Epidemiologic studies suggest an increasing prevalence of celiac disease and non-celiac gluten/wheat sensitivity. With wheat proteins being the main triggers, changes in wheat protein composition are discussed as a potential cause. The goals of breeding toward increased yield and resistance might have inadvertently contributed to a higher immunostimulatory potential of modern wheat cultivars compared to old wheat cultivars. Therefore, agronomic characteristics, protein content, and gluten composition of 60 German winter wheat cultivars first registered between 1891 and 2010 grown in 3 years were analyzed. While plant height and spike density decreased over time, yield and harvest index increased. The protein and gliadin contents showed a decreasing trend, whereas glutenin contents increased, but there were no changes in albumin/globulin and gluten contents. Overall, the harvest year had a more significant effect on protein composition than the cultivar. At the protein level, we found no evidence to support an increased immunostimulatory potential of modern winter wheat.

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Background and objectives Wheat protein composition is commonly characterized by reversed‐phase (RP)‐HPLC‐UV after extraction of albumins/globulins, gliadins (ω5‐, ω1,2‐, α‐, and γ‐gliadins), and glutenins (high‐ and low‐molecular‐weight glutenin subunits). However, this traditional classification does not consider the individual distribution of peaks, resulting in loss of information on protein fingerprints. We developed a new approach to peak integration and evaluated its suitability to differentiate between wheat cultivars and species. Findings Integration events were performed every 20 s, and the relative proportions of the peaks were calculated. We compared the traditional and new integration methods on two sample sets, the first comprising 60 common wheat cultivars from 1891 to 2010 and the second comprising 40 common wheat, spelt, durum wheat, emmer, and einkorn cultivars. The new integration method performed better in differentiating old and modern common wheat cultivars and was also applicable to different wheat species. Conclusions Unique cultivars were identified that stood out because of their protein composition. Four samples warrant further research to identify the specific proteins that are responsible for the differences. Significance and novelty The new integration allowed us to map the cultivar‐ and species‐specific fingerprints, identify cultivars with exceptional protein composition, and group similar cultivars.

A turn-on fluorescent probe, HOCD-RB, for monitoring singlet oxygen (1O2) was developed by linking rhodamine B as fluorophore with dimethylhomoocoerdianthrone (HOCD) as 1O2 reaction site and fluorescence quencher due to the intramolecular energy transfer (ET) between rhodamine B and HOCD moieties. Upon exposure to 1O2 it rapidly forms endoperoxide with HOCD and turns on the fluorescence of rhodamine B by 18-fold. Taking advantage of the HOCD-RB probe that shows fast response, high sensitivity, and selectivity for 1O2, it is applied for imaging of endogenous 1O2 in living cells and the fluorometric assay for evaluating 1O2 quenching activity of selected common flavonoids found in our daily diets. The results show that the 1O2 scavenging activity of flavonoids depends on not only the structure of individual flavonoid but also the competitive interactions between mixed flavonoids. The best antioxidant capacity for individual and mixed flavonoids is epigallocatechin gallate and the mixture of catechin gallate with kaempferol, respectively. Overall, this work provided a new tool for detection and imaging of singlet oxygen activity in a biological system as well as an efficient fluorometric assay of 1O2 scavenging activity.

In non-celiac gluten sensitivity (NCGS), the elimination of wheat results in a clear symptom improvement, but gluten has still not been proven as (the sole) trigger. Due to the increase in the prevalence of gluten-related diseases, the breeding of high-performance wheat cultivars is discussed as a trigger. To analyze the immune stimulation and signal pathways, the immune cells of healthy subjects and patients with NCGS were stimulated with gliadins from wheat, and the expression and secretion of interleukin 1ß (IL1ß) and interleukin 6 (IL6) were studied. To determine the impact of wheat breeding, the monocyte cell line THP1 and human immune cells were stimulated with gliadin, glutenin, and albumin/globulin fractions of ancient and modern cereals, and expression of inflammatory molecules was checked. Immune cells of patients with NCGS showed an increased expression of IL1ß and IL6 after stimulation with gliadins compared to immune cells of healthy controls. Gliadins caused a strong activation of P-STAT3 in immune cells of healthy controls, and inhibitors of JAK and NFκB pathways considerably reduced this response. In addition to gliadins, we further showed that glutenins and albumin/globulins from all wheat cultivars from the last century, and especially from einkorn and spelt, also markedly induced the expression of inflammatory genes in THP1 and human immune cells. There was no correlation between enhanced immune stimulation and ancient or modern cultivars. This does not support the hypothesis that modern wheat breeding is responsible for the increase in gluten-related diseases. An altered immune situation is suggested in patients with NCGS.