C. Lamacchia

Application of capillary electrophoresis to determine the technological properties of wheat flours by a glutenin index.

Capillary electrophoresis was used to characterize glutenin proteins from ancient varieties of Southern Italy common wheat and to determine the technological properties of wheat flours based on a glutenin index. Three zones were identified in the electropherograms, indicated as A, B, and C according to electroelution order. The three zones corresponded to the low molecular weight glutenin subunits and to the y- and x-type high molecular weight subunits, respectively. The ratio B/C was correlated to the alveographic parameter P/L. These results indicated that flours resulting in a B/C ratio lower than 2 produced elastic doughs whereas flours resulting in a B/C ratio higher than 2 produced doughs more resistant to extension. This study showed that capillary electrophoresis is useful for determining the types and quantities of gluten proteins in the evaluation of wheat-flour technological properties of a limited number of noncommercial varieties as evidenced by the x-type content which seems to strongly influence the flour technological parameters.

Polymeric protein formation during pasta-making with barley and semolina mixtures, and prediction of its effect on cooking behaviour and acceptability

Spaghetti were produced in a pilot plant from semolina and semolina blended with increasing amounts of barley flour. According to size exclusion high-performance liquid chromatography (SE-HPLC), barley proteins interact with semolina proteins during pasta making, forming polymers of high molecular weight. Of these, the unextractable polymeric proteins (UPP) were at significantly higher concentrations than in spaghetti made from semolina. The decrease of both S-S bonds and -SH free groups in barley semolina spaghetti, with respect to that made of semolina, suggested that polymerisation among the different classes of proteins involves a new bonding arrangement. Due to β-glucan hydrophilicity and competition with starch for water, the replacement of increasing amounts of semolina with barley flour was able to increase the optimal cooking time. The sensory properties of composite spaghetti were judged as better than the control because of the higher firmness and the lower bulkiness and stickiness of the former.

Impact of gluten-friendly™ technology on wheat kernel endosperm and gluten protein structure in seeds by light and electron microscopy

The main aim of this paper was to assess the impact of Gluten-Friendly™ (GF) technology (Italian priority patent n° 102015000084813 filed on 17th December 2015) on wheat kernel endosperm morphology and gluten protein structure, using SEM, light and immunofluorescent microscopy. Microscopy was combined with immunodetection with specific antibodies for gliadins, γ-gliadins, LMW subunits and antigenic epitopes to gain a better understanding of the technology at a molecular level. The results showed significant changes to gluten proteins after GF treatment; cross-reactivity towards the antibodies recognizing almost the entire range of gluten proteins as well as the antigenic epitopes through the sequences QQSF, QQSY, PEQPFPQGC and QQPFP was significantly reduced. The present study confirms the results from our previous work and shows, for the first time, the mechanism by which a chemical-physical treatment abolishes the antigenic capacity of gluten.

Electronic nose and GC-MS to investigate the volatile component of an italian traditional pasta

The present work investigated the possibility of combining headspace sampling–solid-phase microextraction with gas chromatography–mass spectroscopy (GC-MS) analysis and an array of semiconductor gas sensors to study the volatile fraction of traditional Italian cereal foods. In particular, it studied a pasta recognized as typical by the Italian laws and made with a semolina obtained from a toasted durum wheat. The GC-MS analysis allowed the identification of several volatile compounds, almost always in small concentrations, in raw materials and in fresh and dried pasta. The data deriving from the application of the GC-MS and electronic nose analyses were submitted to principal component analysis to evaluate the suitability of these techniques for emphasizing differences due to composition and/or processing. These preliminary results showed that both the analytical techniques allowed good discrimination among the meals but not among the pasta samples. RESEARCH