Using spent barley grain to lower the sugar content of certain foods
EPFL spin-off Embion Technologies has developed a soluble fiber powder made from barley residue from the beer-making process that can be used to reduce the sucrose content of a wide range of foods. This by-product also appears to lower cholesterol levels and reduce the risk of cardiovascular diseases.
Sugar is the new tobacco, and food manufacturers – under pressure from taxes, laws and health professionals – are struggling to find a good replacement for it. They may soon get what they want in the form of a soluble fiber powder produced from spent barley grain left over from the beer-brewing process. This product, developed by EPFL spin-off Embion Technologies, can be used to make up for the weight and volume difference between sucrose and the natural sweeteners that replace it, such as stevia, which are much more powerful and thus used sparingly. Several major food producers have already expressed interest in this product.
Manufacturers now depend on starch derivatives like maltodextrin and polydextrose to make up for the volume and weight to replace beet or sugar cane. But these fillers have one major drawback: they push up blood sugar levels. "Over the long term, these peaks can result in insulin resistance, which can in turn lead to obesity, hypertension or even type 2 diabetes," says Georgios Savoglidis, CEO of Embion Technologies, which is based at EPFL Innovation Park. The soluble fibers, made up of oligosaccharides known as beta-glucans, are produced using a process that was developed at EPFL and perfected by the startup. The fibers offer two major advantages: they are neutral in flavor and good for human health. Various studies have shown that these oligosaccharides help lower cholesterol and blood sugar levels and reduce the risk of cardiovascular diseases.
Upcycling 50% of the weight of spent barley grain
The process of transforming cellulose – which is abundant in plants – into beta-glucan is still in its early stages. "Our version is the first one to be both robust and efficient. That will allow this product to compete price-wise on the food market," says Savoglidis. His company's approach reduces the polysaccharides in the cellulose to three- or four-molecule oligosaccharides. The patent-protected process extracts half of the weight of the spent barley grain in powder form thirty times faster than existing procedures. Embion uses a one-step method that uses up very little energy because it requires only a moderate temperature and little pressure.
Barley, in addition to the beneficial properties of its fibers, also has a very high cellulose content. Depending on the brewing process and the quality of the plant itself, cellulose may account for up to 30% of the post-brewing spent grain. What's more, the quantity of spent grain available is vast, exists worldwide and moreover is mainly concentrated in large breweries around the world. According to statistics published by the United Nations Food and Agricultural Organization, nearly 200 million tons of beer are brewed every year, and around 20% of that is in the European Union. Spent grain accounts for around 20% of this weight. In Switzerland alone, close to 80,000 tons of spent grain are produced annually. The spent grain is already being upcycled in the form of flours for human and animal consumption. But nowhere near all of it is being used.
Fibers that are good for the microbiome
This approach to upcycling spent grain could make it possible for food manufacturers to eliminate the adverse effects of sugar without using chemical additives. "The spent grain that many people feel has no value actually has significant potential. It's time to rethink how we use our planet's resources," says Savoglidis.
The beta-glucan powder extracted from barley also helps to maintain or restore the health of the human intestinal microbiome. These beta-glucans are a form of prebiotic that can improve the efficacy of the probiotic bacteria present in certain types of enriched foods. "Embion's technology can be adapted to extract prebiotics from a wide range of natural resources," notes Savoglidis. The startup is also attracting the attention of large companies active in the growing prebiotic and microbiome market.
An eco-friendly process with multiple outputs
The process developed by Embion Tehnologies can be repeated numerous times over without any loss of efficiency, and the remaining biomass still contains lignin, proteins and oils that can also be harvested and reused. "Our goal is not only to use our process to find ways to repurpose various agricultural derivative products, but to do so in the most efficient way possible," adds Savoglidis. His company is participating in the Climate-KIC accelerator program for technologies capable of mitigating the effects of climate change. The startup's technique makes it possible to select the extracted compounds and release them either continuously or in batches. It is thus possible to use the same approach in order to extract other compounds for food, cosmetics and pharmaceutical products and even to produce PEF, a green material that could one day replace PET in food packaging.
Jie Zhang et al. Impact of native form oat β-glucan on starch digestion and postprandial glycemia, Journal of Cereal Science (2016). DOI: 10.1016/j.jcs.2016.11.013