Beta-carotene and starch digestion in orange sweet potato bread
What it found
Bread made with orange sweet potato puree contained measurable beta-carotene, and a small portion was released during lab digestion tests.
Adding more sweet potato raised the amount of available beta-carotene.
What they found
Animal and lab studies
Beta-carotene released in digestion
In lab digestion tests, only 1.1% to 7.2% of the different forms of beta-carotene was released into tiny particles the gut could absorb. More sweet potato in the bread meant more beta-carotene was released.
Starch digestion changes
Lab digestion tests showed that adding sweet potato lowered the fast-digesting starch in the bread. It raised the amounts of slowly digestible starch and resistant starch instead.
Other findings
Beta-carotene in bread
Total beta-carotene ranged from 4.3 µg/g in the 10% sweet potato bread to 33.6 µg/g in the 50% version. The calculated vitamin A activity rose from 30.9 to 246.2 RAE per 100 g across those levels.
What the authors conclude
- They say the sweet potato breads hold enough provitamin A carotenoids to be useful foods.
- They suggest these breads could help address vitamin A deficiency and blood sugar issues in people.
How it was done
Vitamin A is needed for vision, growth, immune function and reproduction, and a lack of it causes anemia and poor growth in children. Orange sweet potatoes are rich in beta-carotene, which the body can turn into vitamin A.
Researchers baked wheat breads using 10% to 50% orange sweet potato puree. They measured total beta-carotene in each loaf. They then used lab tests mimicking mouth, stomach and gut digestion to see how much beta-carotene was released.
What it can’t tell you
- We summarised it from the abstract only.
- These were lab digestion tests, not studies in people.
- They cannot show how much beta-carotene the human body actually absorbs from this bread or how it affects blood sugar in real life.
Who paid
- Authors work at
- Biosciences for East and Central Africa at International Livestock Research Institute (ILRI), Kenya
The paper
- Title
- Starch digestibility and β-carotene bioaccessibility in the orange- fleshed sweet potato puree-wheat bread
- Type
- Study
- Evidence
- Animals and lab studies
- Summarised from
- Abstract only
- Cite
- Mbogo D, Muzhingi T, Janaswamy S (2021). Starch digestibility and β-carotene bioaccessibility in the orange- fleshed sweet potato puree-wheat bread. Journal of food science. doi:10.1111/1750-3841.15620PubMed 33565638DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error