Spent Brewer Research Articles

Study of Brewer's Spent Grain Environmentally Friendly Processing Ways.

This article is devoted to the study of the effect of electrochemically activated water (catholyte with pH 9.3) on organic compounds of the plant matrix of brewer's spent grain in order to extract various compounds from it. Brewer's spent grain was obtained from barley malt at a pilot plant by mashing the malt followed by filtration and washing of the grain in water and storing it at (0 ± 2) °C in craft bags. For the organic compound quantitative determination, instrumental methods of analysis (HPLC) were used, and the results were subjected to mathematical analysis. The study results showed that at atmospheric pressure, the alkaline properties of the catholyte showed better results compared to aqueous extraction with respect to β-glucan, sugars, nitrogenous and phenolic compounds, and 120 min was the best period for extraction at 50 °C. The excess pressure conditions used (0.5 ÷ 1 atm) revealed an increase in the accumulation of non-starch polysaccharide and nitrogenous compounds, while the level of sugars, furan and phenolic compounds decreased with increasing treatment duration. The waste grain extract ultrasonic treatment used revealed the effectiveness of catholyte in relation to the extraction of β-glucan and nitrogenous fractions; however, sugars and phenolic compounds did not significantly accumulate. The correlation method made it possible to reveal the regularities in the formation of furan compounds under the conditions of extraction with the catholyte: Syringic acid had the greatest effect on the formation of 5-OH-methylfurfural at atmospheric pressure and 50 °C and vanillic acid under conditions of excess pressure. Regarding furfural and 5-methylfurfural, amino acids had a direct effect at excess pressure. It was shown that the content of all furan compounds depends on amino acids with thiol groups and gallic acid; the formation of 5-hydroxymethylfurfural and 5-methylfurfural is influenced by gallic and vanillic acids; the release of furfural and 5-methylfurfural is determined by amino acids and gallic acid; excess pressure conditions promote the formation of furan compounds under the action of gallic and lilac acids. This study showed that a catholyte allows for efficient extraction of carbohydrate, nitrogenous and monophenolic compounds under pressure conditions, while flavonoids require a reduction in extraction time under pressure conditions.

Life Cycle Assessment of Microbial 2,3-Butanediol Production from Brewer's Spent Grain Modeled on Pinch Technology.

Microbial production of 2,3-butanediol (BDO) has received considerable attention as a promising alternate to fossil-derived BDO. In our previous work, BDO concentration >100 g/L was accumulated using brewer's spent grain (BSG) via microbial routes which was followed by techno-economic analysis of the bioprocess. In the present work, a life cycle assessment (LCA) was conducted for BDO production from the fermentation of BSG to identify the associated environmental impacts. The LCA was based on an industrial-scale biorefinery processing of 100 metric tons BSG per day modeled using ASPEN plus integrated with pinch technology, a tool for achieving maximum thermal efficiency and heat recovery from the process. For the cradle-to-gate LCA, the functional unit of 1 kg of BDO production was selected. One-hundred-year global warming potential of 7.25 kg CO2/kg BDO was estimated while including biogenic carbon emission. The pretreatment stage followed by the cultivation and fermentation contributed to the maximum adverse impacts. Sensitivity analysis revealed that a reduction in electricity consumption and transportation and an increase in BDO yield could reduce the adverse impacts associated with microbial BDO production.

Synthesis of Silver Nanoparticles using Cellulose and Starch Extracted from Brewer Spent Grain: Assessment of their Antimicrobial and Preservatives Activities

Non-porous materials like cellulose and starch can be extracted from agro- industrial wastes and incorporated with nanoparticles for effective biotechnological purposes. In this study, silver nanoparticles (AgNps), silver-cellulose nanoparticles (AgNps-C) and silver-starch nanoparticles (AgNps-S) were characterized by UV-visible spectroscopy. Fourier transform infrared spectroscopy (FTIR) was used to identify viable biomolecules involved in capping and active stabilization of AgNps. Average sizes and morphologies of AgNps, AgNps-C and AgNps-S were further analyzed by scanning electron microscopy (SEM) and the percentage composition of each element was investigated by energy-dispersive X-ray spectroscopy (EDS). Antimicrobial activity of the synthesized AgNPs-C and AgNPs-S was tested against multiple antibiotic resistance microorganisms isolated from fish and meat. Zones of inhibition displayed by AgNPs-C and AgNPs-S ranged from 8.00 to 13.30 mm and 5.00 to 10.30 mm, respectively. The Minimum inhibitory concentration (MIC) for AgNPs-C and AgNPS-S ranged from 125 µg/mL to 500 µg/mL and 500 µg/mL to 1000 µg/mL, respectively. AgNPS-S and AgNPs-C inhibited the growth of microorganisms associated with spoilage of fish and meat. The bio-applications of AgNP –C and AgNP-S can be exploited in food industries as preservative agent or incorporated to packaging materials to elongate the shelf life of food products and reduce the side effects attributed to chemical preservative agents.

A Comparative Study on the Development of Bioactive Films Based on β-glucan from Spent Brewer’s Yeast and Pomegranate, Bilberry, or Cranberry Juices

This study provides new insight into developed bioactive films. The development of film-forming solutions from different fruit juices has demonstrated a major impact of bioactive compounds in film formulation, from smart packaging to bioactive packaging that releases the compounds from the oral solution at the same time as the packaged product. There were significant influences among independent parameters such as yeast β-glucan, gelling agent, fruit juice, or surfactant for each individual film. However, in this study, it was found that the amount of juice was the most significant factor in assigning their properties to all three types of films made of different juices (pomegranate, bilberry, and cranberry). Properties such as WVTR through the film varied within quite wide limits between 3.2562 and 32.1869 g/h·m2, while their solubilization time started from a few seconds for a complete dissolution or ensured only partial dissolution after 10 min of stirring (in the case of films made of β-glucan and cranberry juice). Therefore, natural biopolymer-based films developed with excellent water vapor barrier properties and improved solubility have a huge potential for application as packaging materials for dry powdered such as pharmaceuticals.

Functional Properties of Brewer's Spent Grain Protein Isolate: The Missing Piece in the Plant Protein Portfolio.

Plant protein sources, as a part of developing sustainable food systems, are currently of interest globally. Brewer's spent grain (BSG) is the most plentiful by-product of the brewing industry, representing ~85% of the total side streams produced. Although nutritionally dense, there are very few methods of upcycling these materials. High in protein, BSG can serve as an ideal raw material for protein isolate production. This study details the nutritional and functional characteristics of BSG protein isolate, EverPro, and compares these with the technological performance of the current gold standard plant protein isolates, pea and soy. The compositional characteristics are determined, including amino acid analysis, protein solubility, and protein profile among others. Related physical properties are determined, including foaming characteristics, emulsifying properties, zeta potential, surface hydrophobicity, and rheological properties. Regarding nutrition, EverPro meets or exceeds the requirement of each essential amino acid per g protein, with the exception of lysine, while pea and soy are deficient in methionine and cysteine. EverPro has a similar protein content to the pea and soy isolates, but far exceeds them in terms of protein solubility, with a protein solubility of ~100% compared to 22% and 52% for pea and soy isolates, respectively. This increased solubility, in turn, affects other functional properties; EverPro displays the highest foaming capacity and exhibits low sedimentation activity, while also possessing minimal gelation properties and low emulsion stabilising activity when compared to pea and soy isolates. This study outlines the functional and nutritional properties of EverPro, a brewer's spent grain protein, in comparison to commercial plant protein isolates, indicating the potential for the inclusion of new, sustainable plant-based protein sources in human nutrition, in particular dairy alternative applications.

Upcycling of a by-product of the brewing production chain as an ingredient in the formulation of functional shortbreads

• Brewers Spent Grains (BSGs) are the main by-product of beer industry. • Formulation of shortbreads with BSGs is a feasible strategy for their upcycling. • 30 % of BSGs in shortbread recipe enhances fiber (TDF) and arabinoxylan content. • The TDF content allows for High in fiber label and meets the Gut health EFSA claim. • Experimental shortbreads have acceptable sensory characteristics. This work aims to formulate shortbreads by partial substitution of wheat flour with brewers’ spent grains (BSGs), valorization strategy of this by-product. This study has underlined that replacing 30 % wheat flour with BSGs barley malt flour and BSG enriched with 30 % of oat flakes allows for a significant increase in fiber, particularly arabinoxylan, and protein, compared with the reference biscuit. The fiber content allows for a “high in fiber” label and meets the “gut health” EFSA claim. The obtained food products contribute to the recommended daily intake of bioactive compounds for health benefits, they do not show an increase in sugars and fats, compared to 100 % wheat flour shortbread, and have acceptable sensory characteristics. The formulation of shortbreads by partial substitution of wheat flour with BSGs can be an efficient and feasible strategy for the upcycling and valorization of this by-product throughout the production of functional food.

Effects of Brewer's Spent Yeast Content on the Physicochemical Properties of Extruded High-Moisture Meat Analog

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A preliminary study on using ultrasounds for the valorization of spent brewer’s yeast

Spent brewer’s yeast is a by-product rich in components with biological activity, being considered an innovative and economical viable solution for creating sustainable functional food systems. This work describes the use of ultrasound treatment, performed under various conditions, with the aim to facilitate the cell lysis and to further characterize the released cellular content of the spent brewer’s yeast. Solid residue content of the spent yeast suspensions was positively influenced by both the amplitude and the exposure time (p<0.05), reaching a maximum content (40.02±0.13 g/100 g dry yeast) at 70% amplitude, after 7.5 minutes of ultrasound treatment under pulsation mode, and the minimum after 2.5 minutes of exposure at 20% ultrasound amplitude under continuous mode (31.59±1.2 g/100 g dry yeast). The content of the soluble proteins released from the yeast cells during the ultrasound treatment under pulsation mode, reached a maximum increase at amplitude of 70%, after 7.5 minutes, being by 85% higher compared to the control represented by untreated yeast suspension. The disintegration index, Z, indicated that the maximum degree of yeast cells disintegration was obtained when applying the ultrasound treatment under pulsation mode for 5 minutes, at 50% amplitude. The antioxidant activity of the yeast extracts depended on the ultrasound conditions applied, the maximum antioxidant activity being measured in the sample exposed to ultrasound under pulsation mode for 5 minutes at 50% amplitude. In conclusion, ultrasound is a good approach to release the intracellular components from the spent brewer’s yeast. Further studies factoring ultrasounds power and frequency should be conducted, such to identify the optimum set of parameters which allow the highest release of the intracellular yeast compounds.

The Use of Brewer's Spent Grain after Beer Production for Energy Purposes.

The aim of this study was to assess the possibilities to use brewer’s spent grains (BSGs) left over from beer production for energy purposes, and to determine its calorific value and chemical composition. The research materials were samples of wet spent grain from a brewery in Poland. Three samples, that are different in ingredient composition, were examined. The examined samples of BSGs were characterised by humidity that is typical for this product (approx. 77–80%). Convective drying of the spent grain contributed to a reduction in the water content in the biomass to below 10%. Samples of dry spent grain that were examined contained a similar amount of ash (3.8–4.1% d.m.) and organic matter (91.0–91.9% d.m.). All the examined spent grain samples demonstrated similar volatile matter content—approx. 77.8–78.7% d.m. and calorific value—approx. 15.6–15.9 MJ/kg. The estimated calorific value for wet samples (approx. 1.4–2.0 MJ/kg) indicated that it is necessary to lower water content in the biomass in order to improve its energy properties.

Brewer's Spent Grain: its Value as Renewable Biomass and its Possible Applications

Brewer's Spent Grain: its Value as Renewable Biomass and its Possible Applications

A Simple and Efficient Mechanical Cell Disruption Method Using Glass Beads to Extract β-Glucans from Spent Brewer’s Yeast

β-glucan extraction from spent brewer’s yeast is a long process that starts with the lysis of yeast cells, this step lasting up to 36 h and can be disadvantageous when working on a small scale. In this study, a rapid cell rupture method was selected for the lysis of spent brewer’s yeast to obtain β-glucans. Optimal parameters were determined for the lysis of a cellular suspension of spent brewer’s yeast by vortexing with glass beads. Thus, parameters such as the number of 10 min vortex cycles from 1 to 3, the concentration of cell suspension (5, 10, and 15%), and the ratio of yeast/glass beads (1:1, 1:2, and 1:3) were varied in a Box-Behnken design. A cell lysis mechanism using glass beads allows the cell to rupture and permits the removal of intracellular content. An increase in yeast suspension concentration decreased the disruption efficiency, while a proportional increase was observed with the yeast/glass beads ratio and the increasing number of vortexing cycles. The optimal parameters for cell lysis were found to be a cell suspension concentration of 5%, a ratio of yeast/glass beads of 1:2, and a vortexing cycle of 3, with a disruption efficiency of 99.8%. The β-glucan fraction extracted from the optimal sample showed characteristic absorption bands at 1370.77 and 1153.92 cm−1, the content of β-glucan being 78.53%.

Serial fractionation of spent brewer's yeast protein hydrolysate by ultrafiltration: A peptide-rich product with low RNA content

Spent brewer's yeast (SBY) application as a new source of peptides depends on the development of proper downstream processes. This work aimed to separate yeast hydrolysate peptides from sugars and ribonucleic acids (RNA) by a 3-step designed fractionation process using ceramic ultra and nanofiltration following two sequences: (1) 50, 8 and 1 kDa and (2) 15, 8 and 1 kDa molecular weight cut-off (MWCO) membranes. In step one, 15 kDa MWCO membrane retained more components and increased performance of subsequent steps, when compared to 50 kDa. Peptide composition of the initial hydrolysate was gradually changed until 90% of the peptides smaller than 1 kg mol −1 were found in the final permeate. Fractionation increased peptide purity regarding RNA and total sugars up to 1.7 and 2.7-fold, respectively. Innovative protein-rich ingredients from SBY residue with an RNA content as low as 1.4% were produced by membrane separation technology. High quality ingredients presented different peptide profiles and great potential in food and pharmaceutical industries applications. • Efficient RNA reduction was achieved using membrane separation technology. • RNA content in protein-rich fraction was as low as 1.4% (dry weight). • Membranes of 15–1 kDa range were adapted to spent yeast ultrafiltration. • Protein purity of obtained fractions increased 1.7 and 2.7-fold for RNA and sugars. • A fraction with bioactive potential (65% of the peptides < 1 kg mol −1 ) was produced.

Valorization of Brewer's Spent Grain by Furfural Recovery/Removal from Subcritical Water Hydrolysates by Pervaporation

Valorization of Brewer's Spent Grain by Furfural Recovery/Removal from Subcritical Water Hydrolysates by Pervaporation

A Comprehensive Pathway on the Determination of the Kinetic Triplet and the Reaction Mechanism of Brewer's Spent Grain and Beech Wood Chips Pyrolysis

A Comprehensive Pathway on the Determination of the Kinetic Triplet and the Reaction Mechanism of Brewer's Spent Grain and Beech Wood Chips Pyrolysis

Optimization of Solid-state Fermentation Medium for Preparation of Brewer's Spent Grains Protein Peptide by Aspergillus oryzae

Brewer's spent grains were employed as raw material to prepare protein peptides by solid-state fermentation of Aspergillus oryzae, and the effects of different medium conditions on peptide conversion ratio were studied. The effects of the carbon source type, the amount of carbon source, the amount of potassium dihydrogen phosphate, and the ratio of solid to liquid on the peptide conversion ratio were investigated by single factor experiment, and response surface methodology was used to optimize the medium conditions, the regression equation between the peptide conversion ratio and various influencing factors was established. The results showed that, the optimal conditions for the preparation of brewer's s pent grains protein peptide by Aspergillus oryzae were as follows: Sucrose supplemental level at 4.21%, adding potassium dihydrogen phosphate at 0.51%, and solid-liquid ratio at 1:3（g·mL−1）. Under the condition, the conversion ratio of protein peptides from brewer's s pent grains could reach 50.76%. The results can provide a technical reference for the production of protein peptides from brewer's spent grains.

Supply chain optimization and analysis of Hermetia illucens (black soldier fly) bioconversion of surplus foodstuffs

The human food supply chain is placing great strain upon the environment. This is compounded by the creation of wastes at all points along the supply chain. Yet many of these “wastes” are instead surplus foodstuffs that may yet have the potential to be used. Recapturing the value in these surplus foodstuffs is essential in reducing environmental impact of the food supply chain. Insect bioconversion of such surplus foodstuffs back into animal feed is one promising way of doing this. In this study an optimization-based decision support tool is developed to inform bioconversion businesses what locations to source surplus foodstuffs from, where to locate processing facilities and what business model to pursue. A case study business is presented, which utilizes Hermetia illucens (black soldier fly larvae, BSFL) in small bioconversion units which have flexible location options, i.e. close to individual sources of surplus foodstuffs. Spent brewer's grains (SBG) are used as a case study surplus foodstuff. The quantities and locations of SBG are identified within the South East UK. Three business models are evaluated, one using the live BSFL to feed local poultry and two based upon dried BSFL-meal used in aquaculture feeds. The live BSFL business model is shown to be most viable at present with the best margins, and greatest resilience to model perturbations. The novelty of this study is the application of optimization understand the reality of how insect bioconversion may operate within current supply chains, as opposed to the technical or social aspects more usually studied.

Phenolic Compounds From Brewer's Spent Grains: Toward Green Recovery Methods and Applications in the Cosmetic Industry

Brewers' spent grain (BSG) is the main by-product derived from the brewing industry, where it accounts for 85% of the total waste generated. The total annual production worldwide of this waste is 39 million tons. This lignocellulosic material is traditionally used as cattle feed and sold at a low retail price (~USD 45.00 per ton). However, efforts for the revalorization of this by-product are emerging since research has established that it can be used as a low-cost source of bioactive molecules and commodity chemicals that can bring value to integral biorefinery ventures. Among commodities, phenolic compounds have attracted attention as added-value products due to their antioxidant properties with applications in the food, cosmetic, and pharmaceutical industries. These phytochemicals have been associated with antiaging and anticancer activities that have potential applications on cosmetic products. This mini-review summarizes the most relevant extraction techniques used for the recovery of phenolic compounds from BSG while discussing their advantages and shortcomings and the potential applications from BSG bioactive extracts in the cosmetic industry and their reported beneficial effects. This mini-review also makes a brief comment on the role of phenolic compounds extraction in the economic feasibility of an integral BSG biorefinery.

English

English

Performance and Digestibility of White Fulani Heifers Fed Banana Leaf Ensiled With Brewers Spent Grain and Poultry Waste

Performance and Digestibility of White Fulani Heifers Fed Banana Leaf Ensiled With Brewers Spent Grain and Poultry Waste

Rejuvenated Brewer's Spent Grain: The impact of two BSG-derived ingredients on techno-functional and nutritional characteristics of fibre-enriched pasta

Brewer's Spent Grain (BSG), rich in fibre and protein is mostly used for animal feed but has great potential to be used as an ingredient for cereal based products. Originated from BSG, the two ingredients EverVita Fibra (EVF) high in fibre; and EverVita Pro (EVP) high in protein, were used to produce fibre-enriched pasta and compared to semolina, wholemeal flour and a commercial fibre-rich pasta. Analysis of gluten network development and pasting properties revealed the formation of a stronger network by the incorporation of EVP resulting in a compact pasta structure which led to a higher pasta firmness and tensile strength and a decrease in predicted glycaemic index compared to the controls. EVF resulted in an inferior product compared to EVP but was comparable to the semolina control. Hence, EVF and EVP have the potential to increase nutritional value of pasta while maintaining or even improving pasta quality and encouraging the recycling of by-streams for food production.