Effects of repeated sheeting on rheology and glutenin properties of noodle dough

Explaining the improving effect of dough crumb-sheet composite rolling on fresh noodle quality: From microstructure and moisture distribution perspective

A new technique known as dough crumb-sheet composite rolling (DC-SCR) was used to improve the quality of fresh noodles. However, there is a dearth of theoretical investigations into the optimal selection of specific parameters for this technology, and the underlying mechanisms are not fully understood. Therefore, the effects of dough crumb addition times in DC-SCR on the texture, cooking, and eating quality of fresh noodles were first studied. Then, the underlying regulation mechanism of DC-SCR technology on fresh noodles was analyzed in terms of moisture distribution and microstructure. The study demonstrated that the most significant enhancement in the quality of fresh noodles was achieved by adding dough crumbs six times. Compared with fresh noodles made without the addition of dough crumbs, the initial hardness and chewiness of fresh noodles made by adding six times of dough crumbs increased by 25.32% and 46.82%, respectively. In contrast, the cooking time and cooking loss were reduced by 28.45% and 29.69%, respectively. This quality improvement in fresh noodles made by DC-SCR came from the microstructural differences of the gluten network between the inner and outer layers of the dough sheet. A dense structure on the outside and a loose structure on the inside could endow the fresh noodles made by DC-SCR with higher hardness, a shortened cooking time, and less cooking loss. This study would provide a theoretical and experimental basis for creating high-quality fresh noodles.

Insights into the mechanisms underlying ethanol-induced changes in the dough mechanical properties and quality characteristics of fresh noodles

This study investigated the effects of ethanol (0 %∼6%) on the dough mechanical properties and quality characteristics of fresh noodles and elucidated the relationship between the above changes and physicochemical, structural, and molecular properties of gluten. Ethanol reduced the water absorption (from 59.00 % to 52.33 %), stability time (from 8.17 min to 3.33 min) and viscoelasticity of dough, and increased the development time, weakening degree and compliance. Ethanol also decreased the fracture stress of dough sheet, and increased fracture elongation and adhesiveness (from 46.15 g·s to 75.88 g·s). Ethanol decreased the noodles' hardness (from 5347.41 g to 4442.34 g), break force, tensile distance, and water absorption, while cooking loss was increased. SEM and CLSM showed that ethanol destroyed the compactness of internal structure and inhibited the formation of gluten network in noodles. According to the results of SE-HPLC and RP-HPLC, ethanol dissolved part of the gliadin and inhibited the polymerization of protein.

Folding during sheeting improved qualities of dried noodles through gluten network proteins

The texture properties after cooking for 12 min were selected to optimize the sheeting parameters, and the results were verified using the comprehensive quality of dried noodles. The distribution of water, characteristics of gluten protein, and interaction between gluten network and starch were analyzed to clarify the mechanism of the quality of dried noodles. Results showed that the optimal folding angle was 45°, under this condition, the largest anti-extension displacement perpendicular to the rolling direction and the smallest cooking loss were obtained. The hardness and smoothness of cooked noodles increased by about 14% to 17%. Further, the transverse relaxation time of strongly bound water significantly decreased, while the relative content and binding strength increased. The hydrogen bonds and α-helix contents increased by about 68.8% and 53.1%, respectively. Folding and sheeting enhanced the combination of starch granules and gluten network causing, decreased in the average length and porosity of the gluten network. It is depicted from the results that the method of optimizing the sheeting process based on the texture of dried noodles cooked for 12 min was feasible. And the 45° folding and sheeting could help to improve the quality of dried noodles.

Precooking treatments affect the sensory and tensile properties of autoclaved recooked noodles via moisture distribution and protein structure

To improve the quality of autoclaved recooked noodles (ARNs), this study explored the effects of precooking on the sensory and tensile properties of ARNs from the perspectives of changes in protein structure and water distribution. The results showed that the ARNs of two kinds of pretreatments (Boiling 2 min, Boiling 1 min + Steaming 2 min) presented the best sensory quality (average score ≥ 7.50) and high tensile properties (tensile distance ≥ 45.24 mm). After autoclaving and recooking, the proportion of tightly bound water increased by 11.30%-12.52%, resulting in stronger water-solid interaction. The results of laser confocal microscopy (CLSM) proved that a strengthened gluten network (protein percentage area ≥ 40.28%; junction density ≥ 10.96 × 10^-4) appeared. Therefore, appropriate precooking treatment could effectively improve the sensory quality and tensile properties of ARNs by enhancing the tightly bound water ratio and strengthening the gluten network.

Effects of salt and kansui on rheological, chemical and structural properties of noodle dough during repeated sheeting process

Effects of different levels of salt (1-2%, fwb) and kansui (0.5-1%) on the rheological, chemical and structural characteristics of noodle dough developed by repeated sheeting were studied. The rupture stress was increased by salt and kansui. The rupture elongation was increased by salt while reduced by kansui. The rupture stress and elongation increased to a maximum at 3 or 4 sheeting passes then decreased. The larger polymeric glutenin (LPP) increased while glutenin macropolymer (GMP) and free SH contents declined with the increased sheeting passes except for the dough contained 1% kansui at which these indicators remained constant. The β-sheet was increased while the β-turn was decreased by salt and kansui. The results showed the LPP disaggregated from GMP through physical disentanglement and experienced a reaggregation process with the SS bonds participate in, but the addition of kansui especially at 1% concentration could inhibit the disaggregation of GMP through protein cross-linking.