By-Products in the Malting and Brewing Industries—Re-Usage Possibilities

Abstract

Beer production includes the formation of different by-products such as wastewater, spent grains, spent hops, and yeast. In addition to these well-known by-products, it is necessary to mention germ/rootlets, which also remain after the malting process. Given that a huge amount of beer is produced annually worldwide, by-products are available in large quantities throughout the year. Spent grains, spent hops, and spent yeasts are high-energy raw materials that possess a great potential for application in the branch of biotechnology, and the food industry, but these by-products are commonly used as livestock feed, disposed of in the fields, or incinerated. Breweries by-products can be utilized for microalgae production, biofuel production, extraction of proteins, polyphenolic, antioxidative substances, etc. This paper aims to address each of these by-products with an emphasis on their possible application in biotechnology and other industries.

More than just a beer—the potential applications of by-products from beer manufacturing in polymer technology

“…Moreover, the brewers' spent grain contains multiple micro-and macroelements, mostly silicon, phosphorous, calcium, and magnesium [32]. Combining their content with the presence of vitamins, primarily B3, B4, and B5, the BSG is often investigated in food additives [48,67].…”

“…On the other hand, phenolics such as hydroxycinnamic acids, gallic acid, catechins, anthocyanidines, and others, are precipitated with proteins and removed as a part of hot trub [196]. The essential oils contain noticeable amounts of terpenes [67]. Moreover, myrcene, alpha-humulene, or beta-ceryophyllene are present.…”

“…Brewery spent yeast are also a great source of micro-and macroelements, as well as vitamins. Nevertheless, the mineral composition of yeast can differ depending on the length of fermentation and fermentation cycles [67]. Among the most abundant minerals are sodium, potassium, and magnesium, but noticeable amounts of phosphorous may be present, which could be associated with yeast nutrients in breweries [195].…”

Brewing By-Product Upcycling Potential: Nutritionally Valuable Compounds and Antioxidant Activity Evaluation

“…Finally, valuable and biologically active constituents, such as antioxidant compounds, can be extracted from BSG [ 9 , 10 , 11 ]. In Europe, BSGs, accounting for nearly 34–35 million tons of spent grains every year, are mainly sold to farmers as animal feed, while also being used as a feedstuff in aquaculture, and bakery product preparation [ 12 , 13 , 14 ]. The European legislation establishes limits for the marketing and distribution of BSG: up to 0.3% of dimethylpolysiloxane, up to 1.5% of enzymes and up to 1.8% bentonite [ 15 ].…”

Brewing By-Products as a Source of Natural Antioxidants for Food Preservation

“…The malting and brewing industries are characterized by the generation of large amounts of residues, which account for 85% of their total by-products. In general, these by-products are used as fertilizers, drained into the sewage as waste, or get incinerated [1]. In line with Sustainable Development Goals (SDGs), the food industry is becoming more aware of environmental changes and the negative environmental impacts of their processes and outputs.…”