Industrial Malting Research Articles

Implementación de un sistema de gestión ambiental: recomendaciones para la pequeña y mediana industria

In recent years, the idea that business management must incorporate the criterion of protecting the environment, in addition to quality, safety and health, as an element of competitive advantage, has become increasingly latent. Improved efficiency, energy and raw material savings, as well as an improved corporate image, are just some of the advantages derived from implementing an environmental management system in the company (Fassoula & Rogerson, 2003). On the other hand, it also ensures compliance with the regulatory framework of the different environmental vectors. The development of the work is oriented to applied and/or descriptive research. That is, it shows a mechanism that facilitates the implementation of the environmental management system (EMS), based on the requirements of ISO-14001; the process of implementation of an environmental management system in an industrial malting plant in Lima, Peru, is taken as a reference. The application of this research shows the usefulness for small and medium companies, responsible for the implementation of an environmental management system (EMS); giving them a guide for the work. The research is based on the interpretation and analysis of environmental standards, mainly the requirements of the International Organization for Standardization (ISO) and ISO 14001, as well as others related to the subject in question. On the other hand, the difficulties and advantages involved in the implementation of this environmental management system, based on ISO 14001, are shown.

Industrial evaluation for malting quality of Indian barley varieties

Barley is a preferred cereal for malt making and specialized varieties are required to get superior product quality in industrial malting and brewing uses. The Indian malt barley improvement programme has developed several varieties for this specific purpose. In this study eight malting barley varieties were got evaluated by four malt barley industries in their analysis. Based upon the overall performance, the varieties DWRUB 52, DWRB 101 and DWRB 91 in two-row and DWRUB 64 and DWRB 137 in six-row group were found most suitable with recent industrial specifications. The diastatic power in two rowed genotypes needs to be improved and β-glucan in grain or wort needs to be further lowered in view of the current industrial preferences.

Proteomics reveals commitment to germination in barley seeds is marked by loss of stress response proteins and mobilisation of nutrient reservoirs

Germination is a critical process in the reproduction and propagation of flowering plants, and is also the key stage of industrial grain malting. Germination commences when seeds are steeped in water, followed by degradation of the endosperm cell walls, enzymatic digestion of starch and proteins to provide nutrients for the growing plant, and emergence of the radicle from the seed. Dormancy is a state where seeds fail to germinate upon steeping, but which prevents inappropriate premature germination of the seeds before harvest from the field. This can result in inefficiencies in industrial malting. We used Sequential Window Acquisition of all THeoretical ions Mass Spectrometry (SWATH-MS) proteomics to measure changes in the barley seed proteome throughout germination. We found a large number of proteins involved in desiccation tolerance and germination inhibition rapidly decreased in abundance after imbibition. This was followed by a decrease in proteins involved in lipid, protein and nutrient reservoir storage, consistent with induction and activation of systems for nutrient mobilisation to provide nutrients to the growing embryo. Dormant seeds that failed to germinate showed substantial biochemical activity distinct from that of seeds undergoing germination, with differences in sulfur metabolic enzymes, endogenous alpha-amylase/trypsin inhibitors, and histone proteins. We verified our findings with analysis of germinating barley seeds from two commercial malting facilities, demonstrating that key features of the dynamic proteome of germinating barley seeds were conserved between laboratory and industrial scales. The results provide a more detailed understanding of the changes in the barley proteome during germination and give possible target proteins for testing or to inform selective breeding to enhance germination or control dormancy. SignificanceGermination is critical to the reproduction and propagation of flowering plants, and in industrial malting. Dormancy, where seeds fail to germinate upon steeping, can result in inefficiencies in industrial malting. Our DIA/SWATH-MS proteomics analyses identified key changes during germination, including an initial loss of proteins involved in desiccation tolerance and germination inhibition, followed by decreases in lipid, protein and nutrient reservoir storage. These changes were consistent between laboratory and industrial malting scales, and therefore demonstrate the utility of laboratory-scale barley germination as a model system for industrial malt house processes. We also showed that dormant seeds that failed to germinate showed substantial biochemical activity distinct from that of seeds undergoing germination, consistent with dormancy being an actively regulated state. Our results provide a more detailed understanding of the changes in the barley proteome during germination and give possible target proteins for testing or to inform selective breeding to enhance germination or control dormancy.

Evolution of folate content during barley malt production

AbstractThe aim of this research was to study the effect of micro- and industrial scale malting on the folate content of barley. Two malting barley varieties (one spring and one winter) were studied, applying the same technology. Furthermore, a roasting experiment was carried out at given temperatures for different time periods. The total folate content was determined by microbiological method. The folate content of the barleys was between 10.1 and 23.4 µg/100 g dry matter. For micro- and industrial scale, malting folate content increased 6.5–8-fold and 4–7-fold, respectively, during the malting process. An unexpected result was observed during industrial malting: the folate content increased during kilning by 18–35%, unlike micro scale malting, where a 15–20% decrease was observed. Results obtained during roasting showed that folic acid content did not decrease when roasted for 20 min at 100 °C, but it decreased linearly with increasing temperature. Folate is completely degraded in 20 min at 200 °C. It can be stated that barley malt can serve as a relatively good source of folate, but barley variety and malting technology have significant impact on it.

Malts: Quality and phenolic content of pearl millet and sorghum varieties for brewing nonalcoholic beverages and opaque beers

AbstractBackground and objectivesThe use of malted sorghum and pearl millet in the production of traditional foods and beverages is ubiquitous in Africa and India. However, there is limited industrial production and little data on the phenolic content and quality of pearl millet and sorghum malts of different varieties. Therefore, this study investigated the proximate content, malt quality, and phenolics of pearl millet (Okashana 2, Kantana, and Kangara) and sorghum (Macia and a landrace referred to as Red sorghum) varieties.FindingsMalting increased the protein in all the varieties, except for Kangara. Germinative energies were >97% for all varieties, except for Red sorghum. Malt quality (reducing sugars, free amino nitrogen, and β‐amylase activity) was highest for Macia followed by Kantana. All pearl millet varieties and Macia had no condensed tannins. The total phenolic content and radical scavenging capacity decreased after malting for all the varieties.ConclusionsMacia and Kantana can be candidates for industrial malting for brewing nonalcoholic beverages and opaque beers. Kantana and Red sorghum had higher amounts of phenolic compounds and can potentially be vectors of delivering phenolics into human diets.Significance and noveltyThis study investigated the phenolic content and quality of malts of different pearl millet and sorghum varieties, which can potentially be used to brew particularly low‐alcohol beverages.

Microbial community dynamics of Dan'er barley grain during the industrial malting process

The microbes associated with barley grains are known to have either deleterious or beneficial effects on the malting process, thereby affecting the quality of malt and even beer. Dan'er barley is the major cultivar grown in Jiangsu Province in China, malt derived from this cultivar, however, invariably causes filtration problems. To understand the microbial community of Dan'er barley and its probable effects on malt quality and subsequent brewing process, the present study combined culture-dependent methods and culture-independent PCR denaturing gradient gel electrophoresis (PCR-DGGE) strategies. The results showed that as the dominant microbes, bacterial community structure varied considerably during the malting process, while the fungi load increased at the end of malting process, even in the kilning stage. The great abundance of gram-negative bacteria, which can produce exopolysaccharides and form biofilms, may be the main reason for the filtration defects of Dan'er malt. Pathogenic fungi may also have a negative impact on grain germination and malt nutritional value. Several beneficial lactic acid bacteria and fungi strains were also found. These results may contribute to our knowledge of barley grain-associated microbes, and help optimizing the malting process using the Dan'er barley cultivar to get malt product with better quality.

Electromagnetic Heating for Industrial Kilning of Malt: a Feasibility Study

Industrial malting operations use ~800kWh/t of energy to produce the heat required to kiln malt. Electromagnetic heating technologies are suggested as a way to potentially improve the energy efficiency of the kilning processing. In this work, the potential for using electromagnetic heating to dry malt to commercially acceptable moisture levels, whilst preserving the activity of enzymes critical for downstream brewing processes is investigated. The 2450 MHz bulk dielectric properties of malt at moisture contents consistent with those occurring at different points in the kilning process are evaluated; 12% is shown to be a critical moisture level below which drying becomes more energy intensive. Calculated penetration depths of electromagnetic energy in malt at radio frequency are 100 fold higher than at microwave frequencies, showing a significant advantage for commercial scale batch processing. The moisture contents and alpha and beta amylase activity of malt subjected to RF heating at different temperatures, treatment times and RF energy inputs in the intermediate and bound water drying regions were determined. It is shown for the first time that whilst significantly reduced process times are attainable, significant energy efficiency improvements compared to conventional kilning can only be achieved at higher product temperatures and thus at the expense of enzyme survival. It is suggested that RF heating may be feasible where higher bulk temperatures are not critical for downstream use of the material or when used in hybrid systems.

Determination of Phenolic Content in Different Barley Varieties and Corresponding Malts by Liquid Chromatography-diode Array Detection-Electrospray Ionization Tandem Mass Spectrometry.

A simple and reliable method for the simultaneous determination of nine phenolic compounds in barley and malted barley was established, using liquid chromatography-diode array detection-electrospray ionization tandem mass spectrometry (HPLC-DAD-ESI-MS/MS). The phenolic compounds can be easily detected with both systems, despite significant differences in sensitivity. Concentrations approximately 180-fold lower could be achieved by mass spectrometry analysis compared to diode array detection, especially for the flavan-3-ols (+)-catechin and (−)-epicatechin, which have poor absorptivity in the UV region. Malt samples were characterized by higher phenolic content comparing to corresponding barley varieties, revealing a significant increase of the levels of (+)-catechin and (−)-epicatechin during the malting process. Moreover, the industrial malting is responsible for modification on the phenolic profile from barley to malt, namely on the synthesis or release of sinapinic acid and epicatechin. Accordingly, the selection of the malting parameters, as well as the barley variety plays an important role when considering the quality and antioxidant stability of beer.

An accelerated malting procedure - influences on malt quality and cost savings by reduced energy consumption and malting losses

In times of rapidly increasing energy costs and rising importance of economic efficiency, the malting industry is searching for possibilities to reduce malting time to lower their production costs and to increase production capacities. The aim of this study was to compare a step-wise optimized accelerated malting procedure, combining optimal parameters found in previous individual investigations about steeping, germination and withering with two reference malting programmes: a standard laboratory malting programme according to MEBAK and a programme applied in an industrial malting plant. For five investigated spring barley cultivars, sufficient malt qualities according to the MEBAK specifications could be achieved in a malting process that was about 2 days shorter. Despite slightly lower extract contents, resulting from slightly higher pH values and activities of the starch degrading α- and β-amylases, a reduced and thus improved proteolytic modification, improved malt homogeneities, a reduced thermal impact resulting in lower malt colours, in turn implying an increased oxidative flavour stability, and an improved behaviour of premature yeast flocculation could be observed when malting was accelerated. The lautering properties, cytolytic modifications, deoxynivalenol content and gushing potential were not influenced in a significant positive or negative way. Next to the notable production time reduction, decreased dimethyl sulphide precursor contents imply advantages for the brewing and malting industry with regard to a shorter necessary boiling and kilning time. Further significant cost savings of €1.27–4.87/t malt could be calculated owing to a reduction in the amount of electrical energy used for aerating and cooling during germination and lower malting losses, depending on the cultivar. Copyright © 2015 The Institute of Brewing & Distilling

Bacterial community dynamics during industrial malting, with an emphasis on lactic acid bacteria

Characterization of the microflora during malting is an essential step towards process management and optimization. Up till now, however, microbial characterization in the malting process has mostly been done using culture-dependent methods, probably leading to biased estimates of microbial diversity. The aim of this study was to characterize the bacterial communities using two culture-independent methods, including Terminal Restriction Fragment Length Polymorphism (T-RFLP) and 454 pyrosequencing, targeting the 16S rRNA gene. Studied samples originated from two harvest years and two malting houses malting the same batch of barley. Besides targeting the entire bacterial community (T-RFLP), emphasis was put on lactic acid bacteria (LAB) (T-RFLP and 454 pyrosequencing). The overall bacterial community richness was limited, but the community structure changed during the process. Zooming in on the LAB community using 454 pyrosequencing revealed a total of 47 species-level operational taxonomic units (OTUs). LAB diversity appeared relatively limited since 88% of the sequences were covered by the same five OTUs (representing members of Weissella, Lactobacillus and Leuconostoc) present in all samples investigated. Fluctuations in the relative abundances of the dominant LAB were observed with the process conditions. In addition, both the year of harvest and malting house influenced the LAB community structure.

Biochemical heterogeneity of malt is caused by both biological variation and differences in processing: I. Individual grain analyses of biochemical parameters in differently steeped barley (Hordeum vulgare L.) malts

Using individual grain analyses, the degree of inherent biological variation in germinating barley seeds has been established. Even under homogenous laboratory conditions, the activities of the germination-related enzymes α-amylase, β-amylase and β-glucanase varied by a factor of two to three. The comparison with single grain analyses of different industrially produced malts (steeping systems without aeration, with air suction and pressurised aeration) revealed that the heterogeneity of these malts nearly tripled. This increase may be due to the gradients in O2 and CO2 that arise in large industrial steeping vessels. The most homogenous malting in the industrial systems was achieved without any aeration during steeping. Therefore, to improve homogeneity, the common practise of steep aeration should be omitted. Germination progression was quite different within the three exhaustively aerated attempts, which indicated that gaseous composition was not the only factor affecting germination progression.

Metabolite fingerprinting of barley whole seeds, endosperms, and embryos during industrial malting

Samples of whole seeds, isolated endosperms including the aleurone layer and isolated embryos with attached scutellum from an industrial scale barley malting process (variety Braemar) were analysed for their water soluble metabolites by gas chromatography-mass spectrometry (GC-MS). 73 known metabolites and about 350 unknown signals were detected. Principal component analysis (PCA) showed a time dependent shift of sample profiles. Whole seeds and endosperm samples showed very similar patterns with nearly all compounds rising until the end of germination. In the embryos a maximum concentration of compounds was reached after 72-96 h of malting. Most concentrations decreased afterwards. The kilning step, namely the drying and roasting of germinated seeds, induced variable effects of increases, stability or decreases of metabolites and thereby separated kilned samples from germinated seeds in the PCA. A second barley cultivar (Quench) underwent the same malting and analysis procedures and gave nearly identical results. Fructose, malate, myo-inositol and raffinose exhibited the potential to serve as markers for specific developmental stages of seeds in both varieties. Biological markers represent targets for industrial process control. Their potential application would meet the maltsters' demand to flatten variances in germination properties and to produce equal composed malt by directed malting management.

Proteomes of the barley aleurone layer: A model system for plant signalling and protein secretion

The cereal aleurone layer is of major importance due to its nutritional properties as well as its central role in seed germination and industrial malting. Cereal seed germination involves mobilisation of storage reserves in the starchy endosperm to support seedling growth. In response to gibberellic acid produced by the embryo, the aleurone layer synthesises hydrolases that are secreted to the endosperm for the degradation of storage products. The barley aleurone layer can be separated from the other seed tissues and maintained in culture, allowing the study of the effect of added signalling molecules in an isolated system. These properties have led to its use as a model system for the study of plant signalling and germination. More recently, proteome analysis of the aleurone layer has provided new insight into this unique tissue including identification of plasma membrane proteins and targeted analysis of germination-related changes and the thioredoxin system. Here, analysis of intracellular and secreted proteomes reveals features of the aleurone layer system that makes it promising for investigations of plant protein secretion mechanisms.

Quantification of the inhibitory effect of steep effluents on barley germination

The inhibitory effect of barley steep-out waters was assessed using a new, quick and simple test, based on 24-h barley germination percentage. This original 24-h test was especially relevant for quantifying the inhibitory effect of steep-out water samples, as compared with a conventional 7-to-8-day malting process. The results made it possible to rapidly compare the effect of water samples of different qualities, especially after 3 successive recycling experiments of steep-out waters into the steeping step of barley malting process. The test was used to emphasise the difference of the inhibitory effects of steep-out waters collected from various industrial malting plants. Such a test can be used for investigations on the identification and the elimination of inhibitors.

Yeasts isolated from industrial maltings can suppress Fusarium growth and formation of gushing factors

Fusarium infection of barley and malt can cause severe problems in the malting and brewing industry. In addition to being potential mycotoxin producers, Fusarium fungi are known to cause beer gushing (spontaneous overfoaming of beer). Cereal-derived bacteria and yeasts are potential biocontrol agents. In this study, the antifungal potential of selected yeasts (12 strains) derived from the industrial malting ecosystem was studied in vitro with a plate-screening assay. Several ascomycetous yeast strains showed antagonistic activity against field and storage moulds, Pichia anomala being the most effective strain. The effects of P. anomala VTT C-04565 (C565) were examined in laboratory scale malting with naturally contaminated barley exhibiting gushing potential. P. anomala C565 restricted Fusarium growth and hydrophobin production during malting and prevented beer gushing. Grain germination was not disturbed by the presence of yeast. Addition of P. anomala C565 into the steeping seemed to retard wort filtration, but the filtration performance was recovered when yeast culture was combined with Lactobacillus plantarum VTT E-78076. Well-characterized microbial cultures could be used as food-grade biocontrol agents and they offer a natural tool for tailoring of malt properties.

Yeasts in an industrial malting ecosystem

The malting ecosystem consists of two components: the germinating cereal grains and the complex microbial community. Yeasts and yeast-like fungi are an important part of this ecosystem, but the composition and the effects of this microbial group have been largely unknown. In this study we surveyed the development of yeasts and yeast-like fungi in four industrial scale malting processes. A total of 136 malting process samples were collected and examined for the presence of yeasts growing at 15, 25 and 37 degrees C. More than 700 colonies were isolated and characterized. The isolates were discriminated by PCR-fingerprinting with microsatellite primer (M13). Yeasts representing different fingerprint types were identified by sequence analysis of the D1/D2 domain of the 26S rRNA gene. Furthermore, identified yeasts were screened for the production of alpha-amylase, beta-glucanase, cellulase and xylanase. A numerous and diverse yeast community consisting of both ascomycetous (25) and basidiomycetous (18) species was detected in the various stages of the malting process. The most frequently isolated ascomycetous yeasts belonged to the genera Candida, Clavispora, Galactomyces, Hanseniaspora, Issatchenkia, Pichia, Saccharomyces and Williopsis and the basidiomycetous yeasts to Bulleromyces, Filobasidium, Cryptococcus, Rhodotorula, Sporobolomyces and Trichosporon. In addition, two ascomycetous yeast-like fungi (black yeasts) belonging to the genera Aureobasidium and Exophiala were commonly detected. Yeasts and yeast-like fungi produced extracellular hydrolytic enzymes with a potentially positive contribution to the malt enzyme spectrum. Knowledge of the microbial diversity provides a basis for microflora management and understanding of the role of microbes in the cereal germination process.

The Influence of Starter Cultures on Barley Contaminated with Fusarium Culmorum TMW 4.0754

This study investigates the effects of lactic acid bacteria (LAB) added concomitantly to barley infected with fungal spores or mycelia of Fusarium culmorum TMW 4.0754. The trials were performed in a micromalting plant simulating an industrial malting program. Malt samples were compared with those of nonacidified barley, disinfected nonacidified barley, chemically acidified barley, and barley with additional modified DeMan-Rogosa-Sharpe 4 medium. All control samples had fungal spores and fungal mycelia added. Bacterial cultures were chosen as a result of their enzymatic (proteolytic/amylolytic) activity level or their good acidification properties. The effects of the LAB and Fusarium-infected malts on wort characteristics were investigated. Characteristics such as pH, extract, color, viscosity, total soluble nitrogen (TSN), free amino nitrogen (FAN), apparent fermentability, and lautering performance of the resultant worts were determined. Results showed that spores of F. culmorum TMW 4.0754 do not affect the quality of malt or wort. The quality of wort was reduced when mycelia of F. culmorum were applied in the presence of LAB or chemical lactic acid leading to slower filtration rates, lower extract, fermentability, TSN, and FAN yields along with higher viscosity levels. These effects seemed to depend mainly on the presence of mycelia together with the content of lactic acid present.

Oxygen Deficiency in Barley (Hordeum vulgare) Grain during Malting

The steep water is generally aerated in industrial barley malting. However, it is questionable whether oxygen actually reaches the embryo, which remains entrapped under the husk, testa, and pericarp until chitting occurs. The aim of our study was to investigate whether barley embryos experience oxygen deficiency during steeping, and whether various steeping conditions affect the oxygen deficiency. Alcohol dehydrogenase Adh2 was induced in all steeping conditions studied. Therefore, oxygen deficiency occurred regardless of the steeping conditions. However, steeping conditions affected the rate of recovery from oxygen deficiency, germination rate, and onset of alpha-amylase production. When barley was subjected to oxygen deficiency by applying N(2) gas during steeping, the timing of the treatment determined its effects. The importance of aeration increased as the process proceeded. Oxygen deprivation at the beginning of the process had little effect on malt quality. Therefore, the timing of aeration is important in the optimization of germination during the steeping stage of malting.

The Influence of Lactic Acid Bacteria on the Quality of Malt

In this study three strains of lactic acid bacteria were applied during the malting process to evaluate the impact on malt and wort quality. The trials were performed in a micromalting plant simulating an industrial malting programme. The samples were compared to chemically acidified as well as non-acidified malt. Bacterial cultures were chosen with reference to their enzymatic (proteolytic/amylolytic) activity, or their good acidifying properties. The effects of lactic acid bacteria on wort characteristics were investigated and compared to wort produced from 100% unacidified malt. A chemical food grade lactic acid was also used to acidify the barley for comparison purposes. Characteristics such as pH, extract, colour, viscosity, total soluble nitrogen, free amino nitrogen, apparent fermentability, β-glucan and lautering performance of the resultant worts were determined. Results showed improved levels of β-glucanase in the malt although reduced malt friability was observed where LAB was employed. An improved lautering performance, lower wort viscosity and elevated TSN levels were also reported where LAB exhibiting protease activity were applied.

Characterisation of Barley Transformation into Malt by Three-Way Factor Analysis of near Infrared Spectra

Data collected for the spectral study of time series can be presented as a three-way array in which the three modes are the batches, time and wavelengths. The parallel factor analysis (PARAFAC) model is relevant for the analysis of three-way data tables, while the malting process consists of the time transformation of barley into malt. Furthermore, samples were collected on each day of an industrial malting process and their near infrared spectra were recorded in diffuse reflectance mode from 1100 to 2500 nm. The time and the wavelength modes associated with the first component showed that the spectra intensities allowed the classification of samples according to time. A study of the other loading vectors weighted by their coefficients on the time-mode explain some phenomena taking place during malting [the appearance of soluble substances (1950 nm), β-glucan degradation (2240–2360 nm), moisture modification (1450 and 1950 nm)…]. PARAFAC allowed us to separate batches according to the malting process to which they were submitted. Batches were also differentiated according to the chemical modification rate that occurred as expressed by the biochemical analyses results of the final malts. This work shows that PARAFAC can be a useful tool in the study of time series.