The study explored punicalagin (PGN) as a wheat flour enhancer. The impact of PGN on the physicochemical and structural properties of wheat flour have been investigated. It turned out that PGN increased the formation time, stability, tensile resistance, extension, and viscoelasticity of the dough at the concentrations of 0.13 and 0.26 mg/g. Scan electron microscope images of the cross section of the dough displayed a more compact and ordered network structure with the addition of 0.13 and 0.26 mg/g PGN. Fourier transform infrared spectroscopy spectra indicated an increase of α-helix and β-sheet content. However, nonlinear enhancing effects of PGN on the stretching properties, rheology, and structural properties of the dough were observed at concentrations of 0.39 and 0.52 mg/g. Correspondingly, cleavages were observed on the cross section of the dough and the content of β-sheet showed a trend of reduction in the dough with addition of PGN at high concentrations. Taken together, these results indicated the potential usage of PGN as a wheat flour enhancer of natural origin at the concentration below 0.39 mg/g in the flour.Keywords:punicalagin;wheat flour;dough rheology;gluten protein network
This study investigated the effect of camellia oil gel on rheology, water distribution and microstructure of flour dough for crispy biscuits. Camellia oil gels, numbered 6#, 8#, and 10#, were formed by mixed plant-based wax and camellia oil (6 g/100 g, 8 g/100 g, 10 g/100 g). The results indicated that with the increase of mixed plant-based wax, the fat distribution in the dough changed from an unevenly dispersed droplet to a uniformly distributed film, and the gluten network structure changed from dense to sparse (P < 0.05). The adsorbed bound water coalesced in the multimolecular water layer of oil gel dough was reduced, but the free water was significantly higher than that of the lard added dough. The gluten matrix surface of the dough was partially exposed, the continuity between gluten protein and starch granules was broken, the gluten network structure was weakened, and the protein secondary structure composition and relative content were better than other oil samples (P < 0.05). As a result, 10# gel could be considered to replace or partially replace lard in baked goods to reduce the intake of saturated fatty acids , providing some theoretical support for the development of new plastic fats.
Summary The effects of reduced glutathione (GSH) on dough rheology, water state and distribution, gluten conformation, and protein molecular weight distribution were investigated. Addition of GSH (0.02−0.04%) resulted in a more viscous and less elastic dough with decreased G ′ and increased tanδ values, which suggested decreased cross-links in gluten network and a weakened dough structure. The molecular weight of proteins was reduced by the GSH-induced cleavage of intermolecular disulphide bonds. Fourier transform infrared spectroscopy showed a high fraction of β-sheet formation at the expense of α-helix and β-turns, indicating a destabilised secondary structure and protein depolymerisation. GSH increased water release from the gluten network in dough resulting in an increase in freezable water content and caused water redistributed from bound water to weakly bound water. This study provided insights into correlation between wheat dough rheological properties and gluten structure influenced by GSH.
Incorporation of A. auricula into wheat flour dough could improve their nutritional properties, but utilization of A. auricula is limited as it causes a weakened dough and deterioration in the quality of product. In this study, A. auricula was treated using high temperature high pressure processing combined with acidic solution treatment, and the effect of A. auricula before and after the treatment on the rheological and structural properties of dough was investigated. Results showed that the high temperature high pressure-acidic solution treated A. auricula (HTHPA) did not block the formation of intrachain disulfide bonds in glutenins. On the contrary, it led to a higher aggregation extent of glutenin macropolymer by contributing to the crosslinking of proteins via noncovalent interactions. Rheological tests showed that the doughs with 2–8% HTHPA exhibited higher elastic and viscous moduli and shear-thinning behavior compared to the doughs with 2–8% untreated A. auricula (UA). This will contribute to the volumetric expansion of dough during proofing. Temperature sweep test revealed that addition of 2–8% HTHPA could reinforce the intermolecular interactions in the dough structure. This study will provide a new method to design and produce A. auricula -enriched staple foods with desirable rheological and structural properties.