Three types of solid waste are produced during beer fermentation: spent grain, hot trub, and residual yeast. While the first is used as livestock feed, the seconds has not yet found any real reapplication in the field of circular economy. The aim of this work is to study and characterize these two brewing wastes, i.e., hot trub and residual yeast, to evaluate their potential reuse in the agricultural field. Samples from top-fermented and bottom-fermented beers were chemically investigated. Initially, the safety was assessed via multi-detection analysis of 57 mycotoxins, and all samples were deemed safe. Subsequently, the chemical and elemental composition was examined via ICP-MS and microanalysis, along with phenolic compounds and antioxidant activity via HPLC and spectrophotometric determinations, to achieve a thorough characterization of these waste samples. The C/N ratio of residual yeast from top-fermented beer and hot trub of the bottom-fermented one were near the optimal one (10:1). This research marks an initial step towards repurposing brewery waste materials as fertilizers. The subsequent steps will involve the formulation and field trials.

• Keywords
• agricultural applications, beer, beer by-products, brewer residual yeast, circular economy, hot trub,
• Publication type
• Journal Article MeSH

Pulsed electric field (PEF) has previously been recognized as a method of gentle food processing, and its use has been shown to be helpful in reducing the levels of toxigenic Fusarium micromycetes developed during malting. The aim of this study was to describe the effects of PEF on gene expression and metabolite production at the pre-finishing stage of barley malting by using a novel multi-omics data-driven approach. The study helps to uncover the processes occurring in the germinated grain and discusses the up-/downregulation of genes and metabolites in relation to fungal infection and/or PEF-induced abiotic stress. Among the factors upregulated by PEF and previously described as supportive against Fusarium diseases, we identified the increased expression of genes encoding vegetative gp1-like protein, which positively correlated with flavonoids, (methylsulfanyl)prop-2-enoates, triterpenoid glycosides, and indole alkaloids. On the other hand, some genes associated with barley resistance to fungal infection were also overexpressed in the untreated control (in particular, genes encoding ethylene response factor 3-like, putrescine hydroxycinnamoyltransferase 3-like, and dirigent protein 21-like). This study provides the first 'data-driven' basic research results that contribute to the understanding of the role of PEF as an effective fungal decontamination strategy and allows the formulation of new hypotheses related to Fusarium pathogen crosstalk.

• Keywords
• Fusarium micromycetes, abiotic stress, barley, metabolomics, multi-omics, pulsed electric field, transcriptomics,
• MeSH
• Decontamination * methods   MeSH
• Electricity * MeSH
• Fusarium * pathogenicity   MeSH
• Hordeum * microbiology   genetics   metabolism   growth & development   MeSH
• Edible Grain * microbiology   genetics   metabolism   MeSH
• Multiomics MeSH
• Plant Diseases microbiology   MeSH
• Gene Expression Regulation, Plant MeSH
• Publication type
• Journal Article MeSH

Mycotoxins are secondary metabolites of fungi and represent a serious problem for human health. Due to growing interest, various aspects have been widely studied by scientific groups. One of these aspects relates to the food industry and associated beer production. Mycotoxins can be present in the basic raw materials for beer production as well as in brewed beer. Problematic mycotoxins that pose a serious risk of toxicity are aflatoxins especially aflatoxin B1 (AFB1), fumonisins (FBs), and zearalenone (ZEN) and its metabolites, deoxynivalenol (DON) including its acetylated forms and also the modified form deoxynivalenol-3-glucoside (DON-3G), T-2 toxin, HT-2 toxin, and ochratoxin A. The Research Institute of Brewing and Malting has been dealing with the issue of mycotoxins since 2008. This study describes the analysis of the above mycotoxins during 2020-2024 in barley (n = 775), malt (n = 751), and commercially available beers (n = 522) using QuEChERS, immunoaffinity columns, and UPLC-MS/MS. The results showed positive samples of mycotoxins in brewing and malting matrices at the level of micrograms per kilogram (barley, malt) and nanograms per liter for beer. Therefore, it is a residual concentration and the accurate quantitative determination of mycotoxins, correct interpretation of the results in connection with toxicological values, and the maximum permissible levels of mycotoxins play a key role in global food safety and consumer protection.

• Keywords
• Brewing, Immunoaffinity columns, Malting, Mycotoxins, QuEChERS, UPLC-MS/MS,
• MeSH
• Hordeum chemistry   microbiology   MeSH
• Edible Grain * chemistry   MeSH
• Food Contamination * analysis   MeSH
• Humans MeSH
• Mycotoxins * analysis   MeSH
• Beer * analysis   MeSH
• Tandem Mass Spectrometry MeSH
• Chromatography, High Pressure Liquid MeSH
• Zearalenone analysis   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Mycotoxins * MeSH
• Zearalenone MeSH

The increasing contamination of cereals by micromycetes and mycotoxins during malting still poses an unresolved food safety problem. This study characterises the potential of the novel, rapidly developing food production technology of Pulsed Electric Field (PEF) to reduce the viability of Fusarium fungi and the production of mycotoxins during malting. Barley, artificially inoculated with four Fusarium species, was treated by PEF with two different intensities and then malted using a standard Pilsner-type technology. Concentrations of fungi were quantified by RT-PCR, expression of fungal growth-related genes was assessed using mRNA sequencing, and mycotoxin levels were analysed by U-HPLC-HRMS/MS. Despite the different trends for micromycetes and mycotoxins after application of variously intense PEF conditions, significant reductions were generally observed. The greatest decrease was for F. sporotrichioides and F. poae, where up to six fold lower levels were achieved for malts produced from the PEF-treated barley when compared to the control. For F. culmorum and F. graminearum, up to a two-fold reduction in the PEF-generated malts was observed. These reductions mostly correlated with a decrease in relevant mycotoxins, specifically type A trichothecenes.

• Keywords
• Fusarium micromycetes, RT-PCR, U-HPLC-HRMS/MS, malting, mycotoxins, pulsed electric field,
• MeSH
• Electricity MeSH
• Fusarium * metabolism   genetics   growth & development   MeSH
• Hordeum * microbiology   MeSH
• Edible Grain * microbiology   MeSH
• Food Contamination prevention & control   MeSH
• Food Handling methods   MeSH
• Mycotoxins * biosynthesis   metabolism   MeSH
• Food Microbiology MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Mycotoxins * MeSH