Here’s what the first study comparing two varieties from the same wheat crop in the same field shows.
What does whole wheat flour lack in white? New research reveals key differences in their nutritional value, as well as why they lose (or gain) certain nutrients during the journey from field to table.
The new study is the first to examine flours produced from the same wheat crop in the same field. Also looked at their nutritional value after cooking.
Scientists have been recommending whole grain products over processed white products for years because, if nothing else, they contain more fiber. But this is not their only difference.
“It’s important to track nutrient content from farm to table to know exactly what agricultural products contribute to our diets,” he said. biochemist Dr. David Killilea, from the University of California, San Francisco (UCSF). “Our research showed that both milling and baking significantly affect the levels of many components in flour and bread.”
Dr. Killilea presented the new findings at the American Society for Nutrition’s Annual Conference (Nutrition 2024) held in Chicago. Results presented at medical conferences are considered preliminary until published in a medical review.
Research
As part of their research, the scientists took wheat grains from the manufacturer and crushed them to create three types of flour:
- Traditional whole wheat flour (milled directly from wheat grains)
- Repurposed bran flour (bran flour is added to white flour to make bran)
- Refined white flour (classic white flour, which is obtained when the husk, that is, the bran, is removed)
The researchers measured the levels of various micronutrients and vitamins in the flour. Base metals calcium, magnesium, phosphorus and potassium in wheat. It also contains trace elements and other nutrients, such as:
- Copper
- Iron
- molybdenum
- zinc
- Carotenoids (these are phytochemicals)
- Vitamin E
The researchers measured the levels of the same ingredients while making the bread they baked.
findings
In both types of whole grain flours, the researchers found calcium, magnesium, phosphorus and potassium levels remained unchanged until the final product (bread). In contrast, they were reduced to 72% in refined white flour and bread.
The study also found that whole wheat flour and breads increased by 8-66% trace elementswhom:
- Copper
- Iron
- zinc
The same trace elements decreased up to 64% in white flour and bread. A reduction of up to 77% was observed in both types of bread (white and wholemeal). carotenoids. However, raw flour is increased by 18-30% in both types. This finding indicates that these components are significantly destroyed during baking. The main carotenoids in wheat are lutein and zeaxanthin.
Finally, Vitamin E reduced by up to 20% in bran flour and up to 82% in refined white and all types of bread. Therefore, it is significantly destroyed during processing and cooking.
Scientists are continuing their research to determine how the nutritional value of wheat and its products is affected by different cultivation and processing methods.