Bioavailability of micronutrients iron and zinc is particularly low from plant foods, which is why scientists are looking to evolve a food-based strategy to improve and combat widespread deficiencies of these minerals in certain populations dependent on plant foods.

Researchers at the Central Food Technological Research Institute in India have discovered compounds in garlic and onion may increase the bioaccessibility of iron and zinc from cereals by sevenfold, according to a new study published in the Journal of Agricultural and Food Chemistry.

Researchers at the Central Food Technological Research Institute examined whether sulfur compound-rich Allium spices have a similar potential of beneficially modulating the mineral bioavailability by examining the influence of exogenously added garlic and onion on the bioaccessibility of iron and zinc from food grains.

Researchers studied two cereals—rice and sorghum—and two pulses—whole green gram and chickpea. They analyzed the bioaccessibility of iron and zinc in 10g of raw and cooked food grain and 10g of raw and cooked food grain with either 0.25g of garlic, 0.5g of garlic, 1.5g onion or 3g onion added. Bioaccessibility was determined by using a simulated gastrointestinal digestion procedure. The study found that both spices enhanced the bioavailability of iron in raw and cooked food grains, increasing the cereals iron bioaccessibility by 9.4% to 65.9% and in both pulses by 9.9% to 73.3%. A similar effect was seen for zinc bioaccessibility, with cereals increasing by 10% to 159.4% and in pulses by 9.8% to 49.8%. According to the researchers, both garlic and onion were evidenced to have a promoting influence on the bioaccessibility of iron and zinc from food grains.

The researchers noted that their findings have the potential application in evolving a food-based strategy to improve the bioavailability of trace minerals and contributes to the human health benefit.