Abstract
Bread wheat is a major food cereal, and heritage varieties preserve a broad base of crop diversity. This study compared five Tuscan heritage wheats—Andriolo, Frassineto, Gentil rosso, Inallettabile 96 and Verna—with the modern cultivar Palesio. Heritage varieties were grown alone and in equal two-variety mixtures under organic management at three field sites.
The assessment combined crop morphology and yield with grain minerals, polyphenols, flavonoids, antioxidant activity, protein, gluten and flour rheology. Growing environment had a substantial effect across the measurements. Mixtures did not consistently improve the observed traits, although several combinations showed useful tendencies. The relationship among antioxidant activity, protein, gluten and dough performance was identified as a productive direction for further selection and testing.
Site conditions explained more variation across measured traits than genotype alone.
Mixtures produced some promising trends but no consistent overall improvement.
Verna stood out for polyphenol content and antiradical activity in this trial.
The modern reference showed greater dough strength, while heritage wheats generally required different processing expectations.
Introduction
Renewed interest in heritage wheat reflects its value as germplasm and as a source of crop diversity. These wheats include local landraces and varieties selected from them before high-input production became widespread. In Tuscany, several conserved bread wheats descend from regionally adapted material such as Gentil rosso.
Whole wheat supplies starch and protein alongside fibre, vitamins, minerals and secondary metabolites. Polyphenols and related compounds are concentrated in the bran and germ, so their abundance depends not only on cultivar but also on climate, soil, management and genotype-by-environment interactions.
The central agronomic question is a trade-off. Heritage varieties may offer useful functional characteristics and adaptation, whereas modern cultivars have often been selected for predictable yield and flour performance. This experiment therefore evaluated nutritional, functional and rheological properties together rather than treating them as separate outcomes.
Materials and methods
The trial was conducted during the 2011–2012 growing period at three organic field sites in the Siena area of Tuscany. A randomised block design with two replicates was used at each site. Five heritage genotypes were tested individually and in all ten possible equal two-variety combinations. Palesio served as the modern reference, giving sixteen treatments at each site.
All treatments followed organic management. Seeding was adjusted by thousand-kernel weight to reach a common target density. Investigators recorded crop morphology, yield, thousand-kernel weight and test weight, then collected representative grain samples for whole-grain chemistry and white-flour rheology.
Grain composition
Whole-grain flour was analysed for carbon and nitrogen, with protein calculated from nitrogen. Calcium, potassium, magnesium, sodium, phosphorus, iron, manganese and zinc were measured using plasma emission spectroscopy.
Phenolics and antioxidant activity
Free and bound phenolic fractions were extracted separately. Polyphenols were assessed using the Folin–Ciocalteu method, while flavonoids were determined colorimetrically. Radical-scavenging performance was expressed as antiradical power, where a higher value indicates greater measured activity in the assay.
Flour performance
White flour was evaluated by alveograph for dough strength, tenacity, extensibility and the P/L balance. Dry gluten was determined after washing flour dough to remove starch and soluble proteins.
Statistical approach
A mixed-model analysis of variance tested site, variety and their interaction. Correlations, principal component analysis and cluster analysis were then used to explore relationships among crop, mineral, functional and rheological variables.
Results
Crop and dough characteristics
Site influenced nearly all commercial and rheological measures. Across locations, mean grain yield ranged from approximately 18 to 33 q·ha−1, protein from about 10% to 14%, and thousand-kernel weight from 34 to 45 g. Heritage wheats were taller than Palesio and generally carried larger kernels, while the modern reference produced the highest test weight, dry gluten and dough-strength value.
Some mixtures containing Verna, Inallettabile 96 or Frassineto had stronger dough than the same varieties grown alone. Even so, mixture effects were not uniform. Most heritage entries had a balanced P/L ratio, and Verna remained within the preferred reference range across the tested environments.
| Site summary | Yield (q·ha−1) | Protein (% DM) | Dry gluten (% DM) | Dough strength W |
|---|---|---|---|---|
| Site 1 | 33.2 | 9.9 | 7 | 36 |
| Site 2 | 21.9 | 14.2 | 14 | 81 |
| Site 3 | 18.4 | 13.7 | 13 | 100 |
Minerals
Potassium, phosphorus, manganese and zinc differed among sites. Variety effects were found for calcium, potassium, manganese and zinc. Gentil rosso and its combination with Andriolo were comparatively rich in calcium, Frassineto influenced the higher-potassium combinations, and Andriolo recorded the highest zinc level in the varietal comparison. Palesio had lower calcium, potassium and zinc in this experiment.
Secondary metabolites
Site significantly affected several phenolic, flavonoid and antioxidant measurements. Verna recorded the highest total polyphenols and total antiradical power, while the modern reference had the lowest free-polyphenol value. At genotype level, polyphenol content was more closely associated with measured antioxidant activity than flavonoid content.
Relationships among traits
Rheological traits such as protein, gluten and dough strength were positively related to one another. Polyphenols were also positively associated with measured antiradical power. Calcium, manganese, phosphorus and zinc tended to move together, while potassium often showed the opposite pattern.
Principal component analysis reinforced the strong environmental signal: samples grouped more clearly by growing site than by genotype. This suggests that variety comparisons should be interpreted in the context of soil and seasonal conditions.
Discussion
The study set out to characterise heritage Tuscan wheats across commercial, technological and functional criteria. Growing varieties in mixtures produced moderate gains for selected combinations, but no broad improvement across all measurements. The findings therefore do not support treating mixture cultivation as an automatic route to better grain quality.
The modern reference retained an advantage in conventional flour-strength measures. Heritage varieties had lower W values, which changes the expectations for processing and may favour adapted artisan methods rather than standard industrial formulations. Mixtures containing Verna showed a potentially useful combination of somewhat stronger dough and a more balanced P/L ratio.
The nutritional patterns were more nuanced. Some heritage varieties had higher concentrations of selected minerals and measured secondary metabolites, but these responses depended strongly on environment. Results from one site or season should consequently not be generalised without additional trials.
This agronomic study measured grain composition and laboratory antioxidant activity. These results do not by themselves establish health outcomes, dietary superiority or suitability for people with wheat-related medical conditions.
Conclusion
Environment exerted a stronger influence than genotype on many measured traits in this experiment. Among the heritage wheats, Verna and Gentil rosso showed notable functional or rheological characteristics, and some of those tendencies extended to mixtures containing them.
The most useful breeding direction is not a simple choice between heritage and modern material. Instead, future work can examine how acceptable dough performance, protein and gluten characteristics might be balanced with useful mineral and secondary-metabolite profiles. Multi-site and multi-season testing remains essential.
Selected references
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