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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]

Abstract Products fermented by probiotics are consumed worldwide and play important roles in human nutrition and health. In this study, the effects of fermented and unfermented Agaricus bisporus polysaccharide (FABP and UABP) flours on the structural and antioxidant properties of composite gluten-free (CGF) doughs and cookies were investigated. The extracted Agaricus bisporus polysaccharide flour was subjected to fermentation by Lactobacillus plantarum at 37 °C for 72 h. Incorporation of both FABP flour and UABP flour resulted in larger interconnected structures in doughs, with smoother surfaces being observed compared to the control. Moreover, FABP flour formulations showed higher total phenolic content (20.07–28.12 mg GAE/g, dwb), ABTS radical scavenging activity (82.17–86.82%) and β-carotene bleaching (68.80–83.72%), and UABP flour formulations had greater reducing power (0.61–0.83) and DPPH radical scavenging activity (78.66–91.22%), whereas less antioxidant activity was found in the control. Aggregated spherical granules were observed in all micrographs of CGF cookie formulations, and the control showed both individual and aggregated spherical granules. Several protein bands (20.1, 21.1, 32.0 and 33.1 kDa) with higher intensities were detected in all CGF cookie formulations compared to the control. Overall, the inclusion of mushroom polysaccharide flours could enhance the antioxidant attributes and alter structural characteristics of CGF cookies. Graphical abstract Image 1 Highlights • Novel CGF cookies were prepared by added FABP flour and UABP flour. • CGF cookies after adding polysaccharide flours exhibited different micrographs. • An increase of total phenolic content and antioxidant activities was observed. • Several protein bands were found in the fortified CGF cookies. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Novel CGF biscuits were prepared by added FABP flour and UABP flour. • Rheological properties were improved by both FABP flour and UABP flour. • An increase of fibers, amino acids and minerals of CGF biscuits was observed. • Physical and sensorial properties were enhanced by added polysaccharide flours. Abstract In this study, functional, rheological and physicochemical characteristics were carried out for composite gluten-free (CGF) flours, dough and biscuits, respectively fortified with fermented and unfermented Agaricus bisporus polysaccharide (FABP and UABP) flours. Addition of both FABP flour and UABP flour improved functional properties, while addition of FABP flour decreased viscosity property. Incorporation of both polysaccharide flours in CGF biscuit dough revealed a significant increase in rheological moduli (G′ and G″) and a decrease in tan (δ). Supplementation of UABP flour increased thickness, whereas supplementation of FABP flour increased diameter and spread ratio. All CGF biscuit formulations exhibited lower fracture strength and hardness compared to the control. Furthermore, both UABP flour and FABP flour formulation (F 3) contained the highest nutrients in terms of protein, dietary fibers, amino acids and minerals among the CGF biscuit formulations. The sensory evaluation result showed that FABP flour formulation (F 1) and UABP flour F 1 were most acceptable. [ABSTRACT FROM AUTHOR]

Abstract: The objective of this work was to study the effect of ozone treatment on the quality of bread and its shelf life. Flour was treated with ozone gas a rate of 5 L/min for 5, 15, 25, 35, and 45 min. Baking studies showed that bread made from flour treated with ozone for 15 min exhibited improved quality properties (in terms of specific volume, bread color, and crumb cell numbers). Exposure to ozone for shorter times did not cause obvious changes in the major volatile compounds of bread. A shelf life tests showed that ozone gas treatment influenced the extent of starch crystallinity. The relative starch crystallinity of bread made from flour treated with ozone for 15 min was lower than the control value, as were the hardness, springiness, and cohesiveness. Microscopic examination of crumb structure revealed remarkable differences between control and treated breads. Practical applications: Although ozone is a naturally occurring substance found in the atmosphere, ozone can also be produced synthetically. Recently, ozone has come to be regarded as a new treatment for flour. Especially in countries where the chlorination is forbidden, ozone treatment may be of a great interest if it were associated with significant and reliable changes in flour. Ozone treatment of wheat flour tends to improve bread shelf life and quality in terms of physiochemical, baking properties, X‐ray diffraction data, volatile compound levels, crumb structure, and textural characteristics. Given such findings, desirable shelf life and bread qualities may be achieved when ozone is used as a flour oxidant prior to bread baking. Analyses of the effects of ozone gas on treatment of flour on bread shelf life and quality would aid the production of high quality and extend the shelf life of bread. [ABSTRACT FROM AUTHOR]

We examined the physicochemical and functional properties of whole grain flour (WGF) treated with ozone gas at 5 g/h for 0, 5, 15, 35, and 45 min. The water and oil absorption, swelling power, and solubility all increased significantly with increasing ozonation time, while the pasting properties showed significant decreases in peak viscosity, trough, breakdown, final, and setback viscosity values (all p  ≤ 0.05). Structural analysis revealed changes in the intensities of the O–H, C–H, and CH 2 bending vibrations of protein side chains and lipids with increasing ozonation time. Ozone affected the mean particle size of WGF. Confocal laser scanning microscopy examination of WGF revealed remarkable differences between control and treated flours. [ABSTRACT FROM AUTHOR]

This paper studied the inhibition of water extract of natural or baked black tea on the activity of α-amylase and α- glucosidase. Baking treatment was found to be one effective way to enhance the inhibition of black tea on both α-amylase and α- glucosidase, and IC 50 of water extract of baked black tea (BBTWE) were 1.213 mg/mL and 4.190 mg/mL, respectively, while IC 50 of water extract of black tea (BTWE) were 1.723 mg/mL and 6.056 mg/mL, respectively. This study further studied the mechanism of the effect of water extract on α-amylase and α- glucosidase using HPLC, circular dichroism, and synchronous fluorescence. HPLC analysis of tea polyphenols showed that the content of tea polyphenols with low polarity increased after baking. In addition, BBTWE had higer abilty on decreasing the hydrophobicity of tryptophan residues than BTWE for both α-amylase and α- glucosidase.The increase of α-helix proportion of α-amylase when treated with BBTWE was more obvious than that when treated with BTWE. In a word, thermal process of baked foods may be beneficial for tea polyphenols to reduce the rate of starch digestion. [ABSTRACT FROM AUTHOR]

We treated whole grain flour (WGF) with ozone gas applied at 5 g/h over intervals of 0, 5, 15, 35, and 45 min. We extracted oil from whole grain flour treated and untreated with ozone gas to investigate how the ozone affected the fatty acid composition. The fatty acid value decreased in the treated flour, whereas the peroxide and p -inisidine values increased with ozone gas treatment. The lipase activity was lower in oil extracted from the flour that had been ozonated for more than 35 min compared to the control sample. We also observed levels of oxidation in the volatile compounds heptanal, hexanal, tetradecane, decanal, 1-hexanol, and nonanal after ozone treatment. The oils extracted from the ozone-treated flour showed higher phenolic content and antioxidant activity. [ABSTRACT FROM AUTHOR]

BACKGROUND Bitter taste is the main limiting factor for various applications of protein hydrolysates. Frequently used physicochemical methods for debittering protein hydrolysates come with some undesired side effects. Deamidation-induced modification would be a very promising technique to improve the flavor of wheat gluten hydrolysates ( WGHs). This study was designed to determine the effect of deamidation with certain enzymes or acid treatment on the chemical composition, bitterness and umami properties of WGHs. The difference between umami peptide and free glutamic acid on the suppression of bitterness is emphatically discussed. The optimal scheme is proposed based on the flavor of WGHs and the yield of peptides. RESULTS The generation of umami substances suppressed bitter signal transduction. When the content of umami substances was relatively high, the umami-enhancing properties of umami peptides were obviously effective. The intensity of umami taste was high enough to further suppress bitter taste in the course of neurocognitive functioning. CONCLUSION When WGHs were treated with Glutaminase for 180 min, the umami taste score increased from 1.62 to 4.27 and the bitter taste score decreased from 1.33 to 0.65. © 2016 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

This study compared the deterioration of pre-fermented frozen dough in 1–90 days frozen storage (FS) and 1–4 times of freeze–thaw cycles (FT) by analysing the characteristics of steamed bread, its dynamic rheology and rheofermentation properties, gluten aggregation, yeast viability, cell microstructure and yeast metabolites. The results showed that the specific volume and hardness of steamed bread after 25 days of FS and 1 FT were unacceptable. The decrease in the elasticity modulus and the increase in the viscosity modulus caused by FT were more obvious than those caused by FS. The rheofermentation results indicated that both FS and FT decreased the gas retention and gas production ability, but more significant negative effect was observed during FT than during FS. Further investigation of the gluten aggregation showed that the glutenin macropolymer decreased during FS and FT whether yeast was added or not to the dough, and the yeast increased the decline rate from 0.24 to 0.52 when FT was conducted, which indicated that the yeast had a negative effect on gluten aggregation. The yeast viability and microstructure showed no significant difference during FS and FT, whereas the yeast metabolites results demonstrated that the glucose and fructose contents increased during FS but decreased during FT, which indicate a difference in yeast metabolism. Fructose and glucose could be the indicators of the difference in the deterioration mechanism of FS and FT based on the factor analyses. This study provided novel insights on the deterioration mechanism of pre-fermented frozen dough. [Display omitted] • Elasticity and gas retention of frozen dough decreased more during freeze-thaw than frozen storage. • Yeast increased the decline rate of glutenin macropolymer in frozen dough. • Yeast metabolism was related to the deterioration mechanism of frozen dough. • Glucose and fructose increased during frozen storage, but decreased during freeze-thaw. [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]

• The freeze–thaw tolerance of yeast enhanced with antimicrobial ε-poly- l -lysine. • ε-Poly- l -lysine treated yeast kept high cell viability after 4 times of freeze–thaw. • Fatty acid synthesis pathway of yeast was promoted by ε-poly- l -lysine treatment. • Relative trehalose level increased in ε-poly- l -lysine treated yeast during freeze–thaw. • ε-Poly- l -lysine inhibited TCA cycle and induced high freeze–thaw tolerance of yeast. Antimicrobial polycationic peptide ε-poly- l -lysine (ε-PL) enhanced the freeze–thaw tolerance of industrial yeast; the enhancement mechanism of ε-PL on yeast was studied. Results showed that a ε-PL coating was observed in ε-PL-treated yeast. After 4 times of freeze–thaw, the cell viability, glycerol content, and CO 2 production of 0.6 mg/mL ε-PL-treated yeast were higher than those of untreated yeast, specifically, the cell viability of ε-PL-treated yeast was 87.6%, and that of untreated yeast was 68.5%. Metabolomic results showed that the enhancement mechanism of ε-PL on yeast was related to the promotion of cell membrane-related fatty acid synthesis pathways before freeze–thaw treatment, and the promotion of trehalose biosynthesis and glycerophospholipid metabolism pathways after freeze–thaw. Furthermore, ε-PL induced inhibition of the tricarboxylic acid cycle, resulting in a longer stationary phase at the beginning of the freeze–thaw and ultimately providing a higher level of freeze–thaw stress tolerance than untreated yeast. [ABSTRACT FROM AUTHOR]

Highlights: [•] PSG-1 significantly improved endothelium-dependent relaxation of aorta. [•] PSG-1 significantly increased NO & eNOS levels in aorta of diabetic rats. [•] PSG-1 against endothelial dysfunction in connection with activating the PI3K/Akt/eNOS pathway. [•] PSG-1 against apoptosis by decreasing the ratio of Bax to Bcl-2. [Copyright &y& Elsevier]

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]

• Egg white protein promoted the textural properties of textured wheat gluten. • Egg white protein improved the fibrous structure of textured wheat gluten. • The extent of protein aggregation increased with egg white protein addition. • Disulfide bonds are the main cause of the improvement of fibrous structure. The effect of egg white protein addition on the fibrous structure and protein aggregation of textured wheat gluten (TWG) extrudates was investigated. The hardness, springiness, chewiness, and degree of texturization of TWG significantly increased with the addition of egg white protein. Analysis of morphological characteristics showed a positive effect of egg white protein on the formation of the fibrous structure of TWG. The results of size-exclusion high performance liquid chromatography (SE-HPLC) indicated that the egg white protein improved the degree of wheat gluten aggregation, and the analysis of the protein intermolecular forces proved that disulfide bonds were the main contributor to the cross-linking of protein. In addition, an increase in the β-sheets also indicated an increase in protein aggregation induced by egg white protein. The addition of egg white protein promoted protein interactions and improved the fibrous structure of TWG. [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: The protective effects of the enzymatic hydrolysates of wheat germ protein isolate against the cytotoxicity and apoptosis produced by exposure to H2O2 in PC12 cells were investigated in this work. The cytotoxicity was assessed by cell viability, morphological characteristics, lactate dehydrogenase (LDH) release, the activities of antioxidant enzymes, and malondialdehyde (MDA) production. The apoptosis was monitored by flow cytometry. The results indicated that pretreatment of PC12 cells with WGPIH, prior to H2O2 exposure, significantly increased the survival of cells and the activities of catalase (CAT) and superoxide dismutase (SOD), and reduced the levels of LDH and MDA. The presence of WGPIH attenuated H2O2-induced apoptosis in PC12 cells as evidenced by flow cytometric detection of sub-G1 DNA content and Annexin V assay. The reduction in mitochondrial membrane potential and accumulation of intracellular Ca2+ were also inhibited by WGPIH treatment. These findings suggest that WGPIH can protect PC12 cells against H2O2-induced oxidative stress as a neuroprotective agent. [Copyright &y& Elsevier]

Abstract: The objective of this research was to evaluate the antimicrobial, antioxidant and darkening inhibitory activities of Maillard reaction products (MRPs) prepared from chitosan and xylose, and their effects on the preservation and quality of semi-dried noodles. The development of brown color and UV absorbance changes indicated the proceeding of Maillard reaction. The antimicrobial activity, reducing power, DPPHscavenging activity, copper-chelating activity and PPO inhibitory effects of chitosan–xylose conjugates increased with the reaction. Addition of MRPs could improve the textural and cooking quality of semi-dried noodles. Incorporation of 0.35% MRPs (6h) into semi-dried noodle resulted in an extension of shelf life for more than 7 days than the control noodles (at room temperature). The discoloration caused by the addition of MRPs was limited, and MRPs could inhibit darkening of the noodle effectively. Results suggested that the MRPs could be used as a novel promising preservative for semi-dried noodles. [Copyright &y& Elsevier]

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]

Abstract: Defatted wheat germ (DWG) is the main by-product of the wheat germ oil extraction process. Its nutritional value has well been accepted. In this study, the antioxidant properties of 30% ethanol, 50% ethanol, 70% ethanol, 100% ethanol, and aqueous extracts of DWG were measured using various in vitro assays. Among the DWGEs (DWG extracts) tested, the 70% ethanol extract showed the best DPPH radical scavenging power while the 100% ethanol extract showed the highest ABTS radical scavenging activity and reducing power. In addition, both the 70% ethanol extract and the 50% ethanol extract exhibited relatively higher antioxidant activity in linoleic acid system. The extracts in question exhibited total phenolic contents ranging from 13.98 to 16.75mg GAE/g. DWG, as a source of natural antioxidants, can be used to formulate nutraceuticals with potential applications to reducing the level of oxidative stress. The antioxidant potency of the DWG extracts could be the basis for its health promoting potential. [ABSTRACT FROM AUTHOR]

Wheat gluten was hydrolysed by Alcalase 2.4L under ultrasound. Different antioxidant assays in vitro, such as ferrous ion-chelating activity, reducing power, inhibition of linoleic acid emulsion peroxidation and 2,2′-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) radical scavenging activity, were employed to evaluate the antioxidant activities of the wheat gluten hydrolysate (WGH) obtained. It was found that WGHL (WGH which was obtained by low frequency (LF) ultrasound) exhibited the strongest antioxidant activities, with an EC value of 0.513 mg mL for ferrous iron-chelating activity, as well as a high and dose-dependent reducing power. In the linoleic acid system, a longer induction time indicated a significant decrease of lipid peroxidation. In addition, WGH also exhibited notable ABTS radical scavenging activity. A good correlation was observed between antioxidant activities and the amount of WGH, but a poor correlation was observed between antioxidant activities and degree of hydrolysis. The molecular weight distribution of WGH was affected by ultrasonic frequency and WGHL had the highest proportion of peptide fractions of molecular weight 3000-500 Da. All the results showed that the WGH treated by ultrasound had strong antioxidant activities and low molecular weight. [ABSTRACT FROM AUTHOR]

Abstract: The functional properties and secondary structures of defatted wheat germ protein separated by reverse micelles (DWGRMPI) were investigated and compared with those of defatted wheat germ protein separated by alkaline extraction and isoelectric precipitation (DWGPI). The results showed that DWGRMPI had a higher nitrogen solubility index, fat absorption capacity, foaming capacity, foaming stability and emulsifying stability compared to DWGPI, whilst water holding capacity, surface hydrophobicity and emulsifying activity of DWGRMPI were relatively lower than those of DWGPI. DWGRMPI contained high levels of threonine, histidine, alanine, arginine, glycine, serine, cysteine, proline and especially lysine compared to DWGPI. The denaturation temperature and denaturation enthalpy of DWGPI were both lower than those of DWGRMPI, and DWGPI contained more random coil and less α-helix than DWGRMPI, which suggested that DWGPI has lost its ordered secondary structure. This may possibly due to the conditions the used in protein extraction. [Copyright &y& Elsevier]

Abstract: In this work, an ultrasound-assisted procedure for the extraction of defatted wheat germ proteins by reverse micelles was established. Response surface methodology (RSM) was used to optimize the ultrasound-assisted extraction (UAE) parameters (ultrasonic output power, ultrasonic time and pulse mode) for enhancing the forward extraction efficiency of defatted wheat germ proteins by implementing a three-level, three-variable Box–Behnken experimental design. The independent variable with the largest effect on response was X 2 (ultrasonic time), followed by X 1 (ultrasonic output power) and X 3 (pulse mode). The optimum extraction conditions were found to be ultrasonic output power 363W, ultrasonic time 24min and pulse mode 2.4s on and 2s off (2.4s:2s). Under these conditions, the forward extraction efficiency of defatted wheat germ proteins can increase from 37% to 57%, and the final protein extraction efficiency by reverse micelles can reach 45.6%, making the advantage of reverse micelles much more obvious than alkaline extraction and isoelectric precipitation on the separation of protein. [Copyright &y& Elsevier]

Abstract: In this work, a novel backward extraction procedure of defatted wheat germ protein (DWGP) from reverse micelles was explored. Isooctane was recovered by vaporization firstly. Then the remained residue was dissolved in a small amount of KCl solution. The recovery of DWGP was easily performed by the ternary liquid system (acetone: deionized water: isooctane=15:5:1) precipitation, while most of sulphosuccinic acid bis (2-ethylhexyl) ester sodium salt (AOT) remained in the ternary liquid system. In the end, the precipitation of DWGP was washed with 65% ethanol solution to further remove any residual AOT. The effects of KCl concentration, the amount of KCl solution and pH on the backward extraction efficiency of DWGP were tested. On the basis of single-factor experiments, the optimum backward extraction was achieved by response surface methodology (RSM). When the operation ran under optimized conditions, the backward extraction efficiency of DWGP achieved 80% and the end protein product was completely free of AOT. Industrial relevance: This experimental result confirmed that this novel backward extraction method had many advantages on the extraction of protein compared to the traditional backward extraction method (changing the conditions of pH and ionic strength in a fresh aqueous phase). This method increased the backward extraction efficiency of defatted wheat germ protein (DWGP) from 57% to 80%, saved the water resource and offered the possibility of precipitating nearly pure DWGP, completely free of surfactant. On the basis of these advantages, it appears that this novel backward extraction technique may have great potential for being scaled-up to a commercially extraction process of protein. [Copyright &y& Elsevier]

Abstract: In this work, the forward extraction of defatted wheat germ protein (DWGP) by reverse micelles was studied. The reverse micellar systems were formed by sulphosuccinic acid bis (2-ethylhexyl) ester sodium salt (AOT), isooctane and KCl solution. The effects of AOT concentration, pH, KCl concentration, extraction time, the amounts of defatted wheat germ flour (DWGF), W 0 (the molar ratio of water to surfactant, i.e. W 0 =[H2O]/[AOT]) and temperature on the forward extraction efficiency of DWGP were tested. On the basis of single-factor experiments, the optimum extraction was achieved by response surface methodology (RSM). The experimental results lead to the conclusion that the highest forward extraction efficiency of DWGP was reached at the AOT concentration 0.06g/mL, pH 8, KCl concentration 0.1mol/L, time 30min, the amounts of DWGF 0.500g, W 0 25 and temperature 36°C. Under these conditions, the forward extraction efficiency of DWGP achieved 37%. [Copyright &y& Elsevier]

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]

Plant protein-based meat analogs have attracted attention as alternatives to meat products. To improve the fibrous structure of textured wheat gluten (TWG), different phosphates (sodium tripolyphosphate, sodium pyrophosphate, and sodium hexametaphosphate) were added to wheat gluten at different concentrations (0%, 0.25%, 0.5%, 1%, and 2%) during extrusion cooking. Analysis of the morphological characteristics showed the positive effect of sodium tripolyphosphate on the formation of the fibrous structure of TWG. The textural properties and degree of fibrous structure of TWG significantly improved with sodium tripolyphosphate treatment. Higher specific mechanical energy and lower bulk density were observed in the TWG treated with sodium pyrophosphate than in the control. The sodium dodecyl sulfate (SDS)-extractable protein results showed that sodium tripolyphosphate promoted the extent of gluten polymerization, but the other two phosphates had negative effects. The increased thermal stability of the sodium tripolyphosphate treatment group indicated stronger bonds conformation. The β-sheets content increased with sodium tripolyphosphate treatment. X-ray photoelectron spectroscopy results showed that the phosphate group was successfully introduced into the TWG treated with sodium tripolyphosphate via a phosphorylation reaction. The decrease in elastic modulus and viscous modulus observed with sodium tripolyphosphate treatment was related to changes in surface charges and the water layer of protein, which were affected by PO 4 3−. Thus, sodium tripolyphosphate is a promising candidate that can be used for the improvement of the fibrous structure of TWG. [Display omitted] • Sodium tripolyphosphate treatment significantly improved the fibrous structure of textured wheat gluten. • The extent of protein aggregation increased with sodium tripolyphosphate treatment. • Sodium tripolyphosphate treatment improve the thermal stability, indicating a stronger bonds conformation. • PO 4 3− introduced to protein via phosphorylation reaction with sodium tripolyphosphate treatment. [ABSTRACT FROM AUTHOR]

This work investigated the improvement mechanism of transglutaminase (TG) on the buckwheat-wheat steamed bread qualities from the view of protein structural, foaming and air-water interfacial properties of dough liquor (DL). TG reduced the hardness, ameliorated the crumb structure and enhanced the specific volume of buckwheat-wheat steamed bread by up to 9.0%. The DL yield, protein and water recovery were notably increased as the TG concentration increased to 0.2 U/g, then decreased with the higher TG concentrations. The low TG concentrations (<0.2 U/g) increased the protein molecular weight, and decreased the protein hydrophobicity, free amino and sulfhydryl groups content of DL. The high TG concentrations (>0.2 U/g) tended to induce both protein intermolecular and intramolecular cross-linking, which reduced the average particle size from 9.6 to 4.3 μm as the TG concentration increased from 0.2 to 1.0 U/g. TG markedly improved the foaming capacity and foam stability, decreased the surface tension and strengthened the interfacial films by enhancing the viscoelasticity modulus of buckwheat-wheat DL interfacial protein films. The topography of the air-water interfacial layer revealed that the TG-induced protein cross-linking led to a more homogeneous and denser topographical structure. This work will provide fresh insight into the effects of TG-induced protein cross-linking on gas cell stabilization and relate them to the buckwheat-wheat steamed bread quality properties. [Display omitted] • TG improved the specific volume and crumb structure of buckwheat-wheat steamed bread. • TG induced the protein intramolecular and intermolecular cross-linking in buckwheat-wheat dough liquor. • TG enhanced the foaming capacity and foam stability of buckwheat-wheat dough liquor. • TG strengthened the viscoelasticity of air-water interfacial films of buckwheat-wheat dough liquor. [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]

Summary: This research explored the effect and mechanism of aspartic acid (Asp) on the darkening of fresh wet noodles (FWNs). With increase in the addition of Asp (0.1%‐0.9%), ΔL* and pH of FWN reduced significantly (P < 0.05). Asp could reduce polyphenol oxidase (PPO) activity and increase its retention rate of polyphenol of FWN. When FWNs were adjusted to the same pH by Asp, malic acid (Mal) and hydrochloric acid (HCl), ΔL* and PPO activity of FWN with Asp were lower than that of other two acids. In the vitro PPO solution, the inhibitory effect of Asp on PPO activity was related to the decrease in pH and the ability of chelating Cu2+. According to UPLC‐TOF‐MS analysis, Asp could also react with PPO browning products (‐C12H9O4, ‐C24H19O2 and ‐C12H7O5), transforming browning products into some light‐coloured products. Asp effectively inhibited the darkening of FWN and had the potential use in noodle industry. [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]

[Display omitted] • Endogenous polyphenols (EP) inhibited starch digestion in highland barley noodles. • EP caused disorder and rearrangement of starch molecules' structure. • EP transformed the starch fractions to be more resistant to thermal degradation. • EP reduced rapidly digestible starch by forming V-type structure with amylose. • EP increased resistant starch by lengthening amylopectin chain to form complexes. Highland barley is a type of grain with slow-digesting characteristics. It is worth exploring the impact of non-starch components on starch digestion. In this study, four varieties of highland barley were used to investigate the impacts of endogenous polyphenols (EP) on the relationship between starch structure, physicochemical properties, and the time course digestibility of highland barley noodles. The results showed that EP removal decreased the proportion of long-chain amylopectin and disrupted the crystalline structure, while increasing the short-range ordered structure in the residue. Significant correlations indicated that these structural changes make starch more susceptible to thermal degradation and digestion, causing a 12.60%-52.00% increase in rapidly digestible starch (RDS) and a 12.70%-25.22% decrease in resistant starch (RS). These results revealed the internal factors that affect the slow digestion characteristics of highland barley noodles from the perspective of EP and provide important reference values for a slow digestion diet. [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]

This study elucidated the alkali-induced protein cross-linking behaviors of buckwheat sourdough steamed bread (BSSB). When the alkali concentration increased to 1.5% (on a total flour weight basis), the protein extractability in sodium dodecyl sulfate (SDS) decreased by 2.29% while the disulfide (SS) bond content increased by 5.97 μmol/g protein, indicating that the alkali promoted the SS cross-linking of the proteins. The formation of dehydroalanine (DHA) and lanthionine (LAN) at alkali concentrations of 2.0% and 2.5% demonstrated the occurrence of DHA-derived cross-linking. To explore the role of SS cross-linking in the quality of BSSB, the thiol-blocking agent N-ethylmaleimide (NEM) was also employed. It was determined that the BSSB with NEM had almost no gas cells and that the specific volume was 48.41% lower than the control. The alkali increased the specific volume by up to 26.75% at 2.0% concentration and ameliorated the crumb structure of the BSSB. Dynamic thermo-mechanical analysis revealed that the alkali also delayed the starch gelatinization and gas cell opening, which may have contributed to the gas holding capacity of the BSSB. The amino acid residues involved in the DHA-derived cross-linking and the potential cross-linking sites were identified via liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. It was found that both the Cys197 from wheat peroxidase and the Cys105 from the wheat alpha-amylase/trypsin inhibitor CM16 were crucial to the formation of the DHA-derived cross-links and that the LAN between two cysteines was inter-chain. [Display omitted] • The formation of gas cells largely depends on disulfide cross-linking. • Dehydroalanine-derived cross-linking occurred at 2.0% and 2.5% alkali addition. • Lanthionine between two cysteines was inter-chain. [ABSTRACT FROM AUTHOR]

Summary: The effect of adding barley (Hordeum vulgare L.) β‐glucan (BBG) to dough on the water redistribution and the thermal properties of dough was studied by TGA and DSC. Combined with LF‐NMR to analyse the competition and redistribution mechanism of water at the 1H level. The mass loss of the dough measured by TGA was reduced by an average of 2.11% with BBG added. BBG increased the water retention of the dough, delayed the water loss process. The LF‐NMR results showed that at the same water absorption the T21 of the 3% BBG dough was longer while its T22 was shorter than those of the control. BBG has different effects on the different states of water in the dough. BBG increased the free sulfhydryl content in dough during heating, while the adverse effects of BBG on the biopolymer reactions, such as disulfide bond, could be partially relieved by regulating water content. [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]

Highlights • NaHCO 3 or Na 2 CO 3 addition improved the specific volume of buckwheat Chinese steamed bread. • Alkali addition improved texture properties with increased crumb hardness and resilience. • Alkali addition reduced the extractability of protein in sodium dodecyl sulfate containing medium. • Alkali addition prompted protein to form disulfide and dehydroalanine-derived cross-linkings. Abstract The effects of alkali (NaHCO 3 or Na 2 CO 3) on the quality and protein polymerization of buckwheat Chinese steamed bread (CSB) were investigated. The alkali addition increased the specific volume of CSB, for NaHCO 3 from 1.84 ml/g (control) to 2.66 ml/g. Image analysis showed that alkali increased the pore area fractions. The addition of Na 2 CO 3 exhibited a greater pore count and lower pore average size. The texture properties were improved with the increase of crumb hardness and resilience. The extractability of protein in sodium dodecyl sulfate containing medium (SDSEP) decreased. Furthermore, SDS–PAGE showed an obvious decrease in the intensity of protein bands with lower molecular weight, while intensity of higher molecular protein bands increased. This demonstrated that alkali addition promoted protein aggregation in buckwheat CSB. In addition, the content of degydroalanine and lanthionine increased and free SH decreased, which indicated alkali addition prompted protein to form dehydroalanine-derived and disulfide cross-linkings. [ABSTRACT FROM AUTHOR]

Highlights • The discoloration of green tea noodles was investigated and improved. • One processing method inhibited the polyphenol oxidase activity. • Chlorophyll loss and degradation were decreased by this processing method. • CLSM revealed the microstructures of the green tea noodles. Abstract Different methods used to process green tea powder noodles (GTPN) were compared by analyzing the quality and chemical components of the final products. Significant differences were observed in the discoloration rate, color loss, and lightness of all noodles. Polyphenol oxidase activity was effectively inhibited through the heat treatment, resulting in retardation of the GTPN discoloration rate. However, heat-exposed GTPN showed a higher surface lightness due to a greater loss of chlorophyll. The chlorophyll contents of GTPN prepared with a new method (a combination of water treatment and heat exposure) were prominently higher than those prepared by heat treatment alone, and exhibited less color loss. The heat-exposed noodles had relatively low free polyphenol contents, and their textural properties were not significantly decreased after 28 d. Therefore, combining water treatment and heat exposure in the preparation process has great potential for increasing the stability of GTPN. [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]

Summary: The aim of this study was to investigate the effects of arabinoxylan with different molecular weight on the wheat dough thermo‐mechanical, rheological, microstructural and water mobility properties. Arabinoxylan was extracted from wheat bran and hydrolysed by endo‐1,4‐β‐xylanase (EC 3.2.1.8 from Trichoderma reesei, 10 000 U g−1) for 2 min (AXM) and 10 min (AXL), respectively. The addition of hydrolysed arabinoxylan AXL increased the stability time, decreased the setback value of wheat dough and enhanced the values of storage modulus (G′) and loss modulus (G″), while unhydrolysed arabinoxylan (AXH) reduced these values. Meanwhile, unhydrolysed arabinoxylan increased T2 relaxation time while hydrolysed arabinoxylan AXL decreased T21 and T22. Confocal laser scanning microscope (CLSM) results showed that the addition of hydrolysed arabinoxylan AXL promoted the formation of a more compact and continuous protein network in wheat dough. These results revealed that compared with high molecular weight arabinoxylan, hydrolysed arabinoxylan could improve the rheological properties and processing properties of wheat dough by enhancing the interaction among water molecules, starch and gluten in wheat dough. [ABSTRACT FROM AUTHOR]

The impact of alkali addition on the degree of gluten polymerization and textural characteristics of textured wheat protein was investigated. Results showed that the extrusion process increased the average molecular weight of gluten as evidenced by SDS-PAGE and SDS extractable protein. The addition of alkali not only promoted the degree of gluten polymerization, but also induced dehydroalanine-derived cross-linking. Alkali addition decreased the content of cystine and increased the contents of dehydroalanine and lanthionine. The obvious decrease of free SH showed that dehydroalanine-derived cross-linking was quantitatively less crucial than disulfide cross-linking. Furthermore, the protein cross-linking induced by alkali improved the texture properties of gluten extrudates. SEM analysis showed extrusion under alkaline condition conferred a more fibrous microstructure as a consequence of a compact gluten network. [ABSTRACT FROM AUTHOR]

The present study investigated the combined effects of aqueous ozone treatment and modified atmosphere packaging (MAP) on prolonging the shelf-life of semi-dried buckwheat noodles [SBWN; moisture content (22.5 ± 0.5%)] at 25 °C. Firstly, the different concentrations of ozonated water were used to make SBWN. Subsequently, SBWN prepared with ozonated water were packaged under six different conditions and stored for 11 days. Changes in microbial, chemical-physical, textural properties and sensorial qualities of SWBN were monitored during storage. Microbiological results indicated that adopting 2.21 mg/L of ozonated water resulted in a 1.8 log 10 CFU/g reduction of the initial microbial loads in SBWN. In addition, MAP suppressed the microbial growth with a concomitant reduction in the rates of acidification and quality deteriorations of SBWN. Finally, the shelf-life of sample packed under N 2 :CO 2 = 30:70 was extended to 9 days, meanwhile textural and sensorial characteristics were maintained during the whole storage period. [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, the effects of microwave treatment on the microorganism mortality and PPO activity in whole-wheat flour (WWF) and storage stability of WWF fresh noodles were investigated, as well as the rheological properties of WWF, viscosity and gelatinization properties of starch component, and polymerization and conformational changes of protein. TPC and PPO activity were largely reduced in WWF treated for over 60s. Moreover, it was amazing that microwave treatment significantly increased ( P < 0.05) dough stability and the resistance to extension. Peak and final viscosity of starch were increased after microwave treatment, with no observable loss of birefringence; SDS-extractable proteins were limitedly decreased and protein aggregating occurred mainly on the large and medium glutenin polymers as shown by the SE–HPLC profiles. In addition, microbial growth and darkening rate of WWF fresh noodles were significantly inhibited, shelf-life of the samples was extended for 3 times after treating for 90 s. [ABSTRACT FROM AUTHOR]