Microbial communities and malt quality of durum wheat used in brewing

Abstract

Durum wheat (Triticum durum Desf.) has potential as an adjunct in brewing given its agronomic, chemical and technological properties. The aim of this work were to identify the cultivable microflora and evaluate the technological quality of the durum wheat variety 'Senatore Cappelli' grown and used by a craft brewery in Sardinia, Italy. The isolated bacterial strains were mainly rhizospheric (Kocuria rizophila, Microbacterium aerolatum and Bacillus pumilus) and associated with the microbiota of wheat (Staphylococcus spp.). None have been reported previously as spoilage species in brewing. The dominant yeast genera were Cryptococcus spp. and Rhodotorula spp., followed by Saccharomyces cerevisiae. The dominant filamentous fungus genera were Alternaria and Rhizopus. Low levels of mycotoxigenic Fusarium spp., Aspergillus spp. and Penicillium spp. were isolated. However, the levels of deoxynivalenol, T2-HT2, fumonisin, aflatoxin and ochratoxin detected in the malt and grain were below the thresholds defined by European law. Malt obtained from raw grain showed interesting technological properties, but required specific malting parameters different from those of common wheat and barley. These data suggest that the use of locally grown durum wheat in brewing can increase sustainability and reduce costs, while reinforcing the link with the terroir and promoting reduced mycotoxin levels.Additional supporting information may be found online in the Supporting Information section at the end of the article.Microbial communities and malt quality of durum wheat used in brewing J. Inst. Brew. 2019; 125: 222-229

The role of microorganisms on biotransformation of brewers’ spent grain

“…Therefore, worldwide legal limits of mycotoxins have been established (Tables 3 and 4). The contamination of malt by mycotoxigenic fungi and mycotoxins can occur throughout the entire brewer production chain, from the field to the malting and brewing (Bianco et al 2019(Bianco et al , 2018Mastanjević et al 2018). Mycotoxigenic fungal species that belong to the genera Aspergillus spp.…”

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

“…From the standpoints of nonmainstream wheat cultivars, Benedetti et al [8], Mayer et al [9], and Marconi et al [10] investigated the availability of hulled wheat, such as einkorn, emmer, and spelt, cultivated in Europe as materials for creating new beer styles. Furthermore, Bianco and Fancello [11] attempted to brew beer using Senatore Cappelli, which is a locally grown Italian durum wheat variety.…”

Relevant Fusarium Mycotoxins in Malt and Beer

“…The coexistence of up to 20 Fusarium species might be causing it, each of them having a different mycotoxin production profile: F. graminearum and F. culmorum produce DON, NIV and ZEN, F. avenaceum produces moniliformin (MON) and beauvericin (BEA), F. poae mainly produces NIV, T-2 and HT-2 toxins [ 48 ]. Besides the production of mycotoxins, the species belonging to Fusarium can also produce hydrophobins (that act as surfactants, stabilizing the CO 2 bubbles in beer) and enzymes that decrease the ß-glucans levels in the brewing wort, affecting its viscosity, increasing the rate of soluble nitrogen that can interfere with the fermentation process and changing wort colour [ 49 ]. Habschied et al (2014) [ 50 ] suggested that the infection of F. culmorum in wheat can lead to the increase in fungal proteases and activate the plants’ pathogen-related proteins, which are part of its protective strategy (KI of the infected wheat sample 51% versus 49% in control and fungicide-treated samples).…”