Interactions between polyols and wheat biopolymers in a bread model system fortified with inulin: A Fourier transform infrared study

摘要

One of the ways to improve food safety and reduce community health risks is fortification of these products with inulin. Inulin, in spite of the effects and nutritional benefits, will also have undesirable effects on the quality and shelf life of bread. In this study, the interactions between polyols as improvers (i.e. glycerol, sorbitol and propylene glycol) and major biopolymers of wheat flour (i.e. starch and gluten) were examined in model systems fortified with Serish inulin by Fourier transform infrared (FTIR) spectroscopy. The changes in starch structure were estimated focusing on the ratios of the heights of the bands at 1047 and 1022 cm⁻¹ which expresses the quantity of ordered starch to amorphous starch. At first and 5th days of storage, this ratio of control sample was higher than polyol treated samples. It was proved from Gaussian–Lorenzian curve fitting that the relative contribution of characteristic peaks of β-turns and intramolecular β-sheets was consecutively increased when polyol proportion of models increased. Whereas, content of intermolecular β-sheets and α-helix was slightly decreased with increasing of polyols in the models. Briefly, polyols especially 5% propylene glycol, could be used to reduce the undesirable effects of inulin on the quality parameters of dough and bread.