Biocontrol Using Pythium oligandrum during Malting of Fusarium-Contaminated Barley

This study investigates the potential of Pythium oligandrum (strains M1 and 00X48) as a biocontrol agent in suppressing the growth of Fusarium culmorum and the production of mycotoxins during the malting of naturally contaminated barley (Hordeum vulgare). The effects of the biocontrol agent on F. culmorum-infected barley malt (BM) were evaluated through real-time PCR and its impact on mycotoxin production was determined by quantitative analysis of deoxynivalenol (DON) and deoxynivalenol-3-glucoside (D3G). The effect of treatment on BM and beer quality were also determined through European Brewery Convention (EBC) standard methods. Optimal treatment with P. oligandrum strains M1 and 00X48 yielded a 59% and 48% reduction in F. culmorum contamination, by 37% and 17% lower DON, and 27% and 32% lower D3G, respectively. BM treated with both P. oligandrum strains exhibited quality enhancement; beer produced from the BM treated with P. oligandrum strain M1 resulted in no quality deterioration and with 26% and 18% less DON and D3G, respectively, transferred to the final product.

The effect of barley to wheat ratio in malt blends on protein composition and physicochemical characteristics of wort and beer

The present work explored the effect of barley to wheat ratio in malt blends on protein composition and physicochemical characteristics of wort and beer. Results illustrated that the addition of wheat malt can significantly improve the soluble protein of wort and the final beer, and it can provide more > 2.2 kDa protein in final beer, which is mainly derived from the raw wheat malt, but also including some protein produced in the fermentation process, such as some protein between 29 and 66.4 kDa. Though the content of > 15 kDa protein was relatively lower than the protein whose molecular weight was < 15 kDa, but it had important effects on total nitrogen, total water-soluble protein, free amino nitrogen, chromaticity, and viscosity of final beer. The addition of wheat malt significantly improved the concentration of 2.2-15 and > 15 kDa protein, but higher percentage of addition ratio can decrease the foam stability of the beer. PRACTICAL APPLICATION: This findings can reasonably control the protein content and types of wheat beer, improve the quality of wheat beer, solve the key technological problems, and expand and popularize the application of wheat in beer industry.

Effect of malting process duration on malting losses and quality of wheat malts

The study assesses impact of malting process duration on malting losses and quality of malts obtained from three varieties of winter wheat, i.e., Elixer, Rockefeller and Gimantis. The findings show that increased duration of the malting process (from 4 to 7 days) corresponded to greater total weight loss, with the most significant differences observed between 5-day and 6-day wheat malts. The qualitative analysis of the malts was carried out in accordance with EBC methodology. The assessments showed that the 5-day long malting process applied to the relevant wheat varieties resulted in production of high-quality malt with optimum malting losses observed in the case of Elixer and Rockefeller varieties. Slightly higher malting losses were identified in the case of Gimantis, and the malt obtained from this variety had very high contents of soluble protein (on average 5.34% d.m.) and Kolbach Index (average of 50.49%), which reflects high proteolytic activity during the grain malting process and a need to modify the malting process for this variety.

Research of Malting Procedures for Winter Hard Wheat Varieties-Part II

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.

Research of Malting Procedures for Winter Hard Wheat Varieties-Part I

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.

Research on the Malting Properties of Domestic Wheat Varities

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.

The Influence of Partial Substitution of Malt with Unmalted Wheat in Grist on Quality Parameters of Lager Beer

The aim of this research was to assess whether the grist mixture (50% malt, 34% maize grits, and 16% unmalted wheat) used for the production of beer 1 could be appropriate for lager to retain the declared quality and colloidal stability during the commercial shelf life (6 months) in regards to beer 2 produced completely out of barley malt. Raw materials, worts, and beers were analyzed before and after production and over the period of 6-month storage. All analyses were done in accordance with the European Brewery Convention methods. Beer 1 resulted in a more desirable wort composition considering the total, high molecular weight (HMW) proteins, and viscosity. Beer 1 had less total proteins and polyphenols, lower viscosity and color, and higher starting clarity than beer 2. Haze measurements showed that even though beer 1 had lower starting haze, it resulted in significantly less colloidal stability during the storage of 6 months, in comparison to beer 2. The results indicate that the production of light lager beer using unmalted wheat in grist could be acceptable for colloidal stability only if such beer is to be stabilized by operations that ensure the removal of haze inducers (primarily haze active proteins).