CONICET | Buscador de Institutos y Recursos Humanos

Several epidemiological and experimental studies show that consumption of determined food products can act either as protective or as risk factors on non-transmissible diseases. Recommendations have emerged that aim to reducing the consumption of sugars and fats, or to increase the fiber content (particularly soluble) in the diet. Biscuit dough is a complex system containing abundant components in different states, such as starch, gluten, lipids (flour constituents), sugars, fats and water. In biscuits, both, the incorporation of fibers or reduction of sugar and fat, create number of technological problems in processing and, in some cases, a loss of acceptability [1]. For this reason, it is of great interest to study the effects on the physico-chemical and structural characteristics of biscuit dough upon the incorporation or reduction of these ingredients, as well as their partial replacement with fiber [2]. The study of a multicomponent system is a complex subjet, scarce research can be found on this topic and just a few focuses on the microscopic properties related with the interactions between principal ingredients (flour, water, type of fat and sucrose). Low resolution NMR is an important tool as it allows the study of water mobility by means of relaxation time measurements (T2) in the sample, in a non-invasively, fast and accessible way. Bread dough has been analyzed in several articles by low field NMR [3,4], however systems containing sugar such as cake and biscuits, are less found in literature [5,6]. In such complex systems, many components that reduce the mobility of the water present in the dough coexist, giving rise to a distribution of mobilties. In this way it is possible to identify flour constituents, sugars and fats, by measuring the different proton populations associated with a given relaxation time [6]. In this work we study the proton water mobility in standard biscuit dough through relaxation profiles obtained from CPMG sequence at 0.5 Tesla using a Bruker minispec mq20 spectrometer. Different populations are assigned: the first two correspond to intra and inter-granular water respectively, and can be attributed to protons in interaction with flour constituents, while the third population is associetted with the fat components of the dough. We also corroborate that the second population is the more sensitive to water content and therefore the most affected in the cooking process [6]. Finally, the dependence of mobility as a function of the dough temperature in a cooking process is correlated with the quality of the final product upon the incorporation of soluble and insoluble fiber (inulin and oat fiber respectively) with flour reduction.