Sicilian Rivet Wheat Landraces: Grain Characteristics and Technological Quality of Flour and Bread

In recent years, the growth of tetraploid Sicilian wheat landraces has been arousing increasing interest. In this study, eighteen local genotypes of Triticum turgidum subsp. turgidum, belonging to the groups 'Bufala', 'Ciciredda', 'Bivona' and 'Paola', and two cultivars of Triticum turgidum subsp. durum (the old variety 'Bidì', and a more recent variety 'Simeto') were assessed for the characteristics of the grain and bread-making performance of their flours and doughs, as well as the quality of the loaves. The grain of the twenty genotypes came from a field trial conducted during 2018-2019 in south-eastern Sicily. The main commercial features of the grain (thousand kernel weight and hectolitre weight), including the defects (starchy, black pointed and shrunken kernels), were determined. The wholemeal flours and doughs obtained from the grain of each genotype were evaluated for the main technological quality (physico-chemical and rheological characteristics), and processed into loaves, whose main quality indices (volume, height, weight, moisture and porosity) were assessed. The results from such analyses allowed the authors to evaluate the genotypes' bread-making suitability. In particular, for the grain characteristics, hectolitre weight varied from 68.23 ('Bufala Rossa Lunga 01') to 77.43 ('Bidì 03') kg/hL, passing through the typical values for common and durum wheat. Among the grain defects, the black point defect was absent in all the grain samples, except for that of 'Bufala Nera Corta 01' (2%). Dry gluten content varied from 6.22 to 10.23 g/100 g, and sedimentation test values were low or medium-low, with values ranging from 22 to 35 mL. Amylase activity was low and highly variable among the genotypes, with the maximum value observed for 'Bufala Rossa Corta b01' (509 s). The doughs evidenced a poor quality for bread making with alveograph values of W ranging from 12 to 145 (10^-4 × Joule) and thus the volume of the loaves varied from 346.25 cm³ of 'Bivona' and 'Ciciredda' to 415.00 cm³ of 'Bufala Rossa Lunga'. A Tandem Cluster Analysis was conducted on a set of all the response variables. The Hierarchical Cluster Analysis was initially run. A five-cluster solution identified three clusters further segmented and two single branches. Overall, the study highlighted the possibility of using some of these landraces alone for the production of traditional breads locally appreciated or together with other ingredients for the production of crumbly baked goods such as substitutes for bread and biscuits.