Enzymes from Cereal and Fusarium Metabolism Involved in the Malting Process – A Review

Abstract

the enzymatic properties of brewing malts are an important and sometimes limiting factor in malt and beer production. in order to observe malt quality, multiple analytical tests were developed for determining the various enzymatic activities of brewing-related enzymes in brewing cereals and their corresponding malts. when using the prevailing detection methods, little or no attention has been paid to the microbiological status of the processed cereals. infection of cereals with Fusarium spp. can lead to a deterioration in cereal and malt quality. this weakening in quality during cereal processing is mostly attributed to enzymatic degradations. the enzymes involved can be cereal-borne as well as fungal, in which case enzymes up-or down-regulation can be often ascribed to pathogenesis-related protein secretion or can be a result of host-pathogen interactions. Accordingly, when determining the enzyme activity of infested grain, an increase in enzyme activity is usually detected. Agricultural effects and economic losses due to FHBGiven an increased incidence of FHB, the yield losses caused by FHB has in extreme cases reached as high as 70% in various regions worldwide. [17][18][19][20][21][22] However, the main damage is caused by the mycotoxins produced by Fusarium and food safety is no longer assured in such cases. These mycotoxins lead to symptoms of disease in animal feed and deteriorate the brewing quality of the grain. [23] In addition, there is also a reduction in the germination capacity of the seed. [24] The Fusarium community causes damage to small grain cereals all over the world, including Northern

Prevalence of Fusarium fungi and Deoxynivalenol Levels in Winter Wheat Grain in Different Climatic Regions of Poland

“…Fungal spores germinate on the surface of spikelets, and the mycelium penetrates spikelets passively through the stomata or actively through the cell walls. Fusarium fungi secrete numerous hydrolyzing enzymes that facilitate the penetration of host tissues [15]. Infected kernels are smaller, shriveled and white to light pink in color [6].…”

The Role of Mycotoxins in Interactions between Fusarium graminearum and F. verticillioides Growing in Saprophytic Cultures and Co-Infecting Maize Plants

“…F. graminearum produces a rich cocktail of hydrolases: 85% of proteins identified in the secretome of F. graminearum growing in the presence of wheat flour were glycosidases, proteases, and esterases [ 63 ]. The main source of carbon and energy in maize kernels is starch, and amylases of F. graminearum are so active that they are believed to make a hidden contribution to the amylolytic potential of infected grains during malting [ 64 ]. We hypothesize that nutrients released from maize kernels by extracellular enzymes of F. graminearum accounted for the growth stimulation of F. verticillioides in mixed cultures.…”

Relevant Fusarium Mycotoxins in Malt and Beer

“…Geiβinger, Gastl and Becker (2021) [ 85 ], in their review, discussed the possibility of the alteration of the metabolism of a barley plant, thus producing a change in the set of enzymes and proteins present in the kernels, due to the pathogen–host interactions that occur during a Fusarium infection (e.g., synthesis of an up-regulated ß–amylase, which, besides being in charge of the starch cleavage, also acts as a factor for the programmed cell death of the cells of the grain). Nonetheless, according to the same authors, estimating the impact of the Fusarium infestation on the levels of each enzyme is impossible with the current analytical methods because they cannot distinguish between plants’ endogenous enzymes and the ones originating from the fungi unless gene expression studies are conducted.…”