The peptidomes from the literature of 24 prolyl-endopeptidase-treated beers during fermentation, declared gluten-free, and 13 untreated beers have been characterised and subjected to an extensive study to investigate their safety for celiac patients. The analysis contains 1996 gluten peptides, ascribed to the treated beers, and 1804 to the untreated beers. The prolyl-endopeptidase-untreated malt beers are hazardous for celiac patients. Peptides of most of these beers showed matches with complete celiac immunogenic motifs, and an additional 28% of the peptides have partial matches with complete immunogenic motifs. On the other hand, after the enzyme treatment during fermentation no celiac hazardous gluten peptides are identified in the treated beers. Due to partial matches with complete celiac immunogenic motifs, 11% potentially hazardous gluten peptides are still identified in the treated beers. Only a maximum of 17% of these peptides can be detected by ELISA analysis. A mass spectrometry analysis or the recently developed method based on G12/A1 monoclonal antibody lateral flow immunochromatographic assay seems necessary to thoroughly reveal the potential risk of the treated beers. The actual immune response of treated beer, described in the literature by the response of the serum antibodies of celiac disease (CD)-active patients and by in vitro immune response, could not be related to the presence of known (partial) CD-immunogenic motifs in the gluten peptides.

Lentils, a popular foodstuff worldwide, are gaining more interest for their use in alternative diets. In addition, we are observing an ever-growing demand for new raw materials in the malting and brewing industry and an overall rising interest in a low-gluten lifestyle. Therefore, in this study, malt was produced from green lentils and used in both laboratory- and pilot-scale brewing trials. Malted lentils were used as 10% and 20% adjuncts at the laboratory scale, following the Congress mash procedure, and the most important parameters (e.g., filtration time, pH, color, extract, fermentability) of the wort and beer samples were analyzed with a special focus on the concentrations of metal ions (Mg2+, Ca2+, Zn2+, Fe) in wort. The production of beer with lentil malt as an adjunct was then scaled up to 1 hl, and several beer parameters were analyzed, including the gluten content and foam stability. The results showed that the gluten content was decreased by circa 35% and foam stability was enhanced by approximately 6% when adding 20% lentil malt. Furthermore, the use of lentil malt reduced the filtration time by up to 17%. A trained panel evaluated the sensorial qualities of the produced beers. Overall, the use of green lentil malt shows promising results for its potential use in brewing.

Recent research suggests that gluten-free beers by prolyl-endopeptidase treatment may not be safe for coeliac disease (CD) patients. Therefore, the gluten peptidome of an industrial gluten-free prolyl-endopeptidase treated malt beer (<10 ppm gluten) was compared to its untreated counterpart (58 ppm gluten) as a reference. NanoLC-HRMS analysis revealed the presence of 155 and 158 gluten peptides in the treated and reference beer, respectively. Characterisation of the peptides in treated beer showed that prolyl-endopeptidase activity was not complete with many peptides containing (multiple) internal proline-residues. Yet, prolyl-endopeptidase treatment did eliminate complete CD-immunogenic motifs, however, 18 peptides still contained partial, and potentially unsafe, motifs. In the reference beer respectively 7 and 37 gluten peptides carried (multiple) complete and/or partial CD-immunogenic motifs. Worrying is that many of these partial immunogenic gluten peptides do not contain a recognition epitope for the R5-antibody and would be overlooked in the current ELISA analysis for gluten quantification.

The fate of gluten proteins and (poly)peptides throughout the brewing process of reference and gluten-minimized all-malt beers was monitored on both pilot-scale and industrial-scale. Common process steps such as wort separation, cooking, wort and beer clarification already significantly reduce the mass of gluten proteins (72-99%). Nevertheless, gluten derived (poly)peptides remained present at high concentrations in the final reference beers (58-397 ppm). A lauter tun, with course husk material as filter bed, showed to be more effective in reducing the mass of gluten proteins than a mash filter (33% vs. 18%). The mass of gluten proteins and (poly) peptides could be further significantly reduced (16-89% and 33-81% respectively) depending on the use of tannins, AN-PEP (Prolyl-endopeptidase from Aspergillus niger) and silica gel. To render all-barley malt beers gluten-free (<= 20 ppm) (EC No. 41/2009, 2009) gluten-minimization treatments with AN-PEP and silica gel were combined successfully; these beers contained < 5 ppm gluten proteins and < 10 ppm gluten (poly)peptides.

Gluten is the main family of storage proteins found in barley. During malting and brewing, some of the barley malt's proteinaceous material is hydrolysed into peptides or to amino acids. Most of the gluten proteins are removed with the spent grains and with hot- and cold-breaks. However, some gluten proteins and especially gluten-derived peptides can remain throughout the brewing process and will hamper the gluten-free (<= 20 ppm) status of the beer. In this work, three production batches (a, b and c) of 51 Belgian barley malt beers from 24 breweries were analysed with the sandwich (R7001) and competitive (R7021) Ridascreen gliadin R5-ELISA to quantify gluten proteins and peptides. Although the majority of the beers contained low-gluten protein concentrations of <= 20 ppm (a/45, b/47, c/48), only a minority were truly gluten-free with <= 20 ppm gluten peptides (a/18, b/17, c/15). The grain bill had no influence on the measured gluten concentration, but the use of (combined) clarification techniques and presence of wheat malt in the grist was respectively a positive and negative influence. Ten beers, from four breweries, were gluten free in all analysed samples. These included two wheat beers, reflecting the importance of effective clarification in the management of gluten. These results explore the feasibility of the production of gluten-free barley malt beers. Copyright (C) 2018 The Institute of Brewing & Distilling

To address the ever-growing group of health-conscious consumers, more and more nutritional and health claims are being used on food products. Nevertheless, only very few food constituents, including plant sterols, have been appointed an approved health claim (European Commission and Food and Drugs Administration). Plant sterols are part of those limited lists of approved compounds for their cholesterol-lowering properties but have been praised for their anti-inflammatory and anti-carcinogenic properties as well. Despite this indisputable reputation, direct quantitative data is still lacking for naturally present (conjugated) plant sterols in beverages. This study aimed to fill this gap by applying a validated extraction and UPLC-MS/MS detection method to a diverse range of everyday plant-based beverages. β-sitosterol-β-d-glucoside (BSSG) showed to be by far the most abundant sterol in all beverages studied, with concentrations up to 60–90 mg per 100 mL in plant-based milk alternatives and fresh fruit juices. Ergosterol (provitamin D2) could be found in beers (0.8–6.1 µg per 100 mL, from the yeast) and occasionally in juices (17–29 µg per 100 mL). Overall, the results demonstrated that the concentrations of water-soluble sterol conjugates have been underestimated significantly and that specific plant-based beverages can be good, low-fat sources of these plant sterols.

1 Ghent University, Faculty of Bioscience Engineering, Laboratory of Biochemistry and Brewing, Ghent, Belgium; 2 University College Ghent, Faculty of Nature and Technology, Laboratory of Biochemistry and Brewing, Ghent, Belgium; 3 Ghent University, Faculty of Veterinary Medicine, Laboratory of Chemical Analysis, Merelbeke, Belgium Hordein T-cell epitope Reference Hordein T-cell epitope Reference QQPFPQQPQ QQPQQPFPL C QPQQPFPL QPQQPFPQQ [3] C QQPQQPFPL QPHQP [4] C QIPTPL QPQQPFPQQ [3] AELIIP QQPQQPFPL QPHQP [2] QIPTPLQP QQPFPQQPQ QPL [3] IIP QQPQQPFPL QPHQP [2] QQPQQPFPQ AELIIP QQPQQPFPL [3] C QPFP QQPQQPFPQ PQ [3] ELIIP QQPQQPFPL QPHQPYTQQT [3] C TPLQPQ QPFPQQPQQ PL [3] ELIIP QQPQQPFPL QPHQPY [3] C IIPQQPFPLQP QPFPQQPQQ PLPQPQQP [2] ELIIP QQPQQPFPL QPHQPYTQ [3] QQPQQPYPQ ELIIP QQPQQPFPL Q [3] B1 QP QPYPQQPQQ PFPPQ [5] C QIIP QQPQQPFPL QPHQPY [3] PYPQQPQQP B3 IIP QQPQQPFPL QPQQPQPFPQQPI [6] B1 QPQ PYPQQPQQP FPPQ [5] IIP QQPQQPFPL QPQ [3] Table: Peptides with a complete T-cell epitope characterized in beers