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This study was to investigate the protective effect of magnetic field (MF) on frozen dough processing quality. The texture, microstructure, rheological and physicochemical properties of wheat dough treated by freezing-thawing cycles under different magnetic flux densities (0, 2, 4, 6, 8, and 10 mT) were analyzed. Compared with conventional frozen dough, MF-treated frozen dough had lower hardness and higher elasticity. Scanning electron microscope exhibited that MF treatment minimized the freezing-induced damages on morphology of starch and gluten, which was consistent with the decreased tan δ in rheological analysis. Application of MF facilitated high relative crystallinity and gelatinization enthalpy in starch granules while the depolymerization of gluten macropolymer was inhibited as manifest with more ordered secondary structure and decreased free sulfhydryl groups. The integrated structure in MF-treated frozen dough resulted in lower free water content as shown by low field nuclear magnetic resonance. The results provided valuable knowledge for the MF-assisted freezing technology and made it possible to improve the freezing-induced deteriorations on wheat-based food. • Wheat dough was frozen/thawed with different magnetic field(MF) intensities. • Freezing-induced damages on starch granule and gluten were repaired by MF. • MF resulted in high starch crystallinity and lower gluten depolymerization. • MF caused a softer hardness and higher elasticity compared with frozen dough. [ABSTRACT FROM AUTHOR]

Abstract The aim of this study was to compare effects of linear dextrans (backbones of α-(1 → 6) linkages) varying with weight-average molecular weights (Mw: T10, T70, T250, T750, T2000) on the quality of wheat breads. The firmness of fresh bread crumb was decreased with increasing dextran Mw and the highest Mw dextran (T2000) lowered the staling rate of stored breads. Dough rheology clarified that only the specific dextran (T70) apparently changed dough viscoelastic, strengthening the viscous behavior. Significant decreases in breakdown and setback viscosity of starch slurry were observed by addition of dextrans, especially dextran T2000. Analyses in the long-term retrogradation of starch and starch-gluten systems indicated that the promising antistaling influence of dextran T2000 was caused by either inhibitions of amylopectin retrogradation or beneficial variations induced by gluten. Positive effects of starch-gluten and dextran-gluten associations on amylopectin retrogradation were revealed. These results suggested that the highest Mw dextran (T2000) possessed the potential for increasing consumer acceptance of bread products. Highlights • Dextran T2000 decreased the formation of amylose crystallites. • Dextran T2000 inhibited amylopectin recrystallization. • Retardation of dextrans on the long-term retrogradation of amylopectin was highlighted by gluten. • Starch-gluten and dextran-gluten associations played a powerful role in amylopectin reordering. [ABSTRACT FROM AUTHOR]

In this study, emulsifiers (sugar ester and sodium stearoyl lactylate), hydrocolloids (guar gum and carboxy methyl cellulose), oxidizers (ascorbic acid and azobisformamide), and enzymes (xylanase and α-amylase) were added into refrigerated dough and revealed their totally different characteristics over 5 days of refrigeration. The optimal refrigerated dough formulation appeared to be the one containing 1% sugar ester, 1% sodium stearoyl lactylate (SSL), 10 mg/kg xylanse and 0.04% ascorbic acid. This optimal formulation predicted a continuous and stable gluten matrix. The secondary structure of refrigerated dough containing optimal formulation remained unchanged while a decrease of 7.00% in α-helix content was observed in control refrigerated dough. It might be ascribed to the enhanced physical intra/intermolecular associations (cross-links or entanglements) of the polymeric chains. These results suggested that the combination of certain additives have a synergistic effect on maintaining the structural characteristics of refrigerated dough. [ABSTRACT FROM AUTHOR]

Flavourzyme is a commercial peptidase, mainly with exopeptidase activity. In this study, effects of Flavourzyme addition (0–0.16 g/100 g) on properties of wheat dough and bread were systematically studied. Bread with a low concentration (0.01–0.08 g/100 g) of Flavourzyme addition had a large specific volume and soft texture with a uniform cell structure. The optimal Flavourzyme content was 0.04 g/100 g and the specific volume increased from 3.9 mL/g to 4.4 mL/g, the hardness decreased from 21.7 N to 13.3 N. The gas production capacity of yeast increased with low concentrations of Flavourzyme addition, promoting dough expansion. Flavourzyme had a clear hydrolysis effect on wheat gluten in dough and caused the depolymerization and unfolding of gluten structure, thus decreasing the strength and viscoelasticity of dough. Confocal laser scanning microscopy and scanning electron microscopy results further revealed that a low concentration of Flavourzyme had a slight effect on gluten. However, the gluten structure became discontinuous and open, which made the dough easily collapsed during fermentation, resulting in poor bread quality with high Flavourzyme content. The positive effects of appropriate amount of Flavourzyme addition on dough and bread properties indicated the potential of Flavourzyme as a bread improver by substituting chemical additives. • Moderate amount of Flavourzyme addition improved the quality of bread significantly. • The optimal addition of Flavourzyme is 0.04 g/100 g (based on wheat flour). • Dough expansion was enhanced with moderate Flavourzyme addition. • Moderate Flavourzyme addition did not cause obvious damage to gluten network. [ABSTRACT FROM AUTHOR]

The magnetic field is an emerging physical method used for food preservation, characterized by its high penetrability in food materials. The effect of a static magnetic field (MF, 2 mT) on frozen dough upon freeze-thaw treatments (3, 7, and 10 cycles) was investigated, with conventional freeze-thaw (CF) treatments being used as control. Results showed that the magnetic field ensured the baked bread made from dough a 17.59% larger specific volume and a 30.87% smaller crumb hardness. It accelerated the time for the dough to pass through the maximum ice crystal formation zone by 7 min and reduced the ice melting enthalpy from 63.55 J/g to 56.67 J/g after 10 freeze-thaw cycles. Nuclear magnetic resonance analysis suggested that the conversion of bound water to immobilized water and free water was inhibited. The yeast viability and activity were also better maintained, precisely as the observed increase of 18.18% and 42.23% in its survival and gassing power. After 10 freeze-thaw cycles, the free disulfide (SH) content was determined to be 1.642 μmol/g for CF doughs and 1.624 μmol/g for MF ones, respectively. A reduction of 24.26% in glutenin macropolymer depolymerization was achieved, indicated a more stable gluten structure under the magnetic field. [Display omitted] • Magnetic field improved the quality of frozen dough bread. • Lower depolymerization degree was detected in gluten using magnetic field. • Yeast survival and gassing power were better preserved under magnetic field. • Magnetic field inhibited water migrations and status change. [ABSTRACT FROM AUTHOR]

The effect of superheated steam treatment on the physicochemical properties of wheat flour and quality characteristics of cake were investigated. Superheated steam treatment significantly increased the swelling power, viscosities and gelatinization temperature, but reduced the gelatinization enthalpy (p < 0.05), compared with native wheat flour. However, the dough made from the treated flour was harder to form. Moreover, superheated steam treatment significantly increased the value of falling number. Cake quality was affected by the changes in the physicochemical properties of wheat flour. Results showed that superheated steam treatment significantly decreased the hardness of cake from 1465 g (native flour) to 377 g (150 °C, 1 min), and increased the specific volume of cake from 3.12 mL/g (native flour) to 3.9 mL/g (150 °C, 1 min). The present study suggests that superheated steam treatment has great potential as a flour modification technology for cake quality improvement. • Physicochemical properties of wheat flour treated with superheated steam were studied. • Superheated steam treatment weakened the gluten strength of dough. • Superheated steam treatment promoted the functional properties of wheat flour. • Wheat flour superheated steam treatment could improve cake quality characteristics. [ABSTRACT FROM AUTHOR]