Small deformation rheological behaviour of wheat gluten - octenyl succinyl modified corn starches mixtures

Nanoencapsulation of limonene in octenyl succinic anhydride-modified starch (OSA-ST) and maltodextrin: Investigation and comparison of physicochemical properties, efficiency and morphology of nanoparticles

In recent years, the application of nanoencapsulation has attracted enormous attention for various food and pharmaceutical purposes. In this study, a functional powder containing limonene (the nutraceutical at concentration of 5 and 10 %) was prepared using octenyl succinic anhydride-modified starch (OSA-ST) and maltodextrin as carriers at 15 and 30 %. The emulsions were sonicated at a frequency of 30 kHz and a power of 100 W for 9 and 18 min, and the final nanoparticles were prepared through freeze-drying. The particle sizes were in the ranges of 62-248 and 10-24 nm in the suspensions of OSA and maltodextrin, respectively. The smaller particles of the maltodextrin-prepared sample resulted in more transparency. The zeta potential and consequently the stability of the maltodextrin-prepared emulsions were higher than those of the OSA-ST-prepared ones. As the maltodextrin concentration increased, this parameter was elevated from -42 to -36 as a result of the coverage of the surface-active lipids. The results of solubility correlated with those of the zeta potential (89.21 % for maltodextrin-prepared and 82.51 % for OSA-ST-prepared samples). The highest encapsulation efficiency (EE = 0.9) belonged to the samples prepared with OSA-ST. Comparison of the scanning electron microscopy (SEM) images revealed that the type of the wall material influenced the physical structure of the nanoparticles which were mostly porous and flake-like. Considering its encapsulating-emulsifying properties, OSA-ST can be suggested as a carrier for limonene with the need for emulsifiers.

Heat-moisture treatment can modulate all-purpose wheat flour for short dough biscuit making: Evidences and mechanism

In view of the merits of all-purpose wheat flour (APWF) to soft wheat flour (SWF) in cost and protein supply, the feasibility of heat-moisture treatment (HMT, 19% moisture for 1 h at 60, 80 and 100 °C, respectively) to modify APWF as a substitute SWF in making short dough biscuits was explored. For underlying mechanisms, on the one hand, HMT reduced the hydration capacity of damaged starch particles by coating them with denatured proteins. On the other hand, HMT at 80 °C and 100 °C significantly denatured gluten proteins to form protein aggregates, highly weakening the gluten network in dough. These two aspects jointly conferred APWF dough with higher deformability and therefore significantly improved the qualities of biscuits. Moreover, the qualities of biscuits from APWF upon HMT-100 °C were largely comparable to that from SWF, even higher values were concluded in spread ratio, volume, specific volume and consumer acceptance.

Ionic liquid-mediated regeneration of cellulose dramatically improves decrystallization, TEMPO-mediated oxidation and alkyl/alkenyl succinylation

This work demonstrated a successful strategy that simple ionic liquids (ILs) mediated pretreatment could effectively reduce crystallinity of cellulose from 71 % to 46 % (by C₂MIM.Cl) and 53 % (by C₄MIM.Cl). The IL-mediated regeneration of cellulose greatly promoted its reactivity for TEMPO-catalyzed oxidation, which the resulting COO^- density (mmol/g) increased from 2.00 for non-IL-treated cellulose to 3.23 (by C₂MIM.Cl) and 3.42 (C₄MIM.Cl); and degree of oxidation enhanced from 35 % to 59 % and 62 %, respectively. More significantly, the yield of oxidized cellulose increased from 4 % to 45-46 %, by 11-fold. IL-regenerated cellulose can also be directly subjected to alkyl/alkenyl succinylation without TEMPO-mediated oxidation, producing nanoparticles with properties similar to oxidized celluloses (55-74 nm in size, -70-79 mV zeta-potential and 0.23-0.26 PDI); but in a much higher overall yield (87-95 %) than IL-regeneration-coupling-TEMPO-oxidation (34-45 %). Alkyl/alkenyl succinylated TEMPO-oxidized cellulose showed 2-2.5 times higher ABTS* scavenging ability than non-oxidized cellulose; however, alkyl/alkenyl succinylation also resulted in a significant decline in Fe²⁺ chelating property.