato products differ?
These figures and instructions apply to the named products, not to every tin from each brand; read the label on the one you buy.
ASDA
ASDA Chopped Tomatoes 400g is a plain chopped-tomato base with microwave and hob instructions.
- ASDA Groceries declares 0.01g salt per 100g and lists tomatoes, concentrated tomato juice and citric acid.
- It is not a seasoned lunch. ASDA says to refrigerate unused contents in a non-metallic container and use them within four days.
M&S
M&S Chopped Italian Tomatoes 400g combines chopped tomatoes and tomato juice.
- Marks & Spencer declares 0.02g salt per 100g; its listed ingredients are chopped tomatoes, tomato juice and citric acid.
- For this product, the stated refrigerated period after opening is three days. Check the current label rather than applying its salt figure to the wider range.
Sainsbury’s
Sainsbury’s Chopped Tomatoes Can 400g is a plain tomato and concentrated-tomato-juice option.
- Sainsbury’s declares 0.07g salt per 100g and 0.14g per half-can serving for this tin.
- Its instructions say to decant, refrigerate and use opened contents within two days.
Tesco
Tesco Italian Chopped Tomatoes 400g has a stated hob-heating method.
- Tesco Groceries declares 0.09g salt per 100g and instructs shoppers to heat gently for three to four minutes, stirring occasionally.
- That is a hob method; check the tin’s instructions if your desk-lunch plan relies on a microwave.
Napolina
Napolina describes its standard chopped tomatoes as chunky and suited to thick sauces.
- Napolina declares 0.10g salt per 100g for the cited chopped-tomato product.
- Choose its texture on its own merits: the NHS low-salt threshold is 0.3g or less per 100g, but other cited plain chopped tomatoes have lower declared values.
Mutti
Mutti describes Polpa as finely chopped tomato pulp for fast cooking.
- The fine pieces offer a different stated texture from Napolina’s chunky chopped tomatoes.
- Mutti lists added salt and declares 0.30g per 100g for Polpa. Compare that figure with the plain chopped options if reducing salt is the priority.
Joybuy tomato options for desk lunches
These options include chopped tomatoes for a ready-made tomato base and whole plum tomatoes if you are willing to prepare the texture yourself. Check each pack’s salt label, heating directions and opened-storage instructions against your lunch plans.
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Laila Canned Chopped Tomatoes, 12 x 400g
This 12-can pack is worth considering if you use chopped tomatoes regularly rather than for a single desk lunch. Check the pack’s heating instructions for your workplace appliance and plan how you will use an opened can.
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Napolina Chopped Tomatoes, 4 x 400g
Napolina describes its standard chopped tomatoes as chunky, a distinction to consider if you want pieces in your lunch sauce. This is a four-can pack; check the preparation method before relying on a workplace microwave.
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Laila Canned Plum Tomatoes, 400g
This single 400g tin contains plum rather than chopped tomatoes, so consider whether preparing the tomatoes fits your lunch break. Check the current per-100g salt label if you need to compare it precisely with chopped options, and follow the pack’s heating directions.
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KTC Chopped Tomatoes, 400g
A single tin of chopped tomatoes avoids committing to a multi-pack for an occasional lunch. Compare its current salt label per 100g and check its heating and opened-storage instructions before planning to use it at work.
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Napolina Peeled Plum Tomatoes, 4 x 400g
These are peeled plum tomatoes, not chopped tomatoes: allow for any crushing or other preparation your lunch needs. The four-can format suits repeat use; check the pack’s salt label and microwave directions if those determine your choice.
Questions about lower-salt tinned tomatoes
Which salt figure should I compare between tins?
Compare salt per 100g first, because stated serving sizes may differ. The NHS defines low salt for foods as 0.3g or less per 100g; ASDA Groceries declares 0.01g per 100g for its Chopped Tomatoes 400g, while Mutti declares 0.30g per 100g for Polpa. Check how much of the tin you will actually use as well.
Does ‘no added salt’ mean the nutrition panel will say zero?
No. The cited Biona and Mr Organic chopped tomatoes both state that no salt is added, yet Ocado declares 0.02g salt per 100g for Biona and Mr Organic declares 0.03g per 100g for its product. Read the claim alongside the nutrition panel.
Can I microwave tinned tomatoes at work?
Follow the exact product’s instructions and transfer the tomatoes to a suitable container; do not heat them in the tin. ASDA Groceries instructs shoppers to cover and vent its Chopped Tomatoes 400g in a microwaveable container and heat for two minutes at 900W. Check the directions for your tin and microwave before preparing lunch.
How long can I keep tomatoes after opening the tin?
Follow the period on the exact product and move unused contents to a non-metallic container in the fridge. The cited Sainsbury’s chopped tomatoes specify two days, while the cited M&S, Biona and Mr Organic products specify three days and ASDA Chopped Tomatoes 400g specifies four days.