Diastatic Power Research Articles

English

The aim of this study was to determine the optimum malting conditions, for rice beer production, of seven cultivars of local rice (Oryza sativa L.) cultivated in the North and Far North Regions of Cameroon. Characteristic tests prior to malting (thousand corn weight, germinative energy, germinative capacity and starch content) of the cultivars (NL36, NL56, ITA306, ITA300, BKN, IR46, NL60) were determined using analytical methods described by The American Society of Brewing Chemists (ASBC). The best cultivars used for the experimental design were NL36 and ITA300, having starch contents greater than 60% DM, germinative energies and capacities greater than or equal to 96%. A Box-Behnken Design was used to investigate the influence of the steeping duration (24-48 h), germination duration (4-7 days), and kilning temperature (45-50°C) on the diastatic power and reducing sugar content of NL36 and ITA300 malt. The optimum malting conditions for maximum diastatic power of NL36 malt (38.47 WK) and reducing sugar content (16.79 g/100 g DM) were: steeping duration of 40 h, germination duration of 4 days, and kilning temperature of 50°C with a desirability value of 0.94. The optimal conditions for a maximum diastatic power of ITA300 malt (39.097 WK) and reducing sugar content (10.34 g/100 g DM) were: steeping duration of 43 h, the germination duration of 5 days, and kilning temperature of 50°C with a desirability value of 0.97. Although rice malt has a low diastatic power compared to barley and sorghum malt, it contains limit dextrinase and α-glucosidase, which can act synergistically with α and β-amylases. These rice cultivars can be used as the main cereal for beer production, or as adjuncts to enhance the enzyme potential of sorghum or maize malt.   Key words: Steeping, kilning, diastatic power, reducing sugar, germination, amylases.

Comparative Analyses of Impact of Varying Germination Periods on Malt Quality and Wort Characteristics of Sorghum Bicolor (L) Moench and Sorghum Vulgare Varieties

Three Sorghum bicolor [L] Moench and two Sorghum vulgare varieties were steeped for 20 h at 30 ℃ and germinated for 2 to 6 d. The varieties differed in 1000-grain weight, germination energy, germination capacity, water sensitivity, nitrogen, protein, tannin and moisture contents. Sprouts length increased with germination days and varied with sorghum varieties. Malting loss increased with germination days and differed with cultivars. Cold water extract and hot water extract increased from 2-day to 4-day malts and thereafter decreased. Tannin content varied among cultivars, grains>malts>worts. Diastatic power (DP) and amylase activities increased in both sweet and non-sweet sorghum cultivars from day-2 to day-4 malts and then declined. Sweet sorghum malts revealed higher DP (ca 142.1 ºL) than the non-sweet malts (ca 119.6 ºL). Malts of sweet sorghum varieties had -, β- and γ-amylase activities while non-sweet cultivars indicated only - and β-amylase activities. Sweet sorghum worts had more reducing sugars than non-sweet sorghum varieties. Wort-yields (43.9-68.7%) and reducing sugars differed and increased from day-2 to day-4 malts and then decreased. Worts pH (5.1-6.7) varied with cultivars and the sweet generally had higher pH than non-sweet sorghum cultivars. Generally, the 4-day sweet sorghum malts yielded the best quality malts.

Optimisation of Malting Parameters for Quinoa and Barley: Application of Response Surface Methodology

Quinoa (Chenopodium quinoa Willd) is a nutritious pseudocereal that is more stress-tolerant compared with traditional cereals. It is an excellent example of a climate-smart crop that is more resilient to climate change compared with barley. The purpose of the study was to investigate the optimum malting conditions required to produce quinoa malt using barley as a control. Response surface methodology (RSM) was used to investigate the influence of the two malting parameters steeping time and germination time on Brix (wort extract), diastatic power (DP), and free amino nitrogen (FAN) of the malt. The temperature was set at 15°C during the steeping process. Steeping time ranging from 12 to 48 hours and germination time ranging from 24 to 96 hours were designed using a central composite design (CCD). The kilning temperature for all malts was 65°C. For quinoa malt, there was a notable weak positive correlation between germination time and Brix (r = +0.119). However, there was a strong positive correlation between steeping time and diastatic power (r = +0.893). A similar trend was noted for barley with a weak positive correlation between germination time and Brix (r = +0.142). A strong positive correlation was also recorded between steeping time and diastatic power (r = +0.897) during the malting of barley. There was a relatively stronger correlation between steeping time and FAN (r = +0.895) than germination time and FAN (r = +0.275) in quinoa malt. The optimum values for the malting of barley were 47.68 hrs steeping time and 82.55 hrs germination time with a desirability value of 1.00. The responses for the optimised barley malt were 8.25°Bx, 162.28 mg/L, and 271.69°L for Brix, FAN, and diastatic power, respectively. To produce quinoa malt with Brix, FAN, and diastatic power of 8.37°Bx, 165.60 mg/L, and 275.86°L, respectively, malting conditions of 47.69 hrs steeping time and 95.81 hrs germination time are required. It was noted that quinoa is a very good candidate for producing high-quality malt for the brewing process.

Effect of malting regimen on diastatic power, cold and hot water extracts of malts from sorghum

SummaryIn this study, sorghum grains were malted using different malting regimens and the malt qualities were analysed for cold water extract (CWE), hot water extract (HWE) and diastatic power (DP). Results showed that malting regimen produced sorghum malts with peak CWE, HWE and DP within the pre‐determined limits of malting regimen. From this, predictive models of sorghum malt quality were developed and tested. Whilst steeping duration interacts significantly with the germination period to cause variations in CWE and HWE, only the germination period significantly influenced the DP of sorghum malts. However, the kilning temperature showed no significant impact on the parameters studied. Besides CWE, HWE and DP correlating positively with each other, the developed predictive models were significant (P < 0.05) and satisfy the quality of fit (R2 > 0.70) of the proposed models. The result demonstrated that wort for different purposes can be obtained by varying the malting operational conditions in the predictive model, thus saving time, resources, preliminary studies and research designs. Besides the promotion of a cheaper local alternative material for industrial wort production and brewing purpose, this research provides valuable insight on the brilliant prospect of variable malting regimen in predicting and adjusting the quality characteristics of sorghum malt and wort. Future studies are required to develop models for wort produced from peak CWE, HWE and DP, for predicting wort quality characteristics.

Physico-chemical and Microbiological Characteristics of Infant Porridges Produced from Infant Flours Containing Millet and Sorghum Malt

Women generally use traditional cereal flour porridges for weaning children, which are products rich in starch but low in protein. These porridges with a heavy, viscous, indigestible consistency are difficult for the child to digest, due to the starch which swells during cooking. To do this, this study was conducted with the aim of formulating twelve porridges of good nutritional value with the incorporation of millet and sorghum malt flours from four infant flours in order to increase the energy density of the porridges. The analysis of the physico-chemical, nutritional and microbiological parameters of the porridges was carried out using standard methods. From the results, it emerged that the best malt flour incorporation rates were 0.125% for 48h millet malt flour and 0.2% for 48h red sorghum malt flour with a viscosity of porridges between 90 and 120 mm/30s. The macronutrient parameters (Carbohydrates: 14,91±0,88% - 34,48±0,40 %/DM; Proteins: 34,59±0,54% - 44,90±0,84 %/DM, Fat: 26,34±0,18% - 39,50±0,57 %/DM) and the energy density (89.41±0.81kcal/100g to 124.54±0.57kcal/100g) were in accordance with the standards for processed cereal-based foods intended for infants and young children. The results of the total amino acids profile showed that Lysine presented the best content (0.166 to 0.285 mg/100g). For all the samples, the best values of macronutrient and energy density values were obtained with millet malt which presented a high diastatic power. It emerged from the microbiology results that all of the samples presented quite satisfactory levels of coliforms (Salmonella, yeasts and molds in accordance with the standards for processed cereal-based foods intended for infants and young children. At the end of the study, the results obtained showed that the use of millet and sorghum malts could be an alternative to improve the nutritional quality and increase the energy density of infant porridge.

10 unmalted alternative cereals and pseudocereals: A comparative analysis of their characteristics relevant to the brewing process

To meet consumer demand and remain competitive, brewers attempt to broaden their product range with new, innovative flavors. One way to achieve this is by (partially) replacing barley malt with less common adjuncts, such as the ancient wheat varieties einkorn, emmer, spelt, and khorasan; the pseudocereals quinoa, amaranth, and buckwheat; or the alternative cereals sorghum, teff, and tritordeum. The physical (grain size and thousand kernel weight), chemical (starch, protein, fat, β-glucan, and water content), and physicochemical (gelatinization temperature, amylase content) properties of these alternative cereals and pseudocereals were determined, as well as their aldehyde concentrations and flavor profiles. The starch content ranged from 45.2 ± 1.2 %dm for einkorn to 75.5 ± 0.6 %dm for teff. The protein content ranged from 10.6 ± 0.0 %dm for barley malt to 18.4 ± 0.6 %dm for khorasan. Major differences were found for the diastatic power, with quinoa having the lowest (6 ± 4 °WK) and spelt the highest (277 ± 19 °WK) value. Most alternative cereals and pseudocereals had an onset gelatinization temperature ≤63 °C, making them suitable for common brewing practices. This was not the case for quinoa, amaranth, teff, and sorghum, which had a gelatinization temperature ≥64 °C. Aldehyde concentrations were significantly lower in alternative cereals and pseudocereals, compared to malted barley.

A Malting Barley (Hordeum vulgare L.) Variety, ‘Baegrok’with Resistance to Powdery Mildew and Tolerance to Lodging

Other SectionsAbstract서 언재료 및 방법결과 및 고찰적 요사 사FigureTableReferenceA new malting barley variety, ‘Baegrok’, was developed in 2016 at the National Institute of Crop Science, RDA: Rural development administration by crossing the high-yield ‘Milyang130’ variety with ‘Myoginijo’, which has lodging tolerance and resistance to barley yellow mosaic virus (BaYMV). ‘Baegrok’ is suitable for use in brewing, similar to ‘Hopum’, and has resistance to powdery mildew and tolerance to lodging. From 2014 to 2016, regional yield trials were conducted in four different regions, with ‘Baegrok’ as a breeding line of ‘Iksan176’. The heading dates of ‘Baegrok’ in paddy and upland fields were April 6 and April 11, respectively, 2 days earlier than those of ‘Hopum’. Maturing dates of ‘Baegrok’ in paddy and upland fields were May 16 and May 21, respectively, similar to those of ‘Hopum’. The yield potential of ‘Baegrok’ was approximately 14% and 6% higher than that of ‘Hopum’ in upland and paddy fields. ‘Baegrok’ had a shorter culm length than ‘Hopum’ showing tolerance to lodging. Screening for powdery mildew resistance in the greenhouse showed that ‘Baegrok’ had resistance to powdery mildew, unlike ‘Hopum’ which was susceptible. It also is suitable for use in brewing, similar to Hopum. ‘Baegrok’ showed good grain quality in terms of β-glucan content (3.4%), starch (61.0%), and husk rate (12.7%). Regarding malt quality, ‘Baegrok’ exhibited 75.1% acrospire length, 70.8% friability, 4.4% soluble protein, and 345.8 WK (Windisch-Kolbach) diastatic power, superior to the malt quality of ‘Hopum’. Thus, ‘Baegrok’ is resistant to powdery mildew, tolerant to lodging, and more suitable for brewing. (Registration No. 8399)Keywords : malting barley, variety, malt, powdery mildew, lodging

Barley yield and malt characteristics as affected by nitrogen and final irrigation timing

AbstractIdaho is a major malt barley (Hordeum vulgare L.) producer in the United States. Production is concentrated in the semi‐arid Snake River Plain region of southern Idaho. Irrigation and fertilizer N applications are two of the most important managed factors. Research was conducted at the University of Idaho Kimberly Research & Extension Center near Kimberly, ID, to determine yield, grain quality, and malt characteristics as affected by N application rate (0, 56, 112, and 168 kg N ha−1) and final irrigation timing at Feekes 10.0 (boot; F10.0), Feekes 11.2 (soft dough; F11.2), and +7 d after Feekes 11.2 (+7F11.2). Irrigation termination at F10.0 resulted in decreased yields and unacceptable malt characteristics across N rates. Irrigation termination at F11.2 and +7F11.2 yielded 6,439 kg ha−1 at a fertilizer N application of 56 kg N ha−1, similar to higher N applications. Greater predicted yields up to 6,886 kg ha−1 were calculated by regression analysis with applications up to 147 kg N ha−1. Grain yield, protein, plumps, and test weights did not differ at any N rate for F11.2 or +7F11.2. Malt extract, free amino N, and diastatic power were similar for the F11.2 and +7F11.2 irrigations. Malt β‐glucan content did not differ up to 56 kg N ha−1 for any treatment, but reductions of up to 30 mg kg−1 were measured at higher N rates for the +7F11.2 irrigation. Results warrant further investigations into increased N applications and provide evidence of the effects of irrigation cutoff timing and N for malt barley.

Characterization of technological properties of sorghum and millet malt produced under control condition in Burkina Faso

The aim of this study was to determine the technological properties of sorghum and millet malt produced under controlled conditions in Burkina Faso. Two types of steeping were carried out: steeping at normal pH (6.5) and at alkaline pH (8). Analyzes of the functional properties (diastatic power, alpha and beta amylase activity) of the samples of malts produced were carried out using Bernfeld modified methods. From the results, it appeared that the values of diastatic power, alpha and beta amylase and amylase activity increased significantly during the malting process (p˂0.001). The highest values for the diastatic power of the malts were obtained with millet malt (378.86 UPD and 336.45 UPD respectively for normal steeping and alkaline steeping). As for the diastatic power of sorghum malts, it varied from 79.14 UPD to 266.17 UPD. A negative correlation emerged between the diastatic power and the pH (R = -0.88), it also emerged that the diastatic power was much more correlated with the activity of alpha amylase (R = 0.99) than that of beta amylase (R = 0.6). Overall, the different types of malts exhibited satisfactory diastatic power and functional properties in accordance with standards for cereal malt production. These malts could therefore be used for the production of infant porridge in order to increase the energy density of porridge and also used in bread making to replace commercial enzymes often not appreciated by consumers.

Malting and Wort Production Potential of the Novel Grain Kernza (Thinopyrum intermedium)

As the environmental impacts of beer are of increasing concern to maltsters, brewers, and consumers, perennial cereal crops can offer a more sustainable solution. One new cereal species of interest to the brewing industry is intermediate wheatgrass (Thinopyrum intermedium subsp. intermedium), developed by The Land Institute, in Salina, Kansas, U.S.A., under the branded name Kernza®. It has been touted as a more sustainable alternative to barley and wheat in its requirements for less water and nutrient additions and reduced tilling of agricultural fields. To date, no published research has been performed to assess the potential for this grain for the malt and beer industries as a barley replacement. Here, the “M5” variety Kernza grain was micromalted and the finished malt was compared with both the raw grain and to a reference raw and malted barley (Hordeum vulgare L. var. Copeland). All samples were analyzed for starch gelatinization temperatures via differential scanning calorimetry, amino acid composition, alpha-amylase, diastatic power (DP), total and soluble nitrogen and protein, Kolbach Index (KI), extract, wort free alpha-amino nitrogen (FAN), wort β-glucan, wort color, pH, and clarity. The Kernza malt produced sufficient extract and FAN for typical fermentations with low β-glucan content. However, extract and FAN in the Kernza malts were lower than in the barley reference, and the Kernza worts exhibited higher levels of undesirable soluble protein and haze. Interestingly, the DP for both the raw and malted Kernza were similarly high, indicating that both of the raw grains exhibit high enzymatic activity, which malting did not increase substantially. Results support that Kernza could be an acceptable candidate for malting and subsequent wort production; however, specific techniques may be required to utilize this malt most effectively. Supplemental data for this article is available online at https://doi.org/10.1080/03610470.2022.2026662 .

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.

Sprouted sweet potato flour as a saccharification enhancer to improve the brewing properties of pearl millet malt

The use of high enzyme sprouted sweet potato flour (SSPF) as a saccharification enhancer to improve the brewing properties of pearl millet (Pennisetum glaucum, L.) was investigated. The results show a linear relationship between hot water extract (HWE) and increased substitution levels of SSPF up to a maximum of 363oL/kg at 40% substitution (40SM). Similarly, diastatic power (DP) increased from 21oL in 100% millet malt to 24 and 33oL at 20% (20SM) and 40% substitution (40SM). This can be attributed to the high amylolytic potential of sprouted sweet potato flour. Saccharification time reduced from 40 to 10 minutes for 20SM and 40SM (SSPF/millet malt) mash samples compared to the barley malt control. With increasing levels of SSPF substitution, the free α-amino nitrogen of SSPF/millet malt wort samples declined from 154 mg/L in all millet malt sample to 126 mg/L in 40SM sample. However, all samples had a high rate of apparent attenuation in fermentation. This substitution method offers opportunities to optimise the brewing potential of millet in countries where the cost of importation of barley malt is prohibitive. However, the levels of modification in the composite samples, suggest sweet potato flour could be used in the brewing and distilling industries alone or together with malted millet.

A Malting Barley (Hordeum Vulgare L.) Variety, ‘Nurimaeg’ with Resistance to Barley Yellow Mosaic Virus and Tolerance to Lodging Stress

Other SectionsAbstract서 언재료 및 방법결과 및 고찰적 요사 사FigureTableReferenceA malting barley variety, ‘Nurimaeg’, was developed with resistance to barley yellow mosaic virus (BaYMV), tolerance to lodging stress, and good brewing quality. ‘Nurimaeg’ was developed by crossing Milyang127 and Miharu gold in 2004. Regional yield trials were conducted for ‘Nurimaeg’ as a breeding line ‘Iksan175’ in four different regions from 2014-2016. It has a type I growth habit, and its average heading and maturity dates were April 12 and May 20, respectively-which were 1 day later than the maturity date of ‘Hopum’ variety. As ‘Nurimaeg’ has a shorter culm length (77 cm) than that of ‘Hopum’, it showed tolerance to lodging stress. This variety possesses the rym5 gene and is resistant to BaYMV. It showed a 42.9 g 1000-grain weight and 90% assortment ratio. The yield potential of ‘Nurimaeg’ was 408 kg/10a, which is approximately 18% higher than that of ‘Hopum’. Analysis of grain quality for malting showed that ‘Nurimaeg’ has high quality of low protein and β-glucan content. Malt quality analysis revealed that it has 72.8% extract, 4.2% soluble protein, 38.9% kolbach index, and 243 WK diastatic power, which all were similar to those of ‘Hopum’. ‘Nurimaeg’ would be suitable for cultivation in the areas of Korea that have a daily minimum temperature of -4℃ in the month of January (Registration No. 7960).Keywords : malting barley, BaYMV resistance, lodging resistance, malt, variety

Genetic variation among selected pure lines from Turkish barley landrace 'Tokak' in yield-related and malting quality traits

Aim of study: Improvement of barley cultivars for malting traits suffers from narrow genetic pool in barley for these traits. Landraces are resources that could be used for this purpose. The present study was conducted to determine the variation for malting quality traits within a Turkish barley landrace. Area of study: The study was undertaken in Tokat, a province in Black Sea Region of Turkey. Material and methods: Twenty-five diverse lines, out of 42 unique genotypes previously identified in ‘Tokak’ landrace (PI 470281) based on DNA markers, were evaluated for malting quality traits along with the malting barley cv. ‘Tokak 157/37’ in four field trials. Thousand-seed weight, test weight, grain yield, lodging, malt extract percentage, diastatic power, alpha amylase and malt beta glucanase activities, malt protein and starch contents were determined. Main results: Principal component analysis of malting quality traits revealed that thousand-seed weight, alpha amylase activity, beta glucanase activity and diastatic power were the most discriminatory traits for the lines. As the average of four trials, 15 of the 25 lines evaluated had higher grain yields and 10 of 25 lines had higher malt extract percentages than the standard cultivar ‘Tokak 157/37’. Malt extract was highest in Line 59 in all environments, and this line also had the highest values for beta glucanase activity and starch content. Line 215 had highest values for alpha amylase activity. Lines 59 and 215 clearly had superior malting quality. Research highlights: These lines could harbor novel alleles for these traits to be used in malting barley improvement.

Investigating the Effect of Farm Management, Soil, and Climate on Hop Diastatic Potential

To investigate potential sources for field-to-field variation in hop diastatic power, three varieties of hops (Mosaic®, Simcoe®, and Strata®) from harvest year 2019 were collected from different fields managed by a single hop grower throughout the hop growing region within Oregon’s Willamette Valley. Fields for this study were selected based on soil type and weather patterns, and eleven fields were identified for sampling (3 Mosaic®, 3 Strata®, and 5 Simcoe®). Farm management data on fertilization rates and pesticide applications were collected by the grower (Coleman Agriculture). Using USGS soil maps, five individual sites within each field were identified for soil sampling, and hop bines near those sites were GPS tagged and hand harvested when they were at similar maturities. After harvest, the hops were analyzed for enzymatic activity using an HPLC method. The relationships between hop enzymatic activity and the farm management, soil, and weather data yielded associations with soil texture, growing degree day accumulation, fertilization practice, and pesticide application. The data also suggest a potential link between hop diastatic power and downy mildew (Pseudoperonospora humuli) or powdery mildew (Podosphaera macularis) infection. The links between hop diastatic power and agronomic variables will allow farmers to minimize hop creep potential in the hop field thereby potentially mitigating the effects that brewers see in the cellar.

Characterization of Unmalted Barley Treated with Aspergillus oryzae

Koji is a complex of substrate and the filamentous fungus Aspergillus oryzae. It is used for saccharification in fermented foods and beverages. Its role in co-fermentations is known, but its application in beer brewing contexts is unclear. The goal of this study was to determine what effect A. oryzae has on the characteristics of unmalted barley in brewing contexts, if it might bypass traditional malting, and what sensory attributes a koji beer might exhibit. Koji barley was prepared with pearled barley and a red rice koji strain and compared to untreated pearled barley and malted barley control groups. The total production time of koji barley was nine days and the process consumed 4 ± 2 L water per kg of grain. Coarse grind extract in koji barley was three times greater than pearled barley while approximately ten percent less than malted barley. Diastatic power was over three times greater in malted barley versus koji barley, while no significant difference (p < 0.05) was found between koji barley and untreated pearled barley. Koji barley congress wort exhibited three times more glucose but less than half the maltose content of malted barley wort. Analysis of wort organic acids showed increased concentrations of citric, succinic, and kojic acid in koji barley versus pearled barley. Qualitative sensory analysis of fermented koji barley wort identified moderate tropical, citrus, and sour flavors as well as green apple and tropical fruit aromas. The results demonstrated that koji barley shows characteristics similar to specialty malts and may favor hazy, fruited, and sour beer styles.

Performance evaluation and stability analysis of malt barley (Hordeum vulgare L.) varieties for yield and quality traits in Eastern Amhara, Ethiopia

BackgroundBarley (Hordeum vulgare L.) is an annual cereal crop that belongs to the grass family Poaceae of the tribe Triticeae. It is the fifth most important cereal crop after teff, wheat, maize and sorghum in area coverage in Ethiopia. Important malting barley characteristics include kernel size, kernel protein content, extractable malt and diastatic power. Malt barely is an important crop in the study area; however, the productivity is low in the area varying from 15 kg ha−1 to 21 kg ha−1. The aim of the study was to identify high yielding, standard quality and stable malting barley variety to the study areas and similar agro-ecologies. Field experiments were conducted using eight improved malt barely varieties during the main cropping seasons (from the first week of July to end of October) in 2016 and 2017 at two selected sites Dehana (Amede work) and Lalibela (Medagai)) in north east Ethiopia. Data on grain yield and yield related traits, and quality attributes were recorded. Days to 50% heading (DH), and days to 90% maturity (DM) were recorded on plots basis. Plant height (PH, in cm), spike length (SPL, in cm), and number of seeds per spike (SPS) were measured on five randomly selected plants per plot of the central four rows. Mean grain yield (GY; grams of grain produced per plot, converted in kg ha−1), above ground dry biomass or biological yield (BY; dry weight of the above ground harvested biomass grams per plot, in kg ha−1) and thousand grain weight (TGW; weight of 1000 kernels, in grams) were measured on whole plots. Data were analyzed using SAS software program and significance of the mean difference was tested in least significant difference Test (LSD).ResultThe analysis of variance for grain yield and quality traits showed that the main effects of both genotypes and environments, and their interaction effect, were highly significant (P ≤ 0.01). The environment main effect accounted for 42%, 38% and 50% of the total grain yield, thousand kernel weight and kernel protein content variation, respectively. The average grain yield across varieties varied from 1652 kg ha−1 to 3377 kg ha−1.ConclusionsThree malting barley varieties (IBON174/03, EH1847 and Bahati) were found to be relatively high yielding, stable for grain yield and full fill the quality parameters. Therefore, these varieties are recommended for production. A further study is required on agronomic practices and brewing quality attributes in malt barley.

Barley varieties registered in the Czech Republic after the harvest of 2020

The study presents malting quality and agronomic characteristics obtained during testing of barley varieties in the Czech Republic. After the harvest of 2020, the following spring barley malting varieties were registered: Amidala, Focus, Greenway, KWS Jessie, LG Belcanto, and LG Stamgast. LG Stamgast was recommended for production of the beer with the protected geographical indication České pivo. In addition, the non-malting spring barley variety RGT Gagarin was registered. Amidala, Focus, Greenway, KWS Jessie, LG Belcanto provided malt with the extract content over 83%. These varieties also easily degraded nitrogenous substances. The value of the Kolbach index ranged from 48.6 to 52.1%. Diastatic power was at the optimal level. Degradation of cell walls was also optimal. Friability moved from 89 to 97% and β-glucan content in wort achieved satisfactory values of 65 – 170 mg/l in the given varieties . Wort quality, which is characterized by final attenuation, was at the above average to optimal level of 80.9 – 83.2% in these varieties of spring barley. LG Stamgast showed lower values of proteolytic and cytolytic modification and lower values of final attenuation, which is required for the varieties recommended for the production of the beer with the protected geographical indication České pivo.

Quality Characteristics of Wheat Malts with Different Country of Origin and Their Effect on Beer Brewing

The characteristics of wheat malt, wort, and beer from two Korean wheat varieties (Keumkang and Anzunbaengi; KM and AM, respectively) were compared to those of two commercial wheat malt controls from the USA and Germany (UM and GM), to examine the feasibility of Korean wheat for brewing. The quality parameters of four wheat malts, chemical properties of wort using them, volatile compounds, sensory attributes, and consumer acceptability of four final beers (KB, AB, UB, and GB) were analysed. Additionally, the relationship of each parameter was determined through multiple factor analysis. Korean wheat malts were different from control malts in free amino nitrogen (FAN), soluble and total nitrogen, and Kolbach index. The extract (81.8–83.2%) and diastatic power (407–477 WK°) of all samples were in the brewing field’s recommended range. The FAN and yeast cell population of the wort samples were similar during fermentation except on the initial day, which showed a high FAN and yeast cell population for KM wort. Eleven volatile compounds with variable importance in projection scores above 1.0 were responsible for discrimination of the beer samples by partial least squares discriminant analysis. The four beer samples’ overall acceptance scores were not significantly different. However, their acceptance trends were different depending on consumer preference segments by agglomerative hierarchical clustering analysis, implying the need for product development depending on the target consumer. Regarding sensory attributes, KB had a less fruity flavour than the other beer samples ( p &lt; 0.05 ) and sweetness of AB tended to be higher than the others. An association plot based on multiple factor analysis of the wheat beer samples, volatile compounds, sensory properties, and overall acceptance showed that sweetness, alcohol aroma, and fruity flavour were closely associated with AB and overall acceptance, while 2,3-butanediol and turbidity were placed opposite side of there.

Assessment of Malting Performance of Maize and Sorghum of Similar Total Nitrogen Content in Providing the Hydrolytic Enzymes in the Brewing of Gluten-Free Beers

Malted sorghum is used extensively as source of hydrolytic enzymes in brewing gluten-free beers. Malted barley is often used in combination with un-malted maize adjunct (flakes, grits, flours) to brew non-gluten-free beers. Sorghum and maize are similar in many ways. The potential of using malted maize in brewing gluten-free beers was studied. Sorghum and maize of similar total nitrogen content were malted under comparable conditions. Sorghum and maize grains followed some similar patterns in developing hydrolytic enzymes, measured as diastatic power (DP), when malted. Development of diastatic enzymes in both cereals increased with germination period. When mashed, the hot water extract (HWE) for malted sorghum was similar to malted maize when both had five days of germination. For malted sorghum, the HWE value was already reached after two days of germination. The total soluble nitrogen (TSN) for malted sorghum was, for the five germination times studied, half of the TSN values or less than those found for malted maize. Total soluble nitrogen, indicative of the proteolysis achieved during the malting of cereals, showed good proteolysis for the malted maize. The results suggest that like malted sorghum, malted maize could play a similar role in brewing gluten-free beers.