Structural characterization of proteins in wheat flour doughs enriched with intermediate wheatgrass (Thinopyrum intermedium) flour

• Published in: Food chemistry 2016-03, Vol.194, p.994-1002
• Main Authors: Marti, Alessandra, Bock, Jayne E., Pagani, Maria Ambrogina, Ismail, Baraem, Seetharaman, Koushik
• Format: Article
• Language: English
• Subjects: Aggregate formation; Bread - analysis; Dietary Fiber; Dough; Flour - analysis; Perennial intermediate wheatgrass; Protein secondary structure; Thiol accessibility; Triticum - chemistry
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2015.08.082

•IWG has desirable agronomic traits and high fiber and protein contents.•Structural characteristics of the proteins in IWG-enriched dough are investigated.•In IWG dough protein network is mostly based on non-covalent interactions.•High percentage of enrichment (⩾75%) resulted in a decrease in structural order. The high protein and fiber content of intermediate wheatgrass (IWG) – together with its interesting agronomic traits and environment-related benefits – make this perennial crop attractive also for human consumption. Structural characteristics of the proteins in IWG/hard wheat flour (HWF) doughs (at IWG:HWF ratios of 0:100, 50:50, 75:25 and 100:0) – including aggregate formation, thiols availability, and secondary structure changes during dough mixing – were investigated. Proteins in IWG-doughs had higher solubility and thiol content – as function of IWG content – suggesting that protein network was mostly based on non-covalent interactions. While 50% IWG-enrichment gave an increase in random structures, enrichment at ⩾75% resulted in a decrease in β-sheets with an increase in random structures, indicating a decrease in structural order. The observed differences in protein molecular configuration and interactions in HWF compared to IWG doughs necessitate further investigation to establish their impact on the quality of IWG-enriched bread.