Effect of fat and sugar reduction on cookies on the mobility of its components studied by NMR

R.H. ACOSTA; S. BLANCO CANALIS; P. D. RIBOTTA; M.C. VALENTINUZZI; A. E. LEÓN

Congreso; CICyTAC; 2016

Sweet cookies are characterized by high fat and high sugar content and their quality decreases with the reduction of these components (smaller diameter pieces, smaller height and surface homogeneity). These changes are related to a decrease in lubricating capacity. Nuclear Magnetic Resonance (NMR) determines the decay of signals coming from the protons of the components of a system; longitudinal (T1) and transverse (T2) relaxation are studied, obtaining information on the mobility of atoms in the system. The objective of this work was to identify by NMR the proton populations of cookie dough and baked products (cokkies) and their interactions by analyzing the effects of fat and sugar reduction independently. We worked with three types of formulations: C (control), 50F (reduction of 50% fat) and 50S (reduction of 50% sugar). The populations associated to the solid phase (A) and mobile phase (B) were distinguished. No appreciable changes were found related to the intensities of these populations in the doughs. However, an increase of the solid components by a factor of 5 was observed for the 50F cookie and by a factor of 2 for the 50S cookie compared to the control sample, associated with a decrease in the mobile components. The distribution of the T2 relaxation time of the B (mobile) population shows three peaks related to the following populations: water protons and starch oxidils (population C), water in interaction with starch and sugar (population D) and protons of water interacting with fat (population E). In the case of doughs, the main change observed is that population D of formulation 50S was lower than the other two formulations, indicating that the amount of water in the interaction with sugar is reduced. With respect to the cookie samples, population C was higher in the 50F and 50S formulations, indicating a strong reduction in the number of mobile protons. In addition, bi-dimensional maps T2-T1 were evaluated. The most notable feature in the doughs was that in the 50S formulation each population exhibits a greater mobility, which is denoted by an increase in T1. With respect to cookies, the population C related to water in contact with the starch molecules showed less mobility and an increase in the amount of protons in the 50F and 50S formulations with respect to the control sample.