From seed to bread: variation in quality in a set of old durum wheat cultivars

Assessment of intra- and inter-genetic diversity in tetraploid and hexaploid wheat genotypes based on omega, gamma and alpha-gliadin profiles

Durum and bread wheat are well adapted to the Mediterranean Basin. Twenty-three genotypes of each species were grown to evaluate the intra- and inter-genetic diversity based on omega (ω), gamma (γ) and alpha (α)-gliadin profiles. To achieve this purpose, the endosperm storage proteins (both gliadins and glutenins) were extracted from wheat grains and electrophoresed on sodium dodecyl sulfate (SDS)-polyacrylamide gels. The results of SDS-Polyacrylamide Gel Electrophoresis (SDS-PAGE) revealed nine polymorphic loci out of 16 loci with durum wheat genotypes and nine polymorphic loci out of 18 loci with bead wheat genotypes. The polymorphisms revealed by the SDS-PAGE were 56% and 50% in durum and bread wheat genotypes, respectively. Using the cluster analysis, the durum wheat genotypes were clustered into five groups, while the bread wheat genotypes were grouped into six clusters using un-weighed pair group mean analyses based on ω, γ, and α-gliadins profiles. The 46 durum and bread wheat genotypes were grouped into seven clusters based on the combined ω, γ, and α-gliadins profiles revealed by the SDS-PAGE. The in silico analysis determined the intra-genetic diversity between bread and durum wheat based on the sequences of ω, γ, and α-gliadins. The alignment of ω-gliadin revealed the highest polymorphism (52.1%) between bread and durum wheat, meanwhile, the alignment of γ and α-gliadins revealed very low polymorphism 6.6% and 15.4%, respectively. According to computational studies, all gliadins contain a lot of glutamine and proline residues. The analysis revealed that the bread wheat possessed ω and γ -gliadins with a lower content of proline and a higher content of glutamine than durum wheat. In contrast, durum wheat possessed α-gliadin with a lower content of proline and a higher content of glutamine than bread wheat. In conclusion, the SDS-PAGE, in silico and computational analyses are effective tools to determine the intra- and inter-genetic diversity in tetraploid and hexaploid wheat genotypes based on ω, γ, and α-gliadins profiles.

Farmer vs. Industrial Practices: Impact of Variety, Cropping System and Process on the Quality of Durum Wheat Grains and Final Products

The consumption of artisanal and organic pasta made on-farm from ancient varieties is increasing in France. Some people, namely, those suffering from digestive disorders following the consumption of industrial pasta, consider these artisanal pasta to be more digestible. Most of them have linked these digestive disorders to the ingestion of gluten. We analyzed in this study the impact of industrial and artisanal practices on the protein quality of durum wheat products. The varieties recommended by the industry (IND) were compared to those used by farmers (FAR): the FAR being on average much richer in protein. However, the solubility of these proteins analyzed by Size Exclusion-High Performance Liquid Chromatography (SE-HPLC) and their in vitro proteolysis by digestive enzymes vary little between the two groups of varieties, while differences between varieties in each group are observable. The location of grain production and the tested cropping systems (zero vs. low input) have a low impact on protein quality. Yet, more contrasting modalities should be studied to validate this point. The type of production process (artisanal vs. industrial) is, among those studied, the factor having the greatest impact on protein compositionPasta produced by the artisanal method contains a higher sodium dodecyl sulfate (SDS)-soluble protein fraction and are more in-vitro proteolyzed. Whether these criteria are indicative of what happens during a consumer's digestion remains to be determined. It also remains to be assessed which key stages of the process have the greatest influence on protein quality.

A systematic literature review of life cycle assessments in the durum wheat sector

It is recognised today that the global food system does not always deliver good nutrition for all human beings, and, additionally, dramatically contributes to climate change, environmental degradation, and biodiversity loss. In particular, the cereal sector threatens biodiversity and ecosystem functions, due to environmentally harmful farming activities, that critically alter climate conditions, along with energy, land, and water resources. According to this paper's authors' opinion, this supports the rationale of conducting a systematic literature review of Life Cycle Assessments (LCAs) in the durum wheat (DW) sector, to highlight environmental hotspots and improvement potentials in the phases of cultivation and processing into finished products like pasta and bread. Methodological aspects were also discussed in this paper, to provide useful insights on how to best perform LCA in such agri-food supply chains. Given the findings from the papers reviewed, the authors could document that the cultivation phase is the primary environmental hotspot of DW-derived food products and suggested several mitigation and improvements solution including, organic farming practices, diversified cropping systems, reduction of N fertilisers and pesticides application, and irrigation optimisation strategies. Furthermore, the review highlighted that there exist two main gaps in the literature, mainly related to the scarce attention on the organic farming sector and DW landraces, and the lack of nutritional-property accounting in LCAs. Finally, although specific, the review may be of interest to researchers, LCA practitioners, farmers and producers, policy- and decision-makers, and other stakeholders, and could support the promotion of environmental sustainability in the DW sector.

Suitability of Improved and Ancient Italian Wheat for Bread-Making: A Holistic Approach

Ancient and old wheat grains are gaining interest as a genetic reservoir to develop improved Italian genotypes with peculiar features. In this light, the aim of this study was to assess the baking performance of two improved einkorn (Monlis and Norberto) and two improved emmer (Padre Pio and Giovanni Paolo) genotypes in comparison with two Italian landraces (Garfagnana and Cappelli) and Khorasan. This set was evaluated following a holistic approach considering the flour, dough, and bread properties. The results showed that the flour properties, dough rheology, pasting, and fermentation parameters, as well as the bread properties, significantly differed among the studied genotypes. Cappelli produced the bread with the best quality, i.e., the highest volume and lowest firmness. Despite having the same pedigrees, Giovanni Paolo and Padre Pio resulted in significantly different technological properties. Giovanni Paolo flour showed the highest protein content and provided a dough with a high gas production capacity, resulting in the bread having a similar firmness to Cappelli. Padre Pio flour provided bread having a similar volume to Cappelli but a high firmness similar to Khorasan and Garfagnana. The einkorn genotypes, Monlis and Norberto, showed poor fermentation properties and high gelatinization viscosity that resulted in bread with poor quality. Alternatively, they could be more suitable for making non-fermented flatbreads. Our results showed that the improved wheat showed a high versatility of features, which offers bakers a flexible material to make a genotype of bread types.

Barriers and levers to enhance end-use functional properties of durum wheat (Triticum turgidum L.) grain: An agronomic implication

The current trends in population growth and consumption pattern remain to increase the demand for durum wheat grain. However, multiple biotic and abiotic challenges due to climate change coupled with crop management practices possess major concern to improve durum wheat production and storage proteins. Efforts on developing innovative agronomic and breeding strategies are essential to enhance productivity, and nutritional quality under the changing climate. Nitrogen is an important structural component of protein, and potentially reduce the adverse effect of drought stress through maintaining metabolic activities. Optimum nitrogen fertilization allows durum wheat producing farmers to attain high quality yield, brings economic benefit, and reduces environmental pollution. However, defining an optimum nitrogen fertilizer rate for specific location requires considering yield achievement and quality of the end products. If the producers interest is, geared towards production of high protein content, high nitrogen dose is required. If the interest gears towards grain yield improvement optimization of nitrogen fertilizer rate is important. This indicates that defining product-specific nitrogen application is required for sustainable durum wheat production. Therefore, future challenges of increasing production, productivity, and end-use functional properties of durum wheat will only be achieved through cooperation of multidisciplinary teams who are able to incorporate new technologies.

N Partitioning between Gluten Fractions in a Set of Italian Durum Wheat Cultivars: Role of the Grain N Content

Grain protein content constitutes a key quality trait for durum wheat end-products and may also impact grain protein composition. A total of sixteen durum wheat cultivars were analyzed in a field trial during two seasons at two nitrogen (N) levels to evaluate whether and to what extent the variation in total grain N was associated with variation in the quantity of the various protein fractions and grain quality parameters. Genotypic variation in grain N content correlated with the variation in the content of all three protein fractions, although the strength of the correlation with gliadin and albumin-globulin was higher than that with glutenins. Genotypic variation in gliadin and glutenin content was more tightly correlated with the variation in the sulfur (S)-rich protein groups than with the S-poor protein groups and subunits. The variation in the percentage of unextractable polymeric proteins (UPP%) among genotypes was independent of their glutenin allelic composition. The significant genotypic differences in UPP% and in the ratios between protein groups and subunits were not influenced by the corresponding variation in grain N content. The final grain N content can only account for part of the variation in quality parameters and in the partitioning of total grain N between protein fractions since genotypic differences other than grain N content also contribute to these variations.