Center for Food Safety and Applied Nutrition, U.S. Food and Drug Administration , 5001 Campus Drive, College Park, Maryland 20740, United States.
Anal Chem. 2018 Feb 6;90(3):2111-2118. doi: 10.1021/acs.analchem.7b04371. Epub 2018 Jan 26.
Most gluten-reduced beers are produced using an enzyme called proline endopeptidase (PEP), which proteolyzes the gluten by cleaving at proline residues. However, the gluten content of beers brewed in the presence of PEP cannot be verified since current analytical methods are not able to accurately quantitate gluten in fermented foods. In this work, mass spectrometry was used to qualitatively characterize the gluten in a wheat-gluten-incurred sorghum model beer brewed with and without the addition of PEP. Hydrolyzed gluten peptides and chymotryptic gluten peptides produced from intact gluten proteins were detected in beer brewed in the presence of up to 6 times the manufacturer's recommended dosage of PEP. The observation of chymotryptic gluten peptides indicates that some gluten proteins remained, at least partially, intact after fermentation and enzymatic treatment. Less intact gluten was observed in beer brewed in the presence of PEP, but more hydrolyzed gluten peptides were consequently observed in PEP-containing beer. Gluten peptides that contained immunogenic sequences known to be associated with celiac disease were detected in PEP-containing beer.
大多数低麸质啤酒都是使用一种叫做脯氨酸内肽酶（PEP）的酶生产的，这种酶通过在脯氨酸残基处切割来蛋白水解麸质。然而，由于目前的分析方法无法准确定量发酵食品中的麸质，因此无法验证添加 PEP 酿造的啤酒中的麸质含量。在这项工作中，质谱法用于定性分析在添加和不添加 PEP 的情况下用小麦麸质诱导的高粱模型啤酒中麸质。在添加多达制造商建议剂量 6 倍的 PEP 的情况下酿造的啤酒中检测到了水解麸质肽和糜蛋白酶解麸质肽。在发酵和酶处理后，观察到一些麸质蛋白至少部分保持完整，这表明存在糜蛋白酶解麸质肽。在添加 PEP 的啤酒中观察到的不那么完整的麸质较少，但在含有 PEP 的啤酒中观察到更多的水解麸质肽。在含有 PEP 的啤酒中检测到了与乳糜泻相关的已知具有免疫原性的序列的麸质肽。
