Search Results (11)

Barley (Hordeum vulgare L.) is the second winter crop in Argentina. In the national market, grains are mainly destined to produce malt for beer manufacture. Fusarium species are common, causing Fusarium Head Blight (FHB) in barley, which generates yield and quality losses, as well as mycotoxin occurrence. The aims of this study were to determine (a) the incidence of the main species causing FHB in different locations of the barley-growing region of Argentina, (b) their ability to produce mycotoxins, and (c) the levels of deoxynivalenol (DON) and nivalenol (NIV) natural occurrence in grains at the harvest stage. Additionally, a strain of Bacillus velezensis was studied as a biocontrol agent in order to control F. graminearum sensu stricto and mycotoxin accumulation during the malting process, with the final objective being to reduce DON contamination in the beer manufacture chain. Fusarium graminearum ss was the most prevalent species causing FHB, with Fusarium poae being less distributed. Both species produced several mycotoxins, including NX-2 and NX-3, which is the first report of their production by strains isolated from barley in Argentina. Deoxynivalenol contamination was found in 95% of barley grains during the 2016 harvest season (mean: 0.4 mg/kg), while NIV contamination was present in 29% of samples (mean: 0.49 mg/kg). In the 2017 harvest season, 53.6% of grains were contaminated with DON (mean: 0.42 mg/kg), and 21% with NIV (mean: 0.8 mg/kg). Quantification of F. graminearum ss by real-time PCR during the micro-malting process showed that application of the biocontrol agent before the germination stage was the most effective treatment, with a 45% reduction in fungal DNA levels. Reduction in DON contamination (69.3–100%) in artificially infected grains with F. graminearum ss, was also observed. The present work contributes to the knowledge of FHB in Argentina and to the development of a strategy to control this disease and mycotoxin contamination in barley, promoting at the same time food security. Full article

Innovation in the beer market focuses on research into the different ingredients that make up this popular and sought-after beverage. Some of these innovations have focused on the use of autochthonous ingredients, which bring added value to products, reduce production costs and environmental impact, and provide beers with special organoleptic characteristics. This study focuses on the use of autochthonous ingredients from the Community of Madrid and the design of four recipes that are suited to these ingredients and consumer demand. In terms of the ingredients used, the micromalting of barley grown in the CM was carried out, while hops (Cascade variety for bittering hops and wild hops Rayo verde Tajuña and Torreta Tajuña for aroma) and yeast strains (Saccharomyces cerevisiae G 520 and G 354) were selected from previous studies, which were also sourced from the CM. For the barley malt, parameters such as protein content were determined, which was at the maximum limit but did not affect the final quality of the beers. The content of α- and β-acids in the hops was also determined, being higher in the Cascade variety. Different physicochemical analyses (GC, aromatic compounds, bitterness, colour, SO₂, polyphenols, and antioxidant capacity) were carried out to determine the quality of the beers obtained from the four recipes designed, as well as tastings by a panel of experts and consumers. Finally, two recipes were rated the best by a panel of experts and consumers, where the cereal, hop, and fruit flavours stood out for their aromatic profile. Full article

Rye is used in some applications in the food and beverage industry and for the preparation of functional foods. It is an interesting raw material in malting and brewing due to its characteristic contribution to the beer’s color, turbidity, foam and aroma. The aim of this work was to optimize the micro-malting process of a rye landrace. The response surface methodology (RSM) was applied to study the influence of three malting parameters (germination time, germination temperature and degree of steeping) on the quality traits of malted rye. Long germination times at high temperatures resulted in an increase in the extract and Kolbach index. The model for the apparent attenuation limit showed a particular pattern, whereby time and temperature inversely influenced the response. The lowest viscosities were determined in the worts produced from highly modified malts. Optimization of the variables under study was achieved by means of a desirability function and a genetic algorithm. The two methodologies provided similar results. The best combination of parameters to optimize the malting process on the rye landrace under study was achieved at 6 days, 12 °C and 44 g/100 g. Full article

Differentiating agricultural products has been adopted as a strategy to improve farm profitability and thereby business sustainability. This study aimed to evaluate unique barley varieties for craft malting and brewing markets to enhance profitability for diversified grain growers in southwestern Washington. Advanced barley breeding lines from Washington State University (WSU) were compared to a control variety (CDC-Copeland) through field trials, experimental and commercial malting conditions, and consumer sensory evaluation. The beers differed only by the genotype-dependent malt. Malting conditions (experimental or commercial) and field replicate influenced five out of the eight malt quality traits measured, while genotype influenced seven out of eight of the traits. Consumers differentiated the beers through ranking, open description, and check all that apply during a central location test. Based on consumer liking, breeding lines 12WA_120.14 or 12WA_120.17 could replace CDC-Copeland in beers. A total of 83% of consumers responded that they would pay more for a beer if it would support local farmers. This value proposition represents an opportunity for consumer purchasing to support producers, who form the foundation of the craft malt and beer value chain and whose economic success will determine the sustainability of small farms in minor growing regions. We provide further evidence for the contributions of barley genotype to beer flavor, while tracing the impact of barley genotype from ground to glass. Full article

In malt production, steeping and germination steps offer favorable environmental conditions for fungal proliferation when barley is already contaminated by Fusarium species, T-2 toxin producers. However, the use of G. candidum as a biocontrol agent can prevent this proliferation. Indeed, in previous work, a correlation between phenyllactic acid (PLA) production by G. candidum and the reduction in Fusarium sporotrichioides and F. langsethiae growth and T-2 toxin concentration was demonstrated. In the present study, to improve the efficiency of G. candidum, the effects of the inoculum concentration and the inoculation method of G. candidum on PLA and T-2 toxin concentrations were evaluated. First, co-culture experiments with Fusarium species and G. candidum were conducted in a liquid synthetic medium. The results showed that inoculation of G. candidum in the freeze-dried form at 0.4 g/L allowed the production of PLA from the second day of incubation associated with a reduction in T-2 toxin concentration of 82% and 69% produced by F. sporotrichioides and F. langsethiae, respectively. Moreover, the activated form of G. candidum at 0.4 g/L enhanced PLA concentration leading to better T-2 toxin reduction. Second, experiments were conducted on artificially infected barley kernels with both Fusarium species under conditions mimicking the malting step. As for co-culture experiments, the use of the activated form of G. candidum was established as the best condition for T-2 toxin concentration reduction for a 3 day malting period. Full article

This paper examines the influence of malting process parameters on the wheat malt quality obtained from the assortment of winter red wheat. For this assortment, previous research established that strongly restrictive and strongly intensive malting processes are not suitable, that is, they do not significantly improve the quality of the obtained wheat malts, and in some segments, they even disturb it. Therefore, modifications were introduced to both procedures, and malting was performed with moderately intensive procedure D and moderately restrictive procedure E. Starting wheat, indicators of micromalting process success, and finished wheat malts were analyzed. The results showed that the moderately restrictive malting process (E) significantly improves not only the values for soluble N for almost all tested varieties, but also the values of cytolytic degradation success (wort viscosity, filtration time), and extract yield. The moderately intensive procedure did not improve the determined indicators; for many varieties, the modification even resulted in poorer values. Furthermore, the moderately restrictive procedure allows a strong individual response of a particular variety to the process conditions during malting, which is very important for the assessment of the malting potential for a particular variety. Namely, when assessing the actual malting quality of an individual variety, it is necessary to include amylolytic indicators and indicators of enzymatic strength. In this way, a group of varieties were established which had an increased initial share of total N (varieties no. 7, 8, 9, 10, 12, 13, and 16). These varieties, by this procedure, gave the best quality wheat malts in the entire examined assortment. Full article

This paper examines the influence of the malting process of red hard wheat varieties (which have many characteristics of soft wheat varieties and represent a transitional form between durum and soft wheat). According to the values of total and soluble proteins and viscosity of wort these wheat varieties belong to the second malting quality group. To establish the individual response of each variety and estimate how the chosen varieties respond in groups to different process conditions, sixteen varieties were selected and malted according to the standard procedure (A), restrictive procedure (B), and intense procedure (C). Starting wheat, indicators of micromalting process success, and finished malts were analyzed. It was found that the restrictive procedure (B) gives poor results for the values of proteolysis performance parameters (soluble N, free amino nitrogen (FAN)) with simultaneous disturbance and values of cytolytic degradation (viscosity and filtration time) and extract yield. At the same time, this procedure lacks a stronger individual response of an individual variety to the process conditions during malting (F/C difference and extract yield). The optimal malting process for the specified assortment would include the modification of processes B and C in a way to alleviate the restrictive conditions in process B, or in a way to reduce the intensity of the decomposition in process C. Full article

This study aimed to establish the suitability of new Croatian wheat varieties for the production of pale wheat malt. Four new varieties/breeding lines from the Agricultural Institute Osijek were tested (Indira, OSK. 378/19, OSK. 346/20, and OSK. 353/20). The quality of starting wheat, the success of the micromalting process and the quality of finished malts were analyzed. The obtained results showed that the tested varieties/breeding lines meet the quality criteria for pale beer malt, and can be classified in the II malting quality group. The vast majority of quality indicators examined in this research showed values within the limits recommended for pale wheat malt. The obtained results were very good considering that these varieties are not intended for malting, nor in their selection process attention was paid to meet the brewing quality criteria. Due to the sensory characteristics of beer, the possibility of intervention during the malting process is limited, therefore when selecting wheat for malting, attention should be paid to the lowest possible content of total and soluble proteins, which can be achieved by appropriate agrotechnical measures in cultivation. Full article

The aim of this study was to assess the impact of steeping water change and Fusarium graminearum contamination level on different multi-toxin types and concentrations in barley malt. Malt samples were subjected to two micromalting regimes—steeping water change and the other with no steeping water change. Malt was contaminated with different F. graminearum contamination levels (0%, 10%, and 20%). The results indicate that malt with higher F. graminearum contamination levels ensured higher concentrations of toxins. Higher fungal metabolite concentrations were determined in samples exposed to freshly-changed steeping water, especially zearalenone and its derivates whose values were three to four times higher than in samples with no water change. Zearalenone-4-sulfate showed four (in 10% contamination) and even thirty times (in 20% contamination) higher concentrations than in samples with no water change. Water change during malting resulted in higher levels of multi-toxins in the final product. Full article

This paper aimed to investigate the influence of certain wheat and wheat malt quality indicators on limit of attenuation of wort (LAT). The experiment was conducted using wheats that have been proven to display the best malting properties with heightened total and soluble N and very good viscosity. Standard micromalting and brewing processes and analysis were applied. The obtained results showed that the quality of analyzed malts was satisfying. Statistical analysis determined no significant correlation between the limit of attenuation of wort and any of the other analyzed quality indicators. The lack of close correlations between indicators is probably due to the extremely complex intertwine of factors influencing the LAT, pointing to the fact that this particular indicator should be observed as separate and mainly variety-dependent. Full article

Malting of rye and the use of rye malts presents several challenges to maltsters and brewers, like the lack of a hull, dense packing in steep, and high wort viscosity. While empirical evidence shows that rye genotypes differ in malting and brewing performance and flavor, there is little published information on the malting of rye or the malt quality attributes of rye genotypes. The objective was to evaluate laboratory micro-malting conditions that could be used in quality screening. Parameters included germination time, moisture and kernel size. Wort arabinoxylan and phenolic acid contents were determined in addition to standard malt quality parameters. In general, high extract and lower viscosity were achieved by malting for at least 4 days at 45%–48% moisture under the temperature of 16 °C. However, as some commercial maltsters indicated the difficulty of handling of germinating rye at the highest moisture levels, we recommend 5 days of germination at 45% moisture for the future evaluation of rye cultivars. Full article