Brewers' spent grain Flashcards
What is Brewers’ spent grain (BSG) ?
Brewers’ spent grain (BSG) is the major by-product of the brewing industry, representing around 85% of the total by-products generated. Brewers’ grains (BG) generated at a rate of up to 30% of the weight of the initial malt grist. Worldwide generationof BG has been estimated at 30 billion kilograms per annum.
What is the composition of BSG?
Brewer’s grains are a heterogeneous mixture of grain remnants from which the soluble and mash digestible components of malt have been extracted. BG’s at source are typically 70-85% moisture. BSG is a lignocellulosic material containing about 17% cellulose, 28% non-cellulosic polysaccharides, chiefly arabinoxylans, and 28% lignin.
What are BSG applications?
BSG is available in large quantities throughout the year, but its main application has been limited to animal feeding (90%?). Nevertheless, due to its high content of protein and fibre (around 20 and 70% dry basis, respectively), Brewers’ spent grains are of high nutritive value.
Whilst the protein content (circa 18% of dry matter) and amino acid profile of BG are of nutritional value, the high amount of lignocellulos- ic matter makes it indigestible to many animal species. The majority of BG used for animal feed is fed to
can cope with the high fibre con- tent.
What are the volume of BSG produced?
It was reported that about 3.4 million tonnes of BSG from
the brewing industry are produced in the EU every year
(Stojceska et al., 2008), out of which UK alone contributes over 0.5 million tonnes of this waste annually. However,Brazil, the world’s fourth largest beer producer (8.5 billion litres/year) in 2002, generated ~1.7 million tonnes of BSG (Mussatto et al., 2006).
What are the main BSG processing?
Many breweries have plants for BSG processing
using two-step drying technique, where the water content is first reduced to less than 60% by pressing, followed by drying to ensure the moisture content is below 10% (Santos et al., 2003).
However, the traditional process for drying BSG is
based on the use of direct rotary-drum driers. This procedure is considered to be energy-intensive.
BSG in animal feed constraints
However, high moisture content of BSG (80 to 85%)
together with polysaccharide and protein makes it particularly susceptible to microbial growth and subsequent spoilage in a short period of time (7 to 10 days) (Stojceska et al., 2008).
BSG animal feeding benefits
Their findings showed that BSG supplementation (45% w/w) increased actual milk yield, milk total solids content, and milk fat yield when compared to control containing maize silage (45% w/w). Also, both wet and dried BSG have been utilized asanimal feed (Dhiman et al., 2003). Feeding brewers’ grain dry or wet
BSG for human consumption
Since BSG is derived from materials utilized for
humans, it can be incorporated into so many human
diets, such as breads and snacks; especially where there
is need to boost the fibre contents.
BSG was incorporated into wheat flour for the production
of high-fiber enriched breads.
Comment JP Endres: Le sujet de l’utilisation des drêches pour l’alimentation humaine pose le problème de la teneur en fibre. On peut faire du pain, des cookies etc. mais à ce jour cette utilisation reste anecdotique et est réservé aux micro-brasseries des centres urbains (donc pas la taille industrielle de site qui nous intéresse et qui représente plus de 90% du marché mondial de la production de bière).
BSG - Metal adsorption and immobilization
BSG was studied by Lu and Gibb (2008) for the removal
of Cu(II) ions from aqueous solutions and they found its
maximum adsorption capacity to be 10.47 mg g-1
dry weight at pH 4.2. Based on this, BSG being a process byproduct, has a significant potential as a bioadsorbent for application in the remediation of metal contaminated
wastewater streams.
Challenges with BSG re-use
However, time, location and composition, environmental effectiveness, technological feasibility, social acceptability and economical affordability are among the key challenges associated with reliable and sustainable utilization of BSG.
More
http://www.academicjournals.org/article/article1380725235_Aliyu%20and%20%20Bala.pdf
BG_Nov_Dec_2011_Grains_Feature_937040182.pdf
Marketing identified Opportunities (JP Endres) #1
Brasseries HEINEKEN en SERBIE et en GRECE semblent avoir un souci pour sécuriser le débouché de leurs drêches tels que nous l’a rapporté leur responsable achat car faibles débouchés locaux (faible élevage ovin et bovin), pb de coûts de transports, passage de frontière etc).
Marketing identified Opportunities (JP Endres) #2
Le problème se pose aussi sur de grosses brasseries (plus de 4 million d’hL/an) (telles que celles que l’on trouve en Chine ou en Amérique latine) qui de par leur taille, vont rapidement inonder la région alentour de drêches et doivent transporter les drêches sur de longues distances, au dela de l’attractivité économique (valeur de la drêche vs coût de transport et biodégradabilité).
Current use (JP Endres) #2
Pour la question du coût, les drêches sont parfois vendues (cela peut aller au dela de 40 EUR la tonne selon le coût local des alternatives en alimentation animale), parfois données gratuitement aux éleveurs alentour. ce n’est pas un marché de commodités et dépend des conditions locales.
Market Challenge / opportunity discussion
The environmental implications of increased methane emissions from cows fed this hard to digest material can also be considered as having a negative environmental impact.
The European Feed Manufacturers Federation reported recently that 24 million tonnes of protein-rich material are required annually within the EU for animal feed usage and that approximately 70% of this is currently imported – the principal source is soya. Does it make economic or environmental sense to continue to import this material when there are protein rich co-products like BG which are generated locally in substantial quantities?
