Iodised salt in bouillon seasoning and iodine retention over six months
What it found
Iodine from iodised salt stayed in bouillon cubes and powder during storage and cooking.
Lab tests showed rice cooked in bouillon broth absorbed the iodine.
What they found
Animal and lab studies
Iodine loss during storage
Over 6 months at 40-40.5 °C and 95% humidity, average iodine loss was 4.5%. Powder sachets lost only 0.8%, while cubes lost 13.6%. These were lab storage tests, not studies in people.
Iodine survives cooking
Cooking bouillon into broth for up to an hour did not reduce its iodine content. The amount of water used and whether the pot had a lid on or off made no difference. This was measured in lab cooking tests.
Rice absorbs the iodine
When rice was cooked in bouillon broth until all liquid was gone, it took in the iodine. Lab measurements found between 0.03 mg/kg and 0.41 mg/kg of iodine in the finished rice across three brands.
Other findings
Daily iodine contribution
Using survey data showing daily bouillon intake of 8.6 g in cities and 4.3 g in villages, the authors modelled iodine delivery. Depending on the brand, bouillon could supply between 6.5% and 114.8% of the recommended daily iodine for adults in urban areas. Rural amounts would be about half that.
Wide variation between brands
Iodine levels varied greatly among the 13 products, ranging from 14 µg to 243 µg per package. The authors say this wide spread reflects a lack of regulation of iodised salt at the factory level in Senegal.
What the authors conclude
- They conclude that bouillon seasoning keeps its iodine through storage and cooking, making it a useful way to deliver iodine in the diet.
- The authors advise regulators to monitor the salt ordered by bouillon factories to ensure it meets national iodine standards.
- They recommend including condiments like bouillon when setting rules for salt iodisation to improve nutrition.
How it was done
Adding iodine to salt is the main global plan to prevent iodine deficiency, but rules often ignore salt used in processed foods. In West Africa, bouillon seasoning is a very common source of salt, so the authors wanted to see how much iodine it could provide.
The researchers tested 13 brands of bouillon cubes and powder sachets bought in Senegal. They stored them for 6 months in hot, humid conditions to mimic local homes. They also cooked three brands into broth and rice to measure how much iodine remained.
What it can’t tell you
- This work measured iodine in food products and modelled intake based on surveys.
- It cannot show actual changes in iodine levels in people's bodies.
- The modelling relies on average consumption figures, so individual intakes may differ widely.
The paper
- Title
- Estimation of population iodine intake from iodized salt consumed through bouillon seasoning in Senegal
- Type
- Study
- Evidence
- Animals and lab studies
- Summarised from
- Full text
- Cite
- Spohrer R, Knowles J, Jallier V, et al (2015). Estimation of population iodine intake from iodized salt consumed through bouillon seasoning in Senegal. Annals of the New York Academy of Sciences. doi:10.1111/nyas.12963Free full textPubMed 26767583DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error