Wort Production Research Articles

Micromalting of triticale varieties NS Paun and Odisej

The objective of this study was to evaluate the possibility of application of two triticale varieties, NS Paun and Odisej, as partial substitutes for barley malt in wort production, based on the triticale analyses, micromalting, and analyses of the produced triticale malts, with a highlight on the activity of amylases during the malting process. The analyses of two triticale varieties showed higher extract content and diastatic power in comparison to barley malt. In the varieties NS Paun and Odisej, the extract was by 11.4% and 6.3% higher than the standard values for barley malt, respectively. Diastatic power in varieties NS Paun and Odisej was by 100% and 111.9% higher than in barley malt, respectively. In both varieties, ?- and ?-amylases activities were also high. The ?-amylase activity increased during the micromalting 34 and 20 times, respectively, in comparison to native triticale grain. The ?-amylase activity also increased during micromalting, but to a lesser extent. The produced triticale malts had good technological parameters and could be used as a partial substitute for barley malt in wort production.

St John's wort (Hypericum perforatum) products – an assessment of their authenticity and quality

BackgroundSt John's wort products (Hypericum perforatum L.) are widely available for sale in many countries including the UK via the internet. In the UK, these products are required to hold either a marketing authorisation or Traditional herbal registration (THR) to be sold legally. The THR and other regulatory schemes help to ensure product safety and quality providing an example of best practice but there is a risk if both regulated and un-regulated products continue to be available to consumers. AimsThe project is embedded in a larger study aiming to investigate the quality of different herbal medicinal products along diverse value chains. Here we focus on a comparison of the quality of the finished products and assess phytochemical variation between registered products (THRs) and products obtained from the market without any registration. Methods47 commercial products (granulated powders and extracts) were sourced from different suppliers. We analysed these samples using high performance thin layer chromatography (HPTLC) and 1H NMR spectroscopy coupled with multi-variate analysis software following a method previously developed by our group. ResultsThe consistency of the products varies significantly. Adulteration of the products (36%), possibly with other Hypericum species obtained from China or use of chemically distinct H. perforatum cultivars or chemotypes, and adulteration of the products (19%) with food dyes (tartrazine, amaranth, brilliant blue, sunset yellow) were the principle findings of this study. ConclusionsThere is significant compositional variation among commercial finished products and two main causative quality problems were identified as adulteration by incorrect species or adulteration with food dyes. Generally, food supplements and unlicensed products were found to be of poorer quality than the regulated ones including THRs.

Optimized and Validated HPLC Analysis of St. John's Wort Extract and Final Products by Simultaneous Determination of Major Ingredients.

Aim of this work was to develop a validated high performance liquid chromatography method for the analysis of extracts and final products of St. John's wort, according to international guidelines for bioanalytical method validation. Chromatographic separation was performed on a C18 column with a combination of gradient and isocratic steps; the mobile phase composed of ammonium acetate solution (pH 4.5; 10 mM), acetonitrile and methanol. Quantification and method validation was performed using extract spiked with external reference standards of chlorogenic acid, rutin, hyperoside, isoquercitrin, quercetin and hypericin. Validation study revealed that trans-chlorogenic acid is partially transformed into its cis-isomer during analysis. The method showed good linearity, precision and accuracy. Hyperforin was completely unstable. All other ingredients were stable at -18°C and after three freeze-thaw cycles, while stability of most ingredients was limited at room temperature and 4 - 8°C; quercetin was the most unstable one. The major ingredients of methanolic extracts, infusions and final products of Hypericum perforatum were completely resolved and quantified. Beyond its potential usefulness in the analysis of St. John's wort products, this study addresses the issue of validation from the perspective of the field of bioanalysis and reveals the wealth of critical information which can be derived.

Adulteration of St. John's Wort products: How to identify quality problems

Adulteration of St. John's Wort products: How to identify quality problems

Relevance of Oxygen for the Formation of Strecker Aldehydes during Beer Production and Storage.

Off-flavor in beer is often associated with the appearance of staling aldehydes. In this study, the factors amino acid concentration, carbohydrate concentration, Fe2+ concentration, and oxygen concentration were investigated in terms of their effect on the formation of carbonyl compounds during storage using response surface methodology. From all factors tested, only amino acid concentration and oxygen concentration promoted Strecker aldehyde formation during storage, while all other carbonyls measured were unaffected. A mixture of glucose/xylose, representing carbohydrate sources, as well as Fe2+ concentration were insignificant factors, though carbohydrate additions exhibited a significant role in the formation of 2-furfural. De novo formation of phenylacetaldehyde from phenylalanine during beer storage was observed using labeling experiments and a linear relationship between Strecker aldehydes formed and total packaged oxygen was identified. Capping beers with oxygen barrier crown corks and addition of 10 mg/L EDTA to beers effectively diminished Strecker aldehyde formation. Oxygen was additionally shown to significantly promote Strecker aldehyde formation during sweet wort production. A pathway for the reactive oxygen species-induced degradation of amino acids yielding Strecker aldehydes was proposed and was further scrutinized in buffered model solutions. The insignificant role of Fe2+ in the response surface experiments is discussed.

Brewers' spent grain: a review with an emphasis on food and health

Brewers' spent grain (BSG) is the most abundant by-product generated in the beer-brewing process. This material consists of the barley grain husks obtained as solid residue after the production of wort. BSG is rich in fibre and protein and, to date, the main use for the elimination of this by-product has been as an animal feed. However, because of its nutritional content, BSG is of interest for application and fortification of human food products, particularly in view of its low cost and availability in large amounts. In addition, the importance of BSG as an ingredient and potential source of health-promoting bioactive components is beginning to be recognised. The investigation of alternative uses of BSG is pertinent, not only from the perspective of the brewer who can benefit from valorisation of this by-product, but also from an environmental perspective as the recycling and re-use of industrial wastes and by-products has become increasingly important. This review presents the current knowledge on BSG, covering its production, composition and methods for the release of valuable components, and focuses on the potential health benefits attributed to its constituents and the use of this brewer by-product in food applications. Copyright © 2016 The Institute of Brewing & Distilling

St. John's Wort versus Counterfeit St. John's Wort: An HPTLC Study.

Hypericum perforatum L. is the most commonly used herb for treating depression. Due to the popularity of this botanical, there is a potential for economically driven adulteration of St. John's wort (SJW) products. The goal of this study was to investigate SJW ingredients suspected to be adulterated based on simple preliminary HPTLC tests. Commercial samples were analyzed by HPTLC following the United States Pharmacopeia (USP) monograph methodology, with additional visualization under white light. A number of these samples presented odd methanolic solution colors and unconventional HPTLC fingerprints, suggesting the presence of other species and/or extraneous polar additives. To achieve identification and separation of the polar additives, a new reversed-phase HPTLC method was developed. The adulterants were identified as synthetic dyes in the amounts of 0.51 to 1.36% by weight. Identities of the dyes were confirmed by scanning densitometry and HPTLC-MS. A modified USP method with additional detection mode permitted the identification of eight SJW samples adulterated with dyes and six others with flavonoid fingerprints different from those specified by USP from a total of 37 samples of dry extracts, finished products, and bulk raw herb. A decision flowchart is proposed to guide the detection of adulteration of SJW in a systematic fashion.

Hop-Derived Prenylflavonoids and Their Importance in Brewing Technology – A Review

Beer is one of the world’s most popular beverage products. Beer is all natural ingredients, so moderate consumption contributes to a healthy daily diet. Beer contains a large variety of phenolic compounds which are derived from the processed cereal (70%) and hops (30%) and which are responsible for the antioxidant activity of the beverage. Hops ( Humulus lupulus L.) are an essential ingredient of beer and are a source of polyphenols that contain the prenyl or geranyl group in the chemical structure, xanthohumol, isoxanthohumol, 6-prenilnaringenin and 8-prenylnaringenin. The prenylflavonoid's compounds found in beer have different biological activities demonstrated in vitro as antioxidant, anticarcinogenic, anti-inflammatory, estrogenic and antiviral. Important quantities of prenylflavonoids are lost during wort production. The losses may be explained by the low solubility of these compounds and its insufficient extraction in wort. Using appropriate engineering strategies, improvements in the recovery of prenylflavonoids from hops into beer has involved increased hopping rate, improved brewing process, especially wort boiling, increased colored malt yields and management of beer fermentations. Beer is one of the world’s most popular beverage products. Beer is all natural ingredients, so moderate consumption contributes to a healthy daily diet. Beer contains a large variety of phenolic compounds which are derived from the processed cereal (70%) and hops (30%) and which are responsible for the antioxidant activity of the beverage. Hops ( Humulus lupulus L.) are an essential ingredient of beer and are a source of polyphenols that contain the prenyl or geranyl group in the chemical structure, xanthohumol, isoxanthohumol, 6-prenilnaringenin and 8-prenylnaringenin. The prenylflavonoid's compounds found in beer have different biological activities demonstrated in vitro as antioxidant, anticarcinogenic, anti-inflammatory, estrogenic and antiviral. Important quantities of prenylflavonoids are lost during wort production. The losses may be explained by the low solubility of these compounds and its insufficient extraction in wort. Using appropriate engineering strategies, improvements in the recovery of prenylflavonoids from hops into beer has involved increased hopping rate, improved brewing process, especially wort boiling, increased colored malt yields and management of beer fermentations.

Volatile profile, fatty acids composition and total phenolics content of brewers' spent grain by-product with potential use in the development of new functional foods

Brewers' spent grain (BSG) is the insoluble residue generated from the production of wort in the brewing industry. This plant-derived by-product is known to contain significant amounts of valuable components, which remain unexploited in the brewing processes. Therefore, it is essential to develop a more detailed characterization of BSG in order to highlight its potential in developing new value-added products and simultaneously solve the environmental problems related to its discharge. The content of BSG in several biologically active compounds (fatty acids, polyphenols, flavonoids, antioxidant capacity) as well as its volatile fingerprint were assessed and compared with the composition of barley, malt and wheat flour samples. The obtained results emphasized the importance and the opportunities of the re-use of this agro-industrial by-product.

Addition of Sodium Stearoyl Lactylate to Corn and Sorghum Starch Extrudates Enhances the Performance of Pregelatinized Beer Adjuncts

ABSTRACTDouble mashing for wort production is a time‐consuming process that can be reduced if pregelatinized adjuncts are used. Optimal extruding conditions were determined to obtain brewing adjuncts from corn and sorghum starch. For corn starch extrusion, a Box–Behnken design was devised in which moisture, screw speed, temperature of the barrel, and concentrations of sodium stearoyl lactylate (SSL) were varied, and sorghum starch was extruded according to a 23 model in which the modified variables were moisture, SSL concentration, and temperature. The aim was to maximize starch damage and minimize resistant starch and final viscosity as determined with a Rapid Visco Analyzer. The treatments that satisfied these requirements were mashed, and wort extract yield was determined. Glucose, maltose, and maltotriose concentrations in the resulting worts were determined by HPLC with a refractive index detector. Feedstock tempering and SSL content were the most important factors affecting the response; for corn starch, treatments with lower moisture (20%) and middle levels of SSL (0.5%) or with high levels of both moisture (40%) and SSL (1%) produced the most desirable samples for mashing, whereas for sorghum starch the best treatment was tempering to 20% moisture and containing middle levels of SSL (0.5%). No statistical differences were found between these experimental treatments and the control.

Malted and unmalted oats in brewing

Using oats as a raw material in brewing has recently become the focus of increased interest. This is due to research findings that have shown that oats can be consumed safely by coeliac sufferers. It is also a response to consumer demand for products with novel sensory properties. In this study, beer was produced entirely from oat malt, from barley malt and from oat and barley malts mixed with various quantities of unmalted oats. Compared with barley wort, wort made from malted oats provided a lower extract content and had a higher protein content, but a lower free amino nitrogen content (FAN). The oat wort also showed increased viscosity and haze. The addition of unmalted oats during wort production produced significant changes in the physico-chemical parameters of both oat and barley worts and beers. Unmalted oats caused an increase in wort viscosity and haze, and a reduction in total soluble nitrogen and FAN. Unmalted oats also contributed to lowering the concentration of higher alcohols and esters. Beer made from 100% oat and barley malts exhibited a similar alcohol content. The use of an oat adjunct in both cases resulted in a lower ethanol content. The introduction of enzyme preparations during the production of wort with oat adjunct had many benefits: increased extract content and FAN; a higher volume of wort; and a lower viscosity that led to faster wort filtration. This research suggests that the use of enzymes is necessary to make production using a high proportion of oats in the grist profitable. Copyright © 2014 The Institute of Brewing & Distilling

Simplified Mashing Efficiency. Novel Method for Optimization of Food Industry Wort Production with the Use of Adjuncts

Abstract Malt extracts and malt concentrates have a broad range of application in food industry. Those products are obtained by methods similar to brewing worts. The possible reduction of cost can be achieved by application of malt substitutes likewise in brewing industry. As the malt concentrates for food industry do not have to fulfill strict norms for beer production it is possible to produce much cheaper products. It was proved that by means of mathematic optimization it is possible to determine the optimal share of unmalted material for cheap yet effective production of wort.

Possibilities to improve the antioxidative capacity of beer by optimized hopping regimes

Different hopping regimes were evaluated to investigate the effect on the oxidative stability of wort and beer. Compared with a single hop dosage at the beginning of wort boil, it was possible to increase the concentration of α-acids in pitching wort and beer by applying incremental hop dosage, dry hopping or the use of a pre-isomerized hop product in combination with an α-acid extract, which concomitantly resulted in lower iron concentrations and an enhanced flavour stability as indicated by standard wort and beer analyses, atomic absorption spectroscopy, electron spin resonance spectroscopy and sensory analysis of fresh and force-aged beers. The functional principle of hop dosage variations is explained by saving of α-acids throughout the wort production process, which yields an increased formation and precipitation of pro-oxidative acting transition metal ions (e.g. Fe) in α-acid-complexes during the whirlpool rest and fermentation. Consequently, fewer reactive oxygen species are generated. Additional laboratory trials simulating wort cooling and beer storage in buffered model solutions proved that un-isomerized α-acids are strong iron chelators and confirmed the functional principle of the applied hopping regimes. Negative effects of higher α-acid contents on fermentation performance and depletion of the zinc concentration, which is an essential nutrient for yeast, could be excluded. Copyright © 2014 The Institute of Brewing & Distilling

Decomposition kinetics of dimethyl sulphide

Dimethyl sulphide is a well characterized off-flavour in the brewing industry. The thermal re-creation of dimethyl sulphide by the decomposition of dimethyl sulphide precursor in standardized wort is measured using pressure-controlled boiling processes at different temperatures. The results are used for the calculation of decomposition speed constants and Arrhenius activation energies. Using these data the re-creation of dimethyl sulphide during the wort production processes can be calculated and thereby optimized. Copyright © 2014 The Institute of Brewing & Distilling

Vitamins in brewing: the impact of wort production on the thiamine and riboflavin vitamer content of boiled sweet wort

Wort production contains a number of processing steps that are aimed at the optimal extraction of nutrients from malt, including vitamins. This research revealed that the different wort production processing steps imposed different influences on the thiamine and riboflavin vitamer content of the final sweet wort. These vitamins play vital roles within yeast metabolism, where they act as enzyme cofactors. As such thiamine vitamers play a crucial role in many decarboxylating enzymes, while riboflavin vitamers play an integral role in energy production and redox maintenance. While mashing releases valuable starch into the liquor, both thiamine and riboflavin are also extracted. The extraction of these vitamins is the greatest at 65°C and is indirectly linked to the amylase activity. When the starches are broken down during mashing, the thiamine and riboflavin vitamers are gradually released into the mash liquor. The boiling and trub removal (whirlpool) processes impose losses in both vitamins owing to the high temperatures exhibited during these stages. While hop pellets were shown to contribute a small proportion of the vitamers studied, the use of kettle finings caused a significant reduction in both thiamine and riboflavin vitamers. Copyright © 2014 The Institute of Brewing & Distilling

Brewer's spent grain: a valuable feedstock for industrial applications

Brewer's spent grain (BSG) is the most abundant by-product generated from the beer-brewing process, representing approximately 85% of the total by-products obtained. This material is basically constituted by the barley grain husks obtained as solid residue after the wort production. Since BSG is rich in sugars and proteins, the main and quickest alternative for elimination of this industrial by-product has been as animal feed. However, BSG is a raw material of interest for application in different areas because of its low cost, large availability throughout the year and valuable chemical composition. In the last decade, many efforts have been directed towards the reuse of BSG, taking into account the incentive that has been given to recycle the wastes and by-products generated by industrial activities. Currently, many interesting and advantageous methods for application of BSG in foods, in energy production and in chemical and biotechnological processes have been reported. The present study presents and discusses the most recent perspectives for BSG application in such areas.

Assessing the xylanolytic bacterial diversity during the malting process

The presence of microorganisms producing cell wall hydrolyzing enzymes such as xylanases during malting can improve mash filtration behavior and consequently have potential for more efficient wort production. In this study, the xylanolytic bacterial community during malting was assessed by isolation and cultivation on growth media containing arabinoxylan, and identification by 16S rRNA gene sequencing. A total of 33 species-level operational taxonomic units (OTUs) were found, taking into account a 3% sequence dissimilarity cut-off, belonging to four phyla (Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria) and 25 genera. Predominant OTUs represented xylanolytic bacteria identified as Sphingobacterium multivorum, Stenotrophomonas maltophilia, Aeromonas hydrophila and Pseudomonas fulva. DNA fingerprinting of all xylanolytic isolates belonging to S. multivorum obtained in this study revealed shifts in S. multivorum populations during the process. Xylanase activity was determined for a selection of isolates, with Cellulomonas flavigena showing the highest activity. The xylanase of this species was isolated and purified 23.2-fold by ultrafiltration, 40% ammonium sulfate precipitation and DEAE-FF ion-exchange chromatography and appeared relatively thermostable. This study will enhance our understanding of the role of microorganisms in the barley germination process. In addition, this study may provide a basis for microflora management during malting.

Study on the Gibberellic Acid Residues in Brewing

Gibberellic acid is a plant growth regulator, which can improve the quality of malts when used in the malting process, but it has a potential toxicity. The purpose of this study was to investigate the changes of gibberellic acid (GA3 in particular) during beer brewing process. GA3 residues in 15 kinds of commercial malt and 35 kinds of commercial beer were detected by ultra performance liquid chromatography-mass spectrometry (UPLC-MS). The GA3 residues in all of the malts were proved to be in direct proportion to the use of exogenous GA3 amount. In contrast, the GA3 residues were not detected in any of the selected beer samples. To find its cause, the levels of GA3 residues during mashing and boiling periods were measured. It was found that the GA3 in malts were isomerized in mashing and wort boiling stages, and a new substance with different retention characteristics compared with GA3 was observed in the C18 column. The mass-to-charge ratio (m/z) of the major ions for the new substance were m/z = 369.1 ([M+Na]+), m/z = 715.2 ([2M+Na]+), m/z = 329.2 ([M−H2O+H]+), m/z = 283.1 ([M−H2O−HCO2H+H]+). So, the new substance may be different from GA3 in the position of one or more groups. The new isomeric compound may be one of the GA3 isomers from the wort production. In further research, two dimensional nuclear magnetic resonance (2D NMR) will be used to identify the accurate structure of the new substance.

The application of a DNA-based identification technique to over-the-counter herbal medicines

Reliable methods to identify medicinal plant material are becoming more important in an increasingly regulated market place. DNA-based methods have been recognised as a valuable tool in this area with benefits such as being unaffected by the age of the plant material, growth conditions and harvesting techniques. It is possible that the methods of production used for medicinal plant products will degrade or remove DNA. So how applicable are these techniques to processed medicinal plant products?A simple PCR-based identification technique has been developed for St. John's Wort, Hypericum perforatum L. Thirteen St. John's Wort products were purchased including capsules, tablets and tinctures. DNA was extracted from each product, and the species specific PCR test conducted.DNA was successfully extracted from all thirteen products, using a fast and efficient modified method for extracting DNA from tinctures. Only four products yielded the full length ITS region (850bp) due to the quality of the DNA. All of the products tested positive for H. perforatum DNA.DNA-based identification methods can complement existing methods of authentication. This paper shows that these methods are applicable to a wide range of processed products, provided that they are designed to account for the possibility of DNA degradation.

The Influence of Very Thick and Fast Mashing Conditions on Wort Composition

The mashing process is of highest technological relevance for all following processes of wort and beer production. However, it is time consuming and therefore cost intensive. The influence of important mashing parameters on wort composition was investigated in order to shorten the mashing process by applying the thickest mashes without a negative influence on wort composition. The thickest mash leads to lower energy and water consumption in the brewhouse. On the other hand, the shortest mashing scheme results in the highest throughput. Finally, fine milling, mashing-in above gelatinization temperature, decreased mashing-in pH of 5.2, very thick mash of 1:2.3 malt:water ratio, and a holding time of 30–40 min at 64°C followed by 15–20 min at 72°C guarantees a high extract yield, normal attenuation limit, sufficient FAN level, required buffering capacity, and a reduced fatty acid oxidation. Lowering the pH to 5.2 at mashing-in results in lower glucose levels but the sum of fermentable sugar is not influenced due to a higher level of maltotriose and similar maltose levels. However, not all yeast strains assimilate maltotriose well in industrial fermentations. A mash pH of 5.2, positive for beer flavor stability, may result in a somewhat lower alcohol potential.