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The dextrinization of potato starch was performed using a sophisticated single-mode microwave reactor with temperature and pressure control using 10 cycles of heating with stirring between cycles. Microwave power from 150 to 250 W, a cycle time from 15 to 25 s, and two types of vessels with different internal diameters (12 and 24 mm) and therefore different thicknesses of the heated starch layer were used in order to estimate the impact of vessel size used for microwave dextrinization. The characteristics of resistant dextrins (RD) including solubility in water, total dietary fiber (TDF) content, color parameters, the share of various glycosidic bonds, and pasting and rheological properties were carried out. The applied conditions allowed us to obtain RDs with water solubility up to 74% at 20 °C, as well as TDF content up to 47%, with a predominance of low-molecular-weight soluble fiber fraction, with increased content of non-starch glycosidic bonds, negligible viscosity, and a slightly beige color. The geometry of the reaction vessel influenced the properties of dextrins obtained under the same heating power, time, and repetition amounts. Among the conditions used, the most favorable conditions were heating 10 times for 20 s at 200 W in a 10 mL vessel and the least favorable were 15 s cycles. [ABSTRACT FROM AUTHOR]

Currently, dietary fibre intake is low, which is one of the reasons for the global obesity epidemic and other metabolic disorders. Dietary fibre has many documented health-promoting properties, such as a prebiotic effect, inducing feelings of satiety and reducing postprandial glucose. Therefore, there is an increasing interest in the search for new products rich in dietary fibre. One of the sources of dietary fibre may be resistant dextrins obtained as a result of dextrinization of starch. In this study, soluble dextrin fibre (SDexF) was prepared by heating potato starch in the presence of hydrochloric and citric acids on a semi-industrial scale in the prototype dextriniser. The aim of the study was the optimisation of the preparation of SDexF on a semi-industrial scale and the physicochemical characterisation of the obtained product. Also, the molecular structure of the prepared product was analysed by using SEM and FTIR. The semi-industrial production of SDexF was successfully implemented, achieving approximately 100 times higher product quantities in one process cycle. SDexF was characterised by over 30% total dietary fibre (TDF) content, almost 100% water solubility, low viscosity and no retrogradation tendency. The physicochemical and functional properties of the obtained product indicate the possibility of implementing SDexF to enrich food products. [ABSTRACT FROM AUTHOR]

The study focused on the influence of starch modified by octenyl succinic anhydride (OSA) on the rheological and thermal properties of gluten-free dough containing corn and potato starch with the addition of pectin and guar gum as structure-forming substances. The starch blend used in the original dough recipe was partially (5% to 15%) replaced with OSA starch. The rheological properties of dough samples were determined, and the properties of the resulting bread were analyzed. It was found that the dough samples behaved as weak gels, and the values of storage and loss moduli (G′ and G″, respectively) significantly depended on angular frequency. Various shares of OSA starch in recipes modified dough in different ways, causing changes in its rheological characteristics. The introduction of OSA starch preparations resulted in changes in the bread volume and physical characteristics of the crumb. All the applied preparations caused an increase in bread porosity and the number of pores larger than 5 mm, and there was a parallel decrease in pore density. The presence of OSA starch preparations modified bread texture depending on the amount and type of the applied preparation. The introduction of OSA starches in gluten-free bread formulation caused a significant drop in the enthalpy of retrograded amylopectin decomposition, indicating a beneficial influence of such type of additive on staling retardation in gluten-free bread. [ABSTRACT FROM AUTHOR]