In Vitro Digestibility of Minerals and B Group Vitamins from Different Brewers’ Spent Grains

Abstract

Brewers’ spent grain (BSG), the main by-product of the brewing industry, is a rich source of minerals and water-soluble vitamins such as thiamine, pyridoxine, niacin, and cobalamin. Bioaccessibility through in vitro digestion is an important step toward the complete absorption of minerals and B group vitamins in the gastrointestinal system. Inductively coupled plasma optical emission spectrometry (ICP-OES) together with inductively coupled plasma quadrupole mass spectrometry (ICP-MS) was used for the quantification of the macro- and micro-minerals. An ultra-high performance liquid chromatography (UHPLC) system coupled with a diode array detector (DAD) was used for B group vitamin identification. Four different industrial BSG samples were used in the present study, with different percentages of malted cereals such as barley, wheat, and degermed corn. Calcium’s bioaccessibility was higher in the BSG4 sample composed of 50% malted barley and 50% malted wheat (16.03%), while iron presented the highest bioaccessibility value in the BSG2 sample (30.03%) composed of 65% Pale Ale malt and 35% Vienna malt. On the other hand, vitamin B1 had the highest bioaccessibility value (72.45%) in the BSG3 sample, whilst B6 registered the lowest bioaccessibility value (16.47%) in the BSG2 sample. Therefore, measuring the bioaccessibilty of bioactive BSG compounds before their further use is crucial in assessing their bioavailability.

Brewers' Spent Grain – Simply Waste or Potential Ingredient of Functional Food?

“…Table 2 presents the literature reports on the micro-and macroelements in BSG, which are essential, considering potential applications in the food sector. The content of particular elements differs between literature reports, which can be attributed to the origin of various BSG samples and is a typical phenomenon for plant-based materials [16,61]. Moreover, the nutritional composition of BSG can differ depending on the parameters of water used in the brewing process, which impacts the extraction of particular compounds and elements to wort [54].…”

“…BSG is also a rich source of vitamins, especially group B, such as thiamine (B 1 ), riboflavin (B 2 ), niacin (B 3 ), pyridoxine (B 6 ), biotin (B 7 ), pantothenic (B 5 ) and folic (B 9 ) acids [16]. Moreover, BSG contains noticeable amounts of vitamin E, tocotrienols and tocopherols, which may act as antioxidants, anticarcinogenic and neuroprotective agents, and can beneficially reduce LDL cholesterol levels [50].…”

Cereal By-Products Valorization in Bakery, Pastry, and Gastronomy Products Manufacturing

“…It is an extremely rich source of fiber (up to 70%) mainly formed of cellulose, lignin, hemicellulose, and vitamins such as choline, niacin, pantothenic acid, and riboflavin [18]. It is worthy to mention that minerals such as Ca (calcium), Na (sodium), K (potassium), Mg (magnesium), Fe (iron), and Ni (nickel) are important compounds present in brewer spent grain [19]. Soil fertility, production, barley variety, harvesting time, mashing, and malting conditions are the main factors that could influence the brewer spent grain composition [20].…”

Spent Grain: A Functional Ingredient for Food Applications

“…To support the circular economy and the environment, biomass conversion technologies and biorefineries must be developed so that the biomass-based economy grows. Spent grain is a valuable by-product that is rich in nutrients such as dietary fibers (hemicellulose, cellulose and lignin), proteins, monosaccharides (glucose, xylose and arabinosis), minerals, vitamins and lipids [ 6 ]. Products enriched with spent grain are called fortified foods [ 7 , 8 ].…”