Study explains why sorghum may be better than whole grains

Johannesburg: Sorghum bran, more commonly known as jowar in India, has much higher levels of some essential amino acids and minerals needed for human health and development than a whole grain or dehulled sorghum flour, according to researchers.

India is the second largest producer of sorghum, a climate-resilient cereal, in the world. It is also one of the main cereal crops consumed in India

The study led by a team from the University of Johannesburg in South Africa showed that both white and brown varieties of sorghum bran packs calcium, magnesium, leucine and valine punch much higher than the whole grain flour.

Brown sorghum bran contained high levels of the essential acid leucine (1.60 g/100g) -- required for repairing and building muscle.

Valine -- vital for muscle tissue and repair as well as growth hormone production -- was found in high amounts of up to 0.80 g/100g in the brown sorghum bran.

Brown sorghum bran has calcium (1020.91 mg/100 g) and magnesium (292.25mg/100g) -- minerals which can assist in bone growth and development, while white sorghum bran contained 995.17 mg/100 g of calcium and 226.02 mg/100g of magnesium.

“The reduction of nutrients in sorghum bran has become a matter of nutritional concern. Bran removal, or reduction in bran particle size due to milling or deliberate dehulling, affects the nutritional quality,” said Dr Janet Adebo, a researcher and Dr Kesa the Director of the Food Evolution Research Laboratory (FERL) within the School of Tourism and Hospitality at the university.

“There is strong scientific evidence linking regular consumption of whole grain cereal foods to long-term health benefits. The studies mostly associate this with the bran component included as part of whole grains,” she added.

In the study, published in the journal Heliyon, the researchers analysed crude fibre in the bran samples and found them to be much higher than from other parts of the whole grain.

Compared to the whole grain, white sorghum bran had 278.4 per cent higher crude fibre, and brown sorghum bran had 203 per cent higher crude fibre, the study found.

Further, the team said that the relatively high levels of fat in the bran could potentially open a market for sorghum bran oil -- a ‘plant’-based oil.

Compared to the whole grain, white sorghum bran had 120.7 per cent higher crude fat, and brown sorghum bran flours had 81.3 per cent higher crude fat.

Generally speaking, there is a need for changing dietary choices to locally available food sources, said Dr Hema Kesa from the varsity.

In addition to the macronutrients, Sorghum has resistant starch, aiding in digestion. It is naturally gluten-free, unlike wheat, barley, and rye, making it safe and suitable grain for people with celiac disease or non-celiac gluten sensitivity. It also has a relatively low glycemic index (GI), which helps regulate blood sugar levels particularly important for people with diabetes, Kesa said.

Importantly, being a versatile and climate resilient crop, it can also provide a source of nutrition during disaster relief efforts, Kesa said.

“The use of sorghum in such emergency responses in disasters can create livelihoods, improve nutrition, and promote sustainable agriculture,” she noted.