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BACKGROUND: Gluten composition is an important quality parameter of wheat flour. Reversed‐phase high‐performance liquid chromatography (RP‐HPLC) is a state‐of‐the‐art method for its analysis. As this is a very labour‐intensive and time‐consuming procedure, alternative faster methods are desirable. Enzyme‐linked immunosorbent assay (ELISA) is a high‐throughput method often used for the analysis of gluten traces in gluten‐free products. In this proof‐of‐principle study, we introduce an experimental triple ELISA for the relative quantitation of gliadins, high‐molecular‐weight glutenin subunits (HMW‐GS) and low‐molecular‐weight glutenin subunits (LMW‐GS) of one wheat flour extract. RESULTS: The results of 80 common wheat flour samples obtained from the triple ELISA and RP‐HPLC were correlated. The results for gliadins (r = 0.69) and HMW‐GS (r = 0.81) showed a medium and high correlation, respectively. Only a very weak correlation of ELISA and RP‐HPLC results was observed for LMW‐GS (r = 0.49). Results for glutenins (r = 0.69) and gluten (r = 0.72) had a medium correlation. The gliadin/glutenin ratio (r = 0.47) and LMW‐GS/HMW‐GS ratio (r = 0.40) showed a weak or no correlation. The gliadin, LMW‐GS and gluten contents were lower and the HMW‐GS content was higher in the ELISA measurement compared to RP‐HPLC. CONCLUSION: The quantitation of gliadins and HMW‐GS by the experimental triple ELISA showed comparable results to RP‐HPLC, whereas no strong correlation between the results from the two methods was found for LMW‐GS. Overall, the experimental triple ELISA is suitable for relative gluten quantitation, especially for the analysis of large sample sets. Further work will focus on improving the experimental procedure of the ELISA. © 2024 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Wheat gluten is responsible for the unique baking properties of wheat flour, but it also causes wheat-related disorders in predisposed individuals. Different commercially available gluten materials are commonly used for a variety of assays, but a detailed characterization of their composition is missing in many cases. This is why we aimed to provide an in-depth analysis of three commonly used gliadin and gluten materials from two different batches using gel electrophoretic and chromatographic techniques. The gliadin material did not show the typical qualitative and quantitative protein composition and does not appear to be representative of wheat gliadin. The two gluten materials had the expected protein composition, but both showed large batch-to-batch variability regarding total protein content. Since these variations result in different biochemical, immunological, and functional behaviors, it is important to analyze at least the total protein content of each material and each batch. [ABSTRACT FROM AUTHOR]

Summary: For the various application fields of lipases in food, an accurate and reliable prediction of their performance is needed. This is not provided by the current artificial substrate‐based assays, because natural substrates should be applied. The fluorescent dye Rhodamine B (RB) enables the tracking of released fatty acids in real time and therefore offers the possibility to assess lipase activity towards any substrate. A high‐throughput assay including RB was established, validated and applied to a range of five fats/oils and two isolated lipids for a range of seven lipases. The results show that lipase reactions under different conditions are not comparable. Besides the substrate and the lipase, the milieu of the reaction has a decisive impact. For the prediction of lipase reactions in foods, further aspects such as the accessibility of substrates need to be taken into consideration. [ABSTRACT FROM AUTHOR]

Background and Objectives: Protein and gluten content and composition are important for the baking quality of wheat flours. Our aim was to provide a comprehensive characterization of 82 wheat flours to analyze the influence of protein composition on rheological and baking quality parameters. Findings: Protein composition, starch gelatinization behavior, as well as rheological (microfarinograph, gluten aggregation, extensibility), and baking parameters were determined. The correlation matrix showed no significant correlations between gluten composition and loaf volume. Parameters of the gluten aggregation test allowed a prediction of gluten, gliadin, and glutenin content with an absolute root mean square error of cross validation of 7.5, 6.0, and 3.2 mg/g, respectively, using partial least squares regression. Starch gelatinization temperature had an effect on gluten aggregation. Conclusions: The gluten aggregation test was suitable to predict gluten, gliadin, and glutenin content. The lack of correlations between protein composition and loaf volume indicates that baking quality is the result of a complex combination of different parameters. Significance and Novelty: Our study is the first to comprehensively analyze 82 wheat flours, especially in terms of gluten composition. We show that flour blends can reach excellent baking quality even if quality indicators like crude protein or extensibility are comparatively low. [ABSTRACT FROM AUTHOR]