Effect of vacuum mixing on the quality characteristics of fresh noodles

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

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

Wheat starch particle size distribution regulates the dynamic transition behavior of gluten at different stages of dough mixing

This study investigated the morphology distribution, molecular structure, and aggregative properties variation of gluten protein during dough mixing stage and interpreted the interaction between starch with different sizes and protein. Research results indicated that mixing process induced glutenin macropolymer depolymerization, and promoted the monomeric protein conversion into the polymeric protein. Appropriate mixing (9 min) enhanced the interaction between wheat starch with different particle sizes and gluten protein. Confocal laser scanning microscopy images showed that a moderate increase in B-starch content in the dough system contributed to forming a more continuous, dense, and ordered gluten network. The 50A-50B and 25A-75B doughs mixed for 9 min exhibited a dense gluten network, and the arrangement of A-/B-starch granules and gluten was tight and ordered. The addition of B-starch increased α-helixes, β-turns, and random coil structure. Farinographic properties indicated that 25A-75B composite flour had the highest dough stability time and the lowest degree of softening. The 25A-75B noodle displayed maximum hardness, cohesiveness, chewiness, and tensile strength. The correlation analysis indicated that starch particle size distribution could influence noodle quality by changing the gluten network. The paper can provide theoretical support for regulating dough characteristics by adjusting the starch granule size distribution.

Factors Affecting the Nutritional, Health, and Technological Quality of Durum Wheat for Pasta-Making: A Systematic Literature Review

Durum wheat is one of the most important food sources in the world, playing a key role in human nutrition, as well as in the economy of the different countries in which its production areas are concentrated. Its grain also represents a staple and highly versatile ingredient in the development of health foods. Nonetheless, the aspects determining durum wheat's health quality and their interactions are many, complex, and not entirely known. Therefore, the present systematic literature review aims at advancing the understanding of the relationships among nutritional, health, and technological properties of durum wheat grain, semolina, and pasta, by evaluating the factors that, either positively or negatively, can affect the quality of the products. Scopus, Science Direct, and Web of Science databases were systematically searched utilising sets of keywords following the PRISMA guidelines, and the relevant results of the definitive 154 eligible studies were presented and discussed. Thus, the review identified the most promising strategies to improve durum wheat quality and highlighted the importance of adopting multidisciplinary approaches for such purposes.

Effect of sodium bicarbonate on the physicochemical properties of fermented rice flour and quality characteristics of fermented semi-dried rice noodles

Considering the effect that fermentation can improve the quality of rice noodles, and given that fermented rice noodles usually have a significantly acidic taste that is not generally acceptable to consumers, this study aimed to neutralize or eliminate the acidic taste of fermented rice noodles by adding sodium bicarbonate, and improve the quality of fermented rice noodles. The physicochemical properties of fermented rice flour and quality characteristics of fermented semi-dried rice noodles were investigated in this study in relation to the addition of sodium bicarbonate (0∼0.5%, w/w). With the increase of sodium bicarbonate addition, the pH value was increased, and lipid and protein content were decreased in rice flour. Meanwhile, thermal properties and farinograph properties showed that the pasting temperature, dough water absorption, dough development time and dough stability time of rice flour increased with the addition of sodium bicarbonate. Pasting properties and rheological properties results showed that a small amount of sodium bicarbonate (0∼0.1%) could increase the pasting viscosity, storage modulus (G'), and loss modulus (G″) of rice flour. Additionally, the hardness and chewiness of semi-dried rice noodles increased with the addition of sodium bicarbonate from 0 to 0.1%. With the addition of a small amount of sodium bicarbonate (0∼0.1%), x-ray diffraction showed that it could increase the crystallinity of semi-dried rice noodles. Low-field nuclear magnetic resonance showed that A₂₁ increased, and A₂₂ and A₂₃ decreased in semi-dried rice noodles. Scanning electron microscope showed that it could enhance the starch-protein interaction and starch-protein formed an ordered and stable network structure. Finally, the principal component analysis showed that the chewiness, texture and eating quality of semi-dried rice noodles were the best with the addition of sodium bicarbonate at 0.1%. This study provides practical value for the application of alkali treatment in rice products and provides a reference for the improvement of related rice noodles products.

Study on the quality characteristics of hot-dry noodles by microbial polysaccharides

The effect of curdlan gum (CG), gellan gum (GG), and xanthan gum (XG) on the quality characteristics of hot-dry noodles (HDN) was investigated. The rheology properties were used to evaluate the quality of the dough, the textural, viscosity, cooking characteristics and water states were investigated to study the quality changes of HDN. Three microbial polysaccharides were found that it could improve the quality of wheat flour and significantly increase the starch viscosity of HDN and delay the water migration rate of HDN. When 0.2% CG, 0.5% GG, and 0.5% XG were added, the HDN showed the best flour swelling power, texture, and tensile properties, and the structure of gluten network was significantly improved. The flourier transform infrared spectroscopy results showed that microbial polysaccharides with appropriate concentrations changed the formation of hydrogen bond in HDN, decreased α-helix and increased β-turn content. Meanwhile, the relative continuous and complete gluten network was formed, which could be proven by microstructure observation. This study provides a reference for functionality applications of HDN with microbial polysaccharides.

Effect of Frozen Treatment on the Sensory and Functional Quality of Extruded Fresh Noodles Made from Whole Tartary Buckwheat

Extruded noodles made from whole Tartary buckwheat are widely known as healthy staple foods, while the treatment of fresh noodles after extrusion is crucial. The difference in sensory and functional quality between frozen noodles (FTBN) and hot air-dried noodles (DTBN) was investigated in this study. The results showed a shorter optimum cooking time (FTBN of 7 min vs. DTBN of 17 min), higher hardness (8656.99 g vs. 5502.98 g), and less cooking loss (5.85% vs. 21.88%) of noodles treated by freezing rather than hot air drying, which corresponded to better sensory quality (an overall acceptance of 7.90 points vs. 5.20 points). These effects on FTBN were attributed to its higher ratio of bound water than DTBN based on the Low-Field Nuclear Magnetic Resonance results and more pores of internal structure in noodles based on the Scanning Electron Microscopy results. The uniform water distribution in FTBN promoted a higher recrystallization (relative crystallinity of FTBN 26.47% vs. DTBN 16.48%) and retrogradation (degree of retrogradation of FTBN 34.67% vs. DTBN 26.98%) of starch than DTBN, strengthening the stability of starch gel after noodle extrusion. FTBN also avoided the loss of flavonoids and retained better antioxidant capacity than DTBN. Therefore, frozen treatment is feasible to maintain the same quality as freshly extruded noodles made from whole Tartary buckwheat. It displays significant commercial potential for gluten-free noodle production to maximize the health benefit of the whole grain, as well as economic benefits since it also meets the sensory quality requirements of consumers.

The use of time domain 1 H NMR to study proton dynamics in starch-rich foods: A review

Starch is a major contributor to the carbohydrate portion of our diet. When it is present with water, it undergoes several transformations during heating and/or cooling making it an essential structure-forming component in starch-rich food systems (e.g., bread and cake). Time domain proton nuclear magnetic resonance (TD ¹ H NMR) is a useful technique to study starch-water interactions by evaluation of molecular mobility and water distribution. The data obtained correspond to changes in starch structure and the state of water during or resulting from processing. When this technique was first applied to starch(-rich) foods, significant challenges were encountered during data interpretation of complex food systems (e.g., cake or biscuit) due to the presence of multiple constituents (proteins, carbohydrates, lipids, etc.). This article discusses the principles of TD ¹ H NMR and the tools applied that improved characterization and interpretation of TD NMR data. More in particular, the major differences in proton distribution of various dough and cooked/baked food systems are examined. The application of variable-temperature TD ¹ H NMR is also discussed as it demonstrates exceptional ability to elucidate the molecular dynamics of starch transitions (e.g., gelatinization, gelation) in dough/batter systems during heating/cooling. In conclusion, TD NMR is considered a valuable tool to understand the behavior of starch and water that relate to the characteristics and/or quality of starchy food products. Such insights are crucial for food product optimization and development in response to the needs of the food industry.

Delineating the dynamic transformation of gluten morphological distribution, structure, and aggregation behavior in noodle dough induced by mixing and resting

To understand the formation of gluten network and its regulation on noodle qualities upon mixing and resting, the dynamic distribution and molecular transformation of gluten were tracked and quantified. Confocal laser scanning microscopy and scanning electron microscopy images showed that appropriate mixing (8 min) and resting (60 min) induced a compact gluten network with higher gluten junctions. Both height and width of protein molecular chains were increased by hydration during mixing and reduced after excessive resting (90 min). According to the size exclusion/reversed phase-HPLC profiles, mixing induced slight depolymerization of large glutenin polymer, and α-gliadin subunits were more susceptible to polymerization after appropriate mixing and resting. Increased mixing time was accompanied by the strengthening of ionic and hydrogen bonds, and the weakening of hydrophobic interaction. PCA and correlation analysis revealed the accurate regulation of mixing and resting induced dynamic distribution and evolution of gluten on the macroscopic noodle qualities.

Understanding the Changes in Quality of Semi-Dried Rice Noodles during Storage at Room Temperature

The changes in semi-dried rice noodles during storage at room temperature (25 ± 2 °C) in terms of microbial growth, cooking quality, color, textural properties, thermal properties, crystallinity, and moisture content, and moisture distribution was examined. Total plate count, cooked broken rate, cooking loss, and b* value increased, while rehydration ratio, L* value, and moisture content decreased during storage. The hardness, adhesiveness, and chewiness of semi-dried rice noodles increased significantly, according to textural properties. DSC and XRD showed that the enthalpy of thermal absorption and crystallinity of semi-dried rice noodles increased from 1.67 J/g and 3.48% to 4.21 J/g and 18.62%, respectively. LF-NMR showed that the weakly bound water content in semi-dried rice noodles decreased by 3.71%, and the bound water content and free water content increased by 3.20% and 0.51%, respectively. The results of correlation analysis showed that the changes in quality during storage of semi-dried rice noodles were influenced by the combination of microbial growth, aging of rice noodles, and moisture migration.

Effect of Moisture Distribution Changes Induced by Different Cooking Temperature on Cooking Quality and Texture Properties of Noodles Made from Whole Tartary Buckwheat

While precooking and processing have improved the quality of gluten-free noodles, the effects of different cooking temperatures on their quality—neither gluten-free noodles nor whole Tartary buckwheat noodles—have rarely been clarified. This study investigated the key role of moisture distribution induced by different cooking temperatures in improving the noodle quality of whole Tartary buckwheat. The results showed that cooking temperatures higher than 70 °C led to a sharp increase in cooking loss, flavonoid loss and the rate of broken noodles, as well as a sharp decrease in water absorption. Moreover, the noodles cooked at 70 °C showed the lowest rate of hardness and chewiness and the highest tensile strength of all cooking temperatures from 20 °C to 110 °C. The main positive attribute of noodles cooked at 70 °C might be their high uniform moisture distribution during cooking. Cooking at 70 °C for 12 min was determined as the best condition for the quality improvement of whole Tartary buckwheat noodles. This is the first study to illustrate the importance of cooking temperatures on the quality of Tartary buckwheat noodles. More consideration must also be given to the optimal cooking conditions for different gluten-free noodles made from minor coarse cereals.

The effects of extruded endogenous starch on the processing properties of gluten-free Tartary buckwheat noodles

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.

Effects of vacuum degree, mixing speed, and water amount on the moisture distribution and rheological properties of wheat flour dough

Effects of vacuum degrees (0.00, 0.02, 0.04, 0.06, 0.08 MPa) on water distribution state, tensile properties, stress relaxation properties, and viscoelasticity of dough, as well as the effects of mixing speed (50, 70, 90 rpm/min) and water content (40%, 45%, 50%) under optimum vacuum degree were studied. The results showed that the proper vacuum degree (0.06 MPa) could promote the full contact between flour and water and improved the water-holding capacity of the dough. Meanwhile, the dough had stronger tensile strength, the best viscoelasticity and the ability to recover from external deformation more quickly. Under the vacuum of 0.06 MPa, with the increasing of mixing speed, the response to the external force of dough increased first and then decreased. Adding more water reduced the strength of dough, weakened the response to external forces, and led to a significant decrease in tensile resistance and tensile area of the dough, as well as a decrease in viscoelasticity (p < 0.05). The proper vacuum mixing allowed the preparation of dough to require more water and less energy. PRACTICAL APPLICATION: In the processing of wheat flour products, vacuum mixing is considered to be beneficial to the quality of noodles and breads. As the intermediate of these products, the dough is of great significance for the monitoring of its rheological characteristics. In this study, a moderate vacuum degree led to a significant improvement in the rheological properties of the dough, and the processing performance was the best. Under the optimal vacuum degree, the influence of mixing speed and water amount cannot be ignored. Vacuum mixing is an efficient dough preparation method, which can produce certain economic benefits.

Inhibition of L-Cysteine on the Browning of Fresh Wet Noodles

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.

Effect of Drying Methods on Properties of Potato Flour and Noodles Made with Potato Flour

This work investigated the impact of three drying methods on structural and functional properties of potato flour (PF), as well as the quality characteristics of fresh noodles made from wheat-potato flours. The results indicated that ethanol drying (ED) and oven drying (OD) had small effects on the properties of starch in potato flour, however, freeze drying (FD) caused some pores and channels on the starch granules and disruption of the long- and short-range ordered structure of starch. The maximum addition of potato flour in fresh noodles was 40% for FD-PF and 50% for both ED-PF and OD-PF. With increasing addition of potato flour in noodles, the L* (lightness) values of noodles decreased gradually, while the a* (redness) and the b* (yellowness) values, as well as the hardness and springiness values of fresh potato noodles increased. This study clearly showed that drying methods have different effects on the properties of potato flour, and in turn the quality of fresh noodles made with potato flour.

Understanding the deterioration of fresh brown rice noodles from the macro and micro perspectives

The microbial compositions, quality characteristics, and structural changes in fresh brown rice noodles (FBRN) during storage were investigated. Total plate count and mold and yeast counts increased while the pH decreased during storage. Metagenomic sequencing revealed that the microbial composition of FBRN changed throughout storage. A comprehensive investigation of the variation in lipid content demonstrated that hydrolytic rancidity was responsible for lipid deterioration. LF-NMR showed an increase in the proportion of bound water and a decrease in the proportion of free water in FBRN. Moreover, significant changes in edible qualities were observed. The cooking loss increased three-fold and noodles hardness reduced by approximately 23%. Further, the high initial aldehyde content of FBRN diminished almost completely, while that of alcohols and esters increased, leading to significant flavor deterioration. The correlation and factor analysis suggested that the TPC and MY counts could be used as key indicators of FBRN deterioration.

Functional properties of chitosan derivatives obtained through Maillard reaction: A novel promising food preservative

This review provides an insight about the functional properties of chitosan obtained through Maillard reaction to enhance the shelf life and food quality. Maillard reaction is a promising and safe method to obtain commercial water-soluble chitosan's through Schiff base linkage and Amadori or Heyns rearrangement. Likewise, chitosan derivatives exert an enhanced antimicrobial, antioxidant, and emulsifying properties due to the development of Maillard reaction products (MRPs) like reductones and melanoidins. Additionally, the application of chitosan-MRPs effectively inhibited the microbial spoilage, reduced lipid oxidative, and extended the shelf life and the quality of fresh food products. Therefore, understand the potential of chitosan-MRPs derivatives as a functional biomaterial to improve the postharvest quality and extending the shelf life of food products will scale up its application as a food preservative.

Effects of wheat flour particle size on physicochemical properties and quality of noodles

The effect of particle size on the physicochemical and noodle quality of wheat flours was investigated. Granular wheat flour was ground by adjusting the distance between the rolls (0.02, 0.04, 0.06, 0.08, and 0.1 mm) of the flour mill to obtain wheat flour in five different particle sizes. The results showed that milling intensity significantly reduced the particle size and increased the damaged starch content and sedimentation value, but there were no significant differences in protein or ash contents. The reduction of wheat flour particle size significantly decreased the peak viscosity, trough viscosity, final viscosity, breakdown, and setback of the blends, while there were no significant differences in pasting temperature. Stress relaxation characteristics indicated that as the particle size of wheat flour decreased, dough hardness increased. The noodles made from wheat flour with a smaller particle size had a higher water absorption rate and cooking loss rate. Textural profile analysis parameters showed that as the particle size of wheat flour decreased, the hardness, chewiness, recovery, and adhesiveness of noodles showed increasing trends, and there was no significant difference in elasticity. In summary, it is found that the quality of the noodles made by sample C (D₅₀ : 78.47 µm) is better.

Polyphenol oxidase browning in the formation of dark spots on fresh wet noodle sheets: How dark spots formed

The role of polyphenol oxidase (PPO) in the browning of fresh wet noodle sheets (FWNS) was discussed. To release the chemical formation mechanism of the dark spots formed on FWNS, the reconstituted FWNS and PPO-catechol reaction systems were prepared. Different from the overall color change of FWNS, almost all the melanins in dark spots were indirect products of PPO catalysis. The PPO catalytic dehydrogenation was an essential step for the formation of dark spots, but once the phenol dehydrogenation products were formed, the dark spots could still form through a further polymerization process, even though the PPO was completely deactivated. The optimum pH for the phenolic dehydrogenation in FWNS was about 7, and the alkaline condition was advantageous to the progress of the polymerization. Comprehensively, the maximum amount of dark spots was formed at about pH 9.

Inhibition of hexose oxidase on the dark spots in fresh wet noodle sheets: A feasible prevention of dark spots

Hexose oxidase was a feasible prevention for the dark spots in the fresh wet noodle sheets (FWNS). The chemical mechanism that hexose oxidase recucing the melanins of dark spots was discussed basis on the UPLC-TOF-MS analysis of the polyphenol oxidase (PPO)-catechol system. In the process of PPO browning, hexose oxidase catalyzed the oxidation of o-benzoquinone derivatives and their oligomers, hindering the formation of melanins. Hexose oxidase was efficient in FWNS with low ash content when water addition was 24%~44% or pH range was 4 ~ 7.5. Hexose oxidase could inhubit dark spots in the presence of 10 metal ions. The recommended addition amount was 40 ~ 60 ppm, by which the dark spots could be compolitely inhibited. Hexose oxidase was also suitable for wholewheat and oat FWNS, ΔL_6d of wholewheat and oat FWNS were reduced by 4 and 7.98, respectively.

Deterioration mechanisms of high-moisture wheat-based food - A review from physicochemical, structural, and molecular perspectives

Wheat-based products are staple foods for over a third of the world's population. However, most wheat-based staple foods are provided with a high water content to maintain naturally chewable mouthfeel, which leads to a short shelf life and limits their distribution and marketing. Understanding the fundamental mechanisms and dynamics that drive the quality deterioration is therefore essential for obtaining alternative technologies for optimal quality and extended shelf life. Here, we provide the basis for the physicochemical, structural, and molecular changes occurring in various wheat products during storage, intending to elucidate the underlying deterioration causes. Generally, more desirable qualities are obtained for fresh wheat products, both in appearance and mouthfeel. During storage, changes in the physicochemical properties, structure, main constituents, and water status contribute to the quality deterioration. Based on these changes, deterioration mechanisms are summarized to provide both theoretical and practical references for the quality regulation of high-moisture wheat-based food.

Effects of electron-beam irradiation on inoculated Listeria innocua, microbiological and physicochemical quality of fresh noodles during refrigerated storage

As a nonthermal sterilization technology, electron-beam irradiation (EBI) has attracted great interests for microbial inactivation in food preservation. In this study, the inactivation of inoculated Listeria innocua, natural microbiota, and quality of fresh noodles treated by EBI during refrigerated storage were evaluated. Results showed that the initial L. innocua population (6.38 log CFU/g) was significantly reduced to an undetectable level by treatment with 3.0 kGy EBI. Moreover, treatment with 3 kGy EBI significantly reduced the initial total bacteria counts and fungal counts (mold and yeast) from 5.66 and 3.15 log CFU/g to 2.90 and 2.11 log CFU/g, respectively. However, along with the storage process, the inoculated L. innocua and natural microbiota were recovered resulting in the increased populations of the spoilage microorganisms. Increasing the dose of EBI to 4.0 kGy or 5.0 kGy, the L. innocua population was inhibited to the undetectable level and the microbiological quality of the fresh noodles was kept in the acceptable level during the 28 day storage. In addition, changes of the physicochemical indicators including pH value, color, cooking characteristics, texture, and sensory of fresh noodles treated with EBI were delayed during storage. These results reveal that EBI treatment can improve the microbiological safety and shelf life of fresh noodles without impairing quality.