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Summary: The effects of resting under ultrasonic treatment on the properties of whole wheat dough sheets and noodles were investigated. Compared with the control group, the resting time to reach the maximum breaking force and extensibility of whole wheat dough sheets treated with ultrasound was shortened by 20 min. The proportion of strongly bound water (T21) decreased, while the proportion of weakly bound water (T22) increased during resting, and the ultrasonic treatment could accelerate this moisture redistribution in the dough. The extent of the increase in gluten macropolymer and the decrease in –SH content of ultrasound‐treated wheat dough was higher than that of the control one during the initial 5–15 min resting, which could be related to the improvement of whole wheat dough extensibility. Whole wheat noodles showed a better breaking distance for 10 min of ultrasonic‐assisted resting. Ultrasonic treatment could be used to reduce the resting time of whole wheat dough sheets and improve the texture properties of noodles. [ABSTRACT FROM AUTHOR]

The quality of Chinese traditional hand-stretched dried noodles (CHDNs) and their relationship with major components were investigated by comparison with machine-made dried noodles (MDNs). The results showed that both the processing techniques and formulations could influence the quality of the final noodle products. The CHDNs possessed high cooking and textural qualities. They had lower values of optimal cooking time, cooking loss, and water absorption than MDNs, while the elasticity, firmness, and chewiness values were higher. These phenomena could be explained by the porous structure and continuous gluten network formed during the production of CHDNs. In addition, the starch isolated from CHDNs presented higher values of relative crystallinity, gelatinization enthalpy, and swelling power as well as lower peak viscosity than that from MDNs, which indicated the occurrence of slight hydrolysis during the processing of CHDNs. The differences in the structural and thermal properties of starch could also be responsible for the high quality of CHDNs. In conclusion, the processing technique and formulation of CHDNs enabled the improvement of noodle quality by modifying the physicochemical properties of starch and gluten. The results of this study may also provide some new knowledge and approaches to regulate and achieve high-quality MDN products. [ABSTRACT FROM AUTHOR]

The effect of α‐amylase on the quality attributes of Chinese dried noodles (CDN) was investigated. Adding α‐amylase markedly decreased the cooking time and cooking loss of CDN at the level of 12.5 (mg/100 g flour). The elasticity of CDN was increased significantly (P < 0.05) after adding α‐amylase. The firmness of noodles with 12.5 mg α‐amylase per 100 g flour showed no obvious change compared to the control, whereas it decreased significantly (P < 0.05) when the amount of α‐amylase increased to 25 (mg/100 g flour). In addition, the chewiness of CDN with 12.5 mg α‐amylase per 100 g flour increased, while it showed a significant (P < 0.05) decreasing trend with further increased α‐amylase levels. Starch structural and thermal properties were also changed by α‐amylase, which showed increased relative crystallinity, swelling power, but decreased pasting property. The changed starch property restrained the cross‐linking of gluten. The decrease in optimal cooking time and increase in elasticity of CDN were due to the increased swelling power and decreased peak time of the starch. In addition, the decreased setback of starch and protein cross‐linking degree were responsible for the decreased firmness and chewiness of CDN with α‐amylase ranging from 25 to 50 mg/100 g flour. Overall, α‐amylase could be used as a functional additive to improve the quality of CDN when the amount was at 12.5 mg/100 g flour. [ABSTRACT FROM AUTHOR]

In this study, the changes during storage in the physicochemical, microbiological, and textural properties of semi‐dried noodles prepared with ozonated water were investigated. Results showed that ozonated water could significantly (p <.05) reduce the initial total plate count (TPC) of semi‐dried noodle products. Compared with the control, the initial TPC, bacillus content, and mold and yeast contents of treated noodles were reduced by 1.26 lgCFU/g, 0.34 lgCFU/g, and 0.39 lgCFU/g, respectively. The shelf life of semi‐dried noodles in the presence of ozonated water was prolonged by nearly 24 hr at room temperature. Higher whiteness value could be achieved for semi‐dried noodles and protein polymerization of which was promoted by employing the ozonated water. Ozonated water treatment decreased the cooking loss and improved the texture properties of semi‐dried noodles. Practical applications: Semi‐dried noodles are becoming increasingly popular among people due to the similar taste and flavor to fresh noodles. However, the high final moisture content of semi‐dried noodles, ranging from 20% to 25%, accelerates the growth of microorganisms, which shortens the shelf life of products and hinders the development of noodle industries. Normally, chemical preservatives are used to prevent the survival of microorganisms and minimize the deterioration of products. However, they are inconsistent with the concept of "green" consumerism. Based on the findings of this research, ozonated water could contribute to the shelf life extension and quality improvement of high moisture content noodles product, which is beneficial to consumers as well as food processing industries. [ABSTRACT FROM AUTHOR]

The mechanism by which the heat-moisture induction of a gel-entrapped network affects the texture of Tartary buckwheat noodles was explored by studying starch gelatinisation, starch crystallinity and molecular weight, proton mobility, and microstructure of noodles prepared from extruded starch (ES) and Tartary buckwheat flour during cooking. Noodles with higher ES content showed higher hardness and chewiness during cooking for 4.5 min, whereas the hardness was reduced after optimal cooking.Starch-lipid complexes (SLCs) collapsed and the entrapped networks were disrupted during optimal cooking, while overcooking led to the escape of starch molecules from the noodles and reduced the textural hardness. Proton migration and microstructure evaluations confirmed that water migration was stronger and more cavities appeared in the gel-entrapped network of noodles overcooking. Therefore, the disintegration of SLCs and the appearance of cavities in the gel-entrapped network were closely associated with the deterioration of the texture of noodles. [Display omitted] • Higher levels of extruded starch (HL-ES) retarded starch gelatinisation in noodles. • HL-ES promoted the decrease of noodle hardness after optimal cooking. • HL-ES inhibited the production of new starch-lipid complexes in cooked noodles. • Disruption of starch-lipid complexes (SLCs) promoted more voids in the gel network. • Disruption of SLCs and gel network both promoted deterioration of noodle texture. [ABSTRACT FROM AUTHOR]

In this study, critical temperature, pH value, water content, and water activity inducing the acceleration of fresh noodle deterioration were determined. Total plate count (TPC) and L* value were selected as the visualized parameters to characterize the deterioration of fresh noodles based on our previous study. Results showed that the critical temperature leading to the initial acceleration of fresh noodles was 20°C-25°C, critical water content was between 23% and 24%; the fastest darkening rate was detected at pH 8.0-8.5, while microorganisms kept a high growth rate during the whole range of initial pH 6-10. In addition, shelf-life model was built based on the deteriorating dynamics at room temperature, showing that microbial growth could be well fitted by both Gompertz and Logistic model, with higher fitting precision for Gompertz model and the fitting equation was y = 4.364 exp[−exp (1.032-0.086t)], R2 = .98855; Meanwhile, the darkening of fresh noodles could be fitted by quadratic polynomial model, with the fitting equation y = 76.0629 − 0.0165 x + 5.98587 x2, R2 = .9814. Practical applications This article presents the dynamics during the deterioration of fresh noodles and the critical conditions (moisture content and water activity, pH value, and storage temperature) accelerating the deterioration process. In addition, shelf-life model was built based on the deteriorating dynamics of fresh noodles at room temperature. Based on these results, a shelf-life stable fresh noodle product can be developed by applying different processing techniques and by keeping it in appropriate conditions, which will provide great guiding significance for the production and preservation of these products. [ABSTRACT FROM AUTHOR]

Based on the critical water content (for noodle deterioration) concluded previously, high-temperature–short-time (HTST; 105–135 °C) and medium-temperature–long-time (MTLT; 45–75 °C) dehydrations were introduced in this study to produce semi-dried noodles. The effects of HTST and MTLT on the quality parameters of semi-dried noodles, as well as noodle structure, storage stability, and changes in starch and protein components were thoroughly investigated. Differential scanning calorimeter (DSC) and birefringent analysis presented few starch gelatinization (approximately 30%) in HTST dehydrated noodles. Scanning electron microscopy (SEM) images showed more compact noodle surface, with uniform pores in the cross section, probably due to enhanced protein–starch combination after HTST dehydration. Meanwhile, HTST induced protein polymerizations in semi-dried noodles, mainly by –SH–S–S interchange, and resulted in significantly ( P < 0.05) reduced cooking loss. Furthermore, HTST noodles showed higher microbial and color stability. Shelf-life of dehydrated samples at 120 °C was extended to 5 days from 1 day of the control. [ABSTRACT FROM AUTHOR]

Pasta products and noodles have been staple foods since ancient times in many countries all over the world. These cereal products are still increasingly popular worldwide for their convenience, nutritional properties, special flavor, and taste. Pasta and noodles are essentially the same type of food but differ in their raw materials and shaping process, as well as the people and regions in the world consuming them. Many additives have been developed and are being used today in pasta and noodle products for various purposes. However, due to lack of knowledge about specific uses for some additives, they are sometimes misused by manufacturers. This can lead to opposite technological effects instead and may even cause damage to human health. Due to consumer demands, interest now focuses on natural 'green' food additives with broad-spectrum functions, high effectiveness, and low toxicity. In order to provide detailed references for noodle and pasta production, as well as to provide ideas for developing new types of these products, here we summarize the types of natural additives that are being incorporated in pasta and noodle products, mainly for quality improvement and food preservation. [ABSTRACT FROM AUTHOR]

Highlights: [•] Effect of vacuum mixing on noodle protein changes and gluten formation was evaluated. [•] Remarkable protein aggregates were observed in vacuum mixed noodles. [•] Elasticity, extensibility and structural stability were increased after vacuum mixing. [•] Vacuum mixing induced a more continuous and compact microstructure to noodle sheets. [•] Less deterioration in vacuum mixed noodle structure and water migration was observed. [ABSTRACT FROM AUTHOR]

Superfine green tea powder (SGTP) was premixed with organic acids (ascorbic acid, citric acid) and hydrocolloids (sodium alginate, curdlan), and then mixed with microwave-treated wheat flour to produce green tea fresh noodles (GTFN). Darken-retardant effects of organic acids, hydrocolloids and microwave treatments on GTFN were evaluated, as well as pH, polyphenol oxidase activity, sensory and microstructure characteristics. The results revealed that organic acids exhibited a suppressive effect on discoloration, among which citric acid (CA) displayed more efficient influence with lower pH. After adding hydrocolloids and microwave treatments, retardant effects exhibited more significant (P < 0.05). Specifically, employing citric acid 0.6 g/100 g, sodium alginate 0.2 g/100 g, and 800 W microwave (MW) 50 s would contribute to lower darkening index ΔE * (24 h, 25 °C) at 3.88 ± 0.314, 4.94 ± 0.297, 2.78 ± 0.212, respectively. Furthermore, the combined effect of the above process restrained discoloring rate considerably (ΔE * = 1.92 ± 0.101), also provided pleasant sensory characteristics. The confocal scanning laser microscopy (CSLM) images demonstrated the microstructure of the noodle was strengthened compared with blank GTFN, and sodium alginate could serve as a binding agent to parcel SGTP and starch granules. [ABSTRACT FROM AUTHOR]

ABSTRACT The physicochemical properties of purple sweet potato flour (PSPF)-wheat flour blends and their effects on salted noodle-making quality were investigated. PSPF was substituted at levels of 5, 10, 15, 20, 25 and 30% for wheat flour. Addition of PSPF increased the gelatinization peak temperatures from 66.45 to 67.73C, but decreased paste viscosities at all substitution levels. Texture analysis showed that hardness of flour gels decreased as the amount of PSPF increased, while springiness reached the maximum value with 10% PSPF substitution. Farinographic tests indicated that dough stability decreased from 18.0 to 7.8 min with the increasing levels of PSPF up to 30%. PSPF had a weakening influence on cooking and texture properties of noodles, but could be added to wheat flour under the level of 15% without drastically affecting salted noodle-making quality. PRACTICAL APPLICATIONS Purple sweet potato flour (PSPF) could be served as a substitute for cereal flours, which enhanced products through color and nutrient. Salted noodles made by partially replacing wheat flour with 15% PSPF appeared the attractive color of pink redness and favorable cooking properties, which provided a basis to develop novel colored foods with good antioxidant capacity. [ABSTRACT FROM AUTHOR]

Abstract: In this study, the effects of ozone treatment on the microorganism mortality in wheat flour and shelf-life of fresh noodles were investigated, as well as the physicochemical properties of wheat flour and textural qualities of cooked noodles. Results showed that the total plate count (TPC) can be largely reduced in wheat flour exposed to ozone gas for 30min and 60min. Whiteness of flour and noodle sheet, dough stability, and peak viscosity of wheat starch were all increased by ozone treatment. Free cysteine content in wheat flour was shown to decrease significantly (P <0.05) as the treatment time increased and remarkable protein aggregates were observed in both reduced and non-reduced SDS–PAGE patterns. In addition, ozone treated noodles were generally higher in firmness, springiness, and chewiness, while lower in adhesiveness. Microbial growth and darkening rate of fresh noodles made from ozone treated flour were delayed significantly. [Copyright &y& Elsevier]

Extruded starch could be used as a thickener for food processing due to its pre-gel properties. This study aimed to explore the influence of the addition of extruded endogenous Tartary buckwheat starch (ES) on the process and quality of gluten-free noodles. ES was mixed with Tartary buckwheat flour in different proportions (10–40%) to prepare the blended flour and noodles. When the content of ES was increased, the swelling power of blended flour at 90 °C had no significant changes, and the decrease in peak viscosity of blended flour was reduced. This indicated that the high-content ES could afford better thermal stability for blended flour and inhibit the swelling ability. The higher level of ES was beneficial to the formation and stabilization of dough, and the improvement of noodle tensile strength. Furthermore, there was no difference in cooking loss between noodles with 30% and 40% ES addition. The microstructure and water distribution of the noodles prepared by blended flour indicated that the gel-entrapped structure organized by the higher content ES could be closely related to the above results. In conclusion, higher ES could contribute to improving the processing properties and quality of noodles. [ABSTRACT FROM AUTHOR]

To improve the eating quality of instant wet noodles sterilized via autoclaving, liquid whole egg (LWE) was used as a reinforcer in the noodle recipe and its enhancement mechanism was evaluated. The results revealed that autoclaving significantly decreased the tensile distances of noodles (p < 0.05). The extent of textural deterioration increased with increasing autoclaving temperature. However, the addition of LWE compensated this deterioration. Moreover, LWE inhibited protein unfolding during autoclaving by crosslinking egg proteins with gliadin. The chemical interaction results revealed that the concentration of disulfide bonds increased from 48.95 to 94.96 μmol/g when 20 g/100 g LWE was added to the noodle recipe accompanied by a high proportion of stable conformations (gauche−gauche−gauche), which were transformed to a less stable conformation with increasing autoclaving temperature. A higher concentration of disulfide bonds and stable conformations in instant wet noodles made with LWE inhibited the unfolding of the gluten structure upon autoclaving, stabilizing the secondary structure and contributing to a more compact network upon autoclaving. • Egg addition increased the tensile distance of instant wet noodles. • Disulfide bond was a main interaction in instant wet noodles upon autoclaving. • Egg protein polymerized with gliadin through disulfide bond. • Stable S-S bridge conformation induced high tensile distance upon autoclaving. • Egg addition induced a more compact honeycomb protein network upon autoclaving. [ABSTRACT FROM AUTHOR]

Dried whole wheat noodles (DWWN) are a kind of nutritious convenience food with broad market prospects. However, due to the presence of high content of unsaturated fatty acids (UFAs) and lipid degrading enzymes, the shelf life and edible quality of DWWN are easily affected. This study explored the effect of superheated steam treatment (SST-155 °C-10 s, SST-170 °C-10 s, SST-190 °C-5 s) on the lipid stability of DWWN. The lipase, lipoxygenase and peroxidase of the DWWN treated with superheated steam were completely passivated during storage. After 12 weeks of storage, the fatty acid value of DWWN increased by 35.1, 17.9, 15.9, 24.6 mg NaOH/100 g in the groups of control, SST-155 °C-10 s, SST-170 °C-10 s, SST-190 °C-5 s, respectively; whereas the content of UFAs decreased by 13.5%, 6.8%, 5.4%, and 2.7%, respectively. The content of 2-pentylfuran in the SST-155 °C-10 s, SST-170 °C-10 s, SST-190 °C-5 s group was 0.7, 0.6, and 0.4-fold than that of the control group, respectively. In addition, the total tocopherol and total volatile compounds of the SST-190 °C-5 s group were 2.4 and 0.7-fold than that of the control group, respectively. Therefore, SST should be a new technology that can improve the lipid stability of DWWN. [ABSTRACT FROM AUTHOR]

This research explored the effect of L-cysteine on the browning of fresh wet noodles (FWN). With the increasing addition of L-cysteine (0.02–0.1%), the ΔL* decreased and Δa*, Δb* increased. The L-cysteine could reduce the pH value and polyphenol oxidase (PPO) activity and increase the retention rate of polyphenol of FWN. It suggested that L-cysteine could inhibit the browning of FWN by decreasing pH value, PPO activity, and the oxidation of polyphenols. In the in vitro PPO solution, the inhibitory effect of L-cysteine on PPO activity was related to the decrease in pH and the ability of chelating Cu2+. According to UPLC-TOF-MS analysis, L-cysteine could reduce the generation of browning products, which suggested that L-cysteine could react with the browning intermediate product (quinone) and generate a light-colored substance (-C9H10NO4S). L-cysteine effectively inhibited the browning of FWN and had the potential to be used in noodle industry. [ABSTRACT FROM AUTHOR]

Humidity-controlled dehydration (HCD) was innovatively applied in this paper to control the growth of microorganisms in fresh wet noodles (FWN). Effects of HCD treatment with different temperatures (40, 60 or 80 °C), relative humidity (RH, 50%, 70% or 90%) and treatment time (5–32 min) on the total plate count (TPC), the shelf-life, and qualities of FWN were investigated. The results showed that HCD reduced the initial microbial load on the fresh noodles and extended the shelf-life up to 14–15 days under refrigeration temperature (10 °C). A 1.39 log10 CFU/g reduction for the initial TPC was achieved after HCD treatment at the temperature of 60 °C and RH of 90%. HCD with higher RH had a more positive influence on quality improvement. The L* values, the apparent stickiness, and the cooking properties of the noodle body were improved by HCD while good sensory and texture quality of noodles were still maintained after the dehydration process. [ABSTRACT FROM AUTHOR]

Incorporating green tea powder (GTP) into dried noodles enriched the functional characteristics of noodles. To achieve the maximum benefits from GTP, the water cooking stability of dried green tea noodles (DGTN) should be investigated. Indeed, antioxidant activities and phenolic compounds of DGTN after water cooking markedly decreased. The results showed that large GTP particles caused the increased cooking loss of DGTN, but the phenolic compound loss of DGTN prepared with them was low after cooking. Analysis of texture properties and microstructure showed that DGTN with a 2% concentration of large GTP particles formed some holes in the noodles' network, and its breaking strength decreased. However, we observed that many GTP particles adhered to the surface of DGTN prepared with small GTP particles, and they were easier to lose after water cooking. Comprehensive analysis concluded that cooking loss, functional compounds retention and textural properties of DGTN were related to GTP particle size and concentration via the microstructure. [ABSTRACT FROM AUTHOR]

[Display omitted] • The elastic modulus of dough significantly increases (P < 0.05) after stretching. • The degree of dried dough pasting significant increases (P < 0.05) after stretching. • Resting causes gluten polymerization and promotes repolymerization. • Dough extensibility correlates positively with the degree of gluten cross-linking. The study of the changes in rheological properties and components during the processing of Chinese traditional handmade hollow dried noodle (HHDN) is essential to explaining the excellent quality of HHDN. The dynamic oscillation frequency sweep, stress relaxation, and uniaxial extension characteristics of the dough after kneading, stretching, and resting were investigated at six sampling points during the processing of HHDN. The result showed that stretching led to an increase in G' and G 0 , and a significant decrease (P < 0.05) in extensibility from 131.02 mm to 57.99 mm. Confocal laser scanning microscopy (CLSM) was used to observe the microstructure of the gluten network, which was destroyed during stretching and restored during resting. Studies of changes in components showed that the stretching process resulted in a decrease in GMP content from 3.24 (g/100 g) to 3.18 (g/100 g), and the resting process resulted in β -sheets decreasing significantly (P < 0.05). The degree of starch pasting increased significantly (P < 0.05) after stretching. The results of the correlation analysis showed that components changes were highly correlated with the rheological properties during the processing of HHDN. [ABSTRACT FROM AUTHOR]

In this research, changes in microbial shelf-life and quality characteristics of fresh wet noodles (FWNs) were analyzed under acid and different mild heat treatment conditions. Acid combined with heat treatment at 50 °C for 30 min extended the shelf-life of FWNs by 30–40 d and effectively delayed the color deterioration of FWNs. The water absorption of FWNs was reduced by the mild heat treatment. Meanwhile, the cooking loss of the noodles and hardness significantly (p < 0.05) increased. Differential scanning calorimetry (DSC) analysis showed that the gelatinization enthalpy of the starch in FWNs decreased and the gelatinization temperature increased. The X-ray diffraction (XRD) results showed that the crystallinity of the starch decreased from 27.51% to 24.2% after mild heat treatment. In addition, it was observed by confocal laser scanning microscope that the mild heat treatment made the gluten networks more continuous. The free sulfhydryl content of noodles showed a decreasing trend, while the sodium dodecyl sulfate-extractable protein (SDS-EP) value was also significantly (p < 0.05) reduced. Overall, the combination of mild heat treatment with acid extended the shelf-life of FWNs and had less impact on their quality. [Display omitted] • Acid and mild heat treatment (AMHT) prolonged the shelf-life of fresh wet noodles. • AMHT increased the hardness of noodles and reduced elasticity and water absorption. • AMHT increased the formation of protein network in noodles. • AMHT altered the pasting properties and relative crystallinity of starch in noodles. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ethanol decreased the viscoelasticity and increased the deformability of the dough. • Ethanol reduced the fracture stress and increased the adhesiveness of dough sheet. • Ethanol reduced the hardness and elasticity of noodles but increased cooking loss. • Ethanol reduced cross-linking of gluten network and continuity of internal structure. • Ethanol dissolved part of the gliadin and inhibited the polymerization of gluten. 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. [ABSTRACT FROM AUTHOR]

Temperature fluctuations during transportation all the way to consumption can negatively affect the quality of frozen cooked noodles (FCNs). In response, this work investigated whether gellan enhanced the appearance and texture property of FCNs during freeze-thaw cycles. Compared with the control, adding gellan increased the hardness of FCNs and reduced structural damage during freeze-thaw cycles. In addition, changes in FCNs were explained from the perspectives of freeze-thaw stability and rheology, the former of which was determined according to T 2 relaxation time, magnetic resonance imaging (MRI), and differential scanning calorimetry (DSC). The results showed that adding gellan reduced the percentage of weakly bound water and the relaxation time of FCNs, as well as increased the water-holding capacity of the noodles. MRI pseudo-color maps illustrated that adding gellan stabilized the water gradient in the noodles, and a thermal analysis of FCNs via DSC demonstrated that adding gellan at 0.3% maximized the melting termination temperature. In addition, creep-recovery test results indicated that FCNs compliance increased during freeze-thaw cycles, and the addition of gellan enhanced the zero-shear viscosity and deformation resistance, which explained the texture property change of FCNs. [Display omitted] • The hardness of frozen cooked noodles (FCN) decreased during freeze-thaw cycles. • Gellan was beneficial to the quality of FCN. • The addition of gellan increased the water-binding capacity of FCN. • Added gellan enhances the freeze-thaw stability of FCN. • Adding gellan increased the zero shear viscosity and deformation resistance of FCN. [ABSTRACT FROM AUTHOR]

Phytic acid (PA) could increase the yellowness value of yellow alkaline noodles (YAN), as well as significantly reduce the generation of dark spots on the surface of YAN by suppressing polyphenol oxidase (PPO) browning. In this paper, the inhibition mechanism of PA on PPO browning was mainly studied. In the produced YAN sheets, the PPO activity and free quinone content showed a gradual decrease with increasing PA addition, while the free phenol content gradually increased. This indicated that PA could inhibit PPO browning and was an effective browning inhibitor. In the constructed in vitro PPO solution, the anti-PPO browning mechanism of PA was mainly through chelating Cu2+ in the active center. The DPPH radical scavenging rate of PA was measured, and it was found that PA could inhibit PPO browning, which was related to the antioxidant capacity. The effect of PA on browning products was analyzed using HPLC, and the results of the study showed that PA could reduce the peak area of the browning products, thus reducing the generation of dark spots. [Display omitted] • PA (phytic acid) can effectively improve the appearance of yellow alkaline noodles. • PA significantly reduces the generation of dark spots by inhibiting PPO browning. • PA inhibits PPO activity mainly by binding to active center Cu2+. • PA can enhance the scavenging rate of DPPH free radicals. • PA can reduce the formation of browning products by HPLC analysis. [ABSTRACT FROM AUTHOR]

Highlights • Hardness and tensile force gradually decreased during the prolonged frozen storage. • DSC results showed the content of freezable water significantly (P < 0.05) increased. • A longer T 21 and T 22 were recorded during frozen storage by NMR. • Micromorphology showed the compact and smooth structure was destroyed during frozen storage. • SDS-soluble proteins detected by SE-HPLC increased during frozen storage. Abstract The effects of frozen storage on the quality of frozen cooked noodles were investigated. Texture analysis showed hardness and tensile force reduced during frozen storage. An increasing cooking loss and a decreasing water uptake ratio were determined when testing cooking qualities. As storage time prolonged, differential scanning calorimetry (DSC) detected more freezable water, and an increased relaxation time was recorded by nuclear magnetic resonance (NMR). Magnetic resonance imaging (MRI) revealed water distribution was more heterogeneous. A ruptured microstructure with large pores of frozen cooked noodles was observed by scanning electron microscopy (SEM). The confocal laser scanning microscope (CLSM) photographs demonstrated gluten network lost its integrity and compactness. Size-exclusion high performance liquid chromatography (SE-HPLC) indicated the amount of SDS-soluble proteins increased. The present study showed water characteristics and protein network underwent some changes during frozen storage, which had major effects on the quality of frozen cooked noodles. [ABSTRACT FROM AUTHOR]

Abstract The aim of this study was to investigate the effect of soybean milk addition on the quality of frozen-cooked noodles. Results revealed that sensory and texture properties of frozen-cooked noodles were significantly (P < 0.05) improved after adding soybean milk. Compared with control ones, frozen-cooked noodles with soybean milk addition exhibited a more compact and smooth surfaces. Meanwhile, micro-structure observation revealed that frozen-cooked noodles showed more continuous protein network, accompanied with smaller ice crystal by soybean milk addition. Magnetic resonance imaging (MRI) results indicated that soybean milk addition decreased the transverse relaxation time (T 2) and restrained the ascent of free-water of frozen-cooked noodles. Besides, MRI images showed that soybean milk enhanced the water-holding capacity of frozen-cooked noodles and made water maintain a good crosswise gradient, resulting in better mouthfeel. Thus, soybean milk, as a natural and safe additive, could be used to improve the quality of frozen-cooked noodle. Graphical abstract Image 1 Highlights • Effect of soybean milk addition on quality of frozen-cooked noodles was examined. • Sensory and texture properties of frozen-cooked noodles were improved by adding soybean milk. • We revealed the changes in micro-structure, ice crystal formation and water status of noodles due to soybean milk addition. • Our results provide an insight into natural and safe additive to improve the quality of frozen-cooked noodles. [ABSTRACT FROM AUTHOR]

Chinese traditional handmade hollow dried noodle (HHDN) is a popular wheat-based food among the Chinese people due to its easy cooking qualities and smooth texture, which are significantly correlated with the rheological characteristics of HHDN dough. The effects of water content (55, 60, and 65%) and resting time (0, 30, 60, 90, and 120 min) on the rheology and gluten network formation of the HHDN dough were investigated. The modulus during stress relaxation reduced from 8.62 Pa to 2.30 Pa as the water content increased from 55% to 65%. With resting time increased from 0 min to 120 min, the extensibility of the 60% water content dough increased from 64.33 mm to 152.67 mm. With the water content decreased and resting time increased, the glutenin macropolymer (GMP) content increased and the free sulfhydryl content decreased. The microstructure study of the dough showed that extending the resting time was beneficial to the formation of the gluten network. The covalent interactions promote the formation of the gluten network and change the rheological properties of the dough. The dough with 60% water content and 60 min resting would result in the desired quality of the dough, ultimately improving the quality of the noodles. [Display omitted] • Researched the linear and nonlinear viscoelastic properties of the dough. • The formation of gluten network improves the rheological properties of dough. • Covalent interaction affects the formation of gluten network. • The GMP content increases as the resting time increases. [ABSTRACT FROM AUTHOR]

Changes in the properties of major components (gluten protein and starch) of frozen raw noodles (FRN) during twelve-week frozen storage were investigated. Frozen storage induced quality deterioration to FRN. Increases in optimal cooking time and cooking loss of FRN were determined. The hardness of noodle texture increased in the first six weeks and then decreased. The gluten from FRN showed decreases in the glutenin fractions with prolonging frozen storage. The compliance (J) of the gluten tended to decrease after the third week, accompanied with increasing zero-shear viscosity (η). The rheological parameters indicate the gluten of FRN became stiffer and less flexible in the latter frozen storage. With prolonging frozen storage, the starch of FRN exhibited higher short-range ordered degrees, revealing the increasing compactness of starch structure which contributed to the longer optimal cooking time required for FRN. Increasing yield stress (σ 0) values derived from steady rheological tests indicate the greater force required for the starch gel to initiate flow, which was corresponding to the higher noodle hardness after six weeks. It was concluded that frozen storage induced changes in quality properties of FRN by altering the gluten and starch components. [Display omitted] • Frozen storage caused worse cooking and texture properties of frozen raw noodles(FRN). • Rheological tests showed the gluten became stiffer and less flexible in latter period. • Higher starch short-range orders were related to longer optimal cooking times of FRN. • Greater yield stress (σ 0) of starch gel was related to the greater noodle hardness. • Frozen storage induced quality loss to FRN by altering gluten and starch components. [ABSTRACT FROM AUTHOR]

The impacts and mechanisms of ascorbic acid (Vc) and sodium dihydrogen phosphate on the browning of yellow alkaline noodles were investigated. The combination of sodium dihydrogen phosphate and Vc was found to increase the L* value and decreased the number of dark spots, indicating a synergistic anti-browning effect. This combination reduced the activity of polyphenol oxidase (PPO) slightly but deceased the free quinone content significantly (P < 0.05) in noodles. The addition of sodium dihydrogen phosphate also maintained the anti-oxidation stability of Vc, as evidenced by the increased DPPH radical clearance rate in PPO-catechol systems after 24 h of storage. Quantum chemical calculations revealed that sodium dihydrogen phosphate formed hydrogen bonds with ascorbic acid at hydroxyls of carbon-carbon double bond, which protected the ascorbic acid to some degree. This finding suggested that the synergistic anti-browning capacity of sodium dihydrogen phosphate and Vc could be applied to the noodle processing industry. [Display omitted] • The combination of Vc (ascorbic acid) and sodium dihydrogen phosphate (SDP) inhibited the browning of noodles. • The combination of Vc and SDP showed the synergistic anti-browning capacity. • The addition of Vc and SDP decreased the PPO activity and quinone content. • The addition of Vc and SDP increased in DPPH radical clearance. • The interaction between Vc and SDP was explored using quantum chemical calculations. [ABSTRACT FROM AUTHOR]

[Display omitted] • SHMP inhibited the browning of yellow alkaline noodles. • SHMP inhibited PPO activity by chelating Cu2+ in the active center of PPO. • SHMP inhibited browning by hampering auto-oxidization of quinone. • SHMP reduced brown polymers by decreasing the pH value and converting melanin into light-colored substances. The effect and mechanism of sodium hexametaphosphate (SHMP) on polyphenol oxidase (PPO) enzymatic browning in yellow alkaline noodles (YAN) were investigated. The browning degree and PPO activity in YAN or PPO solutions decreased with the SHMP concentrations increased. Variations in pH values (pH 7–8.5) adjusted by HCl or acetic acid slightly affected the PPO activity, but SHMP inhibited PPO activity more pronounced. The inhibition of SHMP on PPO activity was irreversible. SHMP formed coordinate covalent bonds with Cu2+ to make PPO inactive. HPLC analysis revealed that SHMP reduced the browning products and led to the color of PPO-catechol systems being lightened. Furthermore, SHMP inhibited browning by hampering the auto-oxidization of intermediate products due to the change in pH value. Besides, the HPLC chromatogram, UV–vis spectrum, and mass spectrometry revealed that SHMP could convert melanin (m / z 248.97, 723.5, and 836.58) to light-colored substances (m / z 137.11). [ABSTRACT FROM AUTHOR]

In this study, the effects of chitosan oligosaccharides (COS) on the microbial stability and quality properties of fresh wet noodles were evaluated. The addition of COS prolonged the shelf-life of fresh wet noodles at 4 °C by 3–6 days and effectively inhibited the growth of acidity value. However, the presence of COS increased the cooking loss of noodles significantly (P < 0.05) and decreased the hardness as well as tensile strength significantly (P < 0.05). The enthalpy of gelatinization (ΔH) was decreased by COS in the differential scanning calorimetry (DSC) analysis. Meanwhile, the addition of COS decreased the relative crystallinity of starch (from 24.93 % to 22.38 %) without changing the type of X-ray diffraction pattern, revealing that COS weakened the structural stability of starch. In addition, COS was observed to impair the development of compact gluten network by confocal laser scanning micrographs. Further, the free-sulfhydryl groups content and sodium dodecyl sulphate-extractable protein (SDS-EP) values of cooked noodles increased significant (P < 0.05), confirming the obstruction on the polymerization of gluten proteins during the hydrothermal process. Although COS adversely affected the quality of noodles, it was outstanding and feasible for the preservation of fresh wet noodles. [Display omitted] [ABSTRACT FROM AUTHOR]

In this study, changes in fresh noodles during storage were evaluated at the physico-chemical, structural, and molecular levels. An increase in TPC and decrease in L ∗ value mostly occurred during the first 24 h; the pH value significantly decreased ( P < 0.05) and proteins were partially depolymerized with the deterioration of fresh noodles, as evidenced by free amino acid determination and SDS-PAGE. Changes were also detected in the pasting and viscosity properties of the starch component. Moreover, the water sorption isotherm of fresh noodles decreased during storage, and the NMR transverse relaxation peak shifted right with an increased peak area between 10 and 100 ms. MRI images showed that with increased storage time, the original structure was damaged and water distribution became non-uniform and migrated to the surface. TPC, pH, and L ∗ value were selected as the visualized parameters to characterize the fresh noodle deterioration, based on the correlation and factor analyses. [ABSTRACT FROM AUTHOR]

Sorbitol is commonly used in semi-dried noodles for holding water, thus extending the shelf life. This research analyzed the effect of sorbitol on the in vitro starch digestibility in semi-dried black highland barley noodles (SBHBN). In vitro starch digestion revealed that the hydrolysis extent and digestive rate decreased with increasing sorbitol addition, although its inhibition abated when added >2 %. Compared with the control, adding 2 % of sorbitol lowered the equilibrium hydrolysis (C ∞) significantly (P < 0.05) from 75.18 to 66.57 % and decreased the kinetic coefficient (k) significantly (P < 0.05) by 20.29 %. Adding sorbitol increased the tightness of microstructure, relative crystallinity, V -type crystal, molecular structure order, and hydrogen bond strength of starch in cooked SBHBN. Meanwhile, gelatinization enthalpy change (ΔH) of starch in raw SBHBN was increased by adding sorbitol. In addition, the swelling power and amylose leaching in SBHBN added with sorbitol were reduced. Pearson correlations analysis observed significant (P < 0.05) correlations among short-range ordered structure, ΔH, and related in vitro starch digestion indexes of SBHBN after being added with sorbitol. These results revealed that sorbitol might form hydrogen bonds with starch, making it a potential additive to lower the eGI in starchy foods. [Display omitted] • Adding sorbitol decreased the in vitro starch digestibility and eGI of SBHBN. • The addition of sorbitol induced a more compact starch microstructure. • Sorbitol improved structural order of starch in cooked SBHBN by hydrogen bonds. • Sorbitol formed V -type complex with starch in cooked SBHBN. [ABSTRACT FROM AUTHOR]

Pasteurization, acidification followed by pasteurization, and autoclave extended the shelf-life of cooked noodles (groups S1, S2 and S3) to 3, 180 and 180 days, respectively. Pasteurization increased the hardness of cooked noodles from 53.60 to 58.01 N. However, the growth of thermoduric bacteria caused a decrease in pH, coloration, and hardness of group S1 during storage. Meanwhile, the pH and hardness of group S2 decreased to 4.42 and 39.22 N respectively, while hardness and chewiness increased during storage. In addition, physicochemical-textural characteristics of group S3 are maintained throughout storage. The hardness of groups S1 and S2 is related to the gluten structure. The compact gluten network formed after pasteurization. Meanwhile, acidification inhibited the polymerization of glutenin and gliadin. The starch melted after autoclave, masking the impact of the gluten network and decreasing hardness. During storage, hydrolysis of protein and starch by bacteria resulted in the deterioration of group S1. Recrystallization of starch resulted in the stiffening of group S2. The absence of metabolism of bacteria and presence of stable gluten in group S3 contributed to the stable starch structures, inducing its stable quality. Thermal treatment can be recommended as an effective additional treatment for producing shelf-stable wet instant cooked noodles. • Autoclave maintained the quality of wet instant cooked noodles during storage. • Non-disulfide covalent bonds between glutenin and gliadin were formed during autoclave. • Acidification hindered crosslinks between glutenin and gliadin. • Complete melting of starch crystalline decreased the hardness of noodles. [ABSTRACT FROM AUTHOR]

• Freeze-thaw cycles reduced tensile stress and raised tensile distance of frozen raw noodles (FRN). • More mobile water and less compact microstructure were detected in FRN. • Cooking loss and broken noodle ratio increased and hardness and chewiness decreased. • Weaker strength of gluten was related to the attenuation in FRN. • FRN with high protein and gluten content had better resistance to freeze-thaw cycles. The effects of freeze-thaw cycles (0–8) on the quality of frozen raw noodles (FRN) were investigated. Three types of wheat flour with different protein contents were used to prepare FRN. Freeze-thaw treatment decreased the break force and increased the tensile distance of FRN with higher protein content. More mobile water and less compact microstructure were detected in FRN. Freeze-thaw cycles exerted negative effects on the cooking and texture performance of FRN indicated by increases in the cooking loss (CL) and broken noodle (BN) percentage and decreases in the hardness and chewiness. After four freeze-thaw cycles, FRN with lower protein content exhibited higher CL and BN ratios and less chewiness. The tensile distance and peak force of the gluten isolated from FRN decreased during freeze-thaw cycles, which caused the quality deterioration of FRN. FRN with higher protein content and greater gluten strength demonstrated better resistance to the freeze-thaw treatment. [ABSTRACT FROM AUTHOR]

In this study, the effect of steaming on the quality of frozen cooked noodles was investigated, as well as the microstructure, protein extractability and starch properties of steamed noodles. Furthermore, white salted, yellow alkaline and control noodles (without salt or alkaline) were measured as affected by different steaming times. The results indicated that the cooking and texture properties of frozen cooked noodles were significantly ( P < 0.05) improved by steaming pretreatment, except that yellow alkaline noodles showed larger cooking loss. In addition, steamed noodles except yellow alkaline noodles had compact and smooth surfaces compared with fresh noodles. With the increase of steaming time, the SDS extractable protein and RVA viscosity properties of starch decreased. Gelatinization enthalpy of starch in steamed noodles decreased dramatically upon steaming. The present study indicated that protein polymerization and starch gelatinization when subject to limiting water conditions during steaming accounted for improved noodle quality. [ABSTRACT FROM AUTHOR]

• PS extended shelf-life of semi-dried noodles by decreasing mobility of free water. • SHMP and STPP had a better effect on the quality of noodles than TSPP and MSP. • PS changed the thermal properties of starch in noodles. • A more compact gluten network in noodles was observed owing to PS addition. The effect of four types of phosphate salts (PS) on the shelf-life and quality characteristics of semi-dried noodles, as well as their underlying mechanism were investigated. Microbial analysis showed 0.2% or 0.4% sodium dihydrogen phosphate (MSP) extended the shelf-life of noodles from 3 days to 5 days. Nuclear magnetic resonance analysis revealed PS decreased the mobility of free water in noodles. Cooking and texture analysis showed sodium pyrophosphate (TSPP) increased the cooking loss of noodles, and MSP decreased the tensile force of noodles. Sodium hexametaphosphate (SHMP), TSPP, and MSP increased the hardness of noodles, while sodium tripolyphosphate (STPP) decreased the hardness. Thermal properties analysis indicated STPP and TSPP increased the gelatinization enthalpy (ΔH) of starch in noodles, while SHMP and MSP decreased the ΔH. Furthermore, confocal laser scanning microscopy and scanning electron microscopy showed SHMP, STPP, and MSP strengthened the gluten network formation, while TSPP weakened the network. [ABSTRACT FROM AUTHOR]

To improve highland barley noodles (HBNs) quality, the highland barley flour (HBF) was pre-fermented by Lactobacillus plantarum in this study. The changes in the quality of HBNs, the hydration properties and microstructure of the dietary fiber (DF), and the conformation and cross-linking of the protein in HBNs were measured. With the extension of pre-fermentation time (0–4 h), the overall acceptance of HBNs increased from 7.83 to 8.27, along with a 5.9% reduction in hardness and a 4.5% increase in springiness of HBNs. Meanwhile, confocal laser scanning microscopy (CLSM) revealed that the physical structure of the DF gradually disintegrated, which caused a significant (p < 0.05) decrease in its water retention capacity. In addition, spectral analysis showed a continual increase (from 19.62% to 30.15%) in β-turn content of the protein. The content of the free sulfhydryl group and sodium dodecyl sulfate extractable protein (SDSEP) decreased by 18.1% and 4.12%, respectively. However, with the further extension of pre-fermentation time (6–8 h), the degradation in HBNs sensory quality occurred, accompanied by a significant (p < 0.05) decrease in pH (5.95–5.01). These findings suggested that a moderate duration (4 h) of HBF pre-fermentation could effectively improve the quality of HBNs. [Display omitted] • HBF pre-fermentation by Lactobacillus plantarum degraded the dietary fiber. • HBF pre-fermentation by Lactobacillus plantarum weakened the water-binding capacity of dietary fiber. • Highest sensory quality of HBNs was obtained by 4 h of HBF pre-fermentation. • Optimal network structure in HBNs was formed through 4 h of HBF pre-fermentation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Noodle had the best immersion resistance when wheat flour was post-ripened for 20–40d. • Wheat flour quality was improved and gluten protein aggregated during post-ripening. • Oxidation of free sulfhydryl promoted covalent cross-linking of gluten protein. • Dense gluten network contributed to improving the immersion resistance of noodles. To overcome the problem that takeaway noodles possessed poor immersion resistance, in this study noodles were prepared from post-ripened wheat flour, and changes in textural properties, protein components, and water status of noodles were determined. The firmness and tensile distance of noodles were gradually increased by 7.40%–35.88% when wheat flour was post-ripened for 20–40 d. Afterwards, noodle textural qualities were slightly decreased. Compared with control groups, contents of glutenin macropolymer (GMP) and disulfide bonds were significantly (p<0.05) increased and protein network was also more compact, whereas the Glutenin/Gliadin ratio and free sulfhydryl groups content were significantly (p<0.05) reduced. Contents of sodium dodecyl sulfate extractable protein (SDSEP) were reduced by 3.22%–6.23%. Meanwhile, the decrease in A 23 indicated that wheat flour post-ripening limited water-absorbing capacity of noodles during immersion. In conclusion, wheat flour post-ripening promoted the immersion resistance of noodles by inducing protein cross-linking, and the best post-ripening time was 20–40 d. [ABSTRACT FROM AUTHOR]

Abstract: Effect of vacuum mixing on the physicochemical properties, microstructure and water status of fresh noodles was investigated. Color changes, moisture, water activity, cooking quality and texture properties were measured as affected by different vacuum degrees. In addition, effect of vacuum mixing on the water status in noodles was evaluated at macroscopic, structural and molecular levels. Noodle brightness, cooking and texture properties were significantly (P <0.05) improved as vacuum degrees increased, except that −0.08MPa imparted slightly larger cooking loss and worse texture to low protein noodles. Both high and low protein flour noodles presented the best cooking and textural properties while mixed at −0.06MPa. Furthermore, vacuum mixing induced a more continuous and compact noodle structure, as shown in the SEM investigation. Water–solids interaction in the products was shown to be enhanced by the decreased water mobility, lower freezable water content (FW%), and the stronger proton density of T 21. [Copyright &y& Elsevier]

Abstract: Superfine green tea powder (SGTP) was used to substitute 0g, 1g, 2g, and 3g of 100g wheat flour (defined as 0SGTP, 1SGTP, 2SGTP and 3SGTP respectively) to make fresh noodles. The effects of SGTP on the viscosity, thermodynamic and rheological properties of wheat flour were evaluated, as well as the sheet colour, cooking quality, texture properties and sensory characteristics of green tea noodles. The results revealed that the stability, elastic modulus (G′) and viscous modulus (G″) of wheat dough all increased with the increase of green tea powder proportion. No significant differences were found in gelatinisation properties of the green tea-flour systems. Furthermore, adding SGTP could significantly (P <0.05) retard the retrogradation of the gelatinised wheat flour gel. L ∗ value of fresh noodles decreased as SGTP content increased while |a ∗| value firstly increased and then decreased at 3g/100g. The 2SGTP noodle samples showed the least cooking loss. Sensory evaluation indicated that the control and the 2SGTP fresh noodles scored significantly (P <0.05) higher in terms of colour. No significant difference was detected for the mouthfeel and overall acceptability among all samples. [Copyright &y& Elsevier]

Effects of different wheat bran pre-treatments on storage stability and physico-chemical properties of semi-dried whole wheat noodles (SWWN) were investigated. After bran pre-treatment with liquor koji and yeast, the total plate count of SWWN showed a slower rate of growth and the shelf-life was prolonged, which could be related to the lower pH and higher content of ethanol in noodles. Furthermore, liquor koji and yeast fermentation (LKYF) treatment reduced the optimal cooking time and cooking loss and increased the hardness of SWWN (P < 0.05). The appearance and cross-sectional microstructure of noodles in LKYF changed obviously. Irregular pores in noodles were observed by SEM, which were caused by the gas production during noodle processing. This change had positive effects on the cooking quality and texture property of noodles. The present study showed that bran treatment with LKYF could improve the storage stability and quality characteristics of SWWN. • Liquor koji and yeast pre-fermented bran extended the shelf life of noodles. • Bran pre-fermentation reduced cooking time and cooking loss of noodles. • Bran pre-fermentation decreased pH and increased ethanol content of noodles. • Liquor koji and yeast pre-fermented bran changed appearance of noodles. • Irregular pores in noodles were observed by SEM owing to bran pre-fermentation. [ABSTRACT FROM AUTHOR]

• Fresh egg white addition decreased cooking loss of oat noodles. • The hardness, chewiness, tensile force and distance increased significantly. • Micromorphology showed a compact and smooth structure after adding fresh egg white. • Fresh egg white could promote the protein aggregation through disulfide bonds. The influence of fresh egg white (EW) addition on the quality characteristics and protein aggregation in oat noodles containing wheat flour and gluten was studied. EW addition decreased cooking loss and increased cooking time of 70% oat noodles. The hardness, chewiness, tensile force and tensile distance improved significantly. A smooth surface and continuous protein network were observed by scanning electron microscopy (SEM) after adding EW. After cooking, the peak area in SE-HPLC profile of 70% oat noodles with EW decreased obviously. The extractabilities of protein in sodium dodecyl sulfate containing medium (SDSEP) of cooked wheat and oat noodles under non-reducing condition were lower than those of samples under reducing condition. The protein bands changes in SDS-PAGE profiles showed that EW could induce disulfide cross-linking of proteins in noodles. EW addition promoted proteins interaction and improved the cooking and texture properties of oat noodles. [ABSTRACT FROM AUTHOR]

The color of dried green tea noodles (DGTN) is a crucial determinant of consumer acceptance. Although polyphenol oxidase (PPO) is a key factor inducing the darkening of noodles, its contributions on the discoloration mechanism of DGTN requires clarification. Results revealed that PPO induced the decreased of lightness L value and greenness |a| value via its effects on polyphenol compounds and chlorophyll during the processing of DGTN. The increase of PPO activity significantly accelerated the discoloration rate and the degradation of chlorophyll during storage of the DGTN. Correlation analysis found that the changes of chlorophyll among DGTN made from different PPO activities of wheat flour played a major role in the discoloration. These findings indicated that the control of the negative effects of PPO on polyphenol compounds and chlorophyll could be an effective method to retard discoloration in DGTN. • Polyphenol oxidase is crucial to the discoloration of dried green tea noodles. • Polyphenol oxidase significantly accelerates the lightness and greenness variations. • As polyphenol oxidase increases, the content of phenolic compounds and chlorophyll decreases. • The degradation of chlorophyll is a key factor in the discoloration of dried green tea noodles. [ABSTRACT FROM AUTHOR]

Abstract: In this study, the impact of different mixing and kneading processes on the qualities of frozen cooked noodle were evaluated, including freezable water content and microstructure of the noodle, as well as rheological properties of dough. The results showed that the frozen cooked noodle of manual dough mixing (MM) scored the highest in sensory evaluation, while the one via vacuum dough mixing (VM) way had the best texture and cooking properties with lower water absorption and cooking loss under the same kneading process. The vacuum condition could contribute to a more uniform and continuous matrix of protein during the mixing process. Besides, both machine kneading (MK) and hand kneading (HK) process displayed a significant (p < 0.05) positive effect on the qualities of frozen cooked noodle, such as texture properties, cooking properties, and sensory score. Furthermore, the role of hand kneading process was more evident than machine kneading. Highlights • Systematic study of mixing and kneading process on the effects of noodle's quality. • Frozen cooked noodle's qualities were significantly improved by vacuum mixing. • Kneading process was benefit for the high qualities of frozen cooked noodle. • Hand kneading process has the most significant effect on the noodle's qualities. [ABSTRACT FROM AUTHOR]

The recipe secret of making Chinese cuisine cold skin noodles (liangpi) with wheat flour was revealed by linear and nonlinear rheological characterization of wheat starch gel systems, which were made from different concentrations of liangpi slurry (LPS) and wheat starch slurry (WSS). The peak viscosity of LPS was suppressed at low concentrations and significantly higher than that of WSS at high concentrations. The G′ and G″ of LPS gels were higher than that of WSS gels under the same concentration, while the tanδ values were low in LPS gels and exhibited relatively greater mobility. This difference in LPS may be related to the non-starch components in it. The two starch gel systems were further characterized by the large amplitude oscillatory shear (LAOS) test. Lissajous curves showed that LPS gels follow a highly different elastic and viscous evolution than WSS gels during large deformation cycles. This was also evidenced by more pronounced strain stiffening and shear thickening trends of LPS gels and the larger I 3 / I 1 values. The introduction of non-starch components was responsible for the significant changes in the properties of starch gels, and the LAOS method helped us to better understand these differences. [Display omitted] • The liangpi gels (LPS) differs with wheat starch gels (WSS) in LAOS behaviors. • Analysis on Lissajous curves and stress decomposition confirms the differences. • LPS gels have higher G′ and G″ than WSS gels in the linear viscoelastic region. • Non-starch components enhance the resistance of LPS gels to large deformation. • Concentration affects the pasting viscosity of LPS more notably than that of WSS. [ABSTRACT FROM AUTHOR]

Effects of extruded endogenous starch (EES) on the gel-entrapped network formation in Tartary buckwheat noodles (GF-TBNs) during sheeting were studied. EES was obtained at different extrusion temperatures and mixed with buckwheat flour to prepare GF-TBNs. Higher temperatures (>110 °C) no longer promoted the decrease in the molecular weight of starches. The gel strength of EES could be related to molecular distribution internal EES. Furthermore, the n ′ of GF-TBN dough sheets decreased and G 0 ' increased as the sheeting roller gap reduced, which suggested that the gel network in sheets was extended. The sheeted noodles had higher tensile strength, elasticity and fracture work, which was benefited from the extended gel network. Microstructure images and vascular fitting analysis confirmed the formation of a denser network in the noodles after sheeting. These results indicated that EES gel provided viscosity to the dough and sheeting promoted the formation and extension of gel networks in GF-TBNs. • Higher temperatures no longer promote a decrease in the molecular weight of starch. • Extruded starch gel gave the viscosity of gluten-free noodle (GFN) dough. • The reduction of the roller gaps contributed to increasing the G′ of GFN dough. • Sheeting promoted the formation and extension of gel networks in GFNs. • The extended gel network tended to improve the tensile strength of GFNs. [ABSTRACT FROM AUTHOR]

In this study, the effects of acidity regulators (ARs) on the shelf life, quality, and physicochemical characteristics of fresh wet noodles (FWNs) were investigated. The addition of ARs markedly reduced the pH value of FWNs with a prolonged microbial shelf life of 5–10 days. Moreover, the presence of ARs significantly (p < 0.05) decreased the hardness and tensile distance of cooked FWNs, while increasing the cooking loss of noodles significantly (p < 0.05). The results of confocal laser scanning microscope analysis showed that ARs inhibited the formation of gluten networks in cooked noodles. Sodium dodecyl sulfate-extractable protein (SDS-EP) and free –SH content increased significantly (p < 0.05) when ARs were added. ARs affected the polymerization of proteins by inhibiting the formation of interchain disulfide bonds during cooking. Moreover, X-ray diffraction results showed that the addition of ARs resulted in acid hydrolysis of the amorphous area of the starch in FWNs, decreasing the pasting temperature, peak and trough viscosities of the starch. The reduction in pH value was the main factor that affected the shelf life and quality of FWNs, but different types of ARs had no significant impact. [Display omitted] • Adding acidity regulators (ARs) markedly prolonged shelf life of fresh wet noodles. • ARs reduced the hardness and elasticity of noodles and increased cooking loss. • ARs inhibited the formation of protein networks during cooking. • A decrease in pH value inhibited the formation of interchain disulfide bonds. • ARs changed the pasting properties and relative crystallinity of starch in noodles. [ABSTRACT FROM AUTHOR]

The impact of gluten quality on the textural stability of the cooked noodles and its underlying mechanism were investigated. Textural characterisation and cooking quality analysis were used to evaluate the quality of the noodles. The glutenin macropolymer (GMP) content, glutenin-gliadin ratio, dough rheological properties of the reconstituted wheat flour, water mobility, microstructure, and intermolecular force of the cooked noodles were also determined. When the immersion time was increased, the hardness, tensile distance, and hydrogen bonds in the cooked noodles decreased, whereas the relaxation time (T 22) increased, and the water penetrated gradually into the cooked noodles. A suitable glutenin-gliadin ratio, a moderate dough stabilisation time, and high GMP content contributed to the preservation of the texture of the cooked noodles. The confocal laser scanning microscopy (CLSM) images and network analysis confirmed that the properties of the cooked noodles made from various reconstituted wheat flours were different. [Display omitted] • This study pointed out the gluten quality suitable for the cooked noodles. • Gluten quality affected the textural stability of cooked noodles during immersion. • The quality attenuation law of the cooked noodles during immersion was expounded. • A dense gluten network was conducive to improving the quality of cooked noodles. • The molecular force affected the formation of gluten network in cooked noodles. [ABSTRACT FROM AUTHOR]

The aim was to investigate whether extrusion could improve the storage stability of dried oat noodles by inhibit lipid-degrading enzyme activity and the degradation of lipids. Thus, noodles were made from extrusion-treated oat under two treatment conditions and subjected to 12-week storage. Extrusion completely inactivated lipase and peroxidase in oat flour, while lipoxygenase activity persisted at a low level. Processing of dried oat noodles also influenced enzyme activity dramatically. For instance, the most significant impact was observed for lipase activity, which dropped to ca. 11 U∙min−1∙g−1 in the freshly prepared noodles made from non-heat-treated oat flour. Lipid hydrolysis was greatly controlled in extrusion-treated noodles as fatty acid values did not increase during storage. The total lipids decreased more in the extrusion-treated groups than in the control sample, which may indicate the promotion of extrusion in non-enzymatic reactions, as the initial values of volatile compounds were much higher. Interestingly, the occurrence of non-enzymatic lipid oxidation should not be severe during storage, as the reduction of tocols and the accumulation of volatile compounds were only moderate in extrusion-treated oat noodles. In conclusion, extrusion could be an effective method for enhancing the storage stability of dried oat noodles. [Display omitted] • Lipase and peroxidase were completely inhibited by extrusion in dried oat noodles. • Lipoxygenase persisted activity at low level after extrusion. • Enzymatic reaction was the main factor to cause lipid-degradation during storage. • Formation of volatile lipid oxidation products was greatly controlled by extrusion. • Extrusion may confer some advantages in the production of stable oat food products. [ABSTRACT FROM AUTHOR]

The lack of gluten in Tartary buckwheat has always been the main limiting factor of their development. This paper explored how to improve the processing quality of gluten-free Tartary buckwheat noodles (GF-TBNs) by introducing extruded starch into Tartary buckwheat flour (TBF) and the underlying mechanism was also elucidated. Extruded Tartary buckwheat starch (ETBS) was obtained under different extrusion conditions. The thermal properties, molecular weight, and viscosity of ETBS were examined to determine the key parameters closely related to the water distribution and rheological properties of the dough sheet, and tensile properties of GF-TBNs. The results showed that ETBS with a low molecular weight and high viscosity contributed greatly to the GF-TBNs with good tensile properties. It is proposed that ETBS with a low molecular weight and high viscosity might form a gel-entrapped network inside GF-TBNs, which was confirmed by the morphology of GF-TBNs. • The Tartary buckwheat starches (TBS) were extruded by a twin-screw extruder. • Gluten-free noodles were made with 30% extruded TBS and 70% buckwheat flour. • Extruded TBS with lower molecular weight gave a better elasticity of noodles. • Extruded TBS with high viscosity contributed to forming the gel-entrapped network. [ABSTRACT FROM AUTHOR]