1,721,136 research outputs found
Insights on wheat quality evaluation along the value chain
No full textIn recent years, the needs along the value chain of wheat have changed. For each one of the many wheat uses, specific grain-quality requirements are preferred. The possibility to obtain reliable and quick information about kernels quality from small amount of sample is constantly becoming more important in all the wheat value chain. For instance, people involved in genetic selection need to analyze very large number of new lines in short time. Milling industry requires fast, simple and reliable methods for the control of grain quality during the reception phase. Finally, the bread-making industry is searching for suitable methods able to predict the end-products quality. Although the definition of quality, changes significance depending on the stage of the “value chain” considered, from breeding to processing and final consumption, in general, it can be understood in a similar way throughout the transformation chain. Moreover, the qualitative characteristics of the raw materials are not the only properties to be related to the chemical-physical properties but also, they are related to the properties of the doughs during the kneading phase, the consistency of the finished products and the process efficiency. For this reason, along decades, several approaches have been developed and proposed to assess quality differ along the chain. For instance, some approaches determine dough behavior during mixing or proofing, while other simulate the baking phases measuring the resistance to uniaxial and tridimensional extension. The study of the extensional properties is an important point in the interpretation of flours behavior, because they have a direct effect on the loaf volume and the quality of texture of bread crumb. Among the instruments developed for the evaluation of this properties the Extensograph has been proposed. In this context, the research is focusing not only on the development of quicker methods but also on the possibility of using less sample quantities. Focus will be on an overview of the strength and weakness points of this test and its application along the wheat value chain for predicting the common parameters related to dough rheology and bread loaf volume
Effects of wheat sprouting on starch, gluten, and dough properties
No full textGrain sprouting leads to the development of specific enzymatic pattern (amylases, proteases, cellulases) that may improve both micronutrient bioavailability and sensory characteristics. On the other side, high accumulation in enzymes is usually associated with dough weakening and stickiness.
The aim of this study was to evaluate the effects of wheat sprouting under controlled conditions on the technological performance of both wholegrain and refined flours. The sprouting process was conducted for 2-3 days at 20 °C and 90 % relative humidity, in an industrial plant (Molino Quaglia S.p.A., Vighizzolo d’Este, Padova, Italy).
The effects of sprouting were assessed on gluten (i.e. visco-elasticity by the Glutograph®), aggregation kinetics by the Glutopeak®), starch (i.e. pasting properties by the MicroViscoAmylograph®) and dough (i.e. water absorption, dough development time and stability by the Farinograph®). In addition, amylase activity was evaluated by measuring a- and b-amylase content and by using the Falling Number. Whole grain and refined flours from unsprouted wheat were used as references.
Despite the proteolytic activity developed during sprouting, the gluten proteins were still able to aggregate. However, the decrease in maximum torque, peak maximum time and energy required for gluten aggregation suggested gluten weakening. On the other hand, the sprouting process led to an increase in gluten stretching, suggesting an increase in dough extensibility.
As regards starch, sprouting led to drastic decreases in viscosity during both the heating (i.e. peak viscosity and breakdown) and cooling (i.e. final viscosity and setback) phases, due to the increase in amylase activity. Adding silver nitrate – a strong a-amylases inhibitor – peak and final viscosity greatly increased, indicating that the pasting and gelation properties of starch were not significantly affected by sprouting.
Dough made with sprouted wheat showed decreasing water absorption, stability and development time compared to the unsprouted control flours, as a consequence of the protease activity developed during sprouting.
Further works are ongoing to evaluate the effects of using sprouted wheat on bread characteristics
Modeling Junctions of Plates and Beams by Means of Self Adjoint Extensions
No full textOn the basis of an asymptotic analysis of elliptic problems on thin domains and their junc
tions, a model of a mixed boundary value problem for a secondorder scalar differential equation on
the union of 3D thin beams and a plate is constructed. One end of each beam is attached to the plate,
and on the other end, the Dirichlet conditions are imposed; on the remaining part of the joint bound
ary, the Neumann boundary conditions are set. An asymptotic expansion of the solution to such a
problem has certain distinguishing features; namely, the expansion coefficients turn out to be rational
functions of the large parameter |lnh| (where h ∈ (0, 1] is a small geometric parameter), and the solu
tion to the limit problem in the longitudinal section of the plate has logarithmic singularities at the
junction points with the beams. Thus, the classical settings of boundary value problems are inadequate
to describe the asymptotics, and the technique of selfadjoint extensions and function spaces with sep
arated asymptotics must be used
Controlled Sprouting of Durum Wheat: Effects on Starch and Protein Characteristics
No full textGrain sprouting leads to the development of specific enzymatic pattern that may improve both micronutrient bioavailability and sensory characteristics. On the other side, high accumulation in enzymes is usually associated with dough weakening and stickiness. Thus, a controlled wheat sprouting process could be useful to assess the perfect balance between nutritional advantages and technological performance.
The aim of this study was to evaluate the effects of durum wheat sprouting under controlled conditions on both starch and protein characteristics.
Durum wheat kernels were sprouted at 20 °C and 90 % relative humidity, and sampled after 24, 36, 48, and 62 hours. After sprouting, samples were dried and milled into semolina flour.
The effects of sprouting time were assessed on gluten aggregation kinetics by the Glutopeak® and starch pasting properties by the Rapid Visco Analyzer®. In addition, amylase activity was evaluated by using the Falling Number.
Despite the proteolytic activity developed during sprouting, the gluten proteins were still able to aggregate. However, the decrease in maximum torque and energy required for gluten aggregation suggested gluten weakening. Moreover, after sprouting proteins required more time for aggregation (i.e. high peak maximum time). No significant differences were detected between 36 and 48 hours, whereas the worst aggregation properties were measured after 62 h of sprouting. As regards starch, sprouting led to drastic decreases in viscosity during both the heating (i.e. peak viscosity and breakdown) and cooling (i.e. final viscosity and setback) phases, due to the increase in amylase activity (i.e. decrease in Falling number). Adding silver nitrate – a strong amylase inhibitor – peak and final viscosity greatly increased, indicating that the pasting and gelation properties of starch were not compromised by sprouting.
Further works are ongoing to evaluate the effects of using sprouted durum wheat on bread characteristics
Sprouting under the spotlight
No full textThis presentation will provide an overview of the most recent insights on sprouting, with a focus on the effects of the process on macromolecule functionality and its relationship with breadmaking performance.
Four case-studies will be presented: besides common wheat (i.e., the ideal and widely used raw material for bread production), sprouting was applied to durum wheat, quinoa and sorghum to enhance their use in bread-making in view of their agronomic and/or nutritional features.
The intensity of sprouting was different among the selected grains: the highest α-amylase activity was shown by durum wheat, instead the highest accumulation of proteases was observed for quinoa and sorghum. Such results suggest the importance of monitoring the sprouting process and the impossibility to transfer the optimal conditions from one grain to another. By controlling the process, it was possible to limit the hydrolysis of the main biopolymers (starch and proteins) so that the functional properties of the related flours (i.e., wholegrain or refined) were improved. Thus, sprouting improved volume and specific volume, and crumb softness of bread, even when wholegrain flours were used, suggesting new potential application of sprouting as a pre-treatment of fiber-enriched flours. Finally, sprouting was successfully in solving the main issues related to the incorporation of quinoa and sorghum in bread-making: bitterness and astringency in quinoa, and low protein digestibility in sorghum.
Overall, sprouted grains can be incorporated in wheat-based formulations as new ingredients thanks to their ability to improve bread volume and crumb softness, as well as nutritional and sensory properties
Il frumento germinato: un nuovo ingrediente per la panificazione
No full textLa germinazione è un complesso fenomeno applicato fin dall’antichità a cereali e legumi al fine di migliorarne le proprietà nutrizionali e sensoriali (Hübner & Arendt, 2013). Nel caso del frumento, tuttavia, la germinazione è sempre stata giudicata un evento negativo, da monitorare con attenzione. Infatti, l’elevato accumulo nella cariosside germinata di enzimi idrolitici - osservabile a seguito di andamenti climatici sfavorevoli durante la maturazione in campo - può compromettere la qualità tecnologica del frumento e la sua trasformabilità in pane.
Sulla base di risultati positivi recentemente ottenuti su alcuni legumi (Marengo et al., 2017), in questo studio sono stati valutati gli effetti associati alla germinazione del frumento condotta in condizioni di temperatura e umidità controllate nelle fasi di soaking e sprouting. La farina ottenuta da frumento germinato in tali condizioni (SWF) - se addizionata all’1.5% a farine di modesta qualità panificatoria - può sostituire i convenzionali “miglioratori” commerciali, garantendo non solo un più elevato sviluppo dell’impasto e del pane ma anche un miglior mantenimento della sofficità della mollica durante la conservazione.
La ricerca è quindi proseguita valutando gli effetti associati all’impiego di elevate percentuali (dal 15 al 100 %) della farina SWF sulle caratteristiche reologiche e tecnologiche delle corrispondenti formulazioni arricchite. Sebbene gli indici farinografici indichino l’indebolimento del reticolo glutinico già a partire dalle più basse percentuali di arricchimento con SWF, le proprietà di aggregazione delle proteine, valutate mediante il GlutoPeak test, non subiscono modificazioni significative nelle formulazioni con percentuali di SWF comprese tra 25 e 75%. Infine, le prove di panificazione indicano come il miglior risultato, in termini di volume specifico del pane e mantenimento della sofficità durante la sua conservazione, sia associato alla formulazione contenente il 50% di SWF.
In conclusione, la germinazione in condizioni controllate appare oggi una via praticabile al fine di ottenere farine con ottime performance in panificazione, garantendo al tempo stesso migliori proprietà nutrizionali del prodotto.
Hübner, F., & Arendt, E. K. (2013). Germination of cereal grains as a way to improve the nutritional value: a review. Critical Reviews in Food Science and Nutrition, 53, 853–61.
Marengo, M., Carpen, A., Bonomi, F., Casiraghi, M.C., Meroni, E., Quaglia, L., Iametti, S., Pagani, M.A. and Marti, A., 2016. Macromolecular and micronutrient profiles of sprouted chickpeas to be used for integrating cereal-based food. Cereal Chemistry, 94, 82-88
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