RP-HPLC to Determine Protein Composition and Bread Volume of German Common Wheat Landraces

A recent study published in Current Research in Food Science set out to explore the protein composition and baking quality of 14 common wheat landraces and a control group of six modern varieties cultivated under organic conditions in three consecutive years. The researchers used reversed-phase high-performance liquid chromatography (RP-HPLC) to classify the proteins. This research could mark important step toward the overall objective to meet consumer demands for regional and healthy organic specialties, the scientists wrote (1).

Ancient grain varieties such as landraces have recently gained increasing attention, as they are natural, healthy, and environmentally friendly (2). In addition, associate products made from landraces have better tolerability (3). Landraces have developed due to time and natural selection, thereby providing a large genetic diversity (4), which raised the question from the research team: Has the selection criteria during breeding towards higher yields and increased plant resistance resulted in changes in the protein composition, and thus increased the immunoreactive potential in modern varieties (5)? The researchers deemed this question to be of great importance due to the rise in wheat-related disorders across the population, among them celiac disease, wheat allergy (WA), and non-celiac wheat sensitivity (NCWS) (6).

For the study, fourteen German landraces and six modern varieties of common wheat (Triticum aestivum L.) were cultivated at the Bavarian State Research Center for Agriculture (Ruhstorf an der Rott, Germany) and harvested in 2021, 2022 and 2023; one variety was only available in two harvest years (1).

Crude protein content, proportions of albumins (any of numerous simple heat-coagulable water-soluble proteins that occur in blood plasma or serum, muscle, the whites of eggs, milk, and other animal substances as well as many plant tissues and fluids [7]), globulins (any of a class of simple proteins that are insoluble in pure water, but are soluble in dilute salt solutions, and that occur widely in plant and animal tissues [8]) and gluten (a tenacious elastic protein substance especially of wheat flour that gives cohesiveness to dough [9]), water absorption, and bread volume did not differ between the two groups of wheat analyzed. Proportions of gliadins (any of various simple proteins [promalins] obtained by alcoholic extraction of gluten from wheat and rye [10,11]) were significantly higher in the group of landraces, whereas those of glutenins (simple proteins that occur especially in the seeds of cereals, found especially in wheat and obtained by extracting gluten with dilute alkali [12,13]) were lower. Although the ratio of gliadins to glutenins was higher and the proportion of high-molecular-weight glutenin subunits were lower in the group of landraces than in the group of modern varieties, the bread volumes of both groups did not differ. The principal component analysis with all data confirmed these results, showing no clear distinction between the two groups. Taken together, no clear distinction could be made between landraces and modern varieties in terms of protein composition and baking quality (1)

The authors of the article wrote that their study highlights that common wheat landraces can be a good alternative to modern varieties, especially for organic farming, as they offer a large genetic diversity, are regionally adapted, and offer the possibility of manufacturing products of equal quality compared to the ones of modern varieties. Therefore, the authors state that landraces offer a great opportunity for small and medium-sized companies to make handmade specialty products. It also seems that landraces may not be better tolerated in the context of wheat-related disorders, but further studies focusing on the immunoreactive potential are needed to make a more detailed assessment (1).

Wheat field. © Ryzhkov Oleksandr - stock.adobe.com

References

1. Jahn, N.; Konradl, U.; Fleissner, K.; Geisslitz, S.; Scherf, K. A. Protein Composition and Bread Volume of German Common Wheat Landraces Grown Under Organic Conditions. Curr. Res. Food Sci. 2024, 9, 100871. DOI: 10.1016/j.crfs.2024.100871

2. Teuber, R.; Dolgopolova, I.; Nordström, J. Some Like It Organic, Some Like It Purple and Some Like It Ancient: Consumer Preferences and WTP for Value-Added Attributes in Whole Grain Bread. Food Qual. Prefer.2016, 52, 244-254. DOI: 10.1016/j.foodqual.2016.05.002

3. Seidita, A.; Mansueto, P.; Giuliano, A.; Chiavetta, M.; Mandreucci, F. et al. Potential Tolerability of Ancient Grains in Non-Celiac Wheat Sensitivity Patients: A Preliminary Evaluation. Front. Med.2022, 9, 995019. DOI: 10.3389/fmed.2022.995019

4. Villa, T. C. C.; Maxted, N.; Scholten, M.; Ford-Lloyd, B. Defining and Identifying Crop Landraces. Plant Genet. Res.2007,3, 373-384. DOI: 10.1079/pgr200591

5. Scherf, K. A. Immunoreactive Cereal Proteins in Wheat Allergy, Non-Celiac Gluten/Wheat Sensitivity (NCGS) and Celiac Disease. Curr. Opin. Food Sci. 2019, 25, 35-41. DOI: 10.1016/j.cofs.2019.02.003

6. Sapone, A.; Bai, J. C.; Ciacci, C.; Dolinsek, J.; Green, P. H. R. et al. Spectrum of Gluten-Related Disorders: Consensus on New Nomenclature and Classification. BMC Med.2012, 10, 13. DOI: 10.1186/1741-7015-10-13

7. Albumin definition. Merriam-Webster website.https://www.merriam-webster.com/dictionary/albumin(accessed 2024-10-31)

8. Globulin definition. Merriam-Webster website. https://www.merriam-webster.com/dictionary/globulin(accessed 2024-10-31)

9. Gluten definition. Merriam-Webster website. https://www.merriam-webster.com/dictionary/gluten (accessed 2024-10-31)

10. Gliadin definition. Merriam-Webster website. https://www.merriam-webster.com/dictionary/gliadin (accessed 2024-10-31)

11. Promalin definition. Merriam-Webster website. https://www.merriam-webster.com/dictionary/prolamin (accessed 2024-10-31)

12. Glutenin definition. Merriam-Webster website. https://www.merriam-webster.com/medical/glutenin (accessed 2024-10-31)

13. Glutelin definition. Merriam-Webster website.https://www.merriam-webster.com/medical/glutelin (accessed 2024-10-31)