Production of wheat gluten hydrolysates with reduced antigenicity employing enzymatic hydrolysis combined with downstream unit operations

Publication Type

Journal contribution (peer reviewed)

Authors

Merz, M.; Kettner, L.; Langolf, E.; Appel, D.; Blank, I.; Stressler, T.; Fischer, L.

Year of publication

2015

Published in

Journal of the Science of Food and Agriculture

DOI

10.1002/jsfa.7515

Background
Due to allergies or other health disorders a certain segment of the population is not able to safely consume some plant proteins, which are the main protein support in human nutrition. Celiac disease is a prominent autoimmune disorder and requires a strict adherence to a gluten-free diet.
The aim of this study was to identify suitable combinations of enzymatic hydrolysis and common unit operations in food processing (centrifugation, ultrafiltration) to produce gluten-free wheat gluten hydrolysates for food application. To analyze the hydrolysates, a simple and cheap competitive ELISA protocol was designed and validated in this study as well.
Results
The competitive ELISA was validated using gliadin spiked skim milk protein hydrolysates, due to the latter application of the assay. The limit of quantification was 4.19 mg kg^-1, which allowed the identification of gluten-free (< 20 mg kg^-1) hydrolysates. Enzymatic hydrolysis, including the type of peptidase, and the downstream processing highly affected the antigenicity of the hydrolysates.
Conclusion
Enzymatic hydrolysis and downstream processing operations, such as centrifugation and ultrafiltration, reduced the antigenicity of wheat gluten hydrolysates. Gluten-free hydrolysates were obtained with Flavourzyme after centrifugation (25 g L^-1 substrate) and after 1 kDa ultrafiltration (100 g L^-1 substrate). A multiple peptidase complex, such as Flavourzyme, seems to be required for the production of gluten-free hydrolysates.