Malting, the processing of cereal grains into malt, generates rootlets as a side-stream product, which is currently mostly utilised as animal feed. However, this leftover material has not only a high protein content, but also high amounts of phytochemicals, which makes it a highly potential source of development for the food industry, according to a recent study from the University of Eastern Finland, published in npj Science of Food.

Germination increased the amount of phytochemicals

The study utilised metabolomics to analyse samples from grains of four cereals typically used in malting: barley, rye, wheat, and oats. The researchers were particularly interested in phytochemicals, which are bioactive compounds produced by plants. Many phytochemicals have been shown to work as antioxidants and to have other potential beneficial health effects. Samples were taken during several steps of the malting process, such as from malted grains, wort and water extract, as well as from rootlets and spent grain, the side-stream products of the processing. The main finding of the study was the observation of 285 different phytochemicals, most of which were found in the side-stream products, especially the rootlet. The germination occurring in the beginning of malting increased the levels of several phytochemicals compared to the unprocessed grains, and also produced compounds that were not abundantly present in the original grains.