Nutritional properties of einkorn wheat (Triticum monococcum L.)

Amylase-Trypsin Inhibitors in Wheat and Other Cereals as Potential Activators of the Effects of Nonceliac Gluten Sensitivity

Nonceliac gluten sensitivity (NCGS) is a gluten-related gastrointestinal disorder distinct from celiac disease (CD) and gluten allergy that is not easy to diagnose due to the lack of biomarkers. It is characterized by intestinal symptoms and extraintestinal manifestations with the consumption of gluten-containing foods. In contrast to CD, NCGS patients do not present a genetic predisposition or intestinal villi atrophy. Recent studies question the proinflammatory triggering activity of α-gliadin fraction contained in wheat, since it has been demonstrated that the amylase-trypsin inhibitors (ATIs) exert a strong activating effect on the innate immune response. We aimed to analyze the role of ATIs in the activation of innate immunity and in the development of the symptoms characteristic of NCGS. A systematic literature search was made using databases such as MEDLINE, SciELO, Science Direct, and Scopus, with focus on key words such as "amylase-trypsin inhibitors," "wheat," "gluten," and "celiac." Many studies are available on the structure, inhibition mechanism, and immune system effects of ATIs, mainly focused on IgE-mediated reactions. Recently, with the increase of NCGS interest, has increased the literature on the capacity of ATIs contained in wheat to activate the innate immune system. Literature published to date questions the relationship between activation of the innate immune system and gluten in NCGS. ATIs may have acted as interfering contaminant of gluten and appear as potential activator of innate immunity in NCGS patients. In view of their potential impact, more interventional studies are needed to demonstrate the proinflammatory effect of ATIs.

Integrated Evaluation of the Potential Health Benefits of Einkorn-Based Breads

Nowadays the high nutritional value of whole grains is recognized, and there is an increasing interest in the ancient varieties for producing wholegrain food products with enhanced nutritional characteristics. Among ancient crops, einkorn could represent a valid alternative. In this work, einkorn flours were analyzed for their content in carotenoids and in free and bound phenolic acids, and compared to wheat flours. The most promising flours were used to produce conventional and sourdough fermented breads. Breads were in vitro digested, and characterized before and after digestion. The four breads having the best characteristics were selected, and the product of their digestion was used to evaluate their anti-inflammatory effect using Caco-2 cells. Our results confirm the higher carotenoid levels in einkorn than in modern wheats, and the effectiveness of sourdough fermentation in maintaining these levels, despite the longer exposure to atmospheric oxygen. Moreover, in cultured cells einkorn bread evidenced an anti-inflammatory effect, although masked by the effect of digestive fluid. This study represents the first integrated evaluation of the potential health benefit of einkorn-based bakery products compared to wheat-based ones, and contributes to our knowledge of ancient grains.

Current Trends in Ancient Grains-Based Foodstuffs: Insights into Nutritional Aspects and Technological Applications

For centuries, ancient grains fed populations, but due to their low yield, they were abandoned and replaced by high-yielding species. However, currently, there is a renewed interest in ancient wheat and pseudocereal grains from consumers, farmers, and manufacturers. Ancient wheat such as einkorn, emmer, spelt, and Kamut®, are being reintegrated because of their low fertilizer input, high adaptability and important genetic diversity. New trends in pseudocereal products are also emerging, and they are mostly appreciated for their nutritional outcomes, particularly by the gluten-free market. Toward healthier lifestyle, ancient grains-based foodstuffs are a growing business and their industrialization is taking 2 pathways, either as a raw ingredient or a functional ingredient. This paper deals with these grain characteristics by focusing on the compositional profile and the technological potential.

Grain subproteome responses to nitrogen and sulfur supply in diploid wheat Triticum monococcum ssp. monococcum

Wheat grain storage proteins (GSPs) make up most of the protein content of grain and determine flour end-use value. The synthesis and accumulation of GSPs depend highly on nitrogen (N) and sulfur (S) availability and it is important to understand the underlying control mechanisms. Here we studied how the einkorn (Triticum monococcum ssp. monococcum) grain proteome responds to different amounts of N and S supply during grain development. GSP composition at grain maturity was clearly impacted by nutrition treatments, due to early changes in the rate of GSP accumulation during grain filling. Large-scale analysis of the nuclear and albumin-globulin subproteomes during this key developmental phase revealed that the abundance of 203 proteins was significantly modified by the nutrition treatments. Our results showed that the grain proteome was highly affected by perturbation in the N:S balance. S supply strongly increased the rate of accumulation of S-rich α/β-gliadin and γ-gliadin, and the abundance of several other proteins involved in glutathione metabolism. Post-anthesis N supply resulted in the activation of amino acid metabolism at the expense of carbohydrate metabolism and the activation of transport processes including nucleocytoplasmic transit. Protein accumulation networks were analyzed. Several central actors in the response were identified whose variation in abundance was related to variation in the amounts of many other proteins and are thus potentially important for GSP accumulation. This detailed analysis of grain subproteomes provides information on how wheat GSP composition can possibly be controlled in low-level fertilization condition.

The acute impact of the intake of four types of bread on satiety and blood concentrations of glucose, insulin, free fatty acids, triglyceride and acylated ghrelin. A randomized controlled cross-over trial

The purpose of the present study is to compare the effects of four different breads (one commercial par-baked wheat bread, three sourdough breads prepared with commercial wheat flour, organic wheat flour, organic einkorn flour) in 16 healthy subjects. The primary outcome of this randomized cross-over trial was evaluating intra-individual changes in glycemic areas-under-the-curve (AUCs) after 50g carbohydrate portions of each bread; secondary outcomes were changes in insulin, fatty free acids (FFA), triglyceride, acylated ghrelin and satiety AUCs. Blood samples and satiety ratings were collected every 30-min for 2-h after the consumption of each bread. The einkorn flour showed the lowest amylase activity, the commercial flour the highest; commercial bread had the highest carbohydrate content and the lowest dietary fiber content. Glucose AUCs were significantly lower after the consumption of sourdough breads made with organic (12,754±1433mg/dL×h) and einkorn flour (12,216±1210mg/dL×h), with respect to the commercial bread (13,849±2193mg/dL×h). Insulin AUCs decreased after the consumption of all sourdough breads when compared to commercial bread. FFA and triglyceride AUCs did not differ by kind of breads. Median ghrelin AUC was significantly lower and satiety higher after the einkorn bread (3710pg/mL×h; 3225±2414, respectively) than after commercial bread consumption (4140pg/mL×h; 1706±1766, respectively), but not with other sourdough breads. In conclusion, the use of sourdough may improve the nutritional features of breads; einkorn bread induced the least disturbance in carbohydrate homeostasis and the greater satiety. If confirmed by further research, these results might have implications in the approach towards chronic dysmetabolic diseases.

Geographic differentiation of domesticated einkorn wheat and possible Neolithic migration routes

To analyse the spread of domesticated einkorn into Europe, 136 landraces, 9 wild einkorns and 3 Triticum urartu were fingerprinted by the diversity array technology sequence (DArT-seq) marker technology. The obtained 3455 single-nucleotide polymorphism (SNP) markers confirmed earlier results about the separation of wild and domesticated einkorn from T. urartu and about the pinpointing of the domesticated forms to the Karacadağ Mountains (Turkey). Further analyses identified two major domesticated landrace einkorn groups, one relating to the Prealpine region and the other to the Maghreb/Iberian region. The previously published four geographical provenance groups were mostly identified in our results. The earlier reported unique position of the Maghreb/Iberia einkorns cannot be confirmed, as the three landrace clusters we identified with STRUCTURE also occur in the remaining einkorn, although at different frequencies. The results are discussed with respect to the spreading of domesticated einkorn into Western Europe and two possible Neolithic migration routes are indicated.

Characterization and Discrimination of Ancient Grains: A Metabolomics Approach

Hulled, or ancient, wheats were the earliest domesticated wheats by mankind and the ancestors of current wheats. Their cultivation drastically decreased during the 1960s; however, the increasing demand for a healthy and equilibrated diet led to rediscovering these grains. Our aim was to use a non-targeted metabolomic approach to discriminate and characterize similarities and differences between ancient Triticum varieties. For this purpose, 77 hulled wheat samples from three different varieties were collected: Garfagnana T. turgidum var. dicoccum L. (emmer), ID331 T. monococcum L. (einkorn) and Rouquin T. spelta L. (spelt). The ultra high performance liquid chromatography coupled to high resolution tandem mass spectrometry (UHPLC-QTOF) metabolomics approach highlighted a pronounced sample clustering according to the wheat variety, with an excellent predictability (Q²), for all the models built. Fifteen metabolites were tentatively identified based on accurate masses, isotopic pattern, and product ion spectra. Among these, alkylresorcinols (ARs) were found to be significantly higher in spelt and emmer, showing different homologue composition. Furthermore, phosphatidylcholines (PC) and lysophosphatidylcholines (lysoPC) levels were higher in einkorn variety. The results obtained in this study confirmed the importance of ARs as markers to distinguish between Triticum species and revealed their values as cultivar markers, being not affected by the environmental influences.

Proteomic and phosphoproteomic analysis reveals the response and defense mechanism in leaves of diploid wheat T. monococcum under salt stress and recovery

Salinity is a major abiotic stress factor affecting crops production and productivity. Triticum monococcum is closely related to Triticum urartu (A(U)A(U)), which is used as a model plant of wheat A genome study. Here, salt stress induced dynamic proteome and phosphoproteome profiling was focused. The T. monococcum seedlings were initially treated with different concentrations of NaCl ranging from 80 to 320mM for 48h followed by a recovery process for 48h prior to proteomic and phosphoproteomic analysis. As a result, a total of 81 spots corresponding to salt stress and recovery were identified by MALDI-TOF/TOF-MS from 2-DE gels. These proteins were mainly involved in regulatory, stress defense, protein folding/assembly/degradation, photosynthesis, carbohydrate metabolism, energy production and transportation, protein metabolism, and cell structure. Pro-Q Diamond staining was used to detect the phosphoproteins. Finally, 20 spots with different phosphorylation levels during salt treatment or recovery compared with controls were identified. A set of potential salt stress response and defense biomarkers was identified, such as cp31BHv, betaine-aldehyde dehydrogenase, leucine aminopeptidase 2, Cu/Zn superoxide dismutase, and 2-Cys peroxiredoxin BAS1, which could lead to a better understanding of the molecular basis of salt response and defense in food crops.

BIOLOGICAL SIGNIFICANCE

Soil salinity reduces the yield of the major crops, which is one of the severest problems in irrigated agriculture worldwide. However, how crops response and defense during different levels of salt treatment and recovery processes is still unclear, especially at the post-translational modification level. T. monococcum is a useful model for common wheat. Thus, proteomic and phosphoproteomic analyses of T. monococcum leaves were performed in our study, which provided novel insights into the underlying salt response and defense mechanisms in wheat and other crops.

Allergen relative abundance in several wheat varieties as revealed via a targeted quantitative approach using MS

Food allergy has become a major health issue in developed countries, therefore there is an urgent need to develop analytical methods able to detect and quantify with a good sensitivity and reliability some specific allergens in complex food matrices. In this paper, we present a targeted MS/MS approach to compare the relative abundance of the major recognized wheat allergens in the salt-soluble (albumin/globulin) fraction of wheat grains. Twelve allergens were quantified in seven wheat varieties, selected from three Triticum species: T. aestivum (bread wheat), T. durum (durum wheat), and T. monococcum. The allergens were monitored from one or two proteotypic peptides and their relative abundance was deduced from the intensity of one fragment measured in MS/MS. Whereas the abundance of some of the targeted allergens was quite stable across the genotypes, others like alpha-amylase inhibitors showed clear differences according to the wheat species, in accordance with the results of earlier functional studies. This study enriches the scarce knowledge available on allergens content in wheat genotypes, and brings new perspectives for food safety and plant breeding.

Influence of water biscuit processing and kernel puffing on the phenolic acid content and the antioxidant activity of einkorn and bread wheat

The whole meal flour of wheat is rich in phenolic acids, which provide a relevant antioxidant activity to food products. Aim of this research was to assess the influence of processing on phenolic acid content and antioxidant activity of whole meal flour water biscuits and puffed kernels of einkorn and bread wheat. To this end, the evolution of syringaldehyde, ferulic, vanillic, syringic, p-coumaric, p-hydroxybenzoic, and caffeic acids was studied during manufacturing. Overall, from flour to water biscuit, the total soluble conjugated phenolic acids increased slightly in einkorn, while the insoluble bound phenolic acids decreased in all the accessions as a consequence of losses during the mixing step. In the puffed kernels, instead, the total soluble conjugated phenolic acids increased markedly, while the bound phenolics did not show any clear change, evidencing their high thermal stability. The antioxidant activity, measured by FRAP and ABTS, increased during processing and was highest under the most drastic puffing conditions.

Ancient Wheat Diet Delays Diabetes Development in a Type 2 Diabetes Animal Model

AIM

The main objective was to investigate the physiological effects of ancient wheat whole grain flour diets on the development and progression of type 2 diabetes in Zucker diabetic fatty (ZDF) rats, and specifically to look at the acute glycemic responses.

METHODS

An intervention study was conducted, involving 40 ZDF rats consuming one of 5 different diets (emmer, einkorn, spelt, rye and refined wheat) for 9 weeks. Refined wheat flour and whole grain rye flour were included as negative and positive controls, respectively.

RESULTS

After 9 weeks of intervention, a downregulation of the hepatic genes PPAR-α, GLUT2, and SREBP-1c was observed in the emmer group compared to the control wheat group. Likewise, expression of hepatic SREBP-2 was lower for emmer, einkorn, and rye compared with the control group. Furthermore, spelt and rye induced a low acute glycemic response. The wheat group had higher HDL- and total cholesterol levels.

CONCLUSIONS

Ancient wheat diets caused a downregulation of key regulatory genes involved in glucose and fat metabolism, equivalent to a prevention or delay of diabetes development. Spelt and rye induced a low acute glycemic response compared to wheat.